By Dr. Beth Gruber, CarbSmart Contributor
Posted 11/16/2001
In our last conversation, I began our discussion about fats by initially considering about why it is that "nutritional science" blames dietary fats for so many illnesses, especially the various forms of heart disease.
This fifty-year attack on dietary fat has involved hundreds of millions of dollars being spent to try to prove that low fat diets are better for everyone, and has resulted in the spending of many billions of dollars by food manufacturers who are trying to sell the public various food products that are low in fat, and consequently, high in carbohydrates. "Non-Fat" and "Low-Fat" became the buzz words of good health, or so we have been led to believe.
However, since we in the low carbohydrate world know that, for the most part, we are a lot healthier since giving up the low fat plans, we have many questions about how and why fat became The Enemy.
There Are No Simple Answers
The program against dietary fat started in the early 1950s with the fairly simple observation that heart disease seemed to be more likely to occur in certain men who had high cholesterol levels in their blood. But, over the years, the research began to get complicated when it was discovered that, while some fats may raise certain cholesterol fractions, other fats lower them.
The problem then became even more complicated by the fact that the part played by carbohydrates in the diet was (and still is) largely ignored. More recent studies suggest that high carbohydrate diets contribute not only to heart disease risk, but also to the condition known as Syndrome X, which involves insulin resistance and an even greater increase in heart disease risk.
How did it happen that a mere suggestion that fats might cause heart disease in some men, became the low fat dogma that fats are absolutely bad for everyone because they cause or contribute to a whole host of disease conditions? How did it happen that a few people's point of view became the chant of modern health agencies?
The answers to these questions involve the demands of public health policy, the actions of the media who were eager to find fault with science, and the demands by the general public for simple, uncomplicated advice, despite the fact that real science is not so clear-cut.
A Sort History Of Heart Disease
In the early 20th century, heart disease was a relatively rare condition. There was no such thing as a heart specialist in those early years. Although some people (primarily men) died of heart attacks, it was not common. Most families had not even heard of heart disease.
After 1945 it became obvious that there was a definite increase in coronary heart disease throughout the country. Interestingly, the incidence of heart disease began to increase along with the rise in consumption of sugar and refined carbohydrates, but this was not seen as related at the time. Imagine how things would have been different if some scientist had seen and spoken up about that relationship at the time!
But such was not the case, and by 1952 a well-known biochemist was suggesting that dietary fats might be the cause of the increased rate of heart disease. He admitted there was very little evidence connecting diet to heart disease, but nonetheless, he put forth the suggestion that adults should reduce their fat intake to 30% of total calories, or less. He (and at his urging, the American Heart Association), began advocating low fat diets, which at that time meant not eating meat more than three times a week!
Studies through the 1950s and 1960s showed some link between high cholesterol blood levels and heart disease, but cholesterol levels in the blood do not relate directly to the amount of cholesterol in food. Consequently, as late as 1969 (some twenty years after the beginning of the initial anti-fat suggestions), all the known facts could still be summarized by this single statement: "It is not known whether dietary changes have any effect whatsoever on coronary heart disease."
Scientists On The Other Side Of The Fence
Meanwhile, a prominent panel of scientists which had been doing research on fat and cholesterol became concerned that eating too little fat could also have harmful effects on the body. They pointed out that the brain is 70% fat, and that fat is the primary substance making up all body cell membranes.
These scientists were concerned that changing the proportion of saturated to unsaturated fats in the diet (which changes the fat composition in the cell membranes), might change the permeability of those membranes. This, they said, might alter the transportation in the body of sugars, proteins, hormones, and disease-causing bacteria and viruses. This could result in health problems of unknown proportions.
Why Scientists Didn't Just Run Clinical Tests?
Since there were seen to be both potential benefits and potential problems from low fat diets, scientists realized that the issue could only be settled by testing whether low fat diets actually prolong life. Further, it was clear that such a test would require tens of thousands of people to switch to low fat diets, and their subsequent health compared for years to the health of equal numbers of people who continued eating fat to alleged excess.
At the time (thirty years ago), such a test was estimated to cost $1 billion and take at least ten years. But this was considerably more money and more time than anyone was willing to spend. The data on fat and health remained unclear, and the scientific community retreated into camps, depending on their viewpoint on the issue.
The scientific community remained at polar positions for some time, but when the deadlock was finally broken, it was not by any new science, not by any new studies, not by any proof. The deadlock was broken by politicians!
Next time, I'll tell you how that all happened, and we'll continue with the story. Meanwhile, have a great Thanksgiving with your friends and family.
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