The Futility of Cholesterol Denialism, Part 2: Cholesterol in Populations
Some of the most important research to establish the connection between diet and heart disease has come from comparisons of contrasting cultures. Epidemiology has enabled connections to be made between lifestyle factors and heart disease prevalence within populations.
If you’ve seen The Primitive Nutrition Series, you know I give Loren Cordain credit for at least paying lip service to the appropriateness of low cholesterol targets. He noted that many hunter gatherer cultures had much lower cholesterol levels than is typical in contemporary societies consuming large amounts of animal foods. They also had lower apparent rates of heart disease. Hunter gatherers give us nice opportunities for cross-cultural comparisons, but as I noted in my other videos, an important explanation for their low cholesterol seems to be consistently overlooked by the paleo community.
Without hygienic food preparation and clean water, parasitic infections are common in primitive populations. Parasites gobble up cholesterol in the blood. I found this study by reading the excellent PaleoVeganology blog. Parasites metabolize cholesterol, affecting the lipid profiles of their hosts. The cultures Cordain likes to hold up as models for his diet ideas ate a lot of animal foods, but they didn’t need statins to maintain their cholesterol in a healthy range. They had parasites for that job.
This understanding of the effects of parasites has inspired yet more compelling support for the lipid hypothesis. In this noteworthy experiment on mice, schistosomiasis actually caused the regression of arterial lesions. These scientists recognized the implications of this. Schistosoma parasites can counteract effects of an otherwise atherogenic diet. Any time you see a primitive culture held up by the cholesterol confusionsts as a model of healthy living on a high-fat, high-animal food diet, ask yourself if that culture somehow managed to avoid parasitic infections. I’d say that would be unlikely. Parasites are pretty unpleasant to contemplate. Who wants to imagine themselves hosting tapeworms or toxoplasma. But I think parasites deserve a little more respect as marvels of evolution. Low carbers in sanitized environments tapping on computers don’t seem to understand their pervasiveness throughout human history.
Even today one third of humanity suffers from helminthic infections.
Unfortunately, the malaria parasite is also still quite common, and it lowers blood lipids as well.
Parasites have coevolved with us and all our ancestral species. This is an important aspect of our history. Let’s not pretend otherwise. The low cholesterol of hunter gatherers might also be explained in other ways, including food scarcity and genetic adaptations.
The ATP III panel stated that only in populations with very low serum cholesterol is there a near absence of coronary heart disease.
As you know, the relationship between cholesterol and heart disease was observed in less isolated populations as well. In early heart disease epidemiology, the Japanese were documented to have much lower rates of coronary heart disease than Americans despite their more widespread cigarette smoking and similar rates of high blood pressure. While smoking and hypertension are serious risk factors, without accompanying high cholesterol, they are less dangerous. Their lower serum cholesterol resulted from their lower consumption of saturated fat and dietary cholesterol.
Various African populations were also found to have very low rates of heart disease. Some were described as being “virtually free of hypertension and CHD”.
Their diets were based on cereals, legumes, and greens. Their consumption of animal-sourced foods was minimal.
T Colin Campbell and Chen Junshi reported that low rates of heart disease accompanied low cholesterol and low animal food consumption in China as well. Read The China Study for more on this.
You can hate on T Colin Campbell all you want but there is no reason to doubt his conclusions. Here is a study from 1991 of urban Chinese relating cholesterol concentrations to heart disease deaths. Look as hard as you want at the list of authors. Campbell’s name is nowhere to be found. Yet the study authors wrote that even in this population with relatively low mean cholesterol, there was still a strongly positive association between blood cholesterol and death from coronary heart disease. Only 43 deaths among over 9000 men were attributable to heart disease after 8 to 13 years of follow up. This is a very similar finding to that reported by Campbell. Did all these researchers also have a vegan ideology to push?
What about these researchers who compared ethnic Chinese in Hong Kong and Singapore? They explained the dramatically higher rates of all-cause and cardiovascular mortality in Singapore on their greater saturated fat consumption. The diets of the Singaporeans drove up their total cholesterol and their LDL. The authors didn’t blame animal fat, but rather coconut and palm oils. If they had a vegan agenda, it’s hard to tell from what they wrote. Coconut and palm oils are vegan.
Of course, Ancel Keys’ Seven Countries Study showed clear relationships between serum cholesterol, saturated fat consumption, and deaths from coronary heart disease in this most famous of cross-cultural comparisons.
The relationship between blood cholesterol and coronary heart disease death was also apparent in a 40-year follow-up with the cohorts in those seven countries.
This 1994 cross-cultural comparison reached similar conclusions. Rural Chinese had the lowest cholesterol levels while the Finnish had the highest, and their rates of ischemic heart disease corresponded as we might expect. The researchers said that variations in serum cholesterol accounted for four-fifths of the regional variations they observed in death rates.
Saturated fat apologists try to taint these observations by trying to link the researchers who made them with random vegans. Ancel Keys wasn’t a vegan and vegan fitness enthusiast Noel Polanco hasn’t conducted any research into heart disease, but Denise Minger chose to associate them anyway. This is pure spin. Actually, there is a bit of irony in trying to connect an animal rights activist to a heart disease researcher.
The first chairman of the ATP, which set cholesterol guidelines in the US for the first time, called animal rights activists a problem due to their antiscientific thinking. Ms Minger, have you not noticed how much of the research into heart disease was conducted on experimental animals? You know they usually kill the animals in the experiments, don’t you? These recommendations were not created by vegans or vegan-sympathizers, I assure you.
This is an interesting excerpt from that ATP chairman’s lecture. In The Primitive Nutrition Series, I showed you that the medical community was slow to accept the lipid hypothesis, but they did come around eventually. The public was initially less resistant to the lipid hypothesis than the doctors, however.
We see in this lecture the frustratingly conservative mindset of past cholesterol experts. Diet and drugs were considered treatments to be reserved for at-risk individuals. Why exactly should anyone consume a diet that raises cholesterol? A clear message about nutritional excellence was apparently not considered.
LDL cholesterol was to be the basis for treatment when deemed appropriate. Diet was considered a therapy.
Even the author of this tepid approach, who held animal rights activists in low regard, could see that high protein and high fat diets were dangerous and unscientific.
The science community did not approach the diet-heart question with an agenda to promote animal rights or polyunsaturated oils. Mortality data made their engagement with this question inevitable. The middle of the twentieth century saw a dramatic decline in infectious disease deaths in America as our nation took on the characteristics of a wealthy, modern nation.
Taking the place of infectious disease as our top killer was heart disease. Trend lines like these focused the attention of all public health officials.
This rise in heart disease was accompanied by changes in diet. Carbohydrate consumption measured as a percentage of total calories fell in these years. Carbs were displaced by protein and especially fat, which rose markedly.
Both saturated and unsaturated fats were consumed more.
Those who wish to blame grains for heart disease should know that through this period of rising mortality carbohydrate consumption fell by a quarter, and in comparison to other sources of carbohydrate, grain consumption fell especially fast.
I have highlighted food categories that might be of interest to you. Those in green along the right were eaten less, including potatoes and cereals. Even sugar was eaten a little less during this time. In red to the left you can see that meat and dairy were eaten more. This alone was not the basis for the acceptance of the link between saturated fat with heart disease. I’ll show you a bit of that history in Part 3.