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 Just a few months ago we were being told our fears of saturated fats were outdated.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

High Protein Diets and Weight Loss

Posted October 16, 2018 by Dr. Steve Chaney

Do High Protein Diets Reduce Fat And Preserve Muscle?

Author: Dr. Stephen Chaney

Healthy Diet food group, proteins, include meat (chicken or turkAre high protein diets your secret to healthy weight loss? There are lots of diets out there – high fat, low fat, Paleolithic, blood type, exotic juices, magic pills and potions. But recently, high protein diets are getting a lot of press. The word is that they preserve muscle mass and preferentially decrease fat mass.

If high protein diets actually did that, it would be huge because:

  • It’s the fat – not the pounds – that causes most of the health problems.
  • Muscle burns more calories than fat, so preserving muscle mass helps keep your metabolic rate high without dangerous herbs or stimulants – and keeping your metabolic rate high helps prevent both the plateau and yo-yo (weight regain) characteristic of so many diets.
  • When you lose fat and retain muscle you are reshaping your body – and that’s why most people are dieting to begin with.

So let’s look more carefully at the recent study that has been generating all the headlines (Pasiakos et al, The FASEB Journal, 27: 3837-3847, 2013).

The Study Design:

This was a randomized control study with 39 young (21), healthy and fit men and women who were only borderline overweight (BMI = 25). These volunteers were put on a 21 day weight loss program in which calories were reduced by 30% and exercise was increased by 10%. They were divided into 3 groups:

  • One group was assigned a diet containing the RDA for protein (about 14% of calories in this study design).
  • The second group’s diet contained 2X the RDA for protein (28% of calories)
  • The third group’s diet contained 3X the RDA for protein (42% of calories)

In the RDA protein group carbohydrate was 56% of calories, and fat was 30% of calories. In the other two groups the carbohydrate and fat content of the diets was decreased proportionally.

Feet_On_ScaleWhat Did The Study Show?

  • Weight loss (7 pounds in 21 days) was the same on all 3 diets.
  • The high protein (28% and 42%) diets caused almost 2X more fat loss (5 pounds versus 2.8 pounds) than the diet supplying the RDA amount of protein.
  • The high protein (28% and 42%) diets caused 2X less muscle loss (2.1 pounds versus 4.2 pounds) than the diet supplying the RDA amount of protein.
  • In case you didn’t notice, there was no difference in overall results between the 28% (2X the RDA) and 42% (3X the RDA) diets.

Pros And Cons Of The Study:

  • The con is fairly obvious. The participants in this study were all young, healthy and were not seriously overweight. If this were the only study of this type one might seriously question whether the results were applicable to middle aged, overweight coach potatoes. However, there have been several other studies with older, more overweight volunteers that have come to the same conclusion – namely that high protein diets preserve muscle mass and enhance fat loss.
  • The value of this study is that it defines for the first time the upper limit for how much protein is required to preserve muscle mass in a weight loss regimen. 28% of calories is sufficient, and there appear to be no benefit from increasing protein further. I would add the caveat that there are studies suggesting that protein requirements for preserving muscle mass may be greater in adults 50 and older.

The Bottom Line:

1)    Forget the high fat diets, low fat diets, pills and potions. High protein diets (~2X the RDA or 28% of calories) do appear to be the safest, most effective way to preserve muscle mass and enhance fat loss in a weight loss regimen.

2)     That’s not a lot of protein, by the way. The average American consumes almost 2X the RDA for protein on a daily basis. However, it is significantly more protein than the average American consumes when they are trying to lose weight. Salads and carrot sticks are great diet foods, but they don’t contain much protein.

3)     Higher protein intake does not appear to offer any additional benefit – at least in young adults.

4)     Not all high protein diets are created equal. What some people call high protein diets are laden with saturated fats or devoid of carbohydrate. The diet in this study, which is what I recommend, had 43% healthy carbohydrates and 30% healthy fats.

5)    These diets were designed to give 7 pounds of weight loss in 21 days – which is what the experts recommend. There are diets out there promising faster weight loss but they severely restrict calories and/or rely heavily on stimulants, they do not preserve muscle mass, and they often are not safe. In addition they are usually temporary.  I do not recommend them.

6)    This level of protein intake is safe for almost everyone. The major exception would be people with kidney disease, who should always check with their doctor before increasing protein intake. The only other caveat is that protein metabolism creates a lot of nitrogenous waste, so you should drink plenty of water to flush that waste out of your system. But, water is always a good idea.

7)     The high protein diets minimized, but did not completely prevent, muscle loss. Other studies suggest that adding the amino acid leucine to a high protein diet can give 100% retention of muscle mass in a weight loss regimen – but that’s another story for another day.

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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