Artery-Clogging Saturated Fat Is a Myth

Among doctors and the public alike, there is a popular belief that dietary saturated fat clogs up the arteries and results in coronary heart disease.  A new editorial published in the British Journal of Sports Medicine says that this notion of saturated fat clogging a pipe is "just plain wrong."

According to researchers, 'the conceptual model of dietary saturated fat clogging a pipe is just plain wrong.'

The article is the result of a collaboration between a team of cardiologists, including: Dr. Aseem Malhotra, of Lister Hospital in Stevenage, in the United Kingdom; Prof. Rita Redberg, of the University of California-San Francisco School of Medicine and editor of JAMA Internal Medicine; and Pascal Meier, of University Hospital Geneva in Switzerland and University College London, who is also the editor of BMJ Open Heart.

The team cited reviews that show no association between intake of saturated fat and a greater risk of heart disease, in order to support their argument against the existence of artery-clogging saturated fat.

"It is time to shift the public health message in the prevention and treatment of coronary artery disease away from measuring serum lipids and reducing dietary saturated fat," say the authors. Instead of focusing on lowering blood fats and cutting out dietary saturated fats, the importance of eating "real food," partaking in regular physical activity, and minimizing stress, should all be emphasized.

According to Malhotra, Redberg, and Meier, the current approach to managing heart disease echoes the practice of plumbing, but the notion of improving the condition by "unclogging a pipe" has been invalidated by a series of clinical trials. The trials found that when a stent was inserted to widen narrowed arteries, the risk of heart attack or death was not lessened.

"Decades of emphasis on the primacy of lowering plasma cholesterol, as if this was an end in itself and driving a market of 'proven to lower cholesterol' and 'low fat' foods and medications, has been misguided," the panel contends. These misconceptions may stem from "selective reporting of data," they suggest.

Coronary artery heart disease is the most common type of heart disease and the leading cause of death for men and women in the United States. The chronic inflammatory condition responds positively to a Mediterranean-style diet, rich in the anti-inflammatory compounds often found in extra virgin olive oil, vegetables, oily fish, and nuts, the researchers note.

The best predictor of heart disease risk involves a high total cholesterol (TC) to high-density lipoprotein (HDL) ratio, not low-density lipoprotein. Dietary changes, such as substituting refined carbohydrates with healthful high-fat foods including olive oil and nuts, can significantly reduce the high TC to HDL ratio, the experts explain.

Exercise plays an essential role in preventing heart disease and may increase life expectancy by 3.4 to 4.5 years. Just 30 minutes of moderate activity per day on more than three occasions each week has been shown to make a difference to risk factors for inactive adults. Furthermore, the researchers point out that regular brisk walking may be more effective at preventing coronary disease than running.

Chronic stress is a risk factor for coronary heart disease that "should not be overlooked," the team underline. Chronic stress puts the body's inflammatory response on a continuous state of high alert. Research has shown that environmental stress, such as childhood trauma, can decrease life expectancy by up to 20 years.

The authors write:

"Combining a complete lifestyle approach of a healthful diet, regular movement, and stress reduction will improve quality of life, reduce cardiovascular, and all-cause mortality."

The researchers add that spending just 22 minutes per day walking and eating healthful food can prevent coronary artery disease. However, "there is no business model or market to help spread this simple yet powerful intervention," the authors conclude.

Saturated Fats May Be Healthy

A Norwegian study challenges the long-held idea that saturated fats are unhealthy

A new Norwegian diet intervention study (FATFUNC), performed by researchers at the KG Jebsen center for diabetes research at the University of Bergen, raises questions regarding the validity of a diet hypothesis that has dominated for more than half a century: that dietary fat and particularly saturated fat is unhealthy for most people.

The researchers found strikingly similar health effects of diets based on either lowly processed carbohydrates or fats. In the randomized controlled trial, 38 men with abdominal obesity followed a dietary pattern high in either carbohydrates or fat, of which about half was saturated. Fat mass in the abdominal region, liver and heart was measured with accurate analyses, along with a number of key risk factors for cardiovascular disease.

"The very high intake of total and saturated fat did not increase the calculated risk of cardiovascular diseases," says professor and cardiologist Ottar Nygård who contributed to the study.

"Participants on the very-high-fat diet also had substantial improvements in several important cardiometabolic risk factors, such as ectopic fat storage, blood pressure, blood lipids (triglycerides), insulin and blood sugar."

Both groups had similar intakes of energy, proteins, polyunsaturated fatty acids, the food types were the same and varied mainly in quantity, and intake of added sugar was minimized.

"We here looked at effects of total and saturated fat in the context of a healthy diet rich in fresh, lowly processed and nutritious foods, including high amounts of vegetables and rice instead of flour-based products," says PhD candidate Vivian Veum.

"The fat sources were also lowly processed, mainly butter, cream and cold-pressed oils."

Total energy intake was within the normal range. Even the participants who increased their energy intake during the study showed substantial reductions in fat stores and disease risk.

"Our findings indicate that the overriding principle of a healthy diet is not the quantity of fat or carbohydrates, but the quality of the foods we eat," says PhD candidate Johnny Laupsa-Borge.

Saturated fat increases the "good" cholesterol. Saturated fat has been thought to promote cardiovascular diseases by raising the "bad" LDL cholesterol in the blood. But even with a higher fat intake in the FATFUNC study compared to most comparable studies, the authors found no significant increase in LDL cholesterol.

Rather, the "good" cholesterol increased only on the very-high-fat diet.

"These results indicate that most healthy people probably tolerate a high intake of saturated fat well, as long as the fat quality is good and total energy intake is not too high. It may even be healthy," says Ottar Nygård.

