Cholesterol
Cholesterol is a waxy, fat-like substance that occurs naturally in all parts of the body. There is actually a substance called cholesterol, but what is commonly called âcholesterolâ is a group of cholesterol-related substances called lipids, of which two are most important: âbad cholesterolâ = âlow-density lipidsâ (LDL) and âgood cholesterolâ = âhigh-density lipidsâ (HDL).
Cholesterol is not a foreign, harmful substance, whose presence in the body should be avoided. It is an excessive concentration of cholesterol what is harmful. We may be afraid of eating eggs or meat due to the cholesterol presence there, but there are good reasons why cholesterol is in eggs and meat, in the first place. Cholesterol is a component of every human cell membrane, and it is necessary precursor for bile and for steroid hormones. It also participates in transmission of signals by nerves. High cholesterol may even protect against infections [1] Only part (20-50%) of the body cholesterol comes from food, the other part is synthetized by the body, in the liver. If the food contains too little of cholesterol, own production of cholesterol increases to compensate for that deficiency. The body needs some cholesterol to work properly but if there is too much in the blood, it can stick to the walls of the arteries. This is called plaque. Plaque can narrow the arteries or even block them causing atherosclerosis. Atherosclerisis is unquestionably a killer of millions of people, but what causes atherosclerosis is not so clear. Most commonly, cholesterol is blamed for that, but this corelation is controversial at best, since it has never been proven by research completely free of influence of special-interest groups; more of this is discussed below.
High levels of cholesterol in the blood can increase the risk of heart disease. Cholesterol levels tend to rise as a person gets older. There are usually no signs or symptoms that a person has high blood cholesterol, but it can be detected with a blood test. A person is likely to have high cholesterol if members of their family have it, if they are overweight, or if they eat a lot of fatty foods.
The best way to lower cholesterol is by exercising more and eating more fruits and vegetables.[2] That is true, but many people who exercise, eat fruits and vegetables, still have high cholesterol level, experience heart attacks, strokes, and even die, as the result of atherosclerosis. For this reason doctors prescribe statins to millions of patients. Physicians recognize two types of cholesterol; HDL (high-density lipoproteins) and LDL (low-density lipoproteins). HDL is considered to be "good" cholesterol while LDL is considered to be "bad" cholesterol. Some physicians maintain that for good physical health the ratio between these two be considered rather than the sum, so that a high cholesterol level is not considered an adverse health issue if the ratio between the two (LDL:HDL) is low. Typically the ratio is about 4:1.
Atherosclerosis and the cholesterol issue are not equally pervading around the world. This is an ethnic-related phenomenon, related somehow to national eating cultures, but not exclusively to them. It is mostly Americans who care so much about cholesterol, yet atherosclerosis kills Americans by millions. So called âFrench paradoxâ points out to the well-known fact that many other nations (the French, Swiss, Russians and a numbrer of others) do not have a massive atherosclerosis problem even though their diet is very âunhealthyâ by American standards.