It can effectively lower "bad cholesterol"! It has always been written in the guidelines, but many people don't know it

We often see the words "phytosterols" on the outer packaging of some vegetable oils. Many people are not clear about what "phytosterols" are and what benefits they bring to health.

Figure: E-commerce platform

In this article, we will talk about plant sterols and see what benefits they have for health. Finally, we have compiled a variety of foods that can supplement plant sterols.

What are phytosterols?

The name "phytosterol" may be unfamiliar to many people, but it is actually present in many foods we eat, such as vegetable oils, grains, nuts, etc. This substance is currently recognized by the U.S. Food and Drug Administration and the European Commission as a safe and harmless bioactive substance, and has been used in food, cosmetics, medicine, industry and other fields.

Initially, plant sterols attracted attention because they came from chicken.

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In the 1950s, people discovered that phytosterols can reduce blood lipid levels in chickens fed with high cholesterol, and then phytosterols began to enter the field of scientists. It is a class of natural active ingredients widely found in plants, belonging to triterpenoid compounds, and is a precursor substance for the biosynthesis of various hormones, vitamin D and steroid compounds. Common ones include β-sitosterol, campesterol, stigmasterol and sitostanol.

Phytosterols and cholesterol have similar chemical structures and look very similar, except that the former are found in plants and the latter in animals. The absorption rate of cholesterol in the human body is relatively high, at 40%, while the absorption rate of phytosterols is relatively low, at an average of less than 5%. The absorbed phytosterols will bind to lipoproteins and then be transported to various parts of the body through the blood, while those that are not absorbed will be excreted from the body through feces.

What are the benefits of plant sterols for us?

Phytosterols are known as the "key to life" and are beneficial to our health.

1. Improve blood lipids

Plant sterols are very friendly to vascular health. A large number of human intervention studies have confirmed that plant sterols can lower the serum total cholesterol levels of normal adults, patients with hyperlipidemia, and patients with familial hypercholesterolemia.

This is because plant sterols and cholesterol have similar structures, so they can compete with cholesterol for targets, thereby inhibiting the intestinal absorption of cholesterol, thereby reducing the body's absorption of cholesterol; plant sterols can co-crystallize with cholesterol in the small intestine to form an insoluble precipitate, which is then excreted from the body with feces, reducing the body's absorption of cholesterol; moreover, plant sterols can regulate the activity of cholesterol transport-related proteins and enzymes to achieve a cholesterol-lowering effect.

Most importantly, the "Guidelines for Adult Hyperlipidemia Diet (2023 Edition)" issued by the National Health Commission of my country specifically emphasizes the need to eat more foods rich in plant sterols in the diet, and to consume about 2g of plant sterols per day. Studies have found that consuming 2g of plant sterols per day can effectively reduce the body's low-density lipoprotein cholesterol level (commonly known as bad cholesterol) by 10%, thereby reducing the incidence of coronary heart disease by 10% to 20%.

It should be noted that although plant sterols are very helpful in improving blood lipids, you should also pay attention to a diet low in saturated fat and cholesterol to better lower serum cholesterol levels and prevent and reduce the occurrence of cardiovascular diseases.

2. Improve insulin resistance and sugar metