Are Saturated Fats Bad For You?

Written by Dr. Steve Chaney on . Posted in Saturated Fats and Heart Disease

The Saturated Fat Wars Heat Up Again

Author: Dr. Stephen Chaney

Are saturated fats bad for you? 

are saturated fats bad for youI feel your pain. It is so confusing. Just a few months ago we were being told our fears of saturated fats were outdated. Saturated fats were fine. It was carbohydrates we needed to avoid.

Then, just last week the headlines blared: “Hold your horses. Saturated fats are bad for you. You need to avoid them.” No wonder you are confused!

Last week’s headlines were based on a recently published Presidential Advisory by the American Heart Association (F.M. Sacks et al, Circulation. 2017;135.00-00. DO!: 10.1161/CIR.0000000000000510). A Presidential Advisory is the AHA’s highest-level health advisory. It is meant to guide public health policy by government agencies such as the US Surgeon General’s office, the USDA, and the CDC.

However, the warnings about the dangers of saturated fat are very much like the warnings about the dangers of global warming. They have their believers and their deniers, and both sides passionately defend their positions. I understand the passion of saturated fat deniers. Foods high in saturated fat are an integral part of our heritage and our culture. It is only natural to want to believe those foods are good for us.

Because of this, I knew the AHA advisory would be controversial. After all, if someone is telling us we need to give up the foods we love, they better have darn good evidence to back up their recommendations.

I knew you, my readers, would want a scientifically accurate evaluation of the evidence, so I carefully analyzed the research studies the AHA presented in support of their recommendations. Here is what I found.

How Was The Analysis Done?

saturated fats and heart diseaseThis report was put together by the top heart disease experts, both physicians and research scientists, in the country. They examined over 50 years of research studies. They also examined meta-analyses that combined the results of multiple research studies. In short, they examined the entire body of scientific evidence on diet and heart disease.

The AHA committee used very rigorous criteria in selecting the best studies for their analysis. They only included randomized clinical trials that:

  • Had actual cardiovascular end points – heart attack, stroke, and deaths due to heart disease. Studies looking at things like LDL, HDL, particle size, inflammation etc. only give you part of the picture. They may, or may not, accurately predict risk of dying from heart disease.
  • Lasted two years or more. The fats we eat determine the fat composition of our cell membranes, and that is what ultimately determines our risk of dying from heart disease. This is the one instance it is true to say: “We are what we eat.”  However, changing the fat composition of our cell membranes does not occur overnight. It takes 2 years or more to achieve a 60-70% change in the fat composition of cell membranes.

It also takes time for any intervention to meaningfully impact heart disease risk. For example, with statin drugs it takes 1-2 years before there is a significant reduction in heart disease risk. Thus, for a variety of reasons, studies of less than 2 years duration are doomed to fail.

  • Showed the subjects stuck with the new diet for the duration of the study. Subjects find it difficult to adhere to a diet to which they are not accustomed long term and often revert to their more familiar diet. This requires either very close monitoring of what the subjects are eating or measurement of fat membrane composition to verify diet adherence, or both. Studies that only measured what the subjects were eating at the beginning of the study and then looked at outcomes months or years later may or may not be valid. Without any measurement of diet adherence, it is impossible to know.
  • Carefully controlled or measured what the saturated fats were replaced with. The importance of this criterion will be clear when we look at the results of their study.

They then did a meta-analysis of what they referred to as “core randomized trials” that met all 4 criteria. In short, this was a very rigorous and well-done analysis.

Are Saturated Fats Bad For You?

saturated fats from meatsThe main finding of the report was:

  • Replacing saturated fats from animal products with polyunsaturated fats from vegetable oils decreased the risk of heart disease by 29%. This is equivalent to statin therapy, without the side effects.
  • The conclusions of this report applied equally to the saturated fats that come from meats and dairy products.
  • About 50% of the risk reduction could be due to lowering of LDL cholesterol. The rest came from reduced arterial inflammation, increased flexibility of the arteries, increased membrane fluidity and other factors.
  • When the replacement of saturated fats with polyunsaturated fats occurred in the context of a heart healthy diet such as the Mediterranean diet, heart disease risk was reduced by 47%.

What the saturated fats are replaced with is critically important. The authors of this report calculated what would happen if we were to replace half of our saturated fat calories with equivalent calories from other foods. Replacing half of our saturated fat intake with:

  • Polyunsaturated fats (vegetable oils and fish oil), lowers heart disease risk by 25%.
  • Monounsaturated fats (olive oil & peanut oil), lowers heart disease risk by 15%.
  • Complex carbohydrates (whole grains, fruits & vegetables), lowers heart disease risk by 9%.
  • Refined carbohydrates and sugars (the kind of carbohydrates in the typical American Diet), slightly increases heart disease risk.
  • Trans fats, increases heart disease risk by 5%.
  • The authors did not address the relative value of omega-6 and omega-3 polyunsaturated fats in their report. However, I have addressed the heart health benefits of omega-3s in a previous report, Fish Oil Really Snake Oil.

Why Is There So Much Confusion?

saturated fats and LDL cholesterolYou are probably saying: “If saturated fats are so bad for me, why do I keep seeing diet books and news headlines saying I have nothing to fear from saturated fats?” The answer is pretty simple. The studies that have given rise to misleading headlines about the safety of saturated fats ignored one or more of the criteria described above that are needed to assure a valid conclusion. For example:

  • Some recent headlines claiming that saturated fats did not increase the risk of heart disease were based on studies in which saturated fats were replaced by refined carbohydrates and sugars. Other headlines were based on studies that did not measure what the saturated fats were replaced with.
  • The popular high saturated fat-low carb diets are not backed by any studies looking at their effect on heart attacks, stroke, or heart disease deaths. They are only backed by studies looking at their effect on LDL cholesterol and other imperfect markers of heart disease risk.
  • In contrast, the Mediterranean diet, which lowers saturated fat intake and contains healthy carbohydrates (whole grains, fruits and vegetables), significantly decreases the risk of heart disease. Please reference Mediterranean Diet for Heart Health.

 

What Are The Saturated Fat Deniers Saying?

 

saturated fats deniersThe saturated fat deniers have wasted no time trying to discredit the American Heart Association advisory. Maybe they can’t bear the thought of having to give up their favorite fatty foods. Or maybe they just can’t bear to admit they were wrong.

However, their claims just don’t hold water. Let me give you some examples.

  • The AHA (American Heart Association) is a tool of the pharmaceutical industry. If the AHA were a tool of the pharmaceutical industry, I hardly think their report would have stated that replacing saturated fats with polyunsaturated fats was as effective as statin drugs at reducing heart attack risk.
  • The AHA is a tool of the food industry. If the AHA were a tool of the food industry, I hardly think they would have recommended replacing fats from meat & dairy with polyunsaturated fats.
  • The AHA advisory was based on associations, which do not show cause and effect. False. The AHA committee based their recommendations on randomized clinical trials, the strongest kind of evidence. They merely said that studies looking at the association between saturated fats and heart disease were consistent with their analysis of randomized clinical trials.
  • The AHA advisory was based on LDL cholesterol, which is an imperfect predictor of cardiovascular risk. False. Again, the AHA committee based their recommendations on randomized clinical trials of cardiovascular outcomes, not on LDL levels. They merely estimated that LDL cholesterol levels contributed to about 50% of the risk they observed.
  • saturated fats mythsThe AHA committee ignored an early study in which replacing butter with polyunsaturated fats increased cardiovascular risk. False. That study actually replaced butter with margarine. It was the first study showing that trans fats are worse for us than saturated fats.
  • The AHA committee ignored recent studies that did not fit their hypothesis. False. They developed a valid set of scientific criteria for evaluating clinical studies. As described above, they simply eliminated those studies whose design does not permit a definitive conclusion.
  • The AHA recommends low fat diets containing refined carbohydrates and sugary foods, which are even worse. False. The AHA has consistently recommended low fat diets with complex carbohydrates (whole grains, fruits & vegetables). It is the food industry that corrupted their message. More to the point, this AHA Presidential Advisory specifically recommended lowering saturated fats in the context of a heart healthy diet like the Mediterranean diet.
  • The AHA recommends replacing saturated fats with omega-6 polyunsaturated vegetable fats, which can be harmful if consumed in excess. I have some sympathy with this argument. I would have preferred to have seen more emphasis on omega-3 oils in their report. There should also have been some discussion of the importance of antioxidants to protect against free radicals generated by polyunsaturated fat metabolism. However, their final recommendation to replace saturated fats with polyunsaturated fats in the context of a healthy diet like the Mediterranean diet goes a long way towards satisfying both concerns.

