Mediterranean diet Archives - Health Tips From The Professor

Which Diets Are Heart Healthy?

November 7, 2023 by Dr. Steve Chaney

Which Diet Is Best For You?

Author: Dr. Stephen Chaney

The top 3 claims the advocates of every popular diet make are:

It will help you lose weight.

It reduces your risk of diabetes.

It reduces your risk of heart disease.

The truth is any restrictive diet helps you lose weight. And when you lose weight, you improve blood sugar control. Which, of course, reduces your risk of developing diabetes.

But what about heart disease? Which diets are heart healthy? When it comes to heart disease the claims of diet advocates are often misleading. That’s because the studies these advocates use to support their claims are often poor quality studies. Many of these studies:

Look at markers of heart disease risk rather than heart disease outcomes. Markers like LDL cholesterol, triglycerides, c-reactive protein, etc. are only able to predict possible heart disease outcomes. To really know which diets are heart healthy you have to measure actual heart disease outcomes such as heart attacks, stroke, and cardiovascular deaths.

Are too short to provide meaningful results. Many of these studies last only a few weeks. You need much longer to measure heart disease outcomes.

Are too small to provide statistically significant results. You need thousands of subjects to be sure the results you are seeing are statistically significant.

Have not been confirmed by other studies. The Dr. Strangeloves of the world like to “cherry pick” the studies that support the effectiveness of their favorite diet. Objective scientists know that any individual study can be wrong. So, they look for consensus conclusions from multiple studies.

A recent study (G Karam et al, British Medical Journal, 380: e072003, 2023) avoided all those pitfalls. The investigators conducted a meta-analysis of 40 high-quality clinical studies with 35,548 participants to answer the question, “Which diets are heart healthy?”

How Was The Study Done?

The authors started by searching all major databases of clinical studies for studies published on the effect of diets on heart disease outcomes through September 2021.

They then performed a meta-analysis of the data from all studies that:

Compared the effect of a particular diet to minimal dietary intervention (defined as not receiving any advice or receiving dietary information such as brochures or brief advice from their clinician with little or no follow-up).

Looked at heart disease outcomes such as all cause mortality, cardiovascular mortality, non-fatal heart attacks, stroke, and others.

Lasted for at least 9 months (average duration = 3 years).

Were high-quality studies.

Using these criteria:

They identified 40 studies with 35,548 participants for inclusion in their meta-analysis.

- From those 40 studies, they identified 7 diet types that met their inclusion criteria (low fat (18 studies), Mediterranean (12 studies), very low fat (6 studies), modified fat (substituting healthy fats for unhealthy fats rather than decreasing fats, 4 studies), combined low fat and low sodium (3 studies), Ornish (3 studies), Pritikin (1 study).

One weakness of meta-analyses is that the design of the studies included in the meta-analysis is often different. Sometimes they don’t fit together well. So, while the individual studies are high-quality, a combination of all the studies can lead to a conclusion that is low quality or moderate quality.

Finally, the data were corrected for confounding factors such as obesity, exercise, smoking, and medication use.

Which Diets Are Heart Healthy?

Now that you understand the study design, we are ready to answer the question, “Which diets are heart healthy?” Here is what this study found:

Compared to minimal intervention,

The Mediterranean diet decreased all cause mortality by 28%, cardiovascular mortality by 45%, stroke by 35%, and non-fatal heart attacks by 52%.

Low fat diets decreased all cause mortality by 16% and non-fatal heart attacks by 23%. The effect of low fat diets on cardiovascular mortality and stroke was not statistically significant in this meta-analysis.

- For both the Mediterranean and low fat diets, the heart health benefits were significantly better for patients who were at high risk of heart disease upon entry into the study.

- The evidence supporting the heart health benefits for both diets was considered moderate quality evidence for this meta-analysis. [Remember that the quality of any conclusion in a meta-analysis is based on both the quality of evidence of the individual studies plus how well the studies fit together in the meta-analysis.]

While the percentage of risk reduction appears to be different for the Mediterranean and low fat diets, the effect of the two diets on heart health was not considered significantly different in this study.

The other 5 diets provided little, or no benefit, compared to the minimal intervention control based on low to moderate quality evidence.

The authors concluded, “This network meta-analysis found that Mediterranean and low fat dietary programs probably reduce the risk of mortality and non-fatal myocardial infarction [heart attacks] in people at increased cardiovascular risk. Mediterranean dietary programs are also likely to reduce the risk of stroke. Generally, other dietary programs were not superior to minimal intervention.”

Which Diet Is Best For You?

The fact that this study found both the Mediterranean diet and low fat diets to be heart healthy is not surprising. Numerous individual studies have found these diets to be heart healthy. So, it is not surprising when the individual studies were combined in a meta-analysis, the meta-analysis also concluded they were heart healthy. However, there are two important points I would like to make.

The diets used in these studies were designed by trained dietitians. That means the low fat studies did not use Big Food, Inc’s version of the low fat diet in which fatty foods are replaced with highly processed foods. In these studies, fatty foods were most likely replaced with whole or minimally processed foods from all 5 food groups.

The Mediterranean diet is probably the most studied of current popular diets. From these studies we know the Mediterranean diet improves brain health, gut health, and reduces cancer risk.

As for the other 5 diets (very low fat, modified fat, low fat and low sodium, Ornish, and Pritikin), I would say the jury is out. There is some evidence that these diets may be heart healthy. But very few of these studies were good enough to be included in this meta-analysis. Clearly, more high-quality studies are needed.

Finally, you might be wondering why other popular diets such as paleo, low carb, and very low carb (Atkins, keto, and others) were left out of this analysis. All I can say is that it wasn’t by design.

The authors did not select the 7 diets described in this study and then search for studies testing their effectiveness. They searched for all studies describing the effect of diets on heart health. Once they identified 40 high-quality studies, they grouped the diets into 7 diet categories.

I can only conclude there were no high-quality studies of paleo, low carb, or very low carb diets that met the criteria for inclusion in this meta-analysis. The criteria were:

The effect of diet on heart health must be compared to a control group that received no or minimal dietary advice.

The study must measure heart disease outcomes such as all cause mortality, cardiovascular mortality, non-fatal heart attacks, and stroke.

The study must last at least 9 months.

The study must be high-quality.

Until these kinds of studies are done, we have no idea whether these diets are heart healthy or not.

So, what’s the takeaway for you? Which diet is best for you? Both low fat diets and the Mediterranean diet are heart healthy provided the low fat diet consists of primarily whole or minimally processed foods. Which of these two diets is best for you depends on your food preferences.

The Bottom Line

Many of you may have been warned by your doctor that your heart health is not what it should be. Others may be concerned because you have a family history of heart disease. You want to know which diets are heart healthy.

Fortunately, a recent study answered that question. The authors performed a meta-analysis of 40 high-quality studies that compared the effect of various diets with the effect of minimal dietary intervention (doctors’ advice or diet brochure) on heart disease outcomes.

From this study they concluded that both low fat diets and the Mediterranean diet probably reduce mortality and the risk of non-fatal heart attacks, and that the Mediterranean diet likely reduces stroke risk.

Other diets studied had no significant effect on heart health in this study. That does not necessarily mean they are ineffective. But it does mean that more high-quality studies are needed before we can evaluate their effect on heart health.

So, what’s the bottom line for you? Both low fat diets and the Mediterranean diet are heart healthy provided the low fat diet consists of primarily whole or minimally processed foods Which of these two diets is best for you depends on your food preferences.

For more information on this study, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

___________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Which Diets Are Heart Healthy?

September 26, 2023 by Dr. Steve Chaney

What Does A Heart Healthy Diet Look Like?

Author: Dr. Stephen Chaney

Heart disease is a big deal. According to the CDC, “Heart disease is the leading cause of death for men, women, and people of most racial and ethnic groups in the United States. One person dies every 33 seconds in the United States from cardiovascular disease. About 695,000 people in the United States died from heart disease in 2021 – that’s 1 in every 5 deaths”.

This doesn’t have to happen. According to the Cleveland Clinic, “90 percent of heart disease is preventable through healthier diet, regular exercise, and not smoking”. For this issue of “Health Tips From the Professor”, I will focus on the role of diet on heart health.

The problem is many Americans are confused. They don’t know what a heart-healthy diet is. There is so much conflicting information on the internet.

Fortunately, the American Heart Association has stepped in to clear up the confusion.

In 2021 they reviewed hundreds of clinical studies and published “Evidence-Based Dietary Guidance to Promote Cardiovascular Health”.

And recently they have published a comprehensive review (CD Gardner et al, Circulation, 147: 1715-1730, 2023) of how well popular diets align with their 2021 dietary guidelines.

I will cover both publications below. But first I want to address why Americans are so confused about which diets reduce heart disease risk.

Why Are Americans Confused About Diet And Heart Disease Risk?

I should start by addressing the “elephant in the room”.

As I discussed in last week’s “Health Tips From the Professor” article, Big Food Inc has seduced us. They have developed an unending supply of highly processed foods that are cheap, convenient, easy to prepare, and fulfill all our cravings. These foods are not heart-healthy, but they make up 73% of our food supply.

The Institute of Medicine, the scientific body that sets dietary standards, states that a wide range of macronutrient intakes are consistent with healthy diets. Specifically, they recommend carbohydrate intake at 45% to 65%, fat intake at 20% to 35%, and protein intake at 10% to 35% of total calories. (Of course, they are referring to healthy carbohydrates, fats, and proteins.)

The authors of this article pointed to several reasons why Americans have been misled about heart-healthy diets.

Many of the most popular diets fall outside of the “Acceptable Macronutrient Range”.

Many popular diets exclude heart-healthy food groups.

And, the words of the authors,

“Further contributing to consumer misunderstanding is the proliferation of diet books, [and] blogs [by] clinicians with limited understanding of what the dietary patterns entail and the evidence base for promoting cardiometabolic health.” I call these the Dr. Strangeloves of our world.

What Does A Heart Healthy Diet Look Like?

Let me start by sharing the American Heart Association’s 10 “Evidence-Based Dietary Guidelines to Promote Cardiovascular Health.

#1: Adjust energy intake and expenditure to achieve and maintain a healthy body weight
#2: Eat plenty of vegetables and fruits; choose a wide variety
#3: Choose foods made mostly with whole grains rather than refined grains
#4: Choose healthy sources of protein
	Mostly from plants (beans, other legumes, and nuts)
	Fish and seafood
	Low-fat or fat-free dairy products instead of full-fat dairy products
	If meat or poultry are desired, choose lean cuts and avoid processed forms
#5. Use liquid plant oils (olive, safflower, corn) rather than animal fats (butter and lard) and tropical oils (coconut and palm kernel)
#6. Use minimally processed foods instead of highly processed foods
#7: Minimize intake of beverages and foods with added sugars
#8: Choose and prepare foods with little or no salt
#9: If you do not drink alcohol, do not start; if you choose to drink alcohol, limit intake
#10: Adhere to this guidance regardless of where food is prepared or consumed

Here are my comments on these guidelines:

If you have been reading my “Health Tips From the Professor” blog for a while, you probably realize that these aren’t just guidelines to promote heart health. These guidelines also reduce the risk of diabetes, cancer, inflammatory diseases, and much more.

If you have read my post on coconut oil, you will know that I have a minor disagreement with the AHA recommendation to avoid it. There is no long-term evidence that coconut oil is bad for the heart. But there is also no long-term evidence that it is good for the heart. My recommendation is to use it sparingly.

And you probably know there has been considerable discussion recently about whether full fat dairy is actually bad for the heart. In my most recent review of the topic, I concluded that if full fat dairy is heart healthy, it is only in the context of a primarily plant-based diet and may only be true for fermented dairy foods like unpasteurized yogurt and kefir.

Finally, guideline 10 may need some translation. Basically, this guideline is just asking how easy it is to follow the diet when you are away from home.

Which Diets Are Heart Healthy?

In evaluating how well diets adhered to the American Heart Association guidelines the authors ignored item 1 (energy intake) because most of the diets they evaluated did not provide any guidelines on how many calories should be consumed.

Each diet was given a score between 0 (Fail) and 1 (A+) for each of the other 9 guidelines by a panel of experts. The points for all 9 guidelines were added up, giving each diet a rating of 0 (worst) to 9 (best). Finally, a score of 9 was assigned 100%, so each diet could be given a percentage score for adherence to heart-healthy guidelines.

Here are the results:

Tier 1 diets (the most heart healthy diets) received scores of 86% to 100%. Going from highest (100%) to lowest (86%), these diets were:

DASH, Nordic, Mediterranean, Pescetarian (vegetarian diets that allow fish), and Ovo-Lacto Vegetarian (vegetarian diets that allow dairy, eggs, or both).