"Future studies should examine which people or patients may need to limit their intake of saturated fat," assistant professor Simon Nitter Dankel points out, who led the study together with the director of the laboratory clinics, professor Gunnar Mellgren, at Haukeland university hospital in Bergen, Norway.

"But the alleged health risks of eating good-quality fats have been greatly exaggerated. It may be more important for public health to encourage reductions in processed flour-based products, highly processed fats and foods with added sugar," he says.

Animal Fats Healthier Than Vegetable Oils

The science behind the recommended change to vegetable oils about 50 years ago appears to be very faulty and even the trail itself was not that great. The research suggests that the switch from animal to vegetable (corn) fats may be not only unnecessary, but it may misguided. Studies have arrived at similar findings before, but the new one, which looks at the heart health of people eating animal fats vs. corn oil, suggests that people who use the latter may actually be at an increased heart risk.

The team looked at data from a study that started in the late 60s, using 9,400 residents from several mental hospitals and one nursing home (the participants coming from these two communities may be a problem in itself). It wasn’t published until 1989, for reasons that aren’t very clear, and it reported that switching from animal fats to corn oil was beneficial for cholesterol; it did not report that the switch had any effect on heart disease.

A team at the NIH, the University of North Carolina and several other universities uncovered the entire data set and ran the stats again, because some had been omitted. The reconsidered results were strange: People who ate vegetable oils had lower cholesterol, but also had a significantly higher risk of heart attack.

Though the research authors would not say this, it looks like the previous researchers were cherry picking data to arrive at the conclusion desired at the time. “Altogether, this research leads us to conclude that incomplete publication of important data has contributed to the overestimation of benefits–and the underestimation of potential risks of replacing saturated fat with vegetable oils rich in linoleic acid,” said Daisy Zamora.

The omega-6 fatty acid linoleic acid (LA) is known to have some major health drawbacks. “An odd thing about this is the outdated substitution of linoleic acid for unspecified saturated fat,” says David L. Katz, founder of the Yale Prevention Research Center. “Linoleic acid is an omega-6, and it’s clear now that there are many problems associated with excessive omega-6, notably interference with the production of long-chain omega-3s.”

The two types of fats need to be consumed into the body in balance, otherwise omega-6s usurp the machinery needed to make omega-3s. But researchers have been aware of this danger for some time. Omega-6 has also been linked to increasing, rather than decreasing, inflammation.

Sunflower oil in the US was ‘upgraded’ through selective breeding to produce a high-oleic-acid variety (high monounsaturated fatty acid) that now prevails, and avoids the potential harms noted in this paper. The same thing is now being done to soybean oil, and the high monounsaturated fatty acid version of that will soon replace the old variety.”

So the new study may simply underline that swapping animals fat for corn oil may lead to more health problems than it solves. And as Katz points out, no one today would think that making the swap the study made is terribly informative.

The evidence that replacing saturated fat in general with a balanced portfolio of unsaturated fats from a variety of foods is still questionable. The Dietary Guidelines advise, oils from whole foods: nuts, seeds, avocado, fish. These do not provide the excess of omega-6 likely in this case. Different varieties of imbalance tend to represent different ways of eating badly. The body needs, and responds well to, balance.”

For possible clarification of the unnamed studies and more information, please read this blog by Dr. Malcolm Kendrick. He does name the studies and makes the discussion clearer.

Joslin Supports Ancel Keys on Saturated Fat

This blog has to have been written by someone with at least a registered dietitian nutritionist title. This also means that Joslin supports a very faulty study done by Ancel Keys in 1956. Again, the Joslin website allows anonymity to prevent the public from identifying the author and possibly understanding the reason for a blog. This is the reason for my calling this as I see it.

So few reputable websites allow this anonymity that when a site like Joslin promotes anonymity, we need to wonder what they are trying to hide. The Mayo Clinic identifies their blog authors and on diabetes information articles will provide the author if asked.  Individual bloggers are identified and are accountable for what they write. Just because the Joslin Diabetes Center is a large organization does not exempt them from accountability.

Joslin does use recent information from the American Heart Association and the American College of Cardiology for pushing for low fat. That information is from November 2013 and does not reflect the study published in the Annals of Internal Medicine in March 2013. Even many cardiology doctors are not convinced by the study and will wait for additional studies before they accept saturated fats as being safe.

The author did make some surprising statements, “Even though countless research studies have been completed since 1997, the message (at least possibly until now) has held strong: saturated and trans fats are the enemy.” Then in the next paragraph the author states, “Other factors that come into play are that, in addition to eating saturated fat, our bodies manufacture cholesterol- the amount based on our genetic makeup- and that the type of studies we can do (observational and short-term intervention) don’t provide proof of causality.”

While the most recent study is favorable to saturated fats, the Joslin blog author takes great care to say that the complex statistical relationships is beyond our knowledge. Whether you believe that many studies have shown that eating mono- and polyunsaturated fat does not cause heart disease is entirely up to you. The author says the same can't be said about saturated fat.

The last sentence above is the reason for my stating that the blog author still believes the faulty study from the 1956 “Seven Countries Study” led by Ancel Keys, who started the demonization of saturated fat. Again and again this study has been refuted, but many in the medical profession and especially registered dietitian nutritionists like to use this as proof that saturated fat is bad for us.

I will admit that I would not adopt saturated fat as the only fat in my meal plan, but if some happens to be part of the food I eat, I am no longer worried that it will kill me. That is another reason that I am a more careful reader of blogs by anonymous Joslin bloggers. While I am using a meal plan that is low carbohydrate/high fat and medium protein, I think moderation in the quantity of saturated fat may be a key.

For a great blog on saturated fat and a second blog on the same topic and mono- and polyunsaturated fat, read these blogs by David Mendosa.