Addressing Public Misconceptions of Cholesterol!
Myron Yau, HK BioTek Nutritionist
Many people are threatened by hypercholesterolemia, including both LDL-cholesterol and total blood cholesterol level. Therefore, a number of people believe these cholesterols are ‘evils’ and useless in our body. However, are these true?
Classification of Cholesterol In Blood
Cholesterol in blood can be classified into two groups, low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C). The former one is responsible for distributing cholesterol from liver to other cells all over other parts of the body for their normal metabolisms. Because of its sticky nature, LDL-C may easily attach some of its cholesterol onto the wall of the blood vessels, narrowing them and finally leading to various atherosclerosis or stroke. On the other hand, the latter one for carrying away easily attached cholesterol from LDL-cholesterol on the wall of blood vessels, reducing the risk of cardiovascular diseases due to the narrowing of the blood vessels. Thus, LDL-C is also named as ‘bad’ cholesterol while HDL-C as ‘good’ cholesterol.
The Use of Cholesterol in Human Body
Actually, cholesterol is vital to us. It is one of the main components of cell membranes, especially in the neural cell membranes, which maintains the fluidity of the membrane. Also, it is used to synthesize epinephrine, sex hormones, vitamin D and bile salts. Under certain special circumstances, for example starvation, cholesterol can be used to generate energy and maintain body temperature. Hence, if the body is in the lack of cholesterol, many associated health problems may appear.
The influence of hypercholesterolemia
As mentioned above, LDL-C is prone to stick onto walls of blood vessels, causing arterial blockages in different parts of the body. When the arteries are blocked to a certain extent, the blood supplies to the cells downstream are cut off and so as oxygen and nutrients supplies. In the lack of essential nutrients and oxygen, these cells die and hence resulting in various cardiovascular diseases, such as hypertension, heart disease, stroke, etc.
Appropriate strategies of hypercholesterolemia patients
Most of the people misunderstand that the only way to combat hypercholesterolemia is to reduce the exogenous cholesterol from diet. However, it is not the case. It is because two third (~70%) of cholesterol in blood is synthesized endogenously by the liver while the rest (~30%) is absorbed from daily diet. In order to decrease the cholesterol level in blood effectively, the main focus should be put on the former one. To reduce the endogenous biosynthesis of cholesterol in liver, decreasing the intake of cholesterol-rich foods is not the primary way. On the contrary, choosing ‘good’ fats to eat should be the principal way. The good fats are monounsaturated and polyunsaturated fatty acids. The sources of former one are olive oil, peanut oil, avocado, macadamia nuts, hazelnuts, almonds, cashew nuts, pecan, etc; those of latter one are walnuts, fish oil of deep sea fishes, flaxseeds, sunflower seeds, etc. The good fats can decrease the level of ‘bad’ cholesterol in blood. Moreover, monounsaturated fatty acids can increase level of ‘good’ cholesterol in blood. Oppositely, ‘bad’ fats are saturated fats and trans fat. Saturated fats are from animal subcutaneous fats, butter and some plant oils, including coconut oil and palm oil; Trans fat is come from hydrogenated plant oils, pastry margarine, foods with pastry coatings, etc. These two kinds of fats increase the blood level of ‘bad’ cholesterol and trans fat can even lower the blood level of ‘good’ cholesterol, greatly raising the risk of cardiovascular diseases.
A number of researches indicate that regular exercise, mental relaxation, relieving stress and good eating habits can lower ‘bad’ cholesterol and raise ‘good’ cholesterol level. Then, the hypercholesterolemia patients can be turned into a ‘kind-hearted’ person.