You will notice that these are all primarily plant-based diets.

Tier 2 diets were Vegan and other low-fat diets (TLC, Volumetrics). They both received scores of 78%.

The Vegan diet received 0 points for category 10 (ease of following the diet when eating out). It was also downgraded in category 7 for not having clear guidance for the use of salt when preparing foods.

The other low-fat diets were downgraded in categories 7, 10, and 5 (use of tropical oils).

Tier 3 diets received scores of 64% to 72%. They included very-low fat diets (<10% fat, very strict vegan diets) and low-carb diets (Zone, South Beach, Low-Glycemic Index).

They received 0 points for category 10 and were downgraded for eliminating heart-healthy food groups (liquid plant oils for the very low-fat diets, and fruits, vegetables, whole grains, and plant proteins for the low-carb diets).

Tier 4 diets (the least heart healthy diets) were the Paleo diet with a score of 53% and very low-carb diets (Atkins and Ketogenic) with a score of 31%.

The Paleo diet received 0 points for categories 10, 3 (choose whole grains), and 5 (using liquid plant oils rather than animal fats or tropical oils). It was also downgraded for lack of healthy plant-based protein sources.

The very low-carb diets were the least heart healthy. They received 0 points for categories 2 (eat plenty of fruits and vegetables), 3 (choose whole grains), 3 (healthy protein sources), 5 (use liquid plant oils instead of animal fats), 7 (minimize salt consumption), and 10 (ease of following the diet away from home).

The authors concluded, “Numerous [dietary] patterns [are] strongly aligned with 2021 American Heart Association Dietary Guidance (ie, Mediterranean, DASH, pescetarian, vegetarian) [and] can be adopted to reflect personal and cultural preferences and budgetary constraints.

Thus, optimal cardiovascular health would be best supported by developing a food environment that supports adherence to these patterns wherever food is prepared or consumed.”

Given our current food environment that last statement is wildly optimistic. But at least you have the information needed to make the best food choices for you and your family

The Bottom Line

In 2021 the American Heart Association published 10 guidelines for evaluating heart-healthy diets. A recent study looked at how well popular diets adhered to those guidelines. The authors separated the diets into four categories (tiers) based on how heart-healthy they were. The results were not surprising:

Tier 1 diets (the most heart healthy diets) were DASH, Nordic, Mediterranean, Pescetarian (vegetarian diets that allow fish), and Ovo-Lacto Vegetarian (vegetarian diets that allow dairy, eggs, or both).

Tier 2 diets were Vegan and other low-fat diets (TLC, Volumetrics).

Tier 3 diets included very-low fat diets (<10% fat, very strict vegan diets) and low-carb diets (Zone, South Beach, Low-Glycemic Index).

Tier 4 diets (the least heart healthy diets) were the Paleo diet and very low-carb diets (Atkins and Ketogenic).

Thus, optimal cardiovascular health would be best supported by developing a food environment that supports adherence to these patterns wherever food is prepared or consumed.”

Given our current food environment that last statement is wildly optimistic. But at least you have the information needed to make the best food choices for you and your family.

For more information on this study, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

____________________________________________________________________________

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Is Whole Fat Dairy Healthy?

August 29, 2023 by Dr. Steve Chaney

Is It Dairy Or Diet?

Author: Dr. Stephen Chaney

For years we have been told to select low fat dairy foods. But recent headlines claim, “That’s nonsense. Whole fat dairy foods are healthy.” Are those headlines true?

In previous issues of “Health Tips From the Professor” I have kept you abreast of recent studies suggesting that whole fat dairy foods may not be as bad for us as we thought. I also cautioned you that the headlines may not have accurately represented the studies they described.

Headlines have to be simple. But truth is often more nuanced. If we believed the current headlines, we might be asking ourselves questions like, “Should we ditch the current health guidelines recommending low-fat dairy foods? Are foods like ice cream, sour cream, and cheddar cheese actually be good for us?

To answer these questions, I will look at the study (A Mente et al, European Heart Journal, 44, 2560-2579, 2023) behind the current headlines and put the study into perspective.

Spoiler alert: If I could summarize the study findings in two sentences, they would be, “Whole fat dairy can be part of a healthy diet. But can it be part of an unhealthy diet?”

Stay tuned. I will discuss the science behind that statement below.

How Was This Study Done?

This study started with data collected from the Prospective Urban Rural Epidemiology (PURE) study. The PURE study is an ongoing study correlating diet, lifestyle, and environmental effects on health outcomes. It has enrolled 166,762 individuals, age 35-70, from 21 low-, middle-, and high-income countries on 5 continents.

Habitual food intake was determined using country-specific food frequency questionnaires at the time participants joined the study. Participants (166,762) from the PURE study who had complete dietary information were included in this study and were followed for an average of 9.3 years.

Based on preliminary analysis of data from the PURE study, the authors developed their version of a healthy diet, which they call the PURE diet. Like most other healthy diets, the PURE diet emphasizes fruits, vegetables, legumes, nuts, and fish. However:

Based on studies suggesting that whole fat dairy foods can be part of a healthy diet, the PURE diet includes whole fat dairy foods.

This is different from most other healthy diet recommendations.

They went on to develop what they referred to as the PURE healthy diet score by:

Determining the median intake for each of the 6 food groups included in their PURE diet (fruits, vegetables, legumes, nuts, fish, and whole fat dairy).

Assigning each participant in the study a score of 0 or 1 depending on whether their intake for that food group was below or above the median intake.

Adding up the points. Since 6 food groups were included in the PURE diet, this means that each participant in the study was assigned a PURE diet score ranging from 0-6.

Once they had developed a PURE diet score, they expanded their data by including five additional large independent studies that included people from 70 countries. The combined data from all six studies amounted to 245,597 people from 80 countries. Of the people included in the data analysis:

21% came from high income countries.
60% came from middle income countries.
19% came from low-income countries.

This is very similar to the global population distribution. This is a strength of this study because it allowed them to ask whether the PURE diet score worked as well in low-income countries as in high-income countries.

Finally, they correlated the PURE diet score with outcomes like all-cause mortality, heart attack, and stroke.

Is Whole Fat Dairy Healthy?

The authors of this study divided the participants of all 6 studies into quintiles based on their PURE diet score and compared those in the highest quintile (PURE score of ≥ 5) with those in the lowest quintile (PURE score of ≤ 1).

The people in the highest quintile were eating on average 5 servings/day of fruits and vegetables, 0.5 servings/day of legumes, 1.2 servings/day of nuts, 0.3 servings/day of fish, 2 servings/day of dairy (of which 1.4 servings/day was whole fat dairy), 0.5 servings/day of unprocessed red meat, and 0.3 servings/day of poultry.

The people in the lowest quintile ate significantly less fruits, vegetables, nuts, fish, and dairy; and slightly less legumes, unprocessed red meat, and poultry than those in the highest quintile.

However, they consumed significantly more refined wheat foods and white rice. This study did not track consumption of highly processed foods, but the high consumption of white flour leads me to suspect they ate a lot more highly processed food.

With that in mind, when the authors compared people with the highest PURE diet scores to those with the lowest PURE diet scores:

All-cause mortality was reduced by 30%.

Cardiovascular disease was reduced by 18%.

Heart attacks were reduced by 14%.

Strokes were reduced by 19%.

The PURE healthy eating score was slightly better at predicting health outcomes than the Mediterranean, DASH, and HEI (Healthy Eating Index) scores. But the differences were small. So, I still recommend choosing the healthy diet that best fits your preferred foods and your lifestyle.

The PURE healthy eating score was significantly better at predicting health outcomes than the Planetary diet score. I will discuss the nutritional inadequacy of “sustainable diets” like the Planetary diet in next week’s “Health Tips From the Professor” article.

Because of the size and design of this study, they were able to make three interesting observations.

The PURE, Mediterranean, DASH, and HEI diet scores were predictive of health outcomes in every country across the globe. You no longer have to wonder if what works in the United States will work in low-income countries and in countries with very different food preferences. Previous studies have not been able to make that claim.

2) You don’t have to be perfect.

- A 20% increase (one quintile) in PURE score was associated with a 6% lower risk of major cardiovascular events and an 8% lower risk of mortality. In other words, even small improvements in your diet may improve your health outcomes.

- The health benefits of the PURE diet started to plateau at a score of 3 (with 6 being the highest score). The authors concluded that most of the health benefits were associated with a modestly higher consumption of healthy foods compared to little or no consumption of healthy foods.

Simply put, that means the health benefits gained by going from a moderately healthy diet to a very healthy diet are not as great as the health benefits gained by going from a poor diet to a moderately healthy diet.

[Note: There are still improvements in health outcomes when you go from a moderately healthy diet to a very healthy diet. My recommendation: “You don’t need to achieve perfection, but you shouldn’t accept mediocrity”.]

3) The PURE diet score was more predictive of health outcomes in some countries than in others.

- The PURE diet score was more predictive of health outcomes in low-income countries. The authors felt that was because low-income countries started with average PURE scores of 2.1, whereas higher-income countries started with average PURE scores of 3.5.

The authors felt this was another example getting more “bang for the buck” by going from a poor diet to a moderately healthy diet than from a moderately healthy diet to a very healthy diet. (Remember, the health benefits associated with improving PURE diet scores start to plateau at a PURE score of 3.

- The difference in benefits for low-income countries compared to high-income countries was observed for the Mediterranean, DASH, and HEI diet scores. So, it is probably safe to say for any healthy diet you don’t need to be perfect. You just need to be better.

The authors concluded, “A diet composed of higher amounts of fruit, vegetables, nuts, legumes, fish, and whole fat dairy is associated with a lower risk of cardiovascular disease and mortality in all world regions, especially in countries with lower income where consumption of these foods is low.”

Is It Dairy Or Diet?

The headlines are telling us that recommendations to choose low-fat dairy products are out of date. They say there is no reason to fear whole fat dairy foods. They are good for you. Bring on the ice cream, sour cream, cream cheese, and high fat hard cheeses!

As usual, there is a kernel of truth in the headlines, but headlines have to be simple. And the latest headlines are an oversimplification of what the studies actually show. Let me provide perspective to the headlines by asking two questions.

#1: Is it dairy or diet? A major weakness of this and similar studies is that they fail to consider diet context. What do I mean by that? Let’s dig a little deeper into this study.

Let’s start with a description of the PURE diet. It is a diet that emphasizes fruits, vegetables, legumes, nuts, and fish. In other words, it is a primarily plant-based diet.

Although the authors keep referring to the diet as one that includes whole fat dairy. It would be more accurate to say that it includes dairy, which was 30% low-fat and 70% whole fat.

The authors said that removal of any one food group from this combination reduced the predictive power of the PURE diet. In other words, the beneficial effect of 70% whole fat dairy is best seen in the context of a primarily plant-based diet.

The PURE diet was most effective at predicting health outcomes in low-income countries where a significant percent of the population consumes a primarily plant-based diet because meats are expensive.

So, a more accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet. But that is too complicated for a headline.

#2: If whole fat dairy can be part of a healthy diet, can it also be part of an unhealthy diet?

To answer that question let’s compare the potential effects of whole fat dairy on a primarily plant-based diet compared to the typical American or European diet.

Milk and other dairy foods are excellent sources of calcium, vitamin B12, and iodine and good sources of protein, vitamin D, choline, zinc, and selenium – nutrients that are often low or missing in plant-based diet. And this is true whether the dairy foods are low-fat or whole fat.

Primarily plant-based diets tend to be low in saturated fat, so the potential negative effects of adding a small amount of saturated fat to the diet may be outweighed by the beneficial effects of the nutrients dairy foods provide.

On the other hand,

The typical American or European diet provides plenty of protein and vitamin B12 and significantly more choline, vitamin D, iodine, and zinc than a plant-based diet. The added nutrients from adding dairy foods to this kind of diet is still beneficial, but the benefits are not as great as adding dairy foods to a primarily plant-based diet.

If you read the American Heart Association statement on saturated fats, it does not say that any amount of saturated fat is bad for you. In fact, small amounts of saturated fats play some beneficial roles in our bodies. The American Heart Association says, “Eating too much saturated fat can raise the level of LDL cholesterol in your blood…[which] increases your risk of heart disease and stroke.”

Here is where the problem lies. The typical American or European diet already contains too much saturated fat. Whole fat dairy just adds to that excess.

So, the most accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet but may not be a healthy addition to the typical American diet. But that is way too complicated for a headline.

You are probably wondering what this means for you. Here are my recommendations.

If you eat like most Americans, you should continue to follow the current health guidelines to choose low-fat dairy foods.

If you happen to be among the few Americans who eat a primarily plant-based diet, you will probably benefit by adding a mixture of low-fat and whole fat dairy foods to your diet.

