Are you confused about cholesterol?
Should you eat fat or should you not? And what about eggs (in the news again!) – should you now be only eating 2 a day? Let me explain a few things about why we need cholesterol and why a few over-simplifications in the news makes it even harder to understand what is actually going on.
To start, here a few basic facts to take away even if you read no further:
1. There is no ‘good’ and ‘bad’ cholesterol. It is simply cholesterol. An organic compound with the formula C27H46O.
2. The term ‘good’ and ‘bad’ actually refers to the cholesterol carrier particles, known as lipoproteins, of which there are low density lipoproteins (LDL) the so called ‘bad’ and high density lipoproteins (HDL), the so called ‘good’. There are actually many different sizes and densities of LDL’s as well.
3. Cholesterol is an essential part of cell membrane structure and the myelin sheath around nerves, a precursor for sex hormone production (oestrogen, testosterone, progesterone and DHEA), active vitamin D and cortisol. Without cholesterol we could not produce these hormones.
4. Cholesterol is an essential component of bile acids which are key for eliminating certain waste products from the body (including oestrogen metabolites) and fat absorption from the small intestine.
5. As we age, higher levels of cholesterol are associated with increased longevity (1).
6. Statins not only stop the production of endogenous (that produced in the body) cholesterol but also an important molecule called Co-Q10 which is essential for energy production.
7. Insulin is closely involved in the regulation of cholesterol metabolism – so think blood sugar regulation!
The conventional medical theory has us believe that cholesterol consumed from the diet and saturated fat increase the risk of coronary heart disease by raising the level of cholesterol in the blood and thus risk of arterial plaque formation. This is known as the ‘diet-heart’ hypothesis. I am not going to spend time here debating the evidence on this as I would be here all day but there is a lot of research debunking this theory and showing it was based on cherry-picked data (1 , 2). Instead, I am going to explain how some of the mechanisms involving cholesterol work and their roles in the body. If you understand this, it will help you see beyond those confusing headlines.
Cholesterol can come from two sources – exogenous, that which you eat, and endogenous, which is made in your liver. It is estimated that 80% of your circulating cholesterol is made in your liver and this is regulated by your dietary intake ie if you consume more in your diet, your liver should produce less. There are situations where this negative feedback loop does not work so well, such as when there is insulin resistance, metabolic syndrome, adrenal dysfunction or the genetic condition of familial hypercholesterolemia present and can result in what is known as dyslipidemia.
Cholesterol is transported in the body within the lipoproteins mentioned above, along with triglycerides. Very simply, LDL are involved in delivering cholesterol to cells for either cell membrane or steroid hormone synthesis while HDL is involved in bringing excess cholesterol back to the liver which is then excreted via the formation of bile. LDL particle size and density change as they move around the body and triglycerides are cleaved off and it is currently thought that it is the smaller, denser LDL particles that are more damaging to arterial cell walls due to their ability to be more easily oxidised by free radicals and ‘get stuck’ in arterial walls forming a plaque. HDL particles have been shown to be more resistant to oxidation and are inversely associated with CVD.
What causes LDL to become oxidised? Put simply, inflammation. Where does inflammation come from? Inflammation can come from many things but common reasons are insulin resistance, psychological stress, excess exercise without sufficient recovery, heavy metal toxicity, unwanted parasites, chronic viral infections, food intolerances, allergies, pesticides….the list goes on. Insulin resistance (think long term blood sugar dysregulation) plays an additional role due to its ability alter the action of enzymes that affect fat metabolism.
From a functional perspective, which ever route the cholesterol goes down (bile, steroid pathway etc), enzymes, co-factors and substrates (eg amino acids) are needed for these pathways to work. Thus basic nutrient deficiencies can play a role in elevated cholesterol. Liver function is key, if your liver or your gallbladder (which stores your bile) is not working properly, cholesterol cannot be removed efficiently. If you have poor bile flow, it is feasible you are not fully absorbing your fat soluble vitamins and thus a vicious cycle can evolve. Signs that this pathway may not be working optimally are floating stools, stools that are pale in colour (straw or chalk), constipation, pain between the shoulder blades and nausea.
Issues with bile flow can result in an altered gut microbiome, digestive dysfunction and altered hormonal balance as, for example, more oestrogen breakdown products are reabsorbed into your circulation. Thyroid and adrenal function should also be assessed due to their crucial roles in energy metabolism. Focusing on lowering dietary cholesterol alone usually has little effect on serum cholesterol levels. Be aware that a diet high in sugar and carbohydrates and low in healthy fats is more likely to cause an increase in cholesterol levels as excess sugar is turned into fat and stored, particularity around the middle, a classic sign of insulin resistance.
If you want a great starting place to look assess your body’s overall health, including fat metabolism and cholesterol status, Functional Blood Chemistry Analysis is a great tool – the biggest bang for your buck as they say. A report will allow you to assess GI function, liver function, blood sugar balance, adrenal and thyroid function, immune status, bone health and kidney function by looking at all the various physiological and supporting accessory systems in the body.