Article: Saturated Fat and Heart Disease: Unraveling the Myth
by Laurel Blair, NTP
WaccoBB.net
"The diet-heart hypothesis is the greatest scientific deception of this century, perhaps of any century."
-George Mann, retired professor of biochemistry and medicine at Vanderbilt University
The idea that dietary saturated fat and cholesterol are unhealthy to consume and are the main cause of heart disease is deeply ingrained in the collective psyche of Americans. Saturated fat is referred to as "artery-clogging saturated fat" in the media. The USDA's Dietary Guidelines recommend using only low-fat or non-fat dairy products, limiting the intake of solid fats and eggs, consuming only lean proteins, and replacing meat with vegetable proteins. People are monitoring their cholesterol levels, buying fat-free and cholesterol-free foods, and eating boneless skinless chicken breasts instead of steaks and pork chops. The word fat has practically become a swear word in this country!
So where did this idea come from? And more importantly, is it actually true?
Few people are aware of the mountains of historical and scientific evidence that has piled up over the years to disprove the 'dietary saturated fat and cholesterol = heart disease' concept, also known as the diet-heart hypothesis. Few topics have been researched so thoroughly and for so many years, but the solid proof to support the hypothesis has never emerged. Yet the diet-heart hypothesis has become such a fundamental belief about health for so long that its validity is rarely questioned.
The result is that millions of people have significantly changed their approach to food, in the belief that these changes will improve their health in the long run. And yet, in more than 30 years since reducing saturated fat and cholesterol first became the official recommendations for health, we have seen our health as a nation deteriorate more rapidly than ever before. Average fat intakes as percentage of calories have declined significantly, and average cholesterol levels have also decreased, but the incidence of heart disease itself has not declined at all. A 10- year study from the New England Journal of Medicine in 1998 suggested that heart disease death rates are declining mostly because treatments have become more sophisticated. Between 1979 and 1996, medical procedures related to heart disease more than quadrupled!1 Just as alarming are the rising rates of obesity and diabetes, which both contribute to heart disease risk.
A Hypothesis is Born
At the beginning of the last century, heart attacks were very rare. The incidence of heart attack began to increase rapidly, reaching its highest rate of growth between 1940 and 1967. It was such an alarming problem that the World Health Organization called it the world’s most serious epidemic. Researchers discovered that many people who died of heart attacks had plaque buildup in their coronary arteries, and they theorized that the plaque could cause blockage of the arteries, cutting off the blood supply to the heart and leading to death of heart tissue. Now they just needed to find the culprit behind the excessive plaque buildup.
Ancel Keys, an American scientist, provided a plausible explanation with his famous Seven Countries Study, which began in 1958. Keys took data on percentage of calories from fat and coronary heart disease deaths from seven countries, and plotted them on a graph. The countries he used were Japan, Italy, England, Wales, Australia, Canada, and the United States. The graph curved upwards exponentially, seemingly demonstrating greatly increased death rates from heart disease as calories from fat in the diet went up. He made it seem simple: just lower your fat intake and you'll avoid heart disease!
However, this study has been widely criticized for its selective use of the available data. Keys ignored countries like France, which had a similar percentage of calories from fat as England and Wales, yet had 75% lower rates of heart disease death. He also excluded countries like Israel, which consumed the same amount of fat as Italy yet suffered from triple the rate of heart disease deaths! When the data from additional countries is plotted alongside Keys' graph, the correlation disappears.12
Because it was obvious that there were many exceptions to his "rule", Keys decided next that certain types of fat were harmful, while others were beneficial. Researchers had discovered that atherosclerotic plaques in the arteries contained cholesterol, and they believed that high levels of cholesterol in the blood were the causing the buildup of plaque (this is another hypothesis known as the lipid hypothesis). Keys proposed that dietary saturated fat and cholesterol caused heart disease by raising serum cholesterol levels.