The Bottom Line

Once again, the headlines are telling us that recommendations to choose low-fat dairy products are out of date. The articles say there is no reason to fear whole fat dairy foods. They are good for you. Bring on the ice cream, sour cream, cream cheese, and high fat hard cheeses!

As usual, there is a kernel of truth in the headlines, but headlines have to be simple. And the latest headlines are an oversimplification of what the studies actually show. In this post I looked at the study behind the most recent headlines and provided perspective to the headlines by asking two questions.

#1: Is it dairy or diet? A major weakness of this and similar studies is that they fail to consider diet context.

When you consider diet context a more accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet. But that is too complicated for a headline.

#2: If whole fat dairy can be part of a healthy diet, can it also be part of an unhealthy diet?

When you consider that question the most accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet but may not be a healthy addition to the typical American diet. But that is way too complicated for a headline.

You are probably wondering what this means for you. Here are my recommendations.

If you eat like most Americans, you should continue to follow the current health guidelines to choose low-fat dairy foods.

If you happen to be among the few Americans who eat a primarily plant-based diet, you will probably benefit by adding a mixture of low-fat and whole fat dairy foods to your diet.

For more information on this study, and the science behind my summary of the study, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

_________________________________________________________________________

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Is HDL Good For Your Heart?

June 13, 2023 by Dr. Steve Chaney

Is Everything You Knew About HDL Wrong?

Author: Dr. Stephen Chaney

In last week’s “Health Tips From the Professor” I talked about one of the greatest strengths of the scientific method – namely that investigators constantly challenge, and occasionally disprove, existing paradigms. That allows us to discard old models of how things work and replace them with better ones.

Last week I shared a study that disproved the paradigm that low to moderate alcohol consumption is healthier than total abstinence. This week I share several studies that challenge the belief that HDL cholesterol is good for your heart.

The belief that HDL is good for your heart has all the hallmarks of a classic paradigm.

It is supported by multiple clinical studies.

Elaborate metabolic explanations have been proposed to support the paradigm.

It is the official position of most medical societies, scientific organizations, and health information sites on the web.

It is the recommendation of most health professionals.

It has been repeated so often by so many trusted sources that everyone assumes it must be true.

Once we accept the HDL/heart health paradigm as true, we can construct other hypotheses on that foundation. For example:

Raising your HDL levels naturally takes effort. Pharmaceutical companies have been pursuing the “magic pill” that raises HDL levels without any effort on your part.

Low carb diets like the Keto and Paleo diets are high in saturated fat. The low carb enthusiasts claim this is a good thing because saturated fat raises HDL levels, and HDL is good for your heart.

But what if the underlying HDL/heart health paradigm weren’t true? These hypotheses would be like the parable of a house built on a foundation of sand. The paradigm will be washed away as soon as it is critically tested.

So, let’s look at experiments that have challenged the HDL/heart health paradigm.

Do Drugs That Increase HDL Levels Work?

The first hint that the HDL/heart health paradigm might be faulty happened when a pharmaceutical company developed a drug that selectively increased HDL levels.

The drug company thought they had found the goose that laid golden eggs. Just imagine. People wouldn’t have to lose weight, exercise, or change their diet. They could simply take a pill and dramatically decrease their heart disease risk. A drug like that would be worth $billions.

The problem was that when they tested their drug (torcetrapib) in clinical trials, it had absolutely no effect on heart disease outcomes (AR Tall et al, Atherosclerosis, Thrombosis, and Vascular Biology 27:257-260, 2007).

The pharmaceutical company couldn’t believe it. Raising HDL levels just had to reduce heart disease risk. They concluded they didn’t have the right drug, and they continued to work on developing new drugs.

That was 16 years ago, and no HDL-increasing drug has made it to market. Have they just not found the right drug, or does this mean the HDL/heart health paradigm is incorrect?

Does Saturated Fat Decrease Heart Disease Risk?

Now let’s turn to two claims of low carb enthusiasts.

#1: Saturated fats decrease your risk of heart disease in the context of a low carb diet. I have debunked that claim in several previous issues of “Health Tips From The Professor”. But let me refer you to two articles here – one on saturated fat and heart disease risk and one on low-carb diets.

#2: Saturated fats decrease heart disease risk because they raise HDL levels. This is the one I will address today.

The idea that saturated fats decrease heart disease risk because they raise HDL levels is based on a simplistic concept of HDL particles. The reality is more complex. Several clinical studies have shown:

The type of fat determines the property of the HDL particles.

- When polyunsaturated fats predominate, the HDL particles have an anti-inflammatory effect. When saturated fats predominate, the HDL particles have a pro-inflammatory effect.

Anti-inflammatory HDL particles relax the endothelial cells lining our blood vessels. That makes the lining of our blood vessels more pliable, which improves blood flow and reduces blood pressure.

- Anti-inflammatory HDL particles also help reduce inflammation of the endothelial lining. This is important because an inflamed endothelial lining is more likely to accumulate fatty plaques and to trigger blood clot formation that can lead to heart attacks and strokes.

So, the question becomes, “What good is it to raise HDL levels if you are producing an unhealthy, pro-inflammatory HDL particle that may increase the risk of high blood pressure, heart attacks, and strokes?”

In short, these studies suggest it isn’t enough to just focus on HDL levels. You need to ask what kind of HDL particles you are creating.

Is HDL Good For Your Heart?

Once the studies were published showing that…

Drug-induced increase of HDL levels without any change in health habits is not sufficient to decrease heart attack risk, and…

Not all HDL particles are healthy. There are anti-inflammatory or pro-inflammatory HDL particles, which likely have opposite effects on heart attack risk…

…some people started to question the HDL/heart health paradigm. And one group came up with the perfect study to test the paradigm.

But before I describe the study, I need to review the term “confounding variables”. I described the term and how it affects clinical studies in last week’s article. Here is a brief synopsis:

The studies supporting the HDL/heart health paradigm are association studies. Association studies measure the association between a single variable (in this case, increase in HDL levels) and an outcome (in this case, heart disease events, heart disease deaths, and total deaths).

Associations need to be corrected for other variables known to affect the same outcome (things like age, gender, smoking, and diabetes would be examples in this case).

Confounding variables are variables that also affect the outcome but are unknown or ignored. Thus, they are not used to correct the associations, which can bias the results.

The authors of this study (M Briel et al, BMJ 2009:338.b92) observed that most interventions that increase HDL levels also lower LDL levels. Lowering LDL is known to decrease the risk of heart disease deaths. But this effect had been ignored in most studies looking at the association between HDL and heart disease deaths.

They hypothesized that the change in LDL levels was a confounding variable that had been ignored in previous studies and may have biased the results.

To test this hypothesis the authors searched the literature and identified 108 studies with 299,310 participants that:

Compared the effect of drugs, omega-3 fatty acids, or diet with either a placebo or usual care.
Measured both HDL and LDL levels.
Measured reduction in cardiovascular risk.
Had a randomized control design.
Lasted at least 6 months.

They found that every 10 mg/dl decrease in LDL levels in these studies was responsible for a:

7.1% reduction in heart disease events (both heart disease deaths and non-fatal heart attacks).

7.2% reduction in heart disease deaths.

4.4% reduction in total deaths.

After correcting for the effect of decreased LDL levels on these heart disease outcomes, the increase in HDL levels had no statistically significant effect on any of the outcomes.

The authors concluded, “Available data suggest that simply increasing the amount of circulating HDL cholesterol does not reduce the risk of coronary heart disease events, coronary heart disease deaths, or total deaths. The results support reduction in LDL cholesterol as the primary goal for lipid modifying interventions.”

In other words, this study:

Supports the author’s hypothesis that LDL levels were a confounding variable that biased the studies supporting the HDL/heart health paradigm.

Concludes that increasing HDL levels has no effect on heart disease outcomes, thus invalidating the HDL/heart health paradigm.

Is Everything You Knew About HDL Wrong?

Does that mean that everything you knew about HDL is wrong? Not exactly. It just means that you need to change your perspective.

Don’t focus on HDL levels. Peek behind the curtain and focus on what’s behind the HDL levels. For example:

Losing weight when overweight increases HDL levels. But the decrease in heart disease outcomes is more likely due to weight loss than to the increase in HDL levels.

Exercise increases HDL levels. But the decrease in heart disease outcomes is more likely due to exercise than to the increase in HDL levels.

Reversing pre-diabetes or type 2 diabetes increases HDL levels. But the decrease in heart disease outcomes is more likely due to the reversal of diabetes than to the increase in HDL levels.

High-dose omega-3 fatty acids increase HDL levels. But the decrease in heart disease outcomes is more likely due to the omega-3 fatty acids than to the increase in HDL levels.

The Mediterranean diet increases HDL levels. But the decrease in heart disease outcomes is more likely due to the diet than to the increase in HDL levels.

And if you want to go the drug route:

Statins and some other heart drugs increase HDL levels, but the reduction in heart disease outcomes is probably due to their effect on LDL levels rather than their effect on HDL levels.

On the other hand:

Saturated fats increase HDL levels. But saturated fats increase heart disease risk and create pro-inflammatory HDL particles. So, in this case the increase in HDL levels is not a good omen for your heart.

Drugs have been discovered that selectively increase HDL levels. However, there is nothing of value behind this increase in HDL levels, so the drugs have no effect on heart disease outcomes.

The Bottom Line

In this article I discuss several studies that have challenged the HDL/heart health paradigm – the belief that HDL is good for your heart.

For example, one group of investigators analyzed the studies underlying the HDL/heart health paradigm. They hypothesized that these studies were inaccurate because they failed to account for the effects of LDL levels on heart disease outcomes.

After correcting for the effect of decreased LDL levels on heart disease outcomes in the previous studies, the authors showed that increases in HDL levels had no significant effect on any heart disease outcome.

In other words, this study:

Supports the author’s hypothesis that LDL levels were a confounding variable that biased the studies supporting the HDL/heart health paradigm.

Concludes that increasing HDL levels has no effect on heart disease outcomes, thus invalidating the HDL/heart health paradigm.

Does that mean that everything you knew about HDL is wrong? Not exactly. It just means that you need to change your perspective. Don’t focus on HDL levels. Focus on what’s behind the HDL levels. For more information on that, read the article above.

For more information on this study, and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

____________________________________________________________________________

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Does The Mediterranean Diet Improve Pregnancy Outcomes?

May 23, 2023 by Dr. Steve Chaney

Is The Mediterranean Diet Overrated?

Author: Dr. Stephen Chaney

You may have noticed that certain celebrities are singled out for fame and acclaim, while others of equal talent and accomplishment are virtually ignored.

The same thing occurs in the scientific realm. At present, the Mediterranean diet is the darling of the diet world. Study after study is designed to test the benefits of the Mediterranean diet while other excellent diets are ignored. I will discuss this phenomenon and ask whether the Mediterranean diet is overrated at the end of this article. But let’s start at the beginning.

Multiple studies have shown that the Mediterranean diet is associated with lower risk of heart disease, diabetes, and high blood pressure. Some studies suggest it is associated with lower risk of kidney disease and Alzheimer’s disease.

Studies also suggest that the Mediterranean diet is associated with an increase in lifespan (how long you live) and healthspan (how long you enjoy good health). In other words, these studies suggest that following a Mediterranean diet adds years to your life and life to your years.

Most of these studies have been done with men. However, there are enough studies with women to be confident that the beneficial effects of the Mediterranean diet on disease risk and lifespan apply to women as well as to men.

But what about pregnancy? Does the Mediterranean diet support a healthy pregnancy? Here the data are less clear. Three studies have been published showing that pregnant women who follow the Mediterranean diet are less likely to experience gestational diabetes (diabetes during pregnancy).

But what about other adverse pregnancy outcomes that can affect the health of both the mother and her baby such as:

Gestational hypertension (high blood pressure during pregnancy).
Preeclampsia (high blood pressure and protein in the urine that occurs late in pregnancy. It may be associated with liver and/or kidney damage).
Eclampsia (a severe form of preeclampsia where the mother also has seizures).
Preterm birth (birth prior to 37 weeks).
Low birth weight infant.

This study (N Makarem et al, JAMA Network Open. 5(12): e2248165, 2022) was designed to look at the effect of the Mediterranean diet on all seven of these adverse pregnancy outcomes.

How Was This Study Done?

The data for this analysis came from a large clinical trial called the Nulliparous Pregnancy (first time pregnancy) Outcomes Study. The study enrolled 7798 women in their first trimester of pregnancy from 8 medical centers across the country. The women were racially, ethnically, and geographically diverse.