In short, the saturated fat deniers have no persuasive counter-argument. The evidence that saturated fat causes heart disease is simply overwhelming.

What Does This Mean For You?

replace saturated fats with polyunsaturated fatsThe time for debate is over. The evidence is overwhelming. It should be obvious to any reasonable person that saturated fats increase our risk of heart disease.

It should also be obvious that any diet that claims saturated fats are heart healthy is a myth. There are no long-term studies to back up that claim.

It is time to consider what it would mean if everyone in this country were to follow the AHA recommendations and replace half of the saturated fat in our diet with polyunsaturated fat. That would decrease our risk of heart disease by 29%.

  • 800,000 Americans die of heart disease each year. 232,000 lives would be saved.
  • Heart disease costs our nation $316 billion each year. $92 billion health care dollars would be saved.
  • Heart disease costs are expected to exceed $1 trillion by 2035. $290 billion health care dollars would be saved.

What if we decreased our risk of heart disease by 47% by coupling decreased intake of saturated fats with a heart healthy diet like the Mediterranean diet?

  • 376,000 lives would be saved.
  • $148 billion health care dollars would be saved.
  • $470 billion health care dollars would be saved by 2035.

Each of us has the ability to save our health and our lives by what we put into our mouths every day.

In addition, our health care system will soon become financially non-viable if we continue to focus on disease treatment rather than prevention. Each of us also has the ability to save our health care system by what we put into our mouths every day.

 

The Bottom Line

 

  • The link between saturated fat and heart disease risk is like global warming. It has its believers and its deniers, and both sides passionately defend their viewpoints.
  • The American Heart Association (AHA) recently released a Presidential Advisory on the relationship between saturated fats and heart disease. Because I knew their report would be controversial, I analyzed its scientific accuracy very carefully.
  • The AHA report was prepared by the top heart disease experts in the country. They reviewed over 50 years of clinical studies and used a very rigorous set of criteria to decide which studies to include in their analysis and which to exclude. In my judgement, the criteria they used were valid. Studies that fail to meet one or more of these criteria may not provide valid results. Unfortunately, several of the studies that have generated some of the recent controversy did not meet those criteria.
  • From a meta-analysis of “core studies” meeting these criteria, they concluded:
    • Replacing saturated fats from animal products with polyunsaturated fats from vegetable oils decreased the risk of heart disease by 29%. This is equivalent to statin therapy, without the side effects
    • The conclusions of this report applied equally to the saturated fats that come from meats and dairy products.
    • About 50% of the risk reduction could be due to lowering of LDL cholesterol. The rest came from reduced inflammation, increased flexibility of the arteries, and other factors.
    • When the replacement of saturated fats with polyunsaturated fats occurred in the context of a heart healthy diet such as the Mediterranean diet, heart disease risk was reduced by 47%.
  • The AHA recommends replacing half of the calories from saturated fat with healthier choices. From a detailed analysis of the data, the authors concluded which foods replace the saturated fat is very important. Replacing half of our saturated fat intake with:
    • Polyunsaturated fats (vegetable oils and fish oil), lowers heart disease risk by 25%.
    • Monounsaturated fats (olive oil & peanut oil), lowers heart disease risk by 15%.
    • Complex carbohydrates (whole grains, fruits & vegetables), lowers heart disease risk by 9%.
    • Refined carbohydrates and sugars (the kind of carbohydrates in the typical American Diet), slightly increases heart disease risk.
    • Trans fats, significantly increases heart disease risk.
  • The saturated fat deniers have already started trying to discredit the AHA advisory. I have reviewed their claims and found them to be baseless.
  • The evidence is overwhelming. It should be obvious to any reasonable person that saturated fats increase our risk of heart disease. It should also be obvious that any diet that claims saturated fats are heart healthy is a myth. There are no long-term studies to back up that claim.
  • If everyone in this country were to follow the AHA recommendations and replace half of the saturated fat in our diet with polyunsaturated fat:
    • Between 232,000 and 376,000 lives would be saved next year.
    • Between 92 and 148 billion health care dollars would be saved next year.
    • By 2035 between 290 and 470 billion health care dollars would be saved annually.

In short, each of us has the ability to preserve our health and save our lives by what we put into our mouth every day.

So, are saturated fats bad for you?  The answer is a resounding “yes.”

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.

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Comments (2)

  • Jim Campbell

    |

    Wonderfully, puts the controversy to rest.