Keys observed that many Mediterranean countries had low rates of heart disease despite high fat consumption, and he began to promote the so-called Mediterranean Diet as the ultimate diet for health. The Mediterranean Diet was described by Keys and others as one that is high in vegetables, fruits, whole grains and legumes, moderate to high in unsaturated fat from olive oil and fish, moderate in dairy and red wine, but low in meats, eggs and saturated fat in general. However, such a diet is not truly typical of most of the Mediterranean area. For example, in northern Italy butter and lard are used liberally for cooking, with olive oil used only for salads. In many areas of Italy and the Mediterranean, fatty meats like ham, sausage, and salami are everyday fare.2
The diet-heart hypothesis is directly contradicted by the examples of countries like France and Belgium, whose cuisines are high in saturated fat-rich foods like butter, cream, eggs, organs, and fatty meats. These countries have some of the lowest rates of death from heart disease in all of Europe.3 The people of Vilcabamba, Ecuador, known for their longevity, traditionally ate large amounts of full-fat dairy and raw or nearly raw eggs, a moderate amount of meat (including organ meats), and used lard for cooking.4 The Maasai of Africa have no detectable heart disease when eating their traditional diet of meat, blood, and very rich milk from their special breed of cattle. It's clear from these examples that saturated fat and cholesterol cannot possibly be the cause of heart disease.
The evidence here in America does not support the diet-heart hypothesis either. During the period of the most rapid increase in heart disease rates in America, butter consumption plummeted from 18 pounds per person per year to less than 5 pounds, replaced mostly by margarines and oils that are low in saturated fat.5 In the last 40 years, Americans have also been restricting their intakes of other foods high in saturated fat and cholesterol, like eggs, cream, beef, and pork, while increasing their intake of poultry, which is much lower in saturated fat.6 If the diet- heart hypothesis were correct, we would expect the incidence of heart disease to have declined significantly in America, but it has not.
Despite the multitude of problems with his conclusions, Keys heavily promoted his research and got a lot of hype for his low-fat ideas, even snagging a cover of Time magazine. His ideas quickly caught on with a public that was increasingly health-conscious and concerned about the rising rates of heart disease, previously so rare. Saturated fat and cholesterol began to be viewed as inherently unhealthful, as substances that would build up in the arteries of people who consumed them.
Soon after, Congress got involved by issuing their first ever Dietary Goals for the United States. According to Gary Taubes, author of the book Good Calories, Bad Calories, "it was Senator George McGovern's bipartisan, non- legislative Select Committee on Nutrition and Human Needs--and, to be precise, a handful of McGovern's staff members--that almost single-handedly changed nutritional policy in this country and initiated the process of turning the dietary fat hypothesis into dogma."1 In 1977, the advice to reduce total fat to less than 30% of calories, saturated fat to less than 10% of calories, and cholesterol to less than 300 mg/day became the official government stance, despite the fact that there was literally no solid evidence to back these positions. The guidelines also called for increasing carbohydrate and polyunsaturated fat intake, both very questionable recommendations, to say the least. The people were told that the evidence was so compelling that it justified making dietary changes before the real proof could be obtained (which could take many years of costly research).
Industry Propaganda
Food processing companies were more than happy to promote the diet-heart hypothesis for their own interests. The edible oil industry lobbied heavily in favor of the new dietary guidelines.7 Vegetable oils like corn, soy and cottonseed oil are high in polyunsaturated fats, the kind the government tells us to eat in place of saturated fat. They are much less expensive to produce than butter and are often extracted from byproducts of other industries (soy oil, for example, is a byproduct of the soy protein industry), allowing corporations to make more profit from the same amount of raw material. Industrial agribusiness also jumped on board: not only did they produce the seeds that were used to make vegetable oil, but now they could market breakfast cereals and other grain-based products as "heart healthy" and cholesterol-free". These foods are made from subsidized crops that are dirt cheap to produce and have high profit margins. The ability to market them as health foods is a dream come true for food processors.
Similarly, dairy producers can make more profit by selling low-fat or non-fat milk than they do with whole milk, because they can use the cream that has been removed to make ice cream. But make no mistake: these low-fat foods are not health foods by any stretch of the imagination! Reduced-fat dairy products have been linked to infertility in women.8
Organizations like the American Heart Association quickly adopted the low-fat low-cholesterol diet as the solution to the heart disease epidemic. In 1984 the president of the AHA went so far as to declare that if Americans would just follow their advice and eat less fat, we would have atherosclerosis conquered by the year 2000.1 The AHA currently still endorses the diet-heart hypothesis, even though Americans have dutifully cut their saturated fat and total fat intakes and still have plenty of atherosclerosis. This is hardly surprising, since the AHA takes money from food processing corporations in exchange for allowing those companies to put AHA symbols on their products, declaring their heart-healthy status. The AHA is also funded by numerous pharmaceutical companies.9 Their main concern doesn’t appear to be consumer health, as evidenced by the numerous sugary breakfast cereals that boast AHA symbols. Entire industries have been built around the diet-heart hypothesis, industries that have a vested interest in keeping that hypothesis alive.
