Mechanism of cholesterol’s impact on the body

Cholesterol is an essential component of the body, playing a vital role in life, yet it can become a health risk when imbalanced. It belongs to the sterol group, a type of lipid (fat) with a special structure, appearing as a waxy substance, off-white substance. Cholesterol is part of cell membranes and helps the body produce sex hormones such as testosterone and estrogen, as well as vitamin D, which is crucial for bone health.

Sources of cholesterol

Cholesterol does not only come from food. In fact, about 80% of the body’s cholesterol is produced internally, mainly by the liver and partly by the intestines, while only about 20% comes from diet. This means that even without consuming cholesterol-containing foods, the body still synthesizes it for physiological needs.

Therefore, controlling cholesterol is not only about “eating less fat” but also about adopting a healthy lifestyle that helps maintain a balance between production, utilization, and elimination of cholesterol.

How cholesterol travels in the body

Cholesterol and triglycerides (a type of stored fat for energy) are insoluble in water, so they require “transport vehicles” in the blood, these are lipoproteins. Based on structure and function, lipoproteins are classified into:

• Chylomicrons: Transport cholesterol and triglycerides from food in the intestines to the liver and tissues.
• VLDL (very low-density lipoprotein): Produced by the liver, later converted into LDL.
• LDL (low-density lipoprotein): Carries most of the cholesterol to tissues. Excess LDL can penetrate artery walls, become oxidized, and form plaques that cause narrowing. LDL is therefore known as “bad cholesterol.”
• HDL (high-density lipoprotein): Collects excess cholesterol from tissues and blood vessels, returning it to the liver for processing or elimination. HDL has antioxidant and anti-inflammatory effects, reducing plaque buildup, hence called “good cholesterol.”

Health effects of cholesterol

At adequate levels, it maintains cell stability and supports essential bodily functions. However, when LDL is high and HDL is low, cholesterol becomes harmful, promoting plaque formation in arteries (atherosclerosis). This narrows blood flow and increases the risk of heart disease and stroke.

The concerning part is that high cholesterol rarely causes noticeable symptoms. Many people only discover it through blood tests or after complications have developed.

Cholesterol testing and monitoring

The only way to know your cholesterol level is through a lipid profile test, measuring total cholesterol, LDL, HDL, and triglycerides. The recommends:

• First test between ages 9–11, then again at 17–21.
• From age 20 onwards, if low risk, test every 4–6 years.
• If there’s a family history of heart disease, test more frequently.

Lifestyle-Based Cholesterol Control

Since the body produces most of its cholesterol, a balanced diet and healthy lifestyle habits are key to maintaining optimal cholesterol levels.

Below are seven essential strategies to keep blood lipids in check and protect heart health:

1. Maintain a healthy weight

Being overweight or obese increases LDL cholesterol and lowers HDL cholesterol. Excess body fat slows LDL clearance from the blood, allowing it to accumulate in artery walls. Losing just 5–10% of body weight can significantly improve lipid levels and reduce atherosclerosis risk.

2. Reduce saturated and trans fats

Saturated fats (found in red meat, whole milk, butter, animal fat) and trans fats (in fried foods, pastries, processed snacks) raise LDL and accelerate atherosclerosis. Replace them with healthy fats such as olive oil, canola oil, or avocado to support cardiovascular health.

3. Increase dietary fiber

Soluble fiber (abundant in oats, lentils, apples, pears) helps block cholesterol absorption in the intestines, lowering LDL. Aim for 25–30g of fiber daily to improve lipid profiles, support digestion, and regulate blood sugar.

4. Exercise regularly

Engage in at least 150 minutes per week of moderate activity (brisk walking, cycling, swimming) to boost HDL and lower LDL. Physical activity also improves circulation, lowers blood pressure, and supports weight control. All contributing to healthier cholesterol levels.

5. Quit smoking to protect blood vessels

Chemicals in tobacco smoke damage the endothelium (vessel lining), allowing LDL to infiltrate and form plaques. Just weeks after quitting, HDL levels may start to rise, lowering the risk of heart attack and stroke.

6. Limit alcohol intake

Alcohol increases triglycerides, another blood lipid that harms cardiovascular health when elevated. Excessive drinking also impairs the liver, which regulates cholesterol. Maximum recommended limits: up to 2 drinks/day for men, 1 drink/day for women.

7. Include plant sterols in your diet

Phytosterols are plant compounds structurally similar to cholesterol, competing for absorption sites in the intestines and reducing cholesterol uptake into the blood. They are found in vegetable oils, sunflower seeds, pumpkin seeds, and whole grains. Combining phytosterols with a low-saturated-fat diet enhances cholesterol control.