Why You Should Rethink Cholesterol
For years, we’ve been told to avoid foods that contain cholesterol; we’ve been told to limit egg yolks, avoid fatty cuts of meat, and put down the butter. Cholesterol has been demonized as an artery clogging substance, said to be the cause of heart disease, and has been vilified by doctors and health professionals for over 40 years, but, what if we got it all wrong? The truth is, several decades ago the story of cholesterol took a wrong turn and it’s time to bring it back. In fact, what we have come to realize is that dietary cholesterol does not equal blood cholesterol, and there is actually a big difference between the two. So, it’s time to rethink cholesterol, understand its functions, how it works, and the benefits of having cholesterol in your diet.
What is cholesterol?
Although often considered a fat, cholesterol is technically classified as a sterol, which is a combination of a steroid and alcohol. Cholesterol is an essential structural component of cell membranes, a necessary precursor for sex and stress hormones, and synthesizing bile salts, which help to break down and emulsify fats, which aid in metabolizing vitamin A, D, E and K from the food we consume.
It is also important to understand that although cholesterol can be found in certain foods, the body itself produces cholesterol. On any given day, we have between 1,100 and 1,700 milligrams of cholesterol in our body, up to 85% of which is actually produced by the body in our liver. In fact, because cholesterol is so vital to human life, your body will produce cholesterol in response to what you eat. The body tightly regulates the amount of cholesterol in our blood by controlling its internal production; when cholesterol intake in the diet goes down, the body makes more cholesterol, and when cholesterol intake in the diet goes up, the body makes less cholesterol. In other words, trying to avoid cholesterol in your food has little to no impact on your body’s cholesterol levels since it will simply regulate its own needs.
The Vital Roles of Cholesterol
Although for years we have been told to avoid cholesterol, it turns out that, not only is cholesterol as harmful as it was thought to be, but cholesterol has many important functions in the body, including:
- Formation of cell walls;
- Making the cell walls waterproof for protection;
- Repairing wounds, including tears and irritations in the arteries;
- Creation of vital hormones, including sex hormones;
- Creation of bile salts, needed for the digestion of fats;
- Function of the brain and nervous system;
- Acting as a precursor for vitamin D, formed by the action of ultra-violet (UV-B) light on cholesterol in the skin;
- Protection against depression; it plays a role in the utilization of serotonin, the body’s “feel-good” chemical;
- Protection as an antioxidant against free radicals and cancer;
- Absorption of fats and fat-soluble vitamins (A,D, E and K)
Cholesterol & Heart Disease
However, because cholesterol and heart disease have been so tightly linked for decades it is easy to understand why the concept that cholesterol is beneficial can be tough for many to grasp. The fear of cholesterol began in the 1940s and 50s when the diet-heart hypothesis began to unfold, and the fear of saturated fat and cholesterol began. This theory was launched by a researcher named Ancel Keys who said to have linked heart disease with consumption of saturated fat and cholesterol. However, as it turns out, his research and findings were heavily flawed and remained undisputed for many years, and despite the fact that they have been debunked many times, the concept that saturated fat and cholesterol are bad for you remains one of the biggest nutrition myths of all time.
Although a picture has been painted of cholesterol accumulating in the bloodstream, it is crucial to understand that you don’t have a cholesterol level directly in your blood. Cholesterol is fat-soluble and our blood is primarily composed of water, in other words, they don’t mix well. In order for cholesterol to be transported around the body in the blood, it has to be carried by special proteins called lipoproteins. These lipoproteins are classified according to their density; two of the most important in cardiovascular disease are low-density lipoprotein (LDL) and high-density lipoprotein (HDL). LDL, known as “bad cholesterol”, carries cholesterol from the liver to the cells of the body, while HDL, known as “good cholesterol”, carries cholesterol from the cells of the body to the liver where it is eliminated as waste.
Consider this analogy, if your bloodstream is like a highway, cholesterol is the passengers on the highway, while the lipoproteins are the vehicles carrying them. It used to be believed that it was the total number of passengers on the highway (i.e. total cholesterol) that was problematic, however, it is now understood that it is the total number of vehicles (i.e. total LDL vs. HDL) on the highway that is problematic, not the number of passengers. The more vehicles you have on your highway the more prone you are the back-ups and accidents. So, if 200 hundred passengers are travelling in 4 buses, there will be far less traffic and accidents than if 200 passengers were travelling in 200 vehicles.
Our arteries are essentially hollow tubes with a very thin lining and our blood is in constant contact with this lining. Therefore, going back to our analogy, the more vehicles (lipoproteins) there are on the road, the more prone they will be to crashes and running into (damaging) our artery lining. The kicker? Because cholesterol is vital in the creation and protection of cell membranes, when these “crashes” occur, cholesterol arrives at the site of the accident to repair the damage to the lining. So, although cholesterol may be present in the arteries at the “crash” sites, it is a symptom, not the cause.
But, knowing this, it does beg the question, what is causing the damage? To answer that question you need to go to the root, and the root of the cause is inflammation. If cholesterol is nature’s repair substance, you need to look at what is causing the original damage, and the original damage is caused by inflammation. What exactly is causing the inflammation? That can vary from person to person based on diet and lifestyle factors, and include; alcohol, smoking, stress, lack of activity, consumption of trans fats and vegetable oils, consumption of refined carbohydrates and excess consumption of refined sugar. Of course, there are some people with rare genetic disorders or diseases, but in many cases inflammation can be managed through diet and lifestyle factors.
So, by following conventional guidelines of opting for low-fat foods, vegetable oils, egg whites, and refined grain products you actually end up doing far more harm than good. Why? Because it is these exact type of foods that contribute to inflammation, which causes more damage. Instead, it is best to focus on a diet of whole foods, and that should include foods that contain cholesterol. It is ideal to consume fresh fruit, fibre-rich vegetables, beans and lentils, nuts and seeds, whole grains, whole eggs, seafood and meat, not to mention managing stress, getting adequate sleep and staying active. It is these whole foods that are rich in essential nutrients, vitamins and minerals, and essential lifestyle factors that help to reduce inflammation, as opposed to causing it and then asking cholesterol to come repair the damage.
The Bottom Line
The reality is, cholesterol is not a demon or the cause of heart disease, it is actually a nutrient that is vital for our health. Not only does it not significantly affect blood levels, but it is no longer considered a “nutrient of concern” when it comes to heart disease. That is not to say that you can eat all of the fat and cholesterol-based foods you possibly can, but at the end of the day you should be far more concerned about your sugar-laden granola bars than any little old egg yolk.