    Reply

  • JoAnne Naro

    |

    Thank you Dr. Chaney. I always enjoy reading your very informative Health Tips. All the best to you and yours!

    Sincerely,
    JoAnne Naro
    Shaklee Associate

    Reply

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Latest Article

Should You Avoid Sugar Completely?

Posted October 24, 2017 by Dr. Steve Chaney

Is It The Sugar, Or Is It The Food?

Author: Dr. Stephen Chaney

 

Should we avoid sugar completely?  Almost every expert agrees that Americans should cut down on the amount of sugar we are consuming. However, for some people this has become a “sugar phobia”. They have sworn that “sugar shall never touch their lips”. Not only do they avoid sugar sweetened sodas and junk food, but they also have become avid label readers. They scour the label of every food they see and reject foods they find any form of sugar listed as an ingredient. Is this degree of sugar avoidance justified?

 

Should We Avoid Sugar to Keep it From Killing Us?

 

Let me add some perspective:

  • If you just take studies about the dangers of sugar at face value, sugar does, indeed, look dangerous. Excess sugar consumption is associated with increased risk of obesity, diabetes, and heart disease. However, when you look a little closer, you find that most of these studies have been done by looking at the correlation of each of these conditions with sugar sweetened beverage consumption (sodas and fruit juices).

A few studies have looked at the correlation of obesity and disease with total “added sugar” consumption. However, 71.6% of added sugar in the American diet comes from sugar sweetened beverages and junk food. None of the studies have looked at the sugar from healthy foods like fruits, vegetables, and whole grains. That’s because there is ample evidence that these foods decrease the risk of obesity, diabetes, and heart disease.

  • For example, if apples had a nutrition label, it would list 16 grams of sugar in a medium 80 calorie apple, which corresponds to about 80% of the calories in that apple. The sugar in an apple is about the same proportion of fructose and glucose found in high fructose corn syrup. Apples are not unique. The nutrition label would read about the same on most other fruits. Does that mean you should avoid sugar from all fruits? I think not.

Avoid Sugar or Avoid Certain Foods

 

avoid sugar from junk foodsThe obvious question is: “Why are the same sugars, in about the same amounts, unhealthy in sodas and healthy in fruits?” Let’s go back to those studies I just mentioned—the ones that are often used to vilify sugars. They are all association studies, the association of sugar intake with obesity and various diseases.

The weakness of association studies is the association could be with something else that is tightly correlated with the variable (sugar intake) that you are measuring. Could it be the food that is the problem, not the sugar?

If we look at healthy foods (fruits, vegetables, whole grains) they are chock full of vitamins, minerals, phytonutrients, fiber, and (sometimes) protein. Fiber and protein slow the absorption of sugar into the bloodstream. As a result, blood sugar levels rise slowly and are sustained at relatively low levels for a substantial period of time.

In sodas there is nothing to slow the absorption of blood sugar. You get rapid rise in blood sugar followed by an equally rapid fall. The same is true of junk foods consisting primarily of sugar, refined flour and/or fat.  Avoid sugar from those types of foods.

Another consideration is something called caloric density. Here is a simple analogy. I used to explain the concept of caloric density to medical students in my teaching days. There are about the same number of calories in a 2-ounce candy bar and a pound of apples (around 278 in the 2-ounce candy bar and 237 in a pound of apples). You can eat a 2-ounce candy bar and still be hungry. If you eat a pound of apples you are done for a while. In this example, the 2-ounce candy bar had a high caloric density (a lot of calories in a small package). Perhaps a more familiar terminology would be the candy bar was just empty calories.

Are Sodas and Junk Foods Killing Us?

avoid sugar from candyPutting all that together, you can start to understand why the foods the sugars are in are more important than the sugars themselves. When you consume sugars in the form of sugar sweetened beverages or sugary junk foods, your appetite increases. We don’t know for sure whether it is the intense sweetness of those foods, the rapid increase and fall in blood sugar, or the high caloric density (lots of calories ina small package) that makes us hungrier. It doesn’t matter. We crave more food, and it isn’t usually fruits, vegetables, and complex carbohydrates we crave. It’s more junk. That sets in motion a predictable sequence of events.

