Is Dietary Cholesterol Necessary?
Despite over 40 years of repetitive medical findings demonstrating a clear causal link between dietary cholesterol and heart disease, many people still assert that dietary cholesterol is not only safe, it is in fact healthy.
Whereas established science has weighed in consistently with warnings about the toxicity of cholesterol for nearly half a century, many people insist that the handful of studies that contradict this “consensus” are the honest studies worthy of scholarly attention.
Cholesterol proponents often decry the established science as a conspiracy perpetrated by the statin industry seeking to boost sales in a war against cholesterol. While it is a compelling hypothesis, no one can point to any specific examples to support this claim.
I want to lead off this dissertation by highlighting the frivolity of this assertion for a very important reason. Two things can be true simultaneously. The statin industry is based on junk science, and cholesterol is still bad for you.
If you haven’t already, I highly recommend you watch Part One of this video series where we demonstrated the toxicity of cholesterol. In the interest of time, I’m going to assume everyone has seen that information and that we are all on the same page because we will not be reviewing any information previously covered. Now, let us proceed to answer the next most common question, “Is dietary cholesterol necessary?”
Phytosterols versus Dietary Cholesterol
Many cholesterol proponents push multiple claims forward at once, some true, some false, attempting to weave together a seemingly convincing argument.
For instance, a common argument goes like this: cholesterol is needed to perform certain functions in the body, plant foods have their own form of cholesterol and this is evidence that humans can consume cholesterol safely; however, animal products are the best source of cholesterol.
Let’s pick this apart one claim at a time and see how well the thesis holds up.
Firstly, your liver will produce all of the cholesterol that your body needs. Period. You do not need any from your diet.
Animal products are technically the only dietary sources of cholesterol. While plants do contain a toxic nutriment called phytosterol which is structurally similar to cholesterol, the human body has evolved mechanisms to block its absorption in the intestines because the body recognizes its toxicity.
Moreover, plant phytosterols have ironically been shown to lower LDL cholesterol absorption in the intestine in many studies, as pointed out by Gylling and Simonen in 2015, effectively lowering the risk of coronary heart disease.
It is this lack of dietary cholesterol and the LDL reduction from plant phytosterols that cause vegans to exhibit lower LDL cholesterol levels than omnivores, as first established by Sanders and Roshanai in 1992.
MYTH: Eskimos Have Extremely High Cholesterol and Enjoy Optimal Health
If you have debated meat-proponents before, you have probably heard the myth about the healthy Eskimo.
Cholesterol proponents often point out that the Inuit peoples living in the Arctic subsist almost exclusively on a carnivorous diet and yet they enjoy abundant health and longevity despite having an average cholesterol score of 200mg/dl compared to the optimal range of 50-70mg/dl, as O’Keefe et al. demonstrated in 2004. Now, supposing this is true, and we’ll get to the reasons why it’s not in a moment, this still would speak more to some sort of metabolic adaptation specific to the Inuit people and not to the human race as a whole.
Since, the Eskimos lived in isolation for roughly 6,000 years until the mid-1800s, cholesterol proponents argue that they had lived healthy lives until they were introduced to western diets. However, we know this is not the case because we have strong evidence that directly contradicts these claims.
In 2013, Thompson et al. published a review of mummified remains of Eskimos dating back 2,000 years that displayed extensive atherosclerosis of the heart, brain, and limbs. Anthropologists found the frozen remains of two women, one that died in her 20s and one that died in her 40s, both from heart disease, displaying premature death in the only examples we have of ancient Eskimo remains.
The life expectancy of Eskimos is 12 to 15 years shorter than Canadians who are some of their nearest neighbors. Moreover, the life expectancy of Canadians climbs each year whereas the life expectancy of Eskimos is stagnant and falls increasingly further behind.
This is in large part due to the anomalously high rates of atherosclerosis, osteoporosis, cancer, and parasite infection observed in Eskimo populations. In fact, persistent organic pollutant (POP) body burdens and heavy metal toxicity is such an issue that scientists have found Eskimos exhibit levels 8-10 times higher than non-Eskimos. Inuit women have been found to have levels of PCB’s in their breast milk 5- 10 times higher than women in southern Canada.
Cholesterol proponents have conflated the mere survival of the Eskimos with actual thriving.
Smith-Lemli-Opitz syndrome, or SLOS, is a genetic metabolic disorder that inhibits cholesterol production in the body. SLOS only affects 1 out of every 60,000 babies. However, there is an 80% prenatal or perinatal mortality rate meaning most babies do not even survive. Those that do survive are often left with mental retardation, physical deformities, and other health complications.
The desperation of cholesterol proponents is fairly obvious when they reach for a genetic mutation that affects less than 0.000017% of the population as evidence that dietary cholesterol is necessary.