Diet around the time of conception was assessed with a food frequency questionnaire administered at the mother’s first visit to the clinic (usually around 6-13 weeks after conception). The participants were asked to indicate their usual intake of 120 foods and beverages during the past 3 months. In other words, the participants were asked to indicate their diet prior to conception through early pregnancy.

Adherence to the Mediterranean diet was assessed using something called the aMed or Alternative Mediterranean Diet Score (a version of the Mediterranean diet that considers US food preferences). Each participant was assigned one point for:

Above average intake of vegetables, fruits, nuts, whole grains, legumes, fish, and the ratio of monounsaturated fat to saturated fat.

Below average intake of red meat and processed meats.

Alcohol intake was a bit more complicated:

Participants were given 1 point for one 12-ounce can of beer, 5 ounces of wine, or 1.5 ounces of liquor and 0 points for consumption above or below that amount.

The points for all these dietary components were added up to give an aMed score of 0-9, with 9 representing the best adherence to the Americanized version of the Mediterranean diet.

Does The Mediterranean Diet Improve Pregnancy Outcomes?

The authors started out by dividing the pregnant moms into thirds according to adherence to an Americanized Mediterranean diet based their aMed score. When they compared those in the top third (aMed scores of 6-9) with those in the lowest third (aMed scores of 0-3) the risk of developing:

Any adverse pregnancy outcome was reduced by 21%.

Preeclampsia or eclampsia were reduced by 28%.

Gestational diabetes was reduced by 37%.

Other adverse pregnancy outcomes were not statistically different.

Next, they asked whether stricter adherence to the Mediterranean diet would be even more beneficial. To do this they divided the pregnant moms into fifths. When they compared those in the top fifth (aMed scores of 7-9) with those in the lowest fifth (aMed scores of 0-2) the risk of developing:

Any adverse pregnancy outcome was still reduced by 20%, but…

- Preeclampsia and eclampsia were reduced by 35%.

- Gestational diabetes was reduced by 54%.

- Other adverse pregnancy outcomes were not statistically different.

When they broke the results down into participant subgroups:

The effect of the Mediterranean diet on any adverse pregnancy outcomes was not affected by prepregnancy BMI (a measure of obesity), race, or ethnicity.

However, it was significantly affected by age. Any adverse pregnancy outcome was reduced by:

- 48% in women over 35.

- 15% in women younger than 35.

The authors concluded, “We demonstrate that a Mediterranean diet pattern is associated with lower risk of developing any APO [adverse pregnancy outcome] and multiple individual APOs in US women…Our findings add to the growing body of evidence that the Mediterranean diet pattern may play an important role in preserving the health of women across the lifespan, including during pregnancy.”

Is The Mediterranean Diet Overrated?

At the beginning of this article, I posed the question, “Is the Mediterranean diet overrated?” When the authors broke the results down by food group, it suggested the answer may be, “Yes”.

The reduction in any adverse pregnancy outcome was associated with:

Above average consumption of vegetables, fruits, legumes, and fish.

The reduction in preeclampsia and eclampsia was associated with:

Above average consumption of vegetables, fruits, and fish.

The reduction in gestational diabetes was associated with:

Above average consumption of vegetables, and…

Below average consumption of red meat and processed meats.

If you are saying to yourself, “Wait a minute. Doesn’t this pattern of food consumption describe almost any whole food, primarily plant-based diet”, you would be correct. In theory, this pattern of food consumption is also consistent with the DASH diet, Mind diet, Scandinavian diet, flexitarian diet, pesco-vegetarian diet, and semi vegetarian diet, just to name a few.

In my opinion there is nothing about this study that restricts beneficial pregnancy outcomes to the Mediterranean diet. However, I do have a few caveats about that statement.

A good prenatal supplement is a good idea to make sure you are getting the vitamins and minerals required for a successful pregnancy. However, as I have described in a previous article finding a good prenatal supplement may not be as easy as it should be.

Choline is important for a healthy pregnancy, and it is missing in many prenatal supplements. While choline is found in many plant foods, the best sources of choline are fish, poultry, eggs, and dairy. You want to be sure to include some of these in your diet and/or look for a prenatal supplement containing at least 200 mg of choline.

The long chain omega-3s DHA and EPA are important for a healthy pregnancy and are also missing or present in inadequate amounts in many prenatal supplements.

The best dietary sources of DHA and EPA are cold water fish like salmon, tuna, sardines, and herring. That means:

- If you are following the DASH diet or something similar, you will want to substitute fish for red meat.

- A pesco-vegetarian diet is probably a better choice for you than a semi-vegetarian because it focuses on fish as the main protein source in place of poultry and red meat.

- If you are not a big fish lover, you should consider an omega-3 supplement supplying at least 250 mg of long chain omega-3s with most of it as DHA.

What Does This Study Mean For You?

Let me close by putting a few things into perspective.

1) When I said that the Mediterranean diet may be overrated, I did not mean it wasn’t an excellent diet. I simply mean it is probably not any better than other whole food, primarily plant-based diets (with the caveats I listed above).

2) The pregnancy benefits of the Mediterranean diet (and other healthy diets) are related to the overall health of the mother. A good prenatal supplement is still important to assure adequate amounts of all the nutrients essential for a healthy pregnancy.

For example, the authors pointed out that most women do not change their dietary habits when they become pregnant, and that their pregnancy is more likely to be successful if they are in good health at the time of conception.

3) Most diets of women of childbearing age do not provide adequate amounts of choline and omega-3s, so it is important to choose a prenatal supplement program that provides adequate amounts of choline and omega-3s.

4) Adequate calories and protein are also important for a healthy pregnancy.

Pregnancy is not the time to lose weight, even if you are overweight.

A vegan diet may not provide enough protein unless it has been designed by a dietitian.

You should discuss your current diet with your health care provider, and they may refer you to a dietitian if necessary.

The Bottom Line

The Mediterranean Diet is currently the darling of the nutrition world. Yes, numerous studies have shown that people consuming the Mediterranean diet are healthier and live longer. But we find ourselves in a situation where study after study is being designed to look for other benefits of the Mediterranean diet while equally healthy diets are being ignored.

The study discussed in this article is a perfect example. It was designed to determine whether adherence to the Mediterranean diet prior to and during pregnancy reduced the risk of experiencing adverse outcomes during pregnancy – outcomes that could affect the health of the mother and her baby.

The answer to that question was, “Yes”. Adherence to the Mediterranean diet reduced the risk of:

Any adverse outcome during pregnancy by 20%.

Preeclampsia and eclampsia by 35%.

Gestational diabetes by 54%.

And the risk reduction was even greater for women over 35.

However, when the investigators looked at the foods responsible for the reduction in adverse pregnancy outcomes, it appears likely that any whole food, primarily plant-based diet would provide the same results.

In short, this study showed that adherence to the Mediterranean diet improves pregnancy outcomes. The authors chose to focus on the Mediterranean diet because of its popularity. But their data show it is likely that other whole food, primarily plant-based diets would be equally beneficial.

For more information on this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

___________________________________________________________________________

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Which Diets Are Best In 2023?

February 14, 2023 by Dr. Steve Chaney

Which Diet Should You Choose?

Author: Dr. Stephen Chaney

Many of you started 2023 with goals of losing weight and/or improving your health. In many cases, that involved choosing a new diet. That was only 6 weeks ago, but it probably feels like an eternity.

For many of you the “bloom” has gone off the new diet you started so enthusiastically in January.

Perhaps the diet isn’t working as well as advertised…

Perhaps the diet is too restrictive. You are finding it hard to stick with…

Perhaps you are always hungry or constantly fighting food cravings…

Perhaps you are starting to wonder whether there is a better diet than the one you chose in January…

Perhaps you are wondering whether the diet you chose is the wrong one for you…

If you are rethinking your diet, you might want to know which diets the experts recommend. Unfortunately, that’s not as easy as it sounds. The diet world has become just as divided as the political world.

Fortunately, you have an impartial resource. Each year US News & World Report invites a panel of experts with different points of view to evaluate popular diets. They then combine the input from all the experts into rankings of the diets in various categories.

If you are still searching for your ideal diet, I will summarize the US News & World Report’s “Best Diets In 2023”. For the full report, click on this link.

How Was This Report Created?

US News & World Report recruited a panel of 30 nationally recognized experts in diet, nutrition, obesity, food psychology, diabetes, and heart disease to review the 24 most popular diets.

The diets evaluated are not the same each year. Last year they evaluated the top 40 most popular diets. This year they only reviewed the top 24.

That means some good diets were left off the list. For example, the vegan diet is very healthy, but it is also very restrictive. Very few people follow a pure vegan diet, so it didn’t make the top 24 most popular. However, this year’s list did include several primarily plant-based diets that are more popular with the general public.

The panel is also not the same each year. Some experts are rotated off the panel, and others are added. The experts rate each diet in seven categories:

How easy it is to follow.

Its ability to produce short-term weight loss.

Its ability to produce long-term weight loss.

its nutritional completeness.

Its safety.

Its potential for preventing and managing diabetes.

Its potential for preventing and managing heart disease.

They converted the experts’ ratings to scores 5 (highest) to 1 (lowest). They then used these scores to construct eleven sets of Best Diets rankings:

Best Diets Overall ranks diets on several different parameters, including whether all food groups are included in the diet, the availability of the foods needed to be on the diet and the use of additional vitamins or supplements. They considered if the diet was evidence-based and adaptable to meet cultural, religious, or other personal preferences. In addition, the criteria also included evaluation of the prep and planning time required for the diet and the effectiveness of the diet for someone who wants to get and stay healthy.

Best Plant-Based Diets used the same approach as Best Diets Overall to rank the eight plans emphasizing minimally processed foods from plants that were included in this year’s ratings.

Best Commercial Diet ratings used the same approach to rank 15 commercial diet programs that require a participation fee or promote the use of branded food or nutritional products.

Best Long-Term Weight-Loss Diet ratings were generated by combining the safety of the rate of weight loss promoted and the likelihood of the plan to result in successful long-term weight loss and maintenance of weight loss.

Best Fast Weight-Loss Diets were scored on their effectiveness for someone who wants to lose weight in three months or less.

Best Diabetes Diet ratings were calculated equally from the effectiveness of the diet for someone who wants to lower risk factors for diabetes, the nutritional quality of the diet, and research evidence-based support for the diet.

Best Heart-Healthy Diet ratings were calculated equally from the effectiveness of the diet for someone who wants to lower risk factors for hypertension and other forms of heart disease, the nutritional quality of the diet, and evidence-based support for the diet.

Best Diets for Bone and Joint Health were calculated equally on the effectiveness of the diet for someone who wants to lower their risk factors for inflammation and improve bone and joint health, as well as the nutritional quality and research evidence-based support for the diet.

Best Diets for Healthy Eating combines nutritional completeness and safety ratings, giving twice the weight to safety. A healthy diet should provide sufficient calories and not fall seriously short on important nutrients or entire food groups.

Easiest Diets to Follow represents panelists’ averaged scores for the relevant lifestyle questions, including whether all food groups are included and if the recommended foods are readily available at the average supermarket.

Best Family-Friendly Diets were calculated equally on their adaptability for the whole family, including cultural, religious, and personal preferences, the time required to plan and prep, nutritional value and access to food at any supermarket.

Which Diets Are Best In 2023?

Are you ready? If this were an awards program, I would be saying “Envelop please” and would open the envelop slowly to build suspense.

However, I am not going to do that. Here are the top 3 and bottom 3 diets in each category (If you would like to see where your favorite diet ranked, click on this link.

[Note: I excluded commercial diets from this review. (I have a brief discussion of commercial diets below). If you notice a number missing in my summaries, it is because I eliminated one or more commercial diet from my summary.]

Best Diets Overall

The Top 3:

#1: Mediterranean Diet. The Mediterranean diet has been ranked #1 for 6 consecutive years.

#2 (tie): DASH Diet (This diet was designed to keep blood pressure under control, but you can also think of it as an Americanized version of the Mediterranean diet.)

#2 (tie): Flexitarian Diet (A flexible semi-vegetarian diet).

The Bottom 3:

#20: Keto Diet (A high protein, high fat, very low carb diet designed to achieve ketosis).

#21: Atkins Diet (The granddaddy of the high animal protein, low carb, high fat diets).

#24: Raw Food Diet (A diet based on eating foods that have not been cooked or processed).

Best Plant-Based Diets Overall

The Top 3:

#1: Mediterranean Diet.

#2: Flexitarian Diet.

#3: MIND Diet (This diet is a combination of Mediterranean and DASH but is specifically designed to reduce cognitive decline as we age.)

The Bottom 3:

Since only 8 diets were included in this category, even the bottom 3 are pretty good diets, so I did not include a “list of shame” in this category.

