In Chapter 2, their goal is to debunk the lipid hypothesis through answering four questions – or as they put it, exploding four myths. Before we discuss the first question (or myth), first let's talk about the lipid hypothesis.
The Lipid Hypothesis
What is the lipid hypothesis? This is the theory – just one of many – named in the 1950s by Ancel Keys. It is “the theory that saturated fats and cholesterol in our food raise cholesterol levels in the blood, leading to heart disease.” This hypothesis grew as scientists sought to explain a steep rise in heart disease. At the turn of the 20th century, less than 10% of deaths were from heart disease, but by 1950, heart disease accounted for 30% of all deaths.
Many doctors (President Eisenhower's physician among them) pointed out that the increase in heart disease coincided with an increase of liquid vegetable oil and hydrogenated oil consumption, along with an overall decrease in the consumption of eggs and traditional fats. But other scientists insisted that reducing animal fats was the way to stay healthy. So by the 1970s, the prevailing explanation for the rise in heart disease was the lipid hypothesis.
To reach the end conclusion (that saturated fat and cholesterol leads to heart disease), we must basically make three logical jumps:
- We eat a diet containing too much cholesterol and saturated fat, and as a result we develop a high level of cholesterol in our blood.
- High blood cholesterol causes atherosclerosis [plaque build up in the arteries].
- Atherosclerosis obstructs the vessels that bring blood to the heart, resulting in coronary heart disease.
Dr. Enig and Sally Fallon Morell say that “each of these steps is like a link in a chain, connecting to form the lipid hypothesis. And yet extensive scientific evidence exists that contradicts each step in this “chain” of scientific theory, presented as fact for over five decades.”
Here's a quick recap of the myths Chapter 2 addresses:
- Myth: High fat foods cause heart disease. (Topic of this blog post.)
- Myth: High cholesterol causes heart disease. Blog post here, 3/27/10.
- Myth: High-fat foods increase blood cholesterol. Blog post here, 4/5/10.
- Myth: Cholesterol causes plaque buildup in arteries. Blog post here, 4/12/10.
This week, we'll talk about the first myth.
Myth: High Fat Foods Cause Heart Disease
“Since the 1950s, scientists, medical organizations such as the American Heart Association, and government agencies such as the FDA have issued dietary guidelines, which they claimed were based on scientific research, urging the public to consume fewer animal products and substitute vegetable oils for animal fats. The food industry followed suit with advertising campaigns touting the health benefits of products low in fat or made with vegetable oils.
Yet during the same period, many studies were being carried out whose results directly contradicted the assumptions of the lipid hypothesis.”
Dr. Enig and Sally Fallon Morell share three specific studies carried out during this time that cannot possibly support the lipid hypothesis – and specifically the part of the theory that claims saturated fat raises cholesterol.
First, in the 1960s, Dr. George Mann of Vanderbilt University studied the Masai people of Kenya, whose diet consisted of mostly milk, meat, and blood – a diet high in saturated fat if ever there was one! The Masai were virtually free of heart disease, and their cholesterol was extremely low – about 50% lower than most Americans. In studying the hearts of dead Masai men of all ages, he didn't find the type of arterial plaque that causes obstructions, nor evidence of heart attacks in those men.
Next, a study in 1967. Dr. S. L. Malhotra studied Indian railway employees in Punjab, India. They ate ten to twenty times more fat than vegetarian workers in Madras. Yet, heart disease was seven times more common in the Madras workers, and the Punjabi workers lived twelve years longer.
Third, let's talk about an even larger study by the National Institutes of Health, conducted in 1975 through 1981. 16,000 middle-aged men were studied. “The most significant finding was that the heart attack victims had eaten more polyunsaturated oils than the other group [who had not had heart attacks].”
The Answer Is No
After reviewing available studies, the authors conclude:
“Taken as a whole, then, this research did not – and does not – support the assumption that high-fat foods cause heart attacks.”
The authors also include mention of more recent studies that confirm there is no link between high cholesterol and saturated fats. Even as recently as 2004, a study in Sweden showed that butter protects against heart disease!
Next week, we'll discuss the second myth in Chapter 2 of “Eat Fat, Lose Fat” – does high cholesterol causes heart disease?
Last week, I really enjoyed your comments about saturated fats. I was particularly proud of those of you who said that eating natural fats always made sense to you! And sad though it is, I learned that I was not the only who had fallen for the “saturated fats are evil” line of thinking. I'm glad we can sort this out together. Please share any thoughts you have this week about myth #1!
We only recommend products and services we wholeheartedly endorse. This post may contain special links through which we earn a small commission if you make a purchase (though your price is the same).