High cholesterol is one risk factor for heart disease. So, as it is heart health month in the UK I have decided to discuss cholesterol. Should we be worried about cholesterol? Can it be lowered without prescribed medications from the doctor?
Our body, and the bodies of all animals are a collection of cells. The outside “skin” of these cells is the cell membrane. Cholesterol forms a large and important part of this cell membrane. In fact, without cholesterol the cell could not exist.
Cholesterol is also a building block. Several important hormones and vitamin D are made from it. And, the body needs cholesterol to make bile salts, which help us to digest fats. It also helps to repair damage to blood vessels.
The cholesterol we have in our body can be obtained through eating a diet rich in animal foods. Yet, it is so crucial for life that our liver makes most of our own cholesterol. In fact, up to 80% of the cholesterol in your body was made in your own body. We also reabsorb our own cholesterol from bile salts used in digestion of fats.
Whats more, if you eat less cholesterol your body will compensate and make more of its own. If you eat more cholesterol then most people would make less.
So, if the body is so keen to have plenty of cholesterol why should we worry about it? In part, the problem lies in how cholesterol exists in the body.
Cholesterol is a fatty substance that is not soluble in water or blood. Soluble proteins called lipoproteins carry cholesterol and other fatty substances around the body. There are different types of lipoproteins. The two main types are high density lipoproteins or HDL, and low density lipoproteins or LDL.
HDL and LDL are often known as good and bad cholesterol respectively. Yet this is inaccurate as all cholesterol is identical. The difference is in the lipoproteins carrying the cholesterol.
People with better HDL levels generally have less heart disease. Whereas higher LDL is sometimes associated with heart disease risk. But, that is not the whole story.
We know that there are different subtypes of LDL cholesterol. Researchers found that there are small, dense LDL and large LDL type particles. And, it takes many more small dense LDL particles to carry the same amount of cholesterol.
In studies, people with a higher number of small dense LDL particles have a greater risk of heart disease. It appears the small dense LDL cholesterol is more likely to penetrate the artery walls. LDL cholesterol is also easily oxidised, especially if antioxidants are low. Which means it is easily damaged by free radicals. And, oxidation makes LDL smaller and denser.
If LDL cholesterol penetrates the artery walls, it provokes the immune system. This causes an inflammatory reaction that results in formation of an arterial plaque. These plaques can build up and eventually block the artery. As can happen in the coronary arteries.
Even worse, oxidised LDL cholesterol is even more inflammatory. This inflammation casues the liver to produce more cholesterol. Then, because cholesterol patches up damaged blood vessels, this creates more plaque. And so on…
So, what is the solution? We know that cholesterol production by the body can be reduced with statin drugs. The problem here is that cholesterol is crucial to the body. And, the statin drugs have side effects in a large number of people that take them. Blocking energy production and slowing cell renewal. This is why people on statins often feel tired and in pain.
Changing the amount we eat has little effect on total cholesterol. But, studies show that eating saturated fats can increase cholesterol levels. Yet this was only over the short term. In the longer term they found a different result. Saturated fat intake is insignificant for LDL cholesterol for most people.
As we might expect, there are a lot of research studies on LDL cholesterol and especially small dense LDL. Studies of statins show they do not consistently change the proportion of LDL particles sizes. In fact, it is the blood triglyceride levels that change the number of small dense LDL particles. This makes sense because the lipoproteins also carry triglycerides, which are fats. The body needs more lipoproteins to carry a greater amount of triglycerides.
So, lowering triglycerides may help to change the LDL cholesterol profile. To do this, research shows we must avoid the low fat, high carbohydrate diet. In fact this diet is now being blamed for the epidemic of metabolic syndrome, type 2 diabetes and obesity.
Inflammation and oxidation also have a role. So, we should also keep inflammation low and provide plenty of antioxidant micronutrients. Eating, for example, an anti-inflammatory diet high in vegetables and fruits, lean meat, fatty fish, full fat dairy, eggs, nuts and seeds.
Other methods that show benefits in reducing high cholesterol include intermittent fasting and some specific strains of probiotic bacteria.
It is important to remember that not everyone responds to fat and cholesterol in the diet the same way. Have your cholesterol and triglycerides checked in heart health month!