Recently a co-worker and I were talking about food. He mentioned how much he liked soft-shelled fried crabs but couldn’t have them very often since they were so high in cholesterol. Earlier this week, a friend on a social network typed “Not to stir stuff (actual word substituted), but even skinny people can get clogged arteries.” This was in response to a status update I made about how avocados dredged in egg whites and cream, rolled in ground up pork rinds and fried in lard were not only really delicious, but on my diet. (recipe can be found here for those interested, they really were amazingly good).
It made me realize that while I’ve done a lot of reading about cholesterol and the myths surrounding it, that many people still believe in the “popular wisdom” that they have been fed regardless of the truth surrounding it. There’s a lot of stuff about lowering cholesterol on the web. Go ahead and search it, I’ll wait.
Our bodies manufacture cholesterol because we need it. Our livers manufactures it and it is a critical component in our bodies. It is a major component of our cell membranes, keeping them both properly rigid and flexible. Cholesterol also helps our cells regulate temperature changes and insulates our nerve cells as well. (Uninsulated nerve cells are implicated in diseases such as multiple sclerosis and others which bring on blindness, bladder or bowel dysfunction, double or blurred vision).
So I’ve been re-reading Gary Taubes “Good Calories, Bad Calories” and realizing how pervasively bad the information we get from media, the government, and groups which purport to know what they are doing. It would be laughable if it wasn’t so darn scary.
The idea of lowering cholesterol in the first place to prevent heart attacks comes from what is known as the diet-heart hypothesis, first promulgated by Ancel Keys in the early 1950s. It basically states 2 theories and a premise based on those two theories:
- Dietary saturated fat increases blood cholesterol
- Elevated blood cholesterol increases the risk of having a heart attack
Therefore, dietary saturated fat increases the risk of having a heart attack.
Keys and others who believed in this hypothesis, did everything in their power to promote it, while ignoring any study that didn’t fit. He cherry-picked data that fit and explained away anything else as an aberration. (Ever hear of the French Paradox?).
Good scientific research requires both an open mind and a willingness to discard your hypothesis if the data doesn’t bear it out. If you believe that your hypothesis must be correct before beginning a scientific experiment, that means you interpret your evidence selectively. Unfortunately, in many dietary related studies, the scientists conducting the experiments “knew” what the end results should be and weren’t willing to discard the research when it went against what they knew.
So let’s go into those two theories in a bit more detail.
Elevated Blood Cholesterol increases the risk of having a heart attack.
In 1950, the Framingham Heart Study was launched to study how a single community’s diet and lifestyle choices might reflect with heart disease. 5,200 residents of Framingham, Massachusetts were recruited into this study by 1952 and went through comprehensive physicals which included cholesterol testing. Each person was re-examined every 2 years to see who got heart disease during that time. It was discovered during that time that those men who had a total cholesterol level of over 260 mg/dl ended up having a risk of heart disease 5 times greater than those for men whose cholesterol was under 200. Proof?
Not totally, there was also evidence that as men aged, those with lower cholesterol were more likely to have heart disease then those with higher cholesterol. (Meaning that as a man aged, that cholesterol might have actually had some protective benefits, but we don’t know that since it has never been studied.) There was also only a very slight connection between women under 50 with high cholesterol and the link was non-existent for older women.
So high cholesterol in younger men might be a risk factor for heart disease, but it is not a risk factor at all for older men or women at practically any age. Has your doctor ever told you that? Mine certainly haven’t.
Dietary blood cholesterol increases the risk of having a heart attack.
Keys believed that cholesterol in diet influenced blood cholesterol levels. He also believed that while the benefits of lowering cholesterol in the body hadn’t been established yet, it was simply a matter of time before the evidence showed it (see Framingham above which did not show it).
In the 1940’s Keys framed his dietary cholesterol levels theory on a visit to Italy. While there he concluded that rich people had higher cholesterol then poor people. He attributed it to the meat and fat they were eating which the poorer people had limited access to. (Of course he ignored the refined flours and sugars that the rich people also ate and to which the poor had no access to). He believed (without any scientific evidence to back it up) that fatty diets raised cholesterol levels.
In reality, dietary cholesterol has an insignificant effect on raising blood cholesterol levels. While it might elevate cholesterol levels in a small percentage of individuals who are highly sensitive. It’s actually meaningless in a clinical viewpoint for most of us.
Dietary Cholesterol has little to no effect on blood cholesterol.
Keep in mind though that the connection between cholesterol and heart disease only showed up in younger men who had cholesterol above 260 mg/dl and not at all for older men, or women of any age.
So if there is very little link between cholesterol and heart disease and dietary cholesterol only raises the blood cholesterol levels in some highly sensitive people, how did we get to the point where every doctor points to a cholesterol level of above 200 mg/dl as too high regardless of whether the patient is a man or a woman?
In 1977 Senator George McGovern announced the publication of “Dietary Goals for the United States“, a publication coming out of McGovern’s Senate Select Committee on Nutrition and Human Needs. This committee was originally created to wipe out malnutrition in America. It became something much different.
Most of the committee staff consisted of lawyers and ex-journalists. They were unaware of any controversy in the scientific nutritional world (and there was a lot of it). They bought into the diet-heart thesis simply because that is all they heard about. Because of this lowering fat consumption and raising carbohydrate consumption became the goals of the United States.
Our doctors tend to have one semester of Nutrition before they practice. They don’t go out and research what is real, they parrot what they are told. Additionally, the American Dietetic Association (ADA) which licenses registered dieticians is now a sponsored organization by a number of processed food manufacturers. They don’t get the real information. It’s a simple sound bite to say that eating high-cholesterol foods raises our cholesterol. We like simple facts, even when they aren’t true.
Dietary cholesterol will not raise your cholesterol. There is very little real evidence that cholesterol levels are linked to heart disease in most people. Additionally, we need cholesterol in our systems to stop a whole host of diseases other than heart disease. So ask yourself, is it really necessary to eat less animal fats or take those statins?
There is of course more to it then just this. I’ll get into it in a later post.
I’m not afraid of eating saturated fat from pastured animals. Why are you?
- Standing by Saturated Fat (bodychange.net)
- Clearing Cholesterol (bodychange.net)
- 2011 Nutrition Lessons Learned: #2 Dietary Fat and Cholesterol Summary (Nebraska Engineer)
- Diseases of the Myelin Sheath (Livestrong.com)
- The Cholesterol Myth that Could be Harming Your Health (mercola.com)
- The Cholesterol Myths (Uffe Ravnskov, M.D.)
- Does Dietary Saturated Fat Increase Blood Cholesterol? An Informal Review of Observational Studies (Whole Health Source)
- Cholesterol – Is it Really So Bad? (foodandhealing.com)
- Pushing the LIE (kellythekitchenkop.com)
- “Forks Over Knives”: Is the Science Legit? (rawfoodsos.com)