Best Long-Term Weight-Loss Diets

The Top 3:

#1: DASH Diet

#2 (tie): Volumetrics Diet (A diet based on the caloric density of foods).

#2 (tie): Mayo Clinic Diet (A diet designed to establish lifelong healthy eating habits).

The Bottom 3:

#22 (tie): Keto Diet.

#22 (tie): Atkins Diet.

#24: Raw Food Diet.

Best Fast Weight-Loss Diets

The Top 3:

#1: Keto Diet

#2: Atkins Diet

#7 (tie): Mayo Clinic Diet

#7 (tie): South Beach Diet

#7 (tie): Volumetrics Diet

The Bottom 3:

The diets at the bottom of this list were designed for health and weight maintenance rather than rapid weight loss, so I did not include a “list of shame” in this category.

Best Diabetes Diets

The Top 3:

#1: DASH Diet

#2: Mediterranean Diet

#3: Flexitarian Diet

The Bottom 3:

#20: Atkins Diet

#21: Paleo Diet (A diet based on what our paleolithic ancestors presumably ate. It restricts grains and dairy and is heavily meat-based).

#22: Raw Food Diet.

Best Heart-Healthy Diets

The Top 3:

#1: DASH Diet

#2: Mediterranean Diet

#3 (tie): Ornish Diet (A whole food, semi-vegetarian diet designed to promote heart health).

#3 (tie): Flexitarian Diet

The Bottom 3:

#22 (tie): Raw Foods Diet

#22 (tie): Paleo Diet

#24: Keto Diet

Best Diets for Bone and Joint Health

The Top 3:

#1 (tie): DASH Diet

#1 (tie): Mediterranean Diet

#3: Flexitarian Diet

The Bottom 3:

#21 (tie): Raw Foods Diet

#21 (tie): Paleo Diet

#22: Atkins Diet

#23: Keto Diet

Best Diets for Healthy Eating

The Top 3:

#1: Mediterranean Diet

#2: DASH Diet

#3: Flexitarian Diet

The Bottom 3:

#22: Keto Diet

#23: Atkins Diet

#24: Raw Foods Diet

Easiest Diets to Follow

The Top 3:

#1 (tie): Flexitarian Diet

#1 (tie): TLC Diet (This diet was designed by the NIH to reduce cholesterol levels and promote heart health.)

#3 (tie): Mediterranean Diet

#3 (tie): DASH Diet

The Bottom 3:

#19: Atkins Diet

#20: Keto Diet

#22: Raw Foods Diet

Which Diets Are Best For Rapid Weight Loss?

There are 2 take-home lessons from the rapid weight loss category:

If you are looking for rapid weight loss, any whole food restrictive diet will do.

- Last year’s diet analysis included the vegan diet, and both vegan and keto diets ranked near the top of the rapid weight loss category. Keto and vegan diets are both very restrictive, but they are polar opposites in terms of the foods they allow and restrict.

- - The keto diet is a meat heavy, very low carb diet. It restricts fruits, some vegetables, grains, and most legumes.

- - The vegan diet is a very low-fat diet that eliminates meat, dairy, eggs, and animal fats.

- The Atkins and keto diets toppled this year’s rapid weight loss list, but they were joined by the Mayo Clinic, South Beach, and volumetrics diets. Those diets are also restrictive, but, like the vegan diet, they are very different from the Atkins and keto diets.

- I did not include commercial diets that rated high on this list, but they are all restrictive in one way or another.

2) Whole food, very low carb diets like Atkins and keto are good for rapid weight loss, but they rank near the bottom of the list for every healthy diet category.

- If you choose to lose weight on the Atkins or keto diets, switch to a healthier diet once you reach your desired weight loss.

Which Diet Should You Choose?

With rapid weight loss out of the way, let’s get back to the question, “Which Diet Should You Choose?” My recommendations are:

1) Choose a diet that fits your needs. That is one of the things I like best about the US News & World Report ratings. The diets are categorized. If your main concern is diabetes, choose one of the top diets in that category. If your main concern is heart health… You get the point.

2) Choose diets that are healthy and associated with long term weight loss. If that is your goal, you will notice that primarily plant-based diets top these lists. Meat-based, low carb diets like Atkins and keto are near the bottom of the lists.

“Why is that?”, you might ask? The answer is simple. And it’s not that all 30 experts were prejudiced against low carb diets. It’s that the major primarily plant-based diets like Mediterranean, DASH, and flexitarian are backed by long-term clinical studies showing they are healthy and significantly reduce the risk of diabetes, heart disease, and other chronic diseases.

On the other hand, there are no long-term studies showing the Atkins and keto diets are healthy long term. And since the Atkins diet has been around for more than 50 years, the lack of clinical evidence that it is healthy long term is damming.

3) Choose diets that are easy to follow. The less-restrictive primarily plant-based diets top this list – diets like Mediterranean, DASH, MIND, and flexitarian. They are also at or near the top of almost every diet category.

4) Choose diets that fit your lifestyle and dietary preferences. For example, if you don’t like fish and olive oil, you will probably do much better with the DASH or flexitarian diet than with the Mediterranean diet.

5) Finally, focus on what you have to gain, rather than on foods you have to give up.

On the minus side, none of the diets include sodas, junk foods, and highly processed foods. These foods should go on your “No-No” list. Sweets should be occasional treats and only as part of a healthy meal. Meat, especially red meat, should become a garnish rather than a main course.

On the plus side, primarily plant-based diets offer a cornucopia of delicious plant foods you probably didn’t even know existed. Plus, for any of the top-rated plant-based diets, there are websites and books full of mouth-watering recipes. Be adventurous.

What About Commercial Diets?

I chose not to review commercial diets by name, but let me make a few observations.

If you look at the gaps in my lists, it should be apparent that several commercial diets rank near the top for fast weight loss, but near the bottom on most healthy diet lists.

I do not recommend commercial diets that rely on ready-to-eat, low-calorie, highly processed versions “of your favorite foods”.

- These pre-packaged meals are expensive. Unless you are a millionaire, you won’t be able to afford these meals for the rest of your life.

- These pre-packaged meals are not teaching you healthy eating habits that will allow you to keep the weight off.

If you wish to spend your hard-earned dollars on a commercial diet, choose a diet that:

- Relies on whole foods from all 5 food groups.

- Teaches and provides support for the type of lifestyle change that leads to permanent weight loss.

Meal replacement shakes can play a role in healthy weight loss if:

- They are high quality and use natural ingredients as much as possible.

- They are part of a holistic lifestyle change program.

The Bottom Line

For many of you the “bloom” has gone off the new diet you started so enthusiastically in January. If you are rethinking your diet, you might want to know which diets the experts recommend. Unfortunately, that’s not as easy as it sounds. The diet world has become just as divided as the political world.

There are probably two questions at the top of your list.

#1: Which diets are best for rapid weight loss? Here are 2 general principles:

If you are looking for rapid weight loss, any whole food restrictive diet will do.

2) If you choose to lose weight on the Atkins or keto diets, switch to a healthier diet once you reach your desired weight loss. Atkins and keto diets are good for rapid weight loss, but they rank near the bottom of the list for every healthy diet category.

#2: Which diet should you choose? Here the principles are:

Choose a diet that fits your needs.

2) Choose diets that are healthy and associated with long term weight loss.

3) Choose diets that are easy to follow.

4) Choose diets that fit your lifestyle and dietary preferences.

5) Finally, focus on what you have to gain, rather than on foods you have to give up.

For more details on the diet that is best for you and my thoughts on commercial diets, read the article above.

Which Diet Is Best For Diabetics?

January 10, 2023 by Dr. Steve Chaney

What Did This Study Show?

Author: Dr. Stephen Chaney

When you were first diagnosed with diabetes, your doctor probably told you that your life will forever be changed. Among other things he or she probably told you that you would need to make some radical changes to your diet.

But what changes? Both the American Diabetes Association (ADA) and Diabetes UK (the British version of ADA) recommend:

An individualized approach. This recognizes that we are all different. What works for some diabetics may not work for others.

A diet that incorporates more non-starchy vegetables and minimizes added sugars and refined grains.

But these recommendations are vague. Most people want a specific diet to follow. It’s here that Diabetes UK and the ADA part ways.

Diabetes UK gives its highest recommendation to the Mediterranean diet.

The ADA gives equal recommendations to the Mediterranean diet and both low-carbohydrate and very-low carbohydrate diets.

But which diet is best? It’s hard to know because most studies compare one of these diets to the standard American diet (SAD), and anything is better than the standard American diet.

Fortunately, one recent study (CD Gardner et al, American Journal of Clinical Nutrition, 116: 640-652, 2022) directly compares the two extremes of ADA-recommended diets, the Mediterranean diet and the Keto diet.

How Was This Study Done?

This study recruited 33 participants with diabetes or prediabetes from the San Francisco Bay area. The participants in the study:

Were between 41 and 77 years old (average age = 60.5).
Were 61% male, 45% non-Hispanic white, and mostly (85%) college educated.
Had either prediabetes (61%) or diabetes (39%).
Had BMIs ranging from 22.7 (normal) to 39.7 (obese) (average BMI = 30 (borderline obese).
Had elevated levels of HbA1c (hemoglobin A1c, a measure of long-term blood sugar control).

People were excluded from the study if they were:

Underweight (<110 pounds) or morbidly obese (BMI ≥40).
Had extremely high cholesterol (LDL cholesterol >190 mg/dL) or blood pressure (>169 mmHg).
On insulin or certain medications to lower blood sugar levels.

This was a randomized, crossover, interventional study. Simply put, that means:

The study started with participants eating a typical American diet. The intervention was either a Keto diet or a Mediterranean diet.

Each patient was randomly assigned to one of the diets for 12 weeks. Then they “crossed over” to the other diet for 12 weeks. In this type of study each patient serves as their own control.

Finally, there was a 12-week follow-up period in which they could choose which of the two diets to follow.

It was a very well-controlled study:

Participants were given detailed guidelines to follow and received weekly individual education sessions by a registered dietitian and certified diabetes educator.

During the first 4 weeks of each diet, participants were provided at no cost all meals and snacks from a local food delivery service.

During the next 8 weeks of each diet, the participants purchased their own foods using the same guidelines they had been given during the first 4 weeks.

- They were also provided with a recipe booklet and suggestions for diet-compliant menu items at local restaurants for each diet.

This was not designed as a weight loss diet. The participants were provided with 2,800 calories of food per day and instructed to eat until they were full.

Compliance with the diet was assessed in three ways:

- During week 4 and week 12 of each diet phase, 3 unannounced 24-hour dietary recalls (2 on weekdays and 1 on a weekend day) were administered over the phone by a trained nutritionist.

- Participants were also given an app to log in their food intake daily.

- Participants on the Keto diet were given blood ketone monitors and strips.

Finally, at the beginning and end of the study and during weeks 4 and 12 of each diet phase participants went to a medical facility for blood work and weight measurements.

The primary focus of this study was measuring the effect of each diet on HbA1c. HbA1c measures blood sugar control over the previous 12 weeks (which is why each diet phase was 12 weeks long). But the study also measured the effect of each diet on LDL cholesterol, HDL cholesterol, and triglycerides.

What Were The Diets Like?

These were not ordinary versions of the Mediterranean and Keto diets:

Sugar and refined flour are often part of the diet in Mediterranean regions. So, this study used the “Mediterranean Plus (Med-Plus)” diet which restricts both sugar and refined grains.

Keto convenience foods are often a witch’s brew of artificial ingredients. So, this study used the “Well-Formulated Keto Diet (WFKD)” which is composed of whole, unprocessed foods. In fact, both diets were whole food diets.

In summary, the two diets were:

Alike in that both emphasized non-starchy vegetables and minimized sugar and refined grains.

Alike in that they were both whole food diets.

Different in that the Keto diet eliminated legumes, fruits, and whole grains while the Mediterranean diet included them.

The macronutrient composition of the two diets was about what you would expect.

	USDA Guidelines	Baseline	Keto (Weeks 1-4)	Keto (Weeks 5-12)	Med (Weeks 1-4)	Med (Weeks 5-12)
Protein	10-35%	18%	25%	22%	19%	21%
Carbs	45-65%	41%	12%	18%	37%	37%
Fat	<30%	41%	63%	60%	44%	42%

The baseline diet was typical of the American diet. It was higher than recommended for fat. While carbohydrate intake appeared to be moderate, it was high in sugar and refined grains.

The Keto and Mediterranean diet interventions were separated into 2 phases. In phase 1 (weeks 1-4) every meal and snack were provided to the participants. In phase 2 (weeks 5-12) they purchased their own food.

