Cholesterol, only 20% is produced through food… Can it be lowered by changing diet?

One of the concerns of people with high cholesterol is whether they can lower their levels without taking medication. According to Harvard Health Publishing, a health media outlet run by Harvard Medical School in the United States, changing your diet can help lower your cholesterol levels, but the effect is not very big. You can also try certain supplements (health functional foods), but they are not very effective, so you should consider them carefully.

There are three ways to lower bad cholesterol (LDL cholesterol) levels: diet, taking supplements (dietary supplements), and taking prescription drugs such as statins. Dr. Christopher P. Cannon (preventive cardiology) of Harvard Medical School cautioned, “Many people still don’t know this, but only about 20% of blood cholesterol (total cholesterol) comes from food. For most people, dietary cholesterol doesn’t have as big of an impact as you might think.”

About 80% of the cholesterol in the blood is synthesized in the liver, and only about 20% is made from food intake. In healthy people, if cholesterol intake through food increases, the ratio synthesized in the liver decreases to about 70%, and the ratio of total cholesterol produced through food increases to about 30%.

It is difficult to significantly lower LDL cholesterol with food…““We need to reduce saturated fat and increase unsaturated fat.”

However, Dr. Cannon said, “It should be noted that most of the cholesterol in the general diet comes from animal foods such as meat and dairy products that are high in saturated fat,” and “Since saturated fat increases bad cholesterol (LDL cholesterol), it should be consumed in small amounts.”

Other dietary changes are also important. Replace saturated fats with unsaturated fats (vegetable oils, avocados, fatty fish, etc.). Eat plenty of plant foods rich in fiber (vegetables, fruits, beans, whole grains, especially oats). These foods help lower cholesterol levels by preventing cholesterol from being absorbed in the intestines. For example, if you frequently eat cheeseburgers, ice cream, etc. and then gradually change to a healthier diet, you can noticeably lower your LDL cholesterol (low-density lipoprotein cholesterol). However, if you are already maintaining a healthy diet, you may not notice much of a difference even if you change your diet a little.

“Some people see their LDL cholesterol levels drop after changing their diet, while others don’t,” Dr. Cannon said. “But even if you don’t lower your LDL cholesterol by a lot, a healthy diet is good for your cardiovascular health.” For example, compounds in unprocessed, whole foods reduce inflammation, which helps prevent plaque buildup.

There are many claims on the market that supplements (health supplements) can help lower LDL cholesterol levels and improve cardiovascular health. However, Dr. Cannon said, “There are only a few supplements that help lower LDL cholesterol levels, and even those are not very effective.” Supplements such as psyllium husk powder, plant sterols, and red yeast rice are among the more helpful.

““Psyllium husk, plant sterols, red yeast rice… somewhat effective in lowering LDL cholesterol”

Psyllium husk is a plant that grows in countries such as India and Iran. The powder made by processing the seed husk is called psyllium husk powder. Psyllium husk powder is a fiber supplement and is known as a treatment for constipation. It comes in various forms such as capsules. The powder is mixed with liquid to make a thick gel. Psyllium husk absorbs bile acids and cholesterol and excretes them from the body during bowel movements. The recommended daily dose is 5-10 g. According to the research results published in the Journal of Nutrition (April 2024), eating psyllium husk daily for 1-2 months can lower LDL cholesterol levels by an average of about 6 mg/dL. This figure is about 4.6% of the health standard (less than 130 mg/dL).

Plant sterols are compounds found in the cell membranes of plants, including nuts, soybeans, peas, and rapeseed (the source of canola oil). They are similar in structure to cholesterol. Eating these foods can help limit the amount of cholesterol your body can absorb. Many foods are available with added plant sterols. Plant sterols can also be purchased in capsule form. Previous studies have shown that taking 2 grams of plant sterols daily for eight weeks or more can lower LDL cholesterol levels by up to 10%. However, a recent, strictly controlled trial over four weeks found that plant sterols only reduced LDL cholesterol by 4.4%.

According to a research team at Harvard Medical School, red yeast rice contains monacolin K, the same active ingredient in the prescription cholesterol-lowering drug lovastatin. Red yeast rice is red rice made by steaming white rice with a specific yeast (Monascus purpureus). The study found that taking a supplement containing 4-10 mg of monacolin K can lower LDL cholesterol levels by 20-25%. However, in a recent strictly controlled trial over a period of four weeks, red yeast rice only reduced LDL cholesterol by 6.6%.

Dr. Cannon said, “There have been quite a few cases of patients lowering their LDL cholesterol with safe and inexpensive psyllium husk.” The problem with plant sterols and red yeast rice, as with all supplements, is that there are no regulatory standards for the active ingredients. The amount of active ingredient varies from product to product. If you are going to take these products, it is best to choose a brand that has been tested and verified by a company (ConsumerLab.com) that is overseen by a group of physicians.

Statin-type cholesterol medications can lower LDL cholesterol by 25-55%… Drug side effects are a problem

So what about the effects of the drugs? Statin cholesterol medications contain active ingredients that reduce the amount of cholesterol your body produces and increase your liver’s ability to remove cholesterol from your blood. These drugs can lower LDL cholesterol levels by 25 to 55 percent. “Just because you have high LDL cholesterol doesn’t mean you should take a statin,” says Dr. Cannon. The ultimate goal is to lower your risk of heart disease. Factors such as age and health can affect your risk.

Dr. Cannon said, “The American Heart Association’s risk calculator can help you manage your cholesterol.” The calculator provides advice on managing your LDL cholesterol and heart disease risk factors. Consulting with your doctor based on this information can help prevent and treat the disease. According to the calculator recommendations, taking a moderate-strength statin is recommended.

For those who are reluctant to take statins because of the side effects of the drugs, a ‘coronary calcium score’ can help make a scientific decision. If the coronary calcium score is 116, it means that the coronary arteries are significantly blocked by plaque. A score of zero (0) is normal. “If the coronary arteries are this blocked, the LDL cholesterol level should be lowered to less than 70 mg/dL to effectively prevent further plaque buildup,” said Dr. Cannon. The normal range for LDL cholesterol is usually less than 130 mg/dL, but this means that the management and treatment goals for LDL cholesterol levels may vary from person to person depending on the condition of the coronary arteries.

In any case, cholesterol medications are much more effective than some foods and supplements. However, medications can have various side effects. That is why scientific and rational choices are very important.