Shaky Science
The link between natural, unprocessed saturated fat and cholesterol and increased rates of heart disease in humans has never been proven by any study. In fact, a 2010 meta-analysis of the existing literature concluded that there is no association between cardiovascular disease and dietary saturated fat.10 Three massive Harvard Studies (the Nurses’ Health Study, the Health Professionals Follow-Up Study, and the Nurses’ Health Study II) spanning 30 years and including some 300,000 Americans also failed to demonstrate any significant link between total fat or saturated fat and heart disease.1, 18
The Multiple Risk Factor Intervention Trial (MRFIT) was a very large controlled diet trial during the 1980's that was also unsupportive. The intervention group cut their saturated fat and cholesterol intakes and increased their polyunsaturated fat intake. They were also counseled to quit smoking. After six years, total mortality was slightly higher in the intervention group, a difference that was not statistically significant. This study also established that there is an association between serum cholesterol levels and heart disease death risk in men under 50, but in older people high cholesterol appears to be protective. Other studies have come to similar conclusions. One of the less- publicized results of the MRFIT was the discovery that those with low cholesterol levels have higher risk of death from all causes than those with moderately high cholesterol! Other studies have shown that people with low cholesterol levels are more prone to cancer.11
The famous Framingham Heart Study, which began in 1948 and is still ongoing, is often quoted as evidence for the diet-heart hypothesis. However, the study did not actually come to any conclusions that support the hypothesis. As William Castelli, MD, director of the Framingham Study, said 40 years after the study began, "In Framingham, Massachusetts, the more saturated fat one ate, the more cholesterol one ate, the more calories one ate, the lower people's serum cholesterol....we found that the people who ate the most cholesterol, ate the most saturated fat, ate the most calories weighed the least and were the most physically active."12
The question of why the diet-heart hypothesis has not been discarded despite being proven incorrect so many times can be answered by following the money. After issuing their new dietary guidelines, the government allocated large sums of money to research for the purpose of proving the hypothesis. About this issue, retired professor George Mann has said, "Fearing to lose their soft money funding, the academicians who should speak up and stop this wasteful anti-science are strangely quiet. Their silence has delayed a solution for coronary heart disease by a generation."12
Results of studies were often interpreted in ways that supported the hypothesis, and unsupportive results were not publicized. A variety of methods have been used to make unsupportive studies appear supportive. Studies in rabbits have shown increased arterial plaque from the feeding of cholesterol, but rabbits are herbivores whose natural diet doesn’t contain cholesterol.13 Many studies that supposedly incriminated saturated fats were really done with hydrogenated trans fats, which have been clearly shown to contribute to heart disease. In the past, scientists mistakenly believed that trans fats were the same as saturated fats because they are both solid at room temperature. In one study, margarine eaters had twice as much heart disease as butter eaters.6 It's also fairly common for the abstract of a study to say one thing while the data itself paints an entirely different picture. The Nurses Health Study is an example.
Scientists that have put forward alternative viewpoints about heart disease and diet have been ignored by the mainstream media. A recent article published in the International Journal of Applied and Basic Nutritional Sciences heavily criticized the reasoning used by the USDA and DHHS for their recommendations. It demonstrates how little scientific evidence there truly is to back up many of the dietary guidelines, and also how the committee ignored many studies in their analysis that did not support their preconceived notions about nutrition.14 And yet, those relying on the mainstream media outlets for their information did not hear about this important article.