As expected, carbohydrate intake was much lower, fat intake much higher, and protein intake slightly higher than baseline for the Keto diet. And this pattern was maintained during the 8 weeks the participants purchased their own food.

Macronutrient composition on the Mediterranean diet was not much different than baseline and did not change much during weeks 5-12.

The fat composition of the two diets was also different.

	Baseline	Keto (Weeks 1-4)	Keto (Weeks 5-12)	Med (Weeks 1-4)	Med (Weeks 5-12)
Monounsaturated	42%	48%	43%	52%	45%
Polyunsaturated	23%	15%	19%	23%	25%
Saturated	35%	37%	38%	25%	30%

The Keto diet was significantly lower in percent polyunsaturated fat and slightly higher in percent monounsaturated and saturated fat than baseline (the typical American diet) in weeks 1-4. However, remember that the Keto diet was 50% higher in total fat than the other diets. This makes it significantly higher in saturated fat than either the baseline or Mediterranean diets.

As expected, the Mediterranean diet was significantly higher in percent monounsaturated fat and lower in percent saturated fat than baseline in weeks 1-4.

Not surprisingly, both diets trended towards the baseline diet in the 8 weeks participants were buying their own food.

Other interesting differences between the two diets:

The Keto diet contained around 12% plant protein and 88% animal protein, while the Mediterranean diet contained about 50% of each.

Fiber intake decreased by 33% compared to baseline on the Keto diet, while fiber intake increased by 50% on the Mediterranean diet.

In terms of nutritional adequacy, the Keto diet was significantly lower in fiber, vitamin C, folate, and magnesium than the Mediterranean diet.

What Did The Study Show?

1. Participants consumed around 300 fewer calories/day and lost about 15 pounds on both diets.

- The authors speculated this was because both diets were more filling than the baseline diet, presumably because both diets were whole food diets while the baseline diet contained lots of processed foods high in sugar and refined grains.

2) Both diets reduced HbA1c (a cumulative measure of how much the diets improved blood sugar control compared to the baseline diet) by about the same extent.

3) LDL cholesterol (bad cholesterol) increased by about 10% on the Keto diet, while it decreased by about 9% on the Mediterranean diet. This difference was highly significant.

4) HDL cholesterol increased by about the same extent on both diets.

5) Triglycerides decreased by around 20% on the Keto diet and by 10% on the Mediterranean diet. This difference was also highly significant.

6) Finally, adherence to the Keto diet was less than for the Mediterranean diet. Plus, more people chose the Mediterranean diet during the follow-up phase when they were allowed to choose their own diet.

The authors concluded, “HbA1c values…improved from baseline on both diets, likely due to several shared dietary aspects. The WFKT [Keto diet] led to a greater decrease in triglycerides, but also had untoward risks from elevated LDL cholesterol and lower nutrient intakes from avoiding legumes, fruits, and whole, intact grains, as well as being less sustainable [easy to follow long-term].

Which Diet Is Best For Diabetics?

Once again, I have covered lots of information in this blog. But if you are diabetic, you are probably wondering, “What does this mean for me?” Let me start by reviewing the purpose of this study.

This study was designed to compare the two extremes of recommended diets (Mediterranean and Keto) with respect to their effectiveness at keeping blood sugar under control.

These were both more restrictive versions of the two diets than most people follow. In this study, both diets:

- Were whole food diets. No sodas, processed, or convenience foods were allowed.

- Minimized the consumption of sugars and refined grains.

Now let me divide the discussion into two sections:

Which diet is best for diabetics in the short term (in this case, 12 weeks)?

- Participants consumed 300 fewer calories and lost about 15 pounds on both diets in spite of being given more than they could eat and not being encouraged to lose weight.

- - The authors attributed this to whole food diets being more filling.

- - However, it is also consistent with my contention that any restrictive diet will lead to short-term weight loss and improvement in blood sugar control. I summarize the 5 reasons for this phenomenon in last week’s “Health Tips From the Professor” article

- Blood sugar control over 12 weeks, as measured by HbA1c, improved by the same amount on both diets.

- - That is consistent with the American Diabetes Association’s position that a variety of diets, ranging from Mediterranean to Keto, are suitable for diabetics.

- - This also means that you can forget the advice that diabetics need to follow a low carb diet and give up fruits, whole grains, and legumes to keep their blood sugar under control.

- - However, this is not a “get out of jail free card”. Diabetics do need to avoid sodas, processed, and convenience foods and minimize sugar and refined grains.

- There was considerable individual variability. Some people did better on the Mediterranean diet. Others did better on the Keto diet.

- This is consistent with the American Diabetes Association’s recommendation that diabetic diets should be individualized.

In short, this study suggests that in the short term (12 weeks) the Med-Plus and WFKD Keto diets are equally effective at promoting weight loss and improved blood sugar control for both diabetics and prediabetics.

However, there is considerable individual variability, meaning that diabetics can chose the diet that works best for them.

2) Which diet is best for diabetics in the long term?

If both diets are equally effective short term, the important question becomes whether they are equally successful and equally healthy long term.

As noted in the author’s conclusion, this study raised several “red flags” which suggest the Keto diet might be less successful and less healthy long term. But this is a short-term study.

You may be wondering, “What do long-term studies show?” Unfortunately, there are very few long-term studies to guide us. But here is what we do know.

- There are multiple studies showing that the Mediterranean diet reduces the risk of diabetes, heart disease, and some cancers long term. There is no evidence that meat-based low carb diets are healthy long term. This includes the Atkins diet, which has been around more than 50 years.

- A 6-year study reported that the group with the lowest carbohydrate intake had an increased risk of premature death – 32% for overall mortality, 50% for cardiovascular mortality, 51% for cerebrovascular mortality, and 36% for cancer mortality.

- A 20-year study reported that women consuming a meat-based low carb diet for 20 years gained just as much weight and had just as high risk of diabetes and heart disease as women consuming a high carbohydrate, low fat diet.

In short, the few long-term studies we do have suggest that the Mediterranean diet is a better choice for long-term health and reduced risk of diabetes than low-carb diets.

The Bottom Line

If you are diabetic or prediabetic, the American Diabetes association recommends a diet that is individualized and ranges from Mediterranean to low carb and very low carb (Keto).

However, low carb and Keto enthusiasts insist that diabetics need to follow a low carb or very low carb diet. And that seems to make sense. After all, aren’t carbs the problem for diabetics?

To resolve this question, a recent study was designed to compare the two extremes of the ADA-recommended diets (Mediterranean and Keto) with respect to their effectiveness at keeping blood sugar under control.

These were not ordinary versions of the Mediterranean and Keto diets:

Sugar and refined flour are often part of the diet in Mediterranean regions. So, this study used the “Mediterranean Plus (Med-Plus)” diet which restricts both sugar and refined grains.

Keto convenience foods are often a witch’s brew of artificial ingredients. So, this study used the “Well-Formulated Keto Diet (WFKD)” which is composed of whole, unprocessed foods. In fact, both diets were whole food diets.

In short, this study found that in the short term (12 weeks) the Med-Plus and WFKD Keto diets are equally effective at promoting weight loss and improved blood sugar control for both diabetics and prediabetics.

If both diets are equally effective short term, the important question becomes whether they are equally successful and equally healthy long term.

As noted in the author’s conclusion, this study raised several “red flags” suggesting that the WFKD Keto diet may be less successful and less healthy long term than the Med-Plus diet. However, this was a short-term study.

So, the question becomes, “What do long-term studies show?” There are few long-term studies of low-carb diets, but the few long-term studies we do have suggest that the Mediterranean diet is a better choice for both long-term health and reduced risk of diabetes than most low-carb diets.

For more details on this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Tips For Successful Weight Loss

January 3, 2023 by Dr. Steve Chaney

Which Diet Is Best?

Author: Dr. Stephen Chaney

It’s the beginning of January. Weight loss season has just launched again. Like millions of Americans, you have probably set a goal to eat healthier, lose weight, or both. But which diet is best? Vegan, Paleo, Keto, 360, Intermittent Fasting, low-carb, low fat – the list is endless.

And then there are the commercial diets: Meal replacements, low calorie processed foods, prepared meals delivered to your door – just to name a few of the categories.

You can choose to count calories, focus on portion sizes, or keep a food journal.

And, if you really want to live dangerously, you can try the latest diet pills that claim to curb your appetite and rev up your metabolism.

The advertisements for all these diets sound so convincing. They give you scientific-sounding mumbo jumbo to explain why they work. Then they talk about clinical studies they say prove their diet works.

If you are like most Americans, you have already tried several of these diets. They worked for a while, but the pounds came back – and brought their friends with them.

But, as the saying goes, “Hope springs eternal in the human breast”. Surely some diet you haven’t tried yet will work for you.

There are such diets. But they will require effort. They will require a change of mindset. There is no magic wand that will chase the extra pounds away forever.

If you are searching for the perfect diet to start the new year, let me be your guide. Here are:

4 tips on mistakes to avoid and…

6 tips on what to look for…

7 tips for making weight loss permanent…

…when you are choosing the best diet for you.

Mistakes To Avoid When Choosing The Best Diet

1. Endorsements

Endorsements by your favorite athlete or public person are paid for. They don’t necessarily represent their opinion. Nor do they assure you that they follow that diet or use that diet supplement.

Endorsements by Dr. Strangelove and his buddies can be equally misleading. They usually tell you that the medical establishment has been lying to you, and they have discovered the “secret” to permanent weight loss and the “Fountain of Youth”.

Recommendations of the medical and scientific communities usually represent a consensus statement by the top experts in their field. I would choose their advice over Dr. Strangelove’s opinion any day.

2) Testimonials

Most of the testimonials you see online or in print are either paid for or are fake.

Testimonials by your friends can be equally misleading. We are all different. What works for your friend or for your trainer may not work for you.

For example, some of us do better on low-carb diets, and others do better on low fat diets.

[Note: Some DNA testing companies claim they can sequence your DNA and tell you which diet is best. However, as I reported in a recent article in “Health Tips From The Professor”, independent studies show that DNA testing is of no use in predicting whether low-carb or low-fat diets are better for you.]

3) Diets Based on “Magic” Or “Forbidden” Foods or Food Groups.

I have often said we have 5 food groups for a reason. Each food group provides a unique blend of nutrients and phytonutrients. And each plant food group provides a unique blend of fibers that support the growth of different types of friendly gut bacteria.

The bottom line is that each of us does better with some foods than others, but there are no “magic” or “forbidden” foods that apply to everyone.

4) “Magic” Diets.

I have written perhaps the first diet book, “Slaying The Food Myths”, that doesn’t feature a “magic” diet that is going to make the pounds melt away and allow you to live to 100. Instead, I recommend a variety of healthy diets and suggest you choose the one that fits you best.

However, I understand the allure of “magic” diets. Dr. Strangelove claims the diet will be effortless. He gives you some scientific-sounding mumbo-jumbo to convince you the diet is scientifically sound. Then he cites some clinical studies showing the diet will cause you to lose weight and will improve your health parameters (things like cholesterol, triglycerides, blood sugar, and blood pressure). It sounds so convincing.

Before you fall for Dr. Strangelove’s latest “magic” diet, let me share two things that may blow your mind:

The studies are all short-term (usually 3 months or less).

When you rely on short-term studies, the very low-fat Vegan diet and very low-carb Keto diet give you virtually identical weight loss and improvement in health parameters!

Those two diets are as different as any two diets could be. That means we can forget all the scientific-sounding mumbo-jumbo as to why each of those diets work. Instead, we should ask what these two diets have in common.

The answer is simple:

#1: The clinical studies are comparing “magic” diets to the typical American diet. Anything is better than the typical American diet! It is high in sugar, refined carbohydrates, saturated fat, and highly processed foods. No wonder the “magic” diets look so good.

#2: The diets are whole food diets. Anytime you eliminate sodas, fast foods, and highly processed foods, you will lose weight.

#3: The diets eliminate one or more food groups. Whenever you eliminate some of your favorite foods from your diet, you tend to lose weight without thinking about it. I call this the cream cheese and bagel phenomenon.

If you are following a low-fat diet, it sounds great to say you can eat all the bagels you want. But without cream cheese to go with the bagels, you tend to eat fewer bagels.

If you are following a low-carb diet, it sounds great to say you can eat as much cream cheese as you want, but without bagels to go with your cream cheese, you tend to eat less cream cheese.

#4: Because they eliminate many of your favorite foods, “magic” diets make you focus on what you eat. Whenever you focus on what you eat, you tend to lose weight. That is why food journals and calorie counters are effective.

#5: Finally, whenever you lose weight, your health parameters (cholesterol, triglycerides, blood sugar, and blood pressure) improve.

Tips For Successful Weight Loss

What should you look for in choosing a healthy weight loss diet? Here are my top 6 tips.