Yet, for some incomprehensible reason, many cholesterol proponents will use SLOS and insist that because of an extremely rare genetic disease that kills almost everyone afflicted by it, this is somehow proof that all humans need dietary cholesterol from animal products, forgetting that the exception proves the rule.
This rare syndrome inhibits the body’s production of the enzyme DHCR7 which in turn causes a buildup of the sterols 7DHC and 8DHC in serum at thousands of times higher than optimal levels. In fact, cholesterol lowering statin drugs is often how doctors treat SLOS patients because they help to lower 7DHC levels, as discussed by Svoboda et al. in 2012.
While SLOS is often cited for inhibiting cholesterol production, this is not always the case, as Porter demonstrated in 2008 that SLOS patients can exhibit completely normal levels of cholesterol synthesis. Essentially, scientists are unsure of whether or not cholesterol plays any part at all in the symptoms expressed by SLOS patients.
Combined, these findings render this entire argument invalid.
Case Study: Extremely Low Cholesterol
There exist other genetic abnormalities that we can look to in our investigation that are even rarer than SLOS which also cause extremely low cholesterol levels.
Take, for example, this 1979 case study of a man afflicted with asymptomatic familial hypobetalipoproteinemia which caused his LDL cholesterol baseline to be just 4-8mg/dl as well as HDL levels at half the normal levels. He was described as having “remarkably good health” and exhibited no detectable secondary symptoms.
Although individuals genetically disposed to low cholesterol are at no greater risk for illness or disease, there are simple ways for these individuals to raise their cholesterol levels if they want to without relying on animal products. According to the American Heart Association,
“Some tropical oils, such as palm oil, palm kernel oil and coconut oil, also can trigger your liver to make more cholesterol.”
Etiology of Atherosclerosis
In Part One of this video series, we looked at the causal relationship between dietary cholesterol and coronary heart disease, multiple types of cancer (1, 2, 3), and Alzheimer’s. Now, let’s examine the various ways scientists know that cholesterol causes atherosclerosis.
At the 39th Annual Williamsburg Conference on Heart Disease, medical doctors Mina Benjamin and William Roberts pointed out that while there are 10 risk factors for atherosclerosis, or narrowing of the arteries, 9 of these factors are contributory at most but do not cause the disease in and of themselves. The only risk factor known to cause atherosclerosis is dietary cholesterol.
After spending 50 years researching coronary heart disease, William Roberts published his four key findings proving that this disease manifests from the consumption of cholesterol.
- Atherosclerosis is easily produced experimentally in herbivores (monkeys, rabbits) by giving them diets containing large quantities of cholesterol (egg yolks) or saturated fat (animal fat). Indeed, atherosclerosis is one of the easiest diseases to produce experimentally, but the recipient must be an herbivore. It is not possible to produce atherosclerosis in carnivores (tigers, lions, dogs, etc.). In contrast, it is not possible to produce atherosclerosis simply by raising a rabbit’s blood pressure or blowing cigarette smoke in its face for an entire lifetime.
- Atherosclerotic plaques contain cholesterol.
- Societies with high average cholesterol levels have higher event rates (heart attacks, etc.) than societies with much lower average cholesterol levels.
- When serum cholesterol levels (especially the low-density lipoprotein cholesterol [LDL-C] level) are lowered (most readily, of course, by statin drugs), atherosclerotic events fall accordingly and the lower the level, the fewer the events (“less is more”). Although most humans consider themselves carnivores or at least omnivores, basically we humans have characteristics of herbivores (Table (Table11).
(Editor’s note: I will eventually make a “science explained” video discussing how we know that humans are herbivores.)
Individuals who have a cholesterol score between 50mg and 70mg per dl do not develop atherosclerosis whereas a cholesterol score above 75mg/dl causes the progression of atherosclerosis and this relationship is linear, as in the higher the cholesterol score the faster the atherosclerotic progression.
Throughout this video series, we asked the question “Are animal products healthy to eat?” The short answer is no, but even with the hundreds of studies that I cited, I have barely scratched the surface of the published medical literature that overwhelmingly supports this conclusion.
In producing this video series, it was my hope to teach a couple of secondary lessons outside the scope of nutrition. There are multiple parties deliberately funding junk science or just honestly misconstruing data. Not a lot of people read scientific literature, which is fine – I’m not saying everyone needs to – but those of us that don’t have our work cut out for us.
I caution everyone to exercise discernment when listening to dietary and medical advice, even with my content. Taking accountability for your health is the first step in reclaiming the direction of your life, but do so with the understanding that there is an industry built upon the exploitation of your ignorance on these matters.
Although this is the last installment of this video series, fear not. I will continue to produce similar “science explained” videos on a variety of health topics in addition to the ethical vegan argument that we felt did not belong in this video series.
If this video series has convinced you to try out a plant-based diet, but you are worried that it won’t meet your body’s nutritional needs, please check out my video entitled Vegan Deficiencies.