Some drug trials have shown that cholesterol-lowering drugs decrease total heart attack deaths by modest amounts. Time magazine heralded these results as supportive of the diet-heart hypothesis, with a front cover featuring a frowning face made of bacon and eggs. However, these studies were not diet trials, and their results have nothing to do with dietary saturated fat. Statin drug trials also ignore the more important question of all-cause death rates. Total cholesterol levels are a weak indicator for heart disease risk, and have largely been replaced by more accurate risk factors such as levels of homocysteine, triglycerides, c-reactive protein, Lp(a), and more specific cholesterol indicators like oxidized LDL. High cholesterol levels are certainly not enough of a problem to justify the use of drugs that can cause deficiencies of vitamin D and coenzyme Q10, which are both important nutrients for heart health. Statin drugs and low cholesterol levels have also been linked to violence, suicide, and cancer. And believe it or not, the fine print for Lipitor even states that “Lipitor has not been shown to prevent heart disease or heart attacks”. These are the very conditions for which the drug is being prescribed!15
Furthermore, the idea that people with atherosclerosis have arteries clogged with cholesterol is completely inaccurate. The lipid portion of the atherosclerotic plaques that clog arteries are made up of mostly unsaturated fatty acids (74%).16 There is definitely cholesterol present, but it is not the majority of the plaque. Cholesterol is found in damaged arteries because it is a healing and repair substance. In other words, when there is damage to the arteries, the body wisely sends cholesterol to repair the damage. The cholesterol itself is not the villain in this scenario. The real problem is that the arteries are damaged in the first place! High levels of cholesterol indicate that the body senses a need for a lot of healing and repair. Attempting to reduce cholesterol levels without addressing the true cause of the damage is not a wise course of action. This leads us to our next question . . . what causes damage to the arteries?
The True Causes of Atherosclerosis
While there are many contributing factors in atherosclerosis, one of the main dietary causes of damaged arteries in America is high blood sugar.12 Too much glucose in the blood leads to high levels of insulin and cortisol in the blood, which are both inflammatory at chronically high levels. Ironically, the advice to reduce fat intake has led to increased consumption of refined carbohydrates found in low-fat convenience foods, which in turn has led to an epidemic of high blood sugar, type 2 diabetes, obesity, and increased atherosclerosis. Between 1983 and 1999, average sugar consumption increased 30%, reaching a staggering 158 pounds per person per year!17
Replacing refined sugars in the diet with unrefined, mineral-rich sweeteners can go a long way in reducing your risk for these diseases. Examples of healthy sweeteners include raw honey, Sucanat or Rapadura (also called dehydrated cane juice on ingredient labels - not to be confused with evaporated cane juice, which is refined), palm sugar, blackstrap molasses, maple syrup, and stevia. It's also a good idea to eat fewer sweets in general. The physiological effects of refined flour are similar to those of refined sugar, and it should be avoided as well for optimal health.
Another major dietary cause of arterial damage is the consumption of refined vegetable oils.12 For many years the conventional advice has been to replace saturated fats in the diet with polyunsaturated fats found in vegetable oils such as corn, soy, canola, cottonseed, sunflower, and safflower oils. In fact, the health establishment still has not changed its tune, despite all of the accumulated evidence that high levels of these oils in the diet have a negative effect on health. Never before in history have humans consumed such large amounts of polyunsaturated oils, and one of the effects is the imbalance between omega-3 and omega-6 fatty acids we are currently experiencing. This imbalance creates an inflammatory environment in the body, setting the stage for future heart disease.
Polyunsaturates are delicate and should never be heated, so they are a poor substitute for stable saturated fats. When these oils are heated (in processing and in cooking) they become rancid, full of damaging free radicals. Refined vegetable oils have been shown to increase the body's need for vitamin E.12 Read the label of practically any processed food (cookies, crackers, chips, dips, sauces, condiments, salad dressings, etc.), organic or non-organic, and you will see these oils listed as ingredients. Most of these products are cooked, and even if they are not, the oils are already rancid from the high temperatures and pressures used in processing. Even cold-pressed oils will go rancid if they are exposed to light, as they inevitably are in the supermarket.
Of course, trans fats are also toxic to the heart, just as they are toxic to every cell in your body. When trans fats are consumed, they get incorporated into your cell membranes and interfere with the semi-permeable quality that is so important for proper functioning of the cells. Trans fats inhibit the normal functioning of fatty acids in the body, and they increase levels of oxidized LDL. To avoid trans fats, read ingredient labels and never consume anything that lists hydrogenated or partially hydrogenated oils, even if it says "Trans-Fat Free" on the front.16
A cause of artery damage that is often overlooked is chemical exposure. Personal care, laundry, and cleaning products are full of toxic chemicals that are rapidly absorbed through the skin, bypassing digestion.12 Prescription drugs, smoking, air pollution and inhaled fumes from off-gassing furniture, carpets, etc., are some other common sources of exposure. Processed foods contain chemical pesticides, additives, preservatives, colorings, and flavorings that can damage the arteries. Unfiltered water can contain a wide variety of contaminants. To reduce your risk of atherosclerosis, minimize your exposure to these chemicals as much as possible.