1. Choose whole food diets. Avoid sodas, fast foods, and highly processed foods.

2) Choose primarily plant-based diets. These can range from Vegan through semi-vegetarian, Mediterranean, DASH, and Nordic. All are healthy diets. I have discussed the evidence for this recommendation in my book “Slaying The Food Myths”. Here is a brief summary.

When we look at long term (10-20 year) studies:

Vegetarians weigh less and are healthier than people consuming the typical American diet.

People consuming semi-vegetarian, Mediterranean, and DASH diets are healthier than people consuming the typical American diet.

When we look at low-carb diets:

People consuming plant-based low-carb diets weigh less and are healthier than people consuming the typical American diet.

People consuming meat-based low-carb diets are just as fat and unhealthy as people consuming the typical American diet.

The Atkins low-carb diet has been around for more than 50 years, and there is no evidence it is healthy long-term.

3) Choose diets that include a variety of foods from all 5 food groups. I have discussed the rationale for that recommendation above.

4) Choose diets that consider meat as a garnish, not a main course.

5) Choose diets that feature healthy carbs and healthy fats rather than low-carb or low-fat diets.

6) Think lifestyle, not diet. If you choose a restrictive diet so you can achieve quick weight loss, you will probably be just as fat and unhealthy next December 31^st as you are this year. Instead, choose diets that teach healthy eating and lifestyle changes that you can make a permanent part of your life.

Tips For Keeping The Weight Off

You know the brutal truth. Around 95% of dieters regain everything they lost and then some within a few years. You have probably gone through one or more cycles of weight loss and regain yourself – something called “yo-yo dieting”. You may even be asking yourself if it is worth bothering to try to lose weight this year.

Rather focusing on the negative statistics of weight loss, let’s look at the good news. There are people who lose the weight and keep it off. What do they do?

There is an organization called the National Weight Control Registry that has enrolled more than 10,000 people who have lost weight and kept it off. The people in this group lost weight on almost every diet imaginable. However, here is the important statistic: On average people in this group have lost 66 pounds and kept it off for at least 5 years.

The National Weight Control Registry has kept track of what they have done to keep the weight off. Here is what they do that you may not be doing:

1. They consume a reduced calorie, whole food diet.

2) They get lots of exercise (around 1 hour/day).

3) They have internalized their eating patterns. In short, this is no longer a diet. It has become a permanent part of their lifestyle. This is the way they eat without even thinking about it.

4) They monitor their weight regularly. When they gain a few pounds, they modify their diet until they are back at their target weight.

5) They eat breakfast on a regular basis.

6) They watch less than 10 hours of TV/week.

7) They are consistent (no planned cheat days).

Which Diet Is Best?

Now it is time to get back to the question you are asking right now, “Which diet is best?” I have covered a lot of ground in this article. Let me summarize it for you.

If you are thinking about popular diets:

Primarily plant-based diets ranging from Vegan to Mediterranean and Dash are associated with a healthier weight and better health long term.

- If want to lose weight quickly, you may want to start with the more restrictive plant-based diets, like Vegan, Ornish, Pritikin or semi-vegetarian.

- If you do better with a low-carb diet, my recommendation is the lower-carb version of the Mediterranean diet called Med-Plus. It is a whole food version of the Mediterranean diet that minimizes added sugar and refined grains (I will be talking more about it in next week’s “Health Tips From the Professor”).

- If your primary goal is rapid weight loss, you could also start with one of the healthier of the restrictive low-carb diets, like the Paleo or the 360 diet. I do not recommend the Keto diet.

No matter what diet you start with, plan to transition to the primarily plant-based diet that best fits your lifestyle and food preferences. This is the diet you will want to stick with to maintain your weight loss and achieve better health long term.

Plan on permanent lifestyle change rather than a short-term diet. Otherwise, you are just wasting your time.

Eat whole foods. Big Food keeps up with America’s favorite diets and is only too happy to sell you highly processed foods that match your favorite diet. Avoid those like the plague.

If you are thinking about commercial diets featuring meal replacement products:

Look for meal replacement products that:

- Do not contain artificial sweeteners, flavors, or preservatives.

- Use non-GMO protein. A non-GMO certification for the other ingredients is not necessary. For a more detailed explanation of when non-GMO certification is important and when it is unnecessary, see my article in “Health Tips From the Professor”.

- Have stringent quality controls in place to assure purity. “Organic” and/or “non-GMO” on the label do not assure purity.

Look for programs that can provide clinical studies showing their diet plan is effective for weight loss and for keeping the weight off. Many programs have short-term clinical studies showing they are effective for weight loss, but very few have longer-term studies showing the weight stays off.

Finally, look for programs that teach permanent lifestyle change. This should include guidance on exercise and healthy eating.

I do not recommend most commercial diets that feature prepared low-calorie foods “shipped right to your door” as a major part of their program. The foods are highly processed. Plus, they include all your favorite unhealthy foods as part of the program. Even if they include lifestyle change as part of their program, they are undermining their message with the foods they are providing you.

I would be remiss if I didn’t mention that Weight Watchers is highly recommended by most experts in the field. Weight Watchers emphasizes journaling and counting calories, which is a plus because it makes you focus on what you are eating. They also have a good lifestyle program and support that can help you transition to permanent lifestyle change if you are willing to put in the effort. However, I don’t recommend their prepared low-calorie foods. They are no better than foods provided by the other commercial diet programs.

The Bottom Line

Weight loss season is upon us. If you plan to lose weight and/or adopt a healthier diet this year, you are probably asking, “Which Diet Is Best?” In this issue of “Health Tips From The Professor” I give you:

4 tips on mistakes to avoid when selecting the diet that is best for you.

6 tips on how to choose the best diet.

5 tips on what to look for when selecting a diet featuring meal replacement products.

7 tips on how to keep the weight off.

Then I put all this information together to help you choose the best diet, the best meal replacement product, and/or the best commercial diet program.

For more details read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Can Diet Protect Your Mind?

September 13, 2022 by Dr. Steve Chaney

Which Diet Is Best?

Author: Dr. Stephen Chaney

Alzheimer’s is a scary disease. There is so much to look forward to in our golden years. We want to enjoy the fruits of our years of hard work. We want to enjoy our grandkids and perhaps even our great grandkids. More importantly, we want to be able to pass on our accumulated experiences and wisdom to future generations.

Alzheimer’s and other forms of dementia have the potential to rob us of everything that makes life worth living. What is the use of having a healthy body, family, and fortune if we can’t even recognize the people around us?

Alzheimer’s and other forms of dementia don’t happen overnight. The first symptoms of cognitive decline are things like forgetting names, where you left things, what you did last week. For most people it just keeps getting worse.

Can diet protect your mind? Recent studies have given us a ray of hope. For example, several meta-analyses have shown that adherence to the Mediterranean diet was associated with a 25-48% lower risk of cognitive decline and dementia.

However, there were several limitations to the studies included in these meta-analyses. For example:

For most of the studies the diet was assessed only at the beginning of the study. We have no idea whether the participants followed the same diet throughout the study. This means, we cannot answer questions like:

- What is the effect of long-term adherence to a healthy diet?

- Can you reduce your risk of cognitive decline if you switch from an unhealthy diet to a healthy diet?

These studies focused primarily on the Mediterranean diet. This leaves the question:

- What about other healthy diets? Is there something unique about the Mediterranean diet, or do other healthy diets also reduce the risk of cognitive decline?

This study (C Yuan et al, American Journal of Clinical Nutrition, 115: 232-243, 2022) was designed to answer those questions.

How Was The Study Done?

The investigators utilized data from The Nurse’s Health Study. They followed 49,493 female nurses for 30 years from 1984 to 2014. The average age of the nurses in 1984 was 48 years, and none of them had symptoms of cognitive decline at the beginning of the study.

The nurse’s diets were analyzed in 1984, 1986, and every 4 years afterwards until 2006. Diets were not analyzed during the last 8 years of the study to eliminate something called “reverse causation”. Simply put, the investigators were trying to eliminate the possibility that participants in the study might change their diet because they were starting to notice symptoms of cognitive decline.

The data from the dietary analyses were used to calculate adherence to 3 different healthy diets:

The Mediterranean diet.

The DASH diet. The DASH diet was designed to reduce the risk of high blood pressure. But you can think of it as an Americanized version of the Mediterranean diet.

The diet recommended by the USDA. Adherence to this diet is evaluated by something called the Alternative Healthy Eating Index or AHEI.

Adherence to each diet was calculated by giving a positive score to foods that were recommended for the diet and a negative score for foods that were not recommended for the diet. For more details, read the article.

In 2012 and 2014 the nurses were asked to fill out questionnaires self-assessing the early stages of cognitive decline. They were asked if they had more trouble than usual:

Remembering recent events or remembering a short list of items like a grocery list (measuring memory).

Understanding things, following spoken instructions, following a group conversation, or following a plot in a TV program (measuring executive function).

Remembering things from one second to the next (measuring attention).

Finding ways around familiar streets (measuring visuospatial skills).

The extent of cognitive decline was calculated based on the number of yes answers to these questions.

Can Diet Protect Your Mind?

Here is what the investigators found when they analyzed the data:

At the beginning of the study in 1984 there were 49,493 female nurses with an average age of 48. None of them had symptoms of cognitive decline.

By 2012-2014 (average age = 76-78) 46.9% of them had cognitive decline and 12.3% of them had severe cognitive decline.

Using the data on dietary intake and the rating systems specific to each of the diets studied, the investigators divided the participants into thirds based on their adherence to each diet. The investigators then used these data to answer two important questions that no previous study had answered:

#1: What is the effect of long-term adherence to a healthy diet? To answer this question the investigators averaged the dietary data obtained every 4 years between 1984 and 2006 to obtain cumulative average scores for adherence to each diet. When the investigators compared participants with the highest adherence to various healthy diets for 30 years to participants with the lowest adherence to those diets, the risk of developing severe cognitive decline was decreased by:

40% for the Mediterranean diet.
32% for the DASH diet.
20% for the USDA-recommended healthy diet (as measured by the AHEI score).

#2: Can you reduce your risk of cognitive decline if you switch from an unhealthy diet to a healthy diet? To answer this question, the investigators looked at participants who started with the lowest adherence to each diet and improved to the highest adherence by the end of the study. This study showed that improving from an unhealthy diet to a healthy diet over 30 years decreased the risk of developing severe cognitive decline by:

20% for the Mediterranean diet.
25% for the DASH diet.

There were a few other significant observations from this study.

The inverse association between healthy diets and risk of cognitive decline was greater for nurses who had high blood pressure.

- This is an important finding because high blood pressure increases the risk of cognitive decline.

The inverse association between healthy diets and risk of cognitive decline was also greater for nurses who did not have the APOE-ɛ4 gene.

- This illustrates the interaction of diet and genetics. The APOE-ɛ4 gene increases the risk of cognitive decline. Healthy diets reduced the risk of cognitive decline in nurse with the APOE-ɛ4 gene but not to the same extent as for nurses without the gene.

This study did not investigate the mechanism by which healthy diets reduced the risk of cognitive decline, but the investigators speculated it might be because these diets:

Were anti-inflammatory.
Supported the growth of healthy gut bacteria.

The investigators concluded, “Our findings support the beneficial roles of long-term adherence to the [Mediterranean, DASH, and USDA] dietary patterns for maintaining cognition in women…Further, among those with initially relatively low-quality diets, improvement in diet quality was associated with a lower likelihood of developing severe cognitive decline. These findings indicate that improvements in diet quality in midlife and later may have a role in maintenance of cognitive function among women.”

Which Diet Is Best?

In a sense this is a trick question. That’s because this study did not put the participants on different diets. It simply analyzed the diets the women were eating in different ways. And while the algorithms they were using were diet-specific, there was tremendous overlap between them. For more specifics on the algorithms used to estimate adherence to each diet, read the article.

That is why the investigators concluded that all three diets they analyzed reduced the risk of cognitive decline rather than highlighting a specific diet. However, based on this and numerous previous studies the evidence is strongest for the Mediterranean and DASH diets.

And I would be remiss if I didn’t also mention the MIND diet. While it was not included in this study, the MIND diet:

Was specifically designed to reduce cognitive decline.

Can be thought of as a combination of the Mediterranean and DASH diets.

Includes data from studies on the mind-benefits of individual foods. For example, it recommends berries rather than all fruits.

The MIND diet has not been as extensively studied as the Mediterranean and DASH diets, but there is some evidence that it may be more effective at reducing cognitive decline than either the Mediterranean or DASH diets alone.

Which Foods Are Best?

