Cholesterol: why it should be kept under control

Cholesterol is a very important steroid lipid for the body. It is, in fact, a component of cell membranes, regulating their fluidity and permeability.

It is contained in hemoglobin and bile salts and is the precursor of vitamin D and male and female steroid hormones, such as testosterone and progesterone.

It is especially abundant in the brain, bile and blood. But some of the forms present in the blood can be a great enemy of health: hypercholesterolemia, ie too high levels of “bad” cholesterol, is a powerful cardiovascular risk factor, in the sense that it increases the likelihood of suffering a heart attack.

The good and the bad

Only 10-20% of the cholesterol in our blood comes from food. Mostly, in fact, it is produced by the body, especially in the liver.

Being a lipid molecule it is not soluble in water and its transport in the blood, which is an aqueous solution, can only take place thanks to the binding with the so-called apolipoproteins.

From this association derive three different types of lipoprotein: HDL (high density lipoprotein), LDL (low density lipoprotein) and VLDL (very low density lipoprotein).

The function of the latter is not yet well understood, while it is known that HDL transports cholesterol from tissues to the liver, where it is broken down, and LDL allows the path from the liver to the tissues.

During the journey, LDL, which has a high affinity for the artery wall, can promote the deposit of cholesterol. This gives rise to the formation of thickening, atherosclerotic plaques or atheromas, which reduce the diameter of the arteries, hindering blood flow.

Conversely, HDL removes excess cholesterol. For this reason we talk about good cholesterol (HDL) and bad cholesterol (LDL). What is really important is not, therefore, to have low levels of total cholesterol, but a good level of HDL cholesterol, so as to decrease the likelihood of plaque formation.

If you want to know how exactly diet counts in cholesterol control, listen to the interview with Empoweressence cardiologist Claudio Panciroli.

How much does it matter in heart attack

When an artery, due to atherosclerosis, can no longer transport blood as it should the areas of the body downstream of that vessel remain without oxygen and nutrients.

If the narrowing artery is one of those that carry blood to the heart, the risk of suffering a heart attack or angina pectoris soars.

The level of severity of the situation is measured by the so-called cardiovascular risk index (CRF), i.e. the ratio of total cholesterol to HDL. In men this value must be less than 5, while in women the upper limit is 4.5. All factors that increase HDL cholesterol are, therefore, positive, even if they are accompanied by an increase in total cholesterol.

However, HDL and LDL levels should not be considered the primary cause of artery occlusion. These events, in fact, involve the development of inflammation of the artery wall that recalls lymphocytes, which, in turn, promote the deposition of cholesterol and other substances that form plaques.

Nor, even less, should we fall into the error of believing that cholesterol is solely responsible for cardiovascular diseases: smoking, hypertension, overweight, sedentary lifestyle and diabetes are other important risk factors.

However, it is clear that keeping CRF under control helps to greatly lower the risk of cardiovascular disease.

A genetic predisposition, advancing age or a diet too rich in foods high in cholesterol can cause CRF values to increase alarmingly. In these situations only a balanced diet, the reduction of overweight, regular aerobic physical activity and, possibly, the use of drugs can help to bring the CRF below the alert values.