Conclusion
The diet-heart hypothesis is based on misinterpretations and distortions of the data, and has been disproved time and time again. Saturated fat and cholesterol are not things you need to waste your time avoiding. These are very important nutrients in the body and excluding them from your diet can even be harmful! Worrying about your cholesterol levels is far more likely to contribute to heart disease than the cholesterol levels themselves. So enjoy your butter, eggs, pork chops, or steak with a clear conscience, knowing that these are foods that have nourished humans for many thousands of years.
About Laurel: I'm very passionate about food and nutrition, partly because changing my diet has had a profound impact on my own health, and partly because I love to eat great food! Cooking is one of my favorite things to do - I see food preparation as a form of creative expression and something that brings people together. I'm here to spread awareness of the amazing healing powers of whole foods and traditional diets. My insatiable appetite for learning about nutrition led to my recent certification as a Nutritional Therapist Practitioner. My intention is to share my knowledge with the community and support others in improving their health with real food. Visit my website (www.dynamicbalancenutrition.com) for more information. Blessings to all!
References and Further Reading
1. Taubes, Gary. "The Soft Science of Dietary Fat." Science, Vol. 291, 30 March 2001.
2. https://www.westonaprice.org/traditi...mediterranean-
3. https://www.bhf.org.uk/idoc.ashx?doc...e24&version=-1
4. https://westonaprice.org/book-review...1iYSI7fQ%3D%3D
5. https://westonaprice.org/abcs-of-nut...bout-nutrition
6. https://wholehealthsource.blogspot.c...nsumption.html
7. https://www.westonaprice.org/know-yo...at-coconut-oil
8. https://news.bbc.co.uk/2/hi/health/6400171.stm
9. https://www.cspinet.org/integrity/no...sociation.html
10. https://www.reuters.com/article/2010...61341020100204
11. https://wholehealthsource.blogspot.c...mortality.html
12. Campbell-McBride, Natasha. Put Your Heart in Your Mouth. Soham: Medinform Publishing, 2007.
13. https://www.cholesterol-and-health.c...ease-Myth.html
14. https://download.journals.elsevierhe...0710002893.pdf
15. https://westonaprice.org/modern-dise...f-statin-drugs
16. Enig, Mary. Know Your Fats. Bethedsa Press, 2000.
17. https://www.cspinet.org/new/sugar_limit.html
18. https://wholehealthsource.blogspot.c...iet-heart.html
Re: Saturated Fat and Heart Disease: Unraveling the Myth
More evidence that refutes the diet-heart hypothesis: a new study was just published that found no association between dairy consumption and heart attack risk. The article compared the findings to similar results with egg consumption. Eggs were long viewed as unhealthy because they are a rich source of cholesterol, but studies have shown that people who eat eggs have no more heart disease than those who don't. The obvious conclusion: Nature isn't trying to poison us with natural animal foods!
Here's a link to an article about the study:
https://www.sciencedaily.com/release...0518105728.htm
The sad thing is that the researchers in the study conclude that saturated fat is still harmful, but that the other nutrients in dairy protect us from the evil saturated fat. I guess they aren't aware of the fact that at least 50% of the cell membrane of every cell in the human body is made of saturated fats. Or that diets high in saturated fat have been shown to significantly lower levels of Lp(a), an important marker for heart disease risk. Or that saturated fats are needed for the proper utilization of essential fatty acids like omega-3's.
Laurel Blair, NTP
www.dynamicbalancenutrition.com
Re: Saturated Fat and Heart Disease: Unraveling the Myth
Hey, Laurel--
What you say about saturated fats and heart disease seems to make sense, but what about obesity? Shouldn't I cut down on fats, saturated or otherwise, to lose weight? And I do need to lose weight!
Re: Saturated Fat and Heart Disease: Unraveling the Myth
Quote:
Posted in reply to the post by Dixon:
Hey, Laurel--
What you say about saturated fats and heart disease seems to make sense, but what about obesity? Shouldn't I cut down on fats, saturated or otherwise, to lose weight? And I do need to lose weight!
Hi Dixon,
This is a really great question! Thanks for bringing up this topic. I've just posted an article to address this.
See: Weight Loss, Fat and Leptin.
