Written by Angela Schaefer, FM Health Coach
Cholesterol and saturated fat have been demonised for decades, and unfortunately received much bad press over the years. They were vilified as far back as the 1950s as being the main drivers of heart disease. Even though the findings of these studies were disproved in the 1980s, the “low fat” ideology had become so ingrained (and supported). Many were advised by doctors and healthcare professionals to avoid or cut back on saturated fat consumption and keep tabs on their cholesterol levels, and statins (medication used to reduce serum cholesterol) became the biggest selling class of drugs on the market. In understanding the critical role that cholesterol plays in the body, this misinformation came as a disservice to many, and in his book, Eat Fat Get Thin, Mark Hyman, MD says,
“…… people with the lowest cholesterol as they age are at higher risk of death.” (1)
Going back to basics and understanding exactly what cholesterol is and what it does in the body would be a good place to start in unpacking this misinformation.
Cholesterol is a waxy, yellowish, fatty substance produced mainly by the liver, or acquired by consuming dietary saturated fat from animal sources such as egg yolks, fatty meats and cheese, but to a much lesser extent. It attaches to proteins forming particles called lipoproteins which assist in transporting it through the blood. Some of its many thousands of functions in the body include building cell membranes, forming bile and vitamin D, protecting nerves and the brain and serving as a building block for steroid hormone production. Essentially, it is a critical component of health.
Cholesterol is generally referred to as ‘good’ or ‘bad’ and this is dependent on what type of lipoprotein it is part of: high density lipoprotein (HDL), low density lipoprotein (LDL) or very low-density lipoprotein (VLDL.) The lipoproteins contain cholesterol as well as triglycerides, in varying amounts. VLDLs travel around the body depositing triglycerides into cells where it is used for energy. Excess triglycerides are stored as body fat. After depositing the triglycerides into the cell, the VLDL becomes an LDL. LDLs are tasked with delivering cholesterol to cells that need it. If there is an excess of LDL in the blood, it will make deposits in the blood vessel walls. This fatty material builds up over time forming what is known as plaques, and damaged vessel walls facilitate this process. Eventually the vessels (or arteries) start to narrow and ultimately reduce blood flow to either the heart or the brain resulting in an increased risk for heart disease and stroke. HDL is also made in the liver and has a comparatively lower concentration of cholesterol and triglycerides and more protein. Its main function is to remove excess cholesterol from cells and from the plaques in the blood vessels. It is then transported back to the liver (reverse cholesterol transport) for elimination. HDL is therefore known as ‘good’ cholesterol for assisting the body in getting rid of cholesterol, and LDL and VLDL are known as ‘bad’ cholesterol for the role they play in contributing to atherosclerosis (hardening of the arteries) and heart disease.
How do we ensure that the balance swings towards ‘good’ cholesterol (HDL)? As I mentioned previously, we have been led to believe, for many years, that ‘high’ cholesterol levels are a result of the overconsumption of dietary saturated fat, but after much research and many studies, it has been proven that the main culprits in driving cholesterol levels up are, in fact, sugar and refined carbohydrates. The liver is triggered to produce cholesterol (through the process of lipogenesis) and the amount it produces is directly proportional to the amount of sugar and refined carbohydrates in the bloodstream. Therefore, a diet high in sugar and carbohydrates results in the liver producing not only less HDL particles and more LDL particles, but the size of the LDL particles is reduced making them smaller, denser and more dangerous.
The type of fat one eats will also impact the type of cholesterol produced in the body. Omega-3 fats found in oily fish (salmon, mackerel, anchovy, herring and sardines) as well as monounsaturated fats from nuts, seeds and olive oil have a positive effect on the type and amount of cholesterol produced, whereas Omega-6 polyunsaturated fats, trans and hydrogenated fats found in baked products, refined vegetable oils, etc. produce more of the undesirable cholesterol. Exercise, weight loss and increasing soluble fibre in the diet have a positive effect as well.
Cholesterol testing has also progressed over the years with the result being broken down into a) the number of HDL particles, b) the number of LDL particles and c) total cholesterol, as opposed to just one reading of total cholesterol. This certainly facilitates easier tracking and gives a better understanding of where one is at.
So with all this in mind we certainly don’t need to banish saturated fats for fear of raised cholesterol levels, but to enjoy them in moderation along with everything else.
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1. Hyman, Mark. Eat Fat Get Thin. (2016) Little, Brown and Company. p. 102
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