Is Cholesterol Really Bad?

Julia Cheung, HK BioTek Intern

Many people think that cholesterol is harmful, so they try to avoid it. X Do you know what cholesterol is? Is cholesterol really harmful to our health? Let’s probe into it together!

What Is Cholesterol?

Cholesterol is actually a type of lipid. Only about 20% of cholesterol in human body is absorbed from food. The rest is made by our own liver. Those who are healthy can rely on the self-regulatory mechanism in the body to help control the level of cholesterol. After consuming food high in cholesterol, the body will produce less cholesterol. In contrast, when the content of cholesterol in food is low, the body will produce more cholesterol in order to satisfy our needs.

The Functions of Cholesterol

Cholesterol is an important constituent of cell membranes. It is also fundamental for the synthesis of bile, vitamin D and some hormones (e.g. cortisol and testosterone). A lot of people think that cholesterol is harmful, but it is very crucial for the body. It can help the body function properly, so it is one of the necessary elements for maintaining health.

Many people have heard of “good” cholesterol and “bad” cholesterol. Since cholesterol is important for human body, then why can it be good and bad at the same time? The functions of these two types of cholesterol are as below:

· Low-density lipoprotein cholesterol (LDL-C): It can easily accumulate in the walls of blood vessels, thereby increasing the risk of developing heart disease. It is also known as “bad” cholesterol.

· High-density lipoprotein cholesterol (HDL-C): It can help to collect and carry the “bad” cholesterol in the walls of blood vessels back to the liver, thereby decreasing the risk of developing heart disease. It is also known as “good” cholesterol.

High Cholesterol

When there is too much “bad” cholesterol and too less “good” cholesterol in blood, cholesterol may build up in the walls of blood vessels. Over time, this may lead to atherosclerosis (hardening of arteries), thereby increasing the risk of getting heart disease and stroke. If we want to maintain good health, we must control the level of cholesterol in blood.

Table 1. Recommended cholesterol levels for adults

Type of cholesterol	Recommended level for adults (mmol/L)
Total cholesterol (TC)	< 5.2
Low-density lipoprotein cholesterol (LDL-C)	< 2.7*
High-density lipoprotein cholesterol (HDL-C)	> 1.0
Triglycerides	< 1.7

*Patients with cardiovascular disease or diabetes should maintain an LDL-C levelof 1.8mmol/L or below.

How to Prevent High Cholesterol?

The level of cholesterol in our body is affected by heredity, eating habits and lifestyle. Although genetic factors cannot be altered, we can moderate eating habits and lifestyle in order to control the level of cholesterol. The following eating habits and lifestyle are what we should have:

- Avoid consuming food high in cholesterol and saturated fat (e.g. egg yolk, high-fat meat, cuttlefish, dried scallop, offal, etc.)

- Eat more food rich in fiber (e.g. vegetables, fruits, whole grains, legumes, soy food, etc.)

- Maintain an ideal body weight.

- Do more aerobic exercise (e.g. brisk walking, cycling, jogging, etc.) with a cumulative total of at least 30 minutes every day (or 3 hours every week).

- No smoking.

- No drinking or drink less.

If the above ways cannot help to control the level of cholesterol effectively, you should follow doctors’ instructions to take medication.

References

1. https://www.cfs.gov.hk/english/multimedia/multimedia_pub/multimedia_pub_fsf_ 33_02.html

2. https://www.union.org/new/tc_chi/health_info/health_articles_common1.htm

3. hkah.org.hk/getimage/index/action/images/name/LMC_-_High_Cholesterol.pdf

4. https://www.fhs.gov.hk/tc_chi/health_info/woman/30105.html