Back in 1956, Ancel Keys, the author of the lipid hypothesis, found out that trans fats were bad. In spite of knowing this, Keys, along with all the American Heart Association board members, voted in 1961 to adopt the "prudent" diet. The "prudent" diet used margarine (a source of trans fat) instead of butter, chicken and fish instead of beef and cold cereal instead of eggs.
Since the lipid hypothesis came into effect in the 1950s, there have only been two studies involving humans that actually compared the outcome of a diet based on vegetable oils with a diet based on saturated fat. The first was the Anti Coronary Club which began in 1957 and ended in 1966 and was recorded in the Journal of the American Medical Association. The study compared two groups of New York businessmen, aged 40 to 59 years. One group followed the “Prudent Diet” and the other group ate eggs for breakfast and meat three times a day.
The average serum cholesterol levels of the Prudent group were 220 mg/dl compared to 250mg/dl in the egg and meat eating group. With what we are taught about cholesterol and heart disease, one would expect the egg and meat eating group to drop like flies from heart disease. But that was not the case. Instead, 8 deaths from heart disease occurred in the Prudent group while absolutely no deaths occurred in the egg and meat eating group.
The other study was published in 1965 in the British Medical Journal. Researchers divided patients who had already had a heart attack into three groups. One group received polyunsaturated corn oil, another group received monounsaturated olive oil and the third group received saturated animal fats. After two years, the corn oil group had lowered their cholesterol by 30% but only 52% of the subjects remained alive. Fifty-seven percent of the olive oil group were alive at the end of two years, whereas 75% of the animal fat group remained alive.
These two studies, because they did not support the lipid hypothesis, were not publicized, so most physicians and dietitians don’t even know they exist.
Some would argue that these studies are old and not valid anymore. While I disagree, let’s look at more recent studies. In 2004, a Swedish study published in the British Journal of Nutrition found that butter fat actually protects against heart disease.
Most everyone is familiar with the Framingham study which began in 1948. A 30 year follow up study revealed that “for each 1 mg/dl drop in cholesterol, there was an 11 percent increase in coronary and total mortality.” Yes, you read that right. Lowering cholesterol actually caused heart disease.
A 1993 Russian study published in Circulation found that low levels of LDL cholesterol, the kind we are told to keep as low as possible, were associated with an increased risk of heart disease. Many more recent studies exist that refute the lipid hypothesis.
If this is all true, then why are we so indoctrinated into the low fat, low cholesterol agenda? To answer that question, we need to see who benefits from the lipid hypothesis.
Lipitor, a cholesterol lowering drug, is the number one prescription drug sold in America and is a huge profit maker. The pharmaceutical industry has definitely benefited from the lipid hypothesis and they have successfully frightened healthy Americans into believing they have the disease of cholesterol and need to be medicated.
The food industry also benefits. They get to use cheap vegetable oils instead of expensive animal fats in their products, thus boosting their bottom line. The food industry makes tons of money on fat free and low fat processed foods and very little money on real, whole foods. As a registered dietitian, I get free processed food samples in the mail all the time from companies trying to get me to get my clients on their products.
Just an aside. The American Medical Association did not get on board with the lipid hypothesis until the mid 80's. The only reason they got on board was because the drug industry developed the National Cholesterol Education Program which was specifically designed to get MDs interested in cholesterol screening and prescribing drugs to lower cholesterol. The MD's bought it hook, line and sinker and now we are suffering the consequences; a tasteless diet and more health problems that cost a lot of money to treat.
Next time, I'll tell you why saturated fat is so good for you. It tastes good, too!