  • We overeat. Those excess calories are stored as fat and we become obese. [Note: The low carb enthusiasts will tell you our fat stores come from carbohydrates alone. That is incorrect. All excess calories, whether from protein, fat, or carbohydrate, are stored as fat.]
  • It’s not just the fat you can see (belly fat) that is the problem. Some of that fat builds up in our liver and muscles. This sets up an unfortunate sequence of metabolic events.
  • The fat stores release inflammatory cytokines into our bloodstream. That causes inflammation. Inflammation increases the risk of many diseases including heart disease and cancer.
  • The fat stores also cause our cells to become resistant to insulin. That reduces the ability of our cells to take up glucose, which leads to hyperglycemia and type 2 diabetes. [Note: The low carb enthusiasts will tell you carbohydrates cause type 2 diabetes. That is also incorrect. It is our fat stores that cause insulin resistance and type 2 diabetes. Our fat stores come from all excess calories, not just excess calories from carbohydrates.]
  • Insulin resistance also causes the liver to overproduce cholesterol and triglycerides and pump them into the bloodstream. That increases the risk of heart disease.
  • Sugar sweetened beverages and sugary junk foods also displace healthier foods from our diet. That leads to potential nutrient shortfalls that can increase our risk of many diseases.

However, none of this has to happen. The one thing that every successful diet has in common is the elimination of sodas, junk foods, fast foods and convenience foods. You should avoid sugar from those foods as much as possible. Once you eliminate those from your diet,you significantly enhance your chances of being at a healthy weight and being healthy long term.

 

What About Protein Supplements And Similar Foods?

Of course, the dilemma is what you, as an intrepid label reader, should do about protein supplements, meal replacement bars, or snack bars. They are supposed to be healthy, but the label lists one or more sugars. Even worse, the sugar content is higher than your favorite health guru recommends.  So, should you avoid sugar from supplements and the like?

In this case, a more useful concept is glycemic index, which is a measure of the effect of the food on your blood sugar levels. Healthy foods like apples may have a high sugar content, but they havea low glycemic index.

avoid sugar and consume protein to slow absorbptionThe same is true for the protein supplements and bars you are considering. Rather than looking at the sugar content, you should be looking for the term “low glycemic” on the label. That means there is enough fiber and protein in the food to slow the absorption of sugar into the bloodstream and stabilize your blood sugar levels.

What Does This Mean For You?

Don’t misunderstand me. I am not advocating for unlimited consumption of sugar. We should work on ways to avoid sugar or reduce the amount of sugar in our diet. On the other hand, we don’t need to become so strict that we and our family need to eat foods that taste like cardboard. We also don’t want to replace natural sugars with artificial sweeteners. I have warned about the dangers of artificial sweeteners previously.

We can go a long way towards reducing sugar by just eliminating sodas, other sugar sweetened beverages, junk foods, fast foods, convenience foods, and pastries from our diet. When considering fast foods and convenience foods, we should check the label for hidden sugar. For example, some Starbucks drinks are mostly sugar. When considering foods that are supposed to be healthy, we should look for the term “low glycemic” on the label.

So we don’t have to avoid sugar completely, but we should reduce sugar from sugar sweetened beverages and junk food.

 

The Bottom Line

 

We need to keep warnings about the dangers of sugar in perspective:

  • The studies showing that sugar consumption leads to obesity, diabetes, and heart disease have all been done with sodas and junk foods.
  • Many fruits have just as much sugar as a soda. They also contain about the same proportion of fructose and glucose as high fructose corn syrup. Yet we know fruits are good for us.
  • Diets rich in fruits, vegetables and whole grains decrease our risk of obesity, diabetes, and heart disease.
  • That is because the sugar in whole foods is generally present along with fiber and protein, which slows the absorption of sugar and prevents the blood sugar spikes we get with sodas and junk foods.
  • In the case of prepared foods like protein supplements, you should look for “low glycemic” on the label rather than sugar content. Low glycemic means that there is enough fiber and protein in the product to slow the absorption of sugar and prevent blood sugar spikes.
  • Don’t misunderstand me. I am not advocating for unlimited consumption of sugar. We should all work on ways to avoid sugar from junk foods or to reduce the amount of sugar in our diet. On the other hand, we don’t need to become so strict that we and our family need to eat foods that taste like cardboard. We also don’t want to replace natural sugars with artificial sweeteners.
  • We can go a long way towards reducing sugar by just eliminating sodas, other sugar sweetened beverages, junk foods, fast foods, convenience foods, and pastries from our diet. When considering fast foods and convenience foods, we should check the label for hidden sugar. When considering foods that are supposed to be healthy, we should look for the term “low glycemic” on the label.

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.

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