For years, saturated fats have been criticized as the cause of a long list of human health problems. Mainstream medical personnel, the American government, and the media constantly remind us that eating saturated animal fat will clog our arteries, raise our cholesterol levels, and increase our risk of atherosclerosis and death from heart disease.
However, nothing could be further from the truth, and there are many studies that show these fats are essential for good health. For instance, this paper, published in the Journal of American Medical Association, was based on data from the famous Framingham study and reports that fat in the diet protects against stroke.
In an article titled What if Saturated Fat is Not the Problem, Richard Feinman, a professor of biochemistry at the State University of New York Downstate Medical Center in Brooklyn writes:
“Perhaps the most compelling research was published in a 2004 issue of the American Journal of Clinical Nutrition by researchers from the Harvard School of Public Health. Their study showed that, in postmenopausal women with heart disease, a higher saturated fat intake was associated with less narrowing of the coronary artery and a reduced progression of disease. Even with similar levels of LDL cholesterol, women with lower saturated fat intake had much higher rates of disease progression. Higher saturated fat intake was also associated with higher HDL (the “good” cholesterol) and lower triglycerides.”
Here’s a great talk about the benefits of saturated fats from cardiologist Donald Miller. It’s about an hour-long, but extremely informative.
Saturated Fats and Carbohydrates
In actuality, many studies are showing that carbohydrate consumption is the true villain when it comes to health, because of its effect on insulin within the body.
For example, recently, the media sensationalized a study which claimed that a high-fat diet causes diabetes.
When you actually look at the study data, you find that it was done on specially designed, diabetes-prone mice, not humans.
In addition, the diet that the researchers fed to the mice was high in sugar, casein, and hydrogenated vegetable oils. These pseudo-foods have all been shown to increase inflammation and trigger blood sugar problems.
So the true results of the study were that feeding diabetes-prone mice sugar and trans fats will cause them to become diabetic, yet the media made it seem that the fat content of the diet was the cause.
Denise Minger wrote a great post on this if you are interested in more information.
The True Health Effects of Sat Fat
Saturated Fats, when eaten on a low carb diet have no effect on arterial health or blood sugar and in fact, the lower the carb intake and the higher the sat fat intake, the less fat, blood sugar, and insulin in the bloodstream.
The blood markers that indicate heart disease, insulin resistance and the symptoms of diabetes are improved when eating high fat, low carb diet. Jeff Volek and his colleagues have authored several papers about the relationship between fat intake, carbohydrate intake and health conditions such as atherosclerosis and diabetes.
In one study, Dr. Volek and his team compared the markers for heart disease from the blood of a group of people on a very low-carb diet (35 grams of carbs and 100 grams of fat, with 36% as saturated fat) with a group on a low-fat diet (191 grams of carbs and 24 grams of fat, with half from fat). Both groups ate about 1500 calories per day.
Despite the consumption of three times the saturated animal fat, the group on the lower-carb diet had lower levels of saturated fat in their blood than the low-fat group did.
The explanation for this is that when carbohydrate intake is low, the body burns fat as an energy source instead. Since the body is burning the fat being eaten for energy, there is less left to circulate in the blood.
Bottom line is that the fat content of the diet is not an indicator of the fat content in the bloodstream, and eating fat and cholesterol has nothing to do with how “clogged” your arteries might be.
Here’s a published letter from Dr. Volek that provides an overview of the effects of saturated fat in the diet.
Rather, high levels of blood SUGAR and insulin promote the storage of fat, increase blood triglyceride levels and inflammation within the arteries. This inflammation then triggers the body to deposit cholesterol at the site of the injuries as a repair mechanism.
In other words, the higher the intake of carbohydrates, the higher the blood sugar and insulin and the more likely you will develop heart disease, no matter what your fat intake is.
Older Studies Revisited
In addition, the famous 1964 Framingham study was supposed to show that eating a diet high in saturated fat would increase cholesterol levels.
In 1992, Dr. William Castelli, the director of the Framingham study, declared publicly that the Framingham results did no such thing.
Instead, he said, the data showed that for this group of study subjects, “the more saturated fat one ate, the more cholesterol one ate, the more calories one ate, the lower the persons’ serum cholesterol levels.”
Today, the Harvard School of Public Health website refutes the “low fat” theory, saying:
“Eat a low-fat, low-cholesterol diet” has been the mantra for healthful eating for decades. Touted as a way to lose weight and prevent or control heart disease and other chronic conditions, millions of people have followed (or, more likely, have tried to follow) this advice. Seeing a tremendous marketing opportunity, food companies re-engineered thousands of foods to be lower in fat or fat free. The low-fat approach to eating may have made a difference for the occasional individual, but as a nation it hasn’t helped us control weight or become healthier. In the 1960s, fats and oils supplied Americans with about 45 percent of their calories; about 13 percent of us were obese and under 1 percent had type 2 diabetes, a serious weight-related condition. Today, Americans take in less fat, getting about 33 percent of calories from fats and oils; yet 34 percent of us are obese and 8 percent have diabetes, most with type 2 diabetes.
Walter Willett, the chair of the Department of Nutrition within the Harvard School of Public Health has said that “the focus of dietary recommendations is usually a reduction of saturated fat intake, no relation between saturated fat intake and the risk of CHD was observed in the most prospective study to date.”
The Benefits of Saturated Fats
Dr. Mike Eades wrote a nice post on Tim Ferris’ blog about the health benefits of saturated animal fats. They include:
- Improved cardiovascular risk factors
- Stronger bones
- Improved liver health
- Healthy lungs
- Healthy brain
- Proper nerve signaling
- Strong immune system
Saturated animal and tropical fats are not killers and are not foods to be afraid of or feel guilty about eating. These foods are a necessary and important part of any health building diet, and they are protective substances that humans have been eating for thousands of years.
Duane Graveline, M.D. writes:
“We also should remember that our strongest antagonists in what I chose to call “back to basics” diet will be the food industry for there is relatively little profit in basic foods.
I fondly remember the words of Doctor Paul Dudley White, cardiologist to the presidents back in the mid-fifties. When pressed to support the politically motivated “prudent” diet of fat and cholesterol restriction replied, “See here, I began my practice as a cardiologist in 1921 and never saw a myocardial infarction patient until 1928. Back in the MI-free days before 1920, the fats were butter, whole milk, and lard, and I think we would all benefit from the kind of diet that we had when no one had ever heard of corn oil.”
Today most people have forgotten all about Dr. Dudley White and his prophetic words of advice. If Dudley White had been in control of our dietary destiny then, the cardiovascular disease would probably not be the immense problem it is today.”
“Whatever causes coronary heart disease, it is not primarily a high intake of saturated fat.”–Michael Gurr, PhD, Associate Professor of Biochemistry at the School of Biological & Molecular Sciences in Oxford, editor-in-chief of Nutrition Research Reviews, renowned Lipid Chemist, and author of authoritative study on Coronary Heart Disease
Sources for Further Reading
- Enjoy Sat Fats: They’re Good For You An article by cardiologist Donald Miller
- The Case for Not Restricting Fat on a Low Carbohydrate Diet
- Comparison of Low Fat and Low Carbohydrate Diets on Circulating Fatty Acid Composition and Markers of Inflammation
- Nutrition and Physical Degeneration A book about how introducing process foods to populations consuming traditional diets introduces disease.
- Fat or Carbs – Which is Worse? An article by Andrew Weil, M.D.