The authors of this study felt it was more important to focus on foods rather than diets. This is a better approach because we eat foods rather than diets. With that in mind they analyzed their data to identify the foods that prevented cognitive decline and the foods increased cognitive decline. This is what they found:

Fruits, fruit juices, vegetables, fish, nuts, legumes, low-fat dairy, and omega-3 fatty acids (fish oil) reduced the risk of cognitive decline.

Red and processed meats, omega-6 fatty acids (most vegetable oils), and trans fats increased the risk of cognitive decline.

While this study did not specifically look at the effect of processed foods on cognitive decline, diets high in the mind-healthy foods listed above are generally low in sodas, sweets, and highly processed foods.

What Does This Study Mean For You?

The question, “Can diet protect your mind”, is not a new one. Several previous studies have suggested that healthy diets reduce the risk of cognitive decline, but this study breaks new ground. It shows for the first time that:

Long-term adherence to a healthy diet can reduce your risk of cognitive decline by up to 40%.

- This was a 30-year study, so we aren’t talking about “diet” in the traditional sense. We aren’t talking about short-term diets to drop a few pounds. We are talking about a life-long change in the foods we eat.

If you currently have a lousy diet, it’s not too late to change. You can reduce your risk of cognitive decline by switching to a healthier diet.

- This is perhaps the best news to come out of this study.

Based on current evidence, the best diets for protecting against cognitive decline appear to be the Mediterranean, DASH, and MIND diets.

And if you don’t like restrictive diets, my advice is to:

Eat more fruits, fruit juices, vegetables, fish, nuts, legumes, low-fat dairy, and omega-3 fatty acids (fish oil).

Eat less red and processed meats, omega-6 fatty acids (most vegetable oils), and trans fats.

Eat more plant foods and less animal foods.

Eat more whole foods and less sodas, sweets, and processed foods.

And, of course, a holistic approach is always best. Other lifestyle factors that help reduce your risk of cognitive decline include:

Regular exercise.
Weight control.
Socialization.
Memory training (mental exercises).

The Bottom Line

Alzheimer’s is a scary disease. What is the use of having a healthy body, family, and fortune if we can’t even recognize the people around us?

A recent study looked at the effect of diet on cognitive decline in women. The study started with middle-aged women (average age = 48) and followed them for 30 years. The investigators then used these data to answer two important questions that no previous study had answered:

#1: What is the effect of long-term adherence to a healthy diet? When the investigators compared participants with the highest adherence to various healthy diets for 30 years to participants with the lowest adherence to those diets, the risk of developing severe cognitive decline was decreased by:

40% for the Mediterranean diet.
32% for the DASH diet.
20% for the USDA recommendations for a healthy diet.

#2: Can you reduce your risk of cognitive decline if you switch from an unhealthy diet to a healthy diet? This study showed that improving from an unhealthy diet to a healthy diet over 30 years decreased the risk of developing severe cognitive decline by:

20% for the Mediterranean diet.
25% for the DASH diet.

For more details on the study, which diets, and which foods are best for protecting your mind, and what this study means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Does Olive Oil Help You Live Longer?

March 8, 2022 by Dr. Steve Chaney

Which Fat Is Healthiest?

Author: Dr. Stephen Chaney

If you believe the headlines, olive oil is a superfood. It is often described as the star of the Mediterranean diet. It is referred to as the healthiest of dietary fats. Is this true, or is it hype?

Olive oil’s resume is impressive:

It is rich in monounsaturated fatty acids, which…

- Are less susceptible to oxidation than polyunsaturated oils.

- Make our arteries more flexible, which lowers blood pressure.

- Lower LDL-cholesterol levels, which reduces the risk of heart disease.

Extra-virgin olive oil contains phytonutrients and tocopherols (various forms of vitamin E), which…

- Have anti-inflammatory properties.

- Improve insulin sensitivity and blood sugar control.

Olive oil consumption is also associated with healthier gut bacteria, but it is not clear whether this is due to olive oil or to the fact that a Mediterranean diet is also richer in fresh fruits, vegetables, and whole grains.

Several recent studies have shown that olive oil consumption is associated with a lower risk of heart disease. However, these studies were conducted in Mediterranean countries where the average intake of olive oil (3 tablespoons/day) is much greater than in the United States (0.3 tablespoons/day).

The current study (M Guasch-Ferré et al, Journal of the American College of Cardiology, 79: 101-112, 2022) was designed to test whether:

The amount of olive oil Americans consume decreases the risk of heart disease.

Whether olive oil consumption had benefits beyond a reduction in heart disease risk.

How Was This Study Done?

This study combined data from 60,582 women enrolled in the Nurses’ Health Study and 31,801 men enrolled in the Health Professionals Follow-Up Study). The participants:

Were free of heart disease and diabetes at the start of the study.

Were 56 at the start of the study with an average BMI of 25.6 (Individuals with BMIs in the 25-30 range are considered overweight, so they were at the lowest end of the overweight range).

The Nurses’ Health Study and Health Professional Follow-Up Study are both association studies, meaning they looked at the association between olive oil consumption and health outcomes. They cannot directly prove cause and effect. However, they are very strong association studies because:

Every 2 years, participants filled out a questionnaire that updated information on their body weight, smoking status, physical activity, medications, multivitamin use, and physician-diagnosed diseases.

Every 4 years, participants filled out a comprehensive food frequency questionnaire.

In other words, this study did not just rely on the participant’s lifestyle, dietary intake, and health at the beginning of the study, as so many association studies do. It tracked how each of these variables changed over time.

The participants were followed for an average of 28 years and their average olive oil intake over those 28 years was correlated with all-cause mortality and mortality due to specific diseases.

Deaths were identified from state vital statistics, the National Death index, reports by next of kin, or reports by postal authorities.

Causes of death were determined by physician review of medical records, medical reports, autopsy reports, or death certificates.

Does Olive Oil Help You Live Longer?

During the 28 years of this study:

Olive oil consumption in the United States increased from an average of ~1/3 teaspoon/day to ~1/3 tablespoon/day.

Margarine consumption decreased from 12 g/day to ~4 g/day.

The consumption of all other fats and oils remained about the same.

As I mentioned above, olive oil consumption was averaged over the life of the study for each individual. When the investigators compared people consuming the highest amount of olive oil (>0.5 tablespoon/day) with people consuming the least olive oil (0 to 1 teaspoon/day):

Mortality from all causes was decreased by 35% for the group consuming the most olive oil.

However, the group consuming the most olive oil also was more physically active, had a healthier diet, and consumed more fruits and vegetables than the group who consumed the least olive oil.

After correcting for all those factors, mortality from all causes was decreased by 19% for the group consuming the most olive oil.

The authors concluded, “We found that greater consumption of olive oil was associated with lower risk of total…mortality… Our results support current dietary recommendations to increase the intake of olive oil…to improve overall health and longevity.” (I will fill in the blanks in this statement once I have covered other aspects of this study)

The authors also said, “Of note, our study showed that benefits of olive oil can be observed even when consumed in lower amounts than in Mediterranean countries.”

Are There Other Benefits From Olive Oil Consumption?

The study didn’t stop there. The investigators also looked at the effect of olive oil consumption on the major killer diseases in the United States and other developed countries. When they compared the effect of olive oil consumption on cause-specific mortality, they found that the group who consumed the most olive oil reduced their risk of dying from:

Cardiovascular disease by 19%.

Cancer by 17%

Respiratory disease by 18%.

Neurodegenerative disease (cognitive decline and Alzheimer’s disease) by 29%.

- The reduction in neurodegenerative disease was much greater for women (34% decrease) than for men (19% decrease).

With this information I can fill in one of the blanks in the author’s conclusions: “We found that greater consumption of olive oil was associated with lower risk of total and cause-specific mortality… Our results support current dietary recommendations to increase the intake of olive oil…to improve overall health and longevity.”

Which Fats Are Healthiest?

The sample size was large enough and the dietary information complete enough for the investigators to also estimate the effect of substituting olive oil for other dietary fats and oils.

They found that every ¾ tablespoon of olive oil substituted for an equivalent amount of:

Margarine decreased total mortality by 13%.

Butter decreased total mortality by 14%.

Mayonnaise deceased total mortality by 19%

Dairy fat decreased total mortality by 13%.

- The same beneficial effects of substituting olive oil for other fats were seen for cause-specific mortality (cardiovascular disease, cancer, respiratory disease, and neurodegenerative disease).

- There was a linear dose-response. This means that substituting twice as much olive oil for other dietary fats doubled the beneficial effects on total and cause-specific mortality.

However, substituting olive oil for polyunsaturated vegetable oils had no effect on total and cause-specific mortality.

Now I can fill in the remaining blanks in the author’s conclusion: “We found that greater consumption of olive oil was associated with lower risk of total and cause-specific mortality. Replacing other types of fat, such as margarine, butter, mayonnaise, and dairy fat, with olive oil was also associated with a lower risk of mortality. Our results support current dietary recommendations to increase the intake of olive oil and other unsaturated vegetable oils in place of other fats to improve overall health and longevity.”

What Does This Study Mean For Us?

As I said above, this is an association study, and association studies do not prove cause and effect. However:

1) This is a very strong association study because:

- It is a very large study (92,383 participants).

- It followed the participants over a long time (28 years).

- It utilized a very precise dietary analysis.

- Most importantly, it tracked the participant’s lifestyle, dietary intake, and health at regular intervals throughout the study. Most association studies only measure these variables at the beginning of the study. They have no idea how they change over time.

2) This study is consistent with several previous studies showing that olive oil consumption decreases the risk of dying from heart disease.

3) This study draws on its large population size and precise dietary analysis to strengthen and extend the previous studies. For example:

- The study showed that increased olive oil consumption also reduced total mortality and mortality due to cancer, respiratory disease, and neurodegenerative disease.

- The study measured the effect of substituting olive oil for other common dietary fats.

- The study showed that increased olive oil consumption in the context of the American diet was beneficial.

I should point out that the headlines you have seen about this study may be misleading.

While the headlines may have depicted olive oil as a superfood, this study did not find evidence that olive oil was more beneficial than other unsaturated vegetable oils. Again, this is consistent with many previous studies showing that substituting vegetable oils for other dietary fats reduces the risk of multiple diseases.

The headlines focused on the benefits of increasing olive oil consumption. However, they neglected the data showing that increasing olive oil (and other vegetable oils) was even more beneficial (35% reduction in total mortality) in the context of a healthy diet – one with increased intake of fruits, vegetables, whole grains, nuts, legumes, and long-chain omega-3s and decreased intake of red & processed meats, sodium, and trans fats.

So, my recommendation is to follow a whole food, primarily plant-based diet and substitute extra-virgin olive oil and cold pressed vegetable oils for some of the animal fats in your diet.

Some vegan enthusiasts recommend a very low-fat whole food plant-based diet. They point to studies showing that such diets can actually reverse atherosclerosis. However:

Those studies are very small.

The overall diet used in those studies is a very healthy plant-based diet.

The studies did not include a control group following the same diet with olive oil or other vegetable oils added to it, so there is no comparison of a healthy vegan diet with and without vegetable oils.

If you have read my book, “Slaying the Food Myths”, you know that my recommendations encompass a variety of whole food, primarily plant-based diets ranging all the way from very-low fat vegan diets to Mediterranean and DASH diets. Choose the one that best fits your food preferences and the one you will be most able to stick with long term. You will be healthier, and you may live longer.

The Bottom Line

A recent study looked at the effect of olive oil consumption on the risk dying from all causes and from heart disease, cancer, respiratory disease, and neurodegenerative diseases. When the study compared people consuming the highest amount of olive oil (>0.5 tablespoon/day) with people consuming the least olive oil (0 to 1 teaspoon/day):

Mortality from all causes was decreased by 19% for the group consuming the most olive oil.

They also found that the group who consumed the most olive oil reduced their risk of dying from:

Cardiovascular disease by 19%.

Cancer by 17%

Respiratory disease by 18%.

Neurodegenerative disease (cognitive decline and Alzheimer’s disease) by 29%.

They also found that every ¾ tablespoon of olive oil substituted for an equivalent amount of:

Margarine decreased total mortality by 13%.

Butter decreased total mortality by 14%.

Mayonnaise deceased total mortality by 19%

Dairy fat decreased total mortality by 13%.

However, substituting olive oil for polyunsaturated vegetable oils had no effect on total and cause-specific mortality.

The authors concluded, “We found that greater consumption of olive oil was associated with lower risk of total and cause-specific mortality. Replacing other types of fat, such as margarine, butter, mayonnaise, and dairy fat, with olive oil was also associated with a lower risk of mortality. Our results support current dietary recommendations to increase the intake of olive oil and other unsaturated vegetable oils in place of other fats to improve overall health and longevity.”

For more details and a summary of what this study means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.