In Part 1: The Skinny on Fats, we discussed the different roles, types and benefits of fat. In this post, we dig into the differing research on controversial saturated fat and its relation (or not) to cholesterol and heart health.
Much of the controversy over fat is due to two major hypotheses.
The Lipid Hypothesis states that elevated serum cholesterol causes heart disease, and the Diet-Heart Hypothesis, born in the 1950’s by an influential man named Ansel Keys, states that consumption of animal saturated fat elevates serum cholesterol, which causes heart disease.
Hired by the Minnesota Public Health Department post-war to research the increasing rates of heart disease, he manipulated data in his famous “Seven Countries Study,” which showed a correlation between saturated fat intake, high cholesterol, and heart disease.
However, the data actually included twenty-two countries, of which there was no true positive correlation, and four of Key’s handpicked seven countries actually had the highest levels of margarine consumption (Shanahan & Shanahan, 2009).
Justifying Keys’ research was the famous Framingham Heart Study, which began in 1948 and involved 6,000 people (Dawber, Gilcin, Meadors & Moore, 1950).
The study showed that half the people with heart disease had low cholesterol, and half the people without heart disease had high cholesterol.
It did show that those who weighed more with abnormally high blood cholesterol levels were at a greater risk for heart disease, but there was a positive relationship between falling cholesterol levels and mortality (Anderson, Casteli & Levi, 1987). The director of the study even admitted:
“In Framingham, Mass., the more saturated fat one ate, the more cholesterol one ate, the more calories one ate, the lower the person’s serum cholesterol” (Fallon & Enig, 2000, p. 5).
Another cited proof is The Pritikin Program, which includes less than 10% fat intake and minimal animal protein.
Based on one-hundred scientific studies published in leading medical journals over thirty years, it also advises a large amount of vegetables, exercise, and mind-body health; all components that have been linked to lower heart disease.
There have been complaints with the program, however, including low energy, difficulty concentrating, depression, weight gain and mineral deficiencies (Gittleman, 1980).
In fact, the flaws in Pritikin’s plan may have been confirmed when he committed suicide after his diagnosis of leukemia (Fallon, 2001).
Contrary to these examples, numerous real world cases and studies disprove the link between saturated fat intake, cholesterol, and heart disease.
The Other Side to Fat’s Story
Assuming Ancel Keys’ research and the government food recommendations are right, a decrease in butter consumption would equate to a decrease in heart disease, right?
Similarly, an increase in government recommended vegetable oil consumption would equate to a decrease in heart disease.
Let’s see how the facts pan out.
1900: Heart disease rare
Butter Consumption: 18 lbs./person/yr
Vegetable Oil Consumption: 11 lbs./person/yr
2012: Heart disease leading cause of death
Butter Consumption: 4 lbs./person/yr
Vegetable Oil Consumption: 59 lbs./person/yr
And heart disease?
Though death resulting from a heart attack has decreased, thanks to medical advancements, it appears that decreasing butter consumption and increasing vegetable oil consumption has resulted in a resounding FAIL for heart disease prevention.
This makes sense, since we learned of the importance of a low Omega-6: Omega-3 fatty acid ratio in Part 1, and how vegetable oils high in Omega-6 fatty acids can contribute to systemic inflammation.
Taking a look at ancestral cultures, the Masai of Africa consume very little carbohydrates and mostly milk, blood, and beef, all very high in saturated fat (Mann, Shaffer, Anderson, & Sandstead, 1964).
Averaging 300 grams of animal fat per day, they are slim, fit, and virtually free of heart disease. Their average blood cholesterol levels at 170mg/dl are well below the government’s desirable range of less than 200 mg/dl.
Other cultures, such as the Tokelau and Pukapuka of the Pacific Islands, consume high amounts of saturated fat with coconut making up 63% and 34% of their diets, respectively. The Tokelauans do have serum cholesterol levels 35 – 40 mg higher than the Pukapukans, yet:
“Vascular disease is uncommon in both populations and there is no evidence of the high saturated fat intake having a harmful effect in these populations (Prior, Davidson, Salmond & Czochanska, 1981).”
More recently, a 2010 meta-analysis including 5 – 23 years of follow-up of 347,000 people showed that saturated fat intake was NOT associated with an increased risk of cardiovascular disease (Siri-Tarino, Sun, Hu & Krauss, 2009).
Therefore, the Diet-Heart Hypothesis does not appear to have scientific justification that saturated fat, high cholesterol, and heart disease are connected.
Rather, as Dr. Cate Shanahan proves in Deep Nutrition, hydrogenated vegetable oils,excessive Omega-6 fatty acids, and sugar consumption are the real culprits (Shanahan & Shanahan, 2009).
After all, if the body can survive forty days without food because of its ability to utilize fat, why would something so vital to life be denounced?
If this is new information for you, I’d love to hear your reaction and comments! For those that have already come to this conclusion, I’d love for you to share ways that you changed from “fat phobic” to “fat lover!”
Anderson, K. M., Castelli, W. P., & Levy, D. “Cholesterol and mortality. 30 years of follow-up from the Framingham study.” Journal of American Nutrition Association. 1987 Apr 24;257(16):2176-80. http://www.ncbi.nlm.nih.gov/pubmed/3560398.
Dawber, Thomas R., Gilcin, M.D., Meadors, M.D., and Felix E. Moore, Jr. National Heart Institute, National Institutes of Health, Public Health Service, Federal Security Agency, Washington, D. C., Epidemiological Approaches to Heart Disease: The Framingham Study. Presented at a Joint Session of the Epidemiology, Health Officers, Medical Care, and Statistics Sections of the American Public Health Association, at the Seventy-eighth Annual Meeting in St. Louis, Mo., November 3, 1950.
Enig, Mary G. “Fat and Cholesterol in Human Milk.” The Weston A. Price Foundation. 31 December 2001, http://www.westonaprice.org/childrens-health/fat-and-cholesterol-in-human-milk.
Fallon, Sally and Mary G. Enig. Nourishing Traditions. New Trends Publishing, Inc., Washington, D.C.: 2001.
Gittleman, Ann Louise, MS, Beyond Pritikin, 1980, Bantam Books: New York, N.Y.
Mann, G.V., Shaffer, R.D., Anderson, R.S., and Sandstead, H.H. “Cardiovascular Disease in the Masai.” Journal of Atherosclerosis Research. 1964 Jul-Aug:4:289-312. http://www.ncbi.nlm.nih.gov/pubmed/14193818.
Prior, I.A., Davidson, F., Salmond, C.E. and Czochanska, Z. “Cholesterol, coconuts, and diet on Polynesian atolls: a natural experiment: the Pukapuka and Tokelau island studies.” American Journal of Clinical Nutrition. 1981, August; 34(8): 1552-61. http://www.ncbi.nlm.nih.gov/pubmed/7270479.
Shanahan, Catherine and Luke Shanahan. Deep Nutrition. Bantom Books, Hawaii, 2009.
Siri-Tarino, Patty W., Sun, Qi, Hu, Frank B., Krauss, Ronald M. “Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease.” The American Journal of Clinical Nutrition. 25 Nov. 2009. http://ajcn.nutrition.org/content/early/2010/01/13/ajcn.2009.27725.abstract.