Cholesterol is a lipid (fat) in the body made by the liver. It is classified as a sterol, which is a steroid. The word cholesterol comes from the Greek words ‘chole’ meaning bile and ‘stereos’ meaning solid, stiff. Cholesterol is necessary for so many functions in the body. It makes vitamin D, sex hormones, bile salts, cell membranes, lubricates skin, protects cells, insulates nerve fibers, just to name a few. It is carried throughout the bloodstream by vehicles called lipoprotein carriers.
There are 3 main types: high density lipoprotein (HDL), low density lipoprotein LDL) and very low density lipoprotein (VLDL). HDL is often referred to as the ‘good cholesterol’ and LDL is considered ‘bad cholesterol’. HDL carries cholesterol from the cells back to the liver where it is broken down or excreted as waste. LDL does the opposite and brings cholesterol from the liver to the cells. If there is too much for the cells to use it can build up in the arteries. VLDL is similar to LDL but it carries both cholesterol and triglycerides (fats) from the liver to the cells and body fat for storage.
The liver synthesizes about 85% of the body’s total cholesterol, which means that only around 15% actually comes from diet. This is why eating foods, like eggs that are considered to be high in cholesterol because they contain 186mg of cholesterol each, isn’t necessarily a problem. The recommended daily intake for cholesterol in a healthy individual is only 300mg so one egg is already over half of that amount. This is where the crazy don’t eat egg yolks belief came from, but it’s just that…crazy! Not only are eggs high in cholesterol, (which is actually pretty minimal considering the liver does most of the work in contributing to blood cholesterol levels) they are also high in a very important nutrient called lecithin. Lecithin is only found in the egg yolks though so eating egg whites doesn’t give you any lecithin whatsoever. In fact, lecithin means ‘egg yolk’ in Greek.
Lecithin has many roles in the body. It makes up 2/3’s of myelin sheaths, which are the coverings of nerve axons that speed up nerve conduction. It is also necessary to supply choline, which makes up acetyl-choline, a neurotransmitter in the brain. Approximately 1/3 of the brain is made up of lecithin, the other 2/3s being phosphatidylserine and DHA. Therefore, it is an extremely important nutrient for the nervous system. It also helps with the absorption of fat-soluble minerals in the digestive system, but let’s focus on its role in cholesterol maintenance.
Lecithin acts like a detergent in the body. It emulsifies fat in the liver, cleaning it and allowing it to work more effectively. As well, it emulsifies cholesterol that has settled in the artery walls so that it can be excreted from the body. It also keeps cholesterol that is flowing through the blood vessels soluble so that it doesn’t settle and build up plaque on the walls for no reason. Another interesting point about lecithin and eating only egg whites is that a deficiency in lecithin also lowers testosterone levels, which no one wants when working out hard and trying to increase muscle mass.
If cholesterol-rich foods like eggs don’t raise cholesterol then what does raise it to unhealthy levels? The answer to that is a polluted environment and diet. It is from toxins, refined carbohydrates and free-radical damage that excess cholesterol needs to be made in order to protect cells and blood vessels. When there are free radicals circulating throughout the blood vessels they cause knicks in the arterial linings. Cholesterol is a slippery, waxy substance that deposits along rough artery walls so that blood cells don’t get damaged going through. A combination of cells, calcium and protein eat the debris and form a patchwork over the area. This whole process narrows the arterial space and causes a hardening of the arteries.
So, hopefully that helps to shed some light on the “eggs are bad for you” nonsense. They are a great source of protein and an excellent choice for a post-workout food. Furthermore, the egg yolk, or ‘liquid gold’ contains valuable lecithin that our bodies need to keep cholesterol levels at a healthy level.
By: Megan McDonald CNP
- Book: Fats that Heal Fats that Kill by Udo Erasmus
- Book: The World’s Healthiest Foods by George Mateljan