|Last update November 11, 2021, article reviewed & updated multiple times since January 11, 2002.|
What You Need to Know
The Official Option About Dietary Fat Revisited
So far in these articles:
- What Are Fats? Misconceptions & Truths
- The Attack On Dietary Fat
- Dietary Fats – Getting to The Official Opinion
- Perhaps Fats Are Not So Evil – Positive Information About Dietary Fats
we have seen that a government committee seeking to alleviate malnutrition among the poor was largely at the root of The Official Opinion that low fat eating equals good health. We have discussed how, despite having no scientific proof, health agencies began advising everyone to restrict their fat intake. And that, even when the Surgeon General’s Office tried to publish the science behind the low fat idea as late as 1999, they could not find clear supporting evidence for the low fat opinion!
The incidence of heart disease has not declined, despite a decrease in fat intake. The most recent studies indicate that total dietary fat has no relation to heart disease risk, that monounsaturated fats (like olive oil) actually lower the risk of cardiovascular disease, and that man-made trans-fatty acids (the type of fats in margarine) are the fats that are unhealthful.
Yet The Official Opinion continues to be supported by agencies and medical groups. There only can be two logical reasons for this. Some supporters apparently don’t know The Official Opinion is not based on proof, and the rest of them have so much time and ego (or money) invested in supporting the low-fat myth that they can’t let it go.
Frightening The Public
Although The Official Opinion is weakening, and there is a lessening of the propaganda that all fats are bad, we still constantly hear about cholesterol. Just this very morning, I heard a so-called “public information announcement” on TV telling viewers how it is important to have their cholesterol levels checked every three years.
The public has become so frightened about cholesterol that most people believe it should be avoided like the plague. Even in casual conversation, people say things like, “I can feel the cholesterol clogging my arteries while I eat this!!” But cholesterol is not a devil. It is, in fact, essential to life. Cholesterol does not cause heart disease, and some experts have even gone so far as to say that the more cholesterol-containing foods people eat, the healthier they become!
Where Is Cholesterol Found?Cholesterol is a substance found in animal fats, blood, nerve tissue, and bile. It is not found in any plant foods. Cholesterol is important for the structure of cell membranes throughout the body. It is vital to keep the membranes intact and permeable so that nutrients can pass into the cells, and waste products can leave them. When people radically restrict their cholesterol intake to the point that there is not enough cholesterol to repair and build tissue, cell growth is disrupted. Although there is not yet any proof, it is thought by some that a deficiency of cholesterol might contribute to certain cancers because cancer is a type of abnormal cell division.
What Does Cholesterol Do, and What Happens If We Don’t Get Enough Dietary Cholesterol?
Cholesterol is important to maintain normal hormone production and the proper functioning of the immune system. It is part of the substance of Vitamin D, it is part of the make-up of the sex hormones in both men and women, and it is crucial to the manufacture of the important anti-stress factor, cortisol. Cholesterol is essential for nerve transmission and for brain function, and it is possible that it protects against multiple sclerosis. But here is the major evidence that cholesterol is not a devil, but is absolutely required: our own bodies will produce cholesterol if we do not eat enough of it in our diets.
The production of cholesterol in our bodies takes place under the direction of the liver, which makes it from the carbohydrates we have eaten. This is normal metabolism, and no amount of calling cholesterol bad names will alter the fact. If you do not eat cholesterol, your body reacts as if you are living through famine conditions. In the presence of insulin, the liver produces a special enzyme that stimulates the production of cholesterol from carbohydrates. And since a low-fat diet is nearly always a high carbohydrate diet, the amount of cholesterol produced from consumed carbohydrates is in excess of what is needed. This constitutes dangerous cholesterol.
Cholesterol that is eaten in foods is regulated by the body. Dietary cholesterol doesn’t contribute to excess cholesterol production in the body, since it does not stimulate insulin production. But, there is no mechanism for “turning off” the internal manufacture of cholesterol from carbohydrates when the person is following a low fat, high carbohydrate diet. High levels of carbohydrates mean more insulin production; more insulin with high carbohydrates means more enzymes for excess internal cholesterol production. The only successful way to shut down the enzyme that triggers excess cholesterol production is to eat cholesterol-containing foods.
In other words, when people restrict their dietary cholesterol and force their bodies to manufacture their own cholesterol, their bodies will make more than is needed, and this is especially true when carbohydrates make up a large percentage of their diets. Consequently, the way to be certain that you will have the type of high blood cholesterol that may result in serious heart problems and blood vessel disease is to eat a low fat/low cholesterol and high therefore a carbohydrate diet.
Cholesterol Levels That Are Too Low Can Be DangerousIt is also becoming clear that low cholesterol levels are not a good thing. In Japan, doctors point to very low blood cholesterol as a cause of stroke. And when investigators tracked all deaths, instead of just heart disease deaths, they found that while men with very high cholesterol levels tended to die prematurely from heart disease and related conditions, men with low levels (below 160 mg) tended to die prematurely from cancer, and both respiratory and digestive diseases. Then, to make everything a little more complicated, in the case of women, it appeared that the higher their cholesterol was, the longer they lived.
Now, these study results can be interpreted in two ways. The interpretation preferred by low-fat advocates is that the studies aren’t meaningful at all. They claim that the excess deaths at low cholesterol levels must be due to pre-existing conditions and that chronic illness leads to low cholesterol levels, not the other way around. But the argument that the other conditions are pre-existing and are just coincidentally associated with low cholesterol levels leaves open the equally likely argument that heart disease is just coincidentally associated with high cholesterol levels, and that heart disease leads to high cholesterol levels, not the other way around.
However, the more likely interpretation of the effects of low cholesterol levels is that whatever a low-fat diet does to blood cholesterol levels is only one factor of the low-fat diet’s effect on general health. In other words, while a low-fat diet might help prevent heart disease, it might also raise susceptibility to other disease conditions.
We’re Not Done Yet
The science of fat and cholesterol started in the 1950s as a simple story. Since then it has developed into a very complicated one, and we aren’t finished yet.
Please join me next time when we’ll continue with the story of cholesterol.
The Science of Low-Carb & Keto Diets
|About Dr. Beth Gruber
Dr. Gruber is a graduate of the Southern California University of Health Sciences and has been in private chiropractic practice in Long Beach, California since 1964. She also received both a Bachelor’s Degree and a Master’s Degree from California State University at Long Beach. She has written on health-related subjects for over 30 years, for several different publications. She lives in Southern California with her husband of 33 years. Both she and her husband follow and live the low-carb lifestyle full time.