In the past few weeks, I have encountered several people who were under the impression that humans must eat cholesterol. These individuals didn’t just believe that consuming cholesterol is not unhealthy, they believed it to be essential for human survival. I had not previously heard anyone say this, but perhaps the misperception is more widespread than I imagined. That said, this blog will briefly explain why the belief that humans must consume cholesterol to be healthy is patently false.
Cholesterol is something humans do need for survival. It is a compound that the human body manufactures in the liver, and is a critical component of cells. In fact, vitamin D is synthesized by the skin in sunlight from a form of cholesterol in the skin. Yet your liver produces all of the cholesterol that you need; anything else is excess. You absolutely do not need the cholesterol that you consume from foods. In fact, people should not consume cholesterol from foods at all, as this consumption is detrimental to health.
There is confusion in the mass public that surrounds whether dietary cholesterol intake is related to blood cholesterol levels, and many believe that it’s all genetic and out of a person’s control. Unfortunately, industry-funded studies have purposely muddied the waters on the truth.
If dietary cholesterol was genetic or unrelated to diet, then individuals who cease consuming cholesterol altogether would not experience significant drops in their blood cholesterol levels. Yet instead, we see that when people who switch to plant-based diets that focus on high-fiber foods and contain no cholesterol, they can expect a great decrease in their LDL (bad) cholesterol levels. In contrast, individuals living on predominantly plant-based diets will experience a spike in cholesterol as they move to areas where a more animal-product-intense diet is consumed.
An examination of decades of research on the relationship between blood serum cholesterol shows that an increase in dietary cholesterol results in an increase of blood serum cholesterol. The reason why cholesterol myths remain so persistent in society is because profitable industries have the incentive to propagate them.
The study most often used to “prove” that dietary cholesterol does not affect blood cholesterol was published in 1971 and used an analysis of only 8 (!) people. Abysmal study design is a common pattern among articles that industry uses to “prove” the health if their products. For example, the study used to “prove” that diet doesn’t affect skin health was conducted in 1969, and the procedure was thus: participants, all of whom had moderate acne, were separated into two groups. One group was assigned to eat two chocolate bars a day that were highly enriched with cocoa, while the other ate two candy bars that contained no chocolate. At the end of the study period, the number of pimples on subjects’ faces were counted. Not exactly a gold star research design!
A related question to the issue of dietary cholesterol and blood serum cholesterol is whether eggs are a healthy food to be consumed. One misperception about eggs is that they contain healthy HDL cholesterol, and so they are beneficial to consume.
The best available studies prove otherwise. One egg contains about 180 mg of dietary cholesterol, along with a great deal of fat. A meta-analysis demonstrates how egg consumption contributes to the risk of heart disease and diabetes. The cholesterol in eggs can raise an individual’s LDL levels, forming more arterial plaque and contributing to heart disease. Meanwhile, more fat-intensive diets lead to an increase in intramyocellular lipids, which clog muscles and prevent insulin from doing its job, contributing to diabetes.
In conclusion, humans definitely do not need to eat dietary cholesterol to survive. Quite to the contrary: consuming dietary cholesterol puts people at greater risk of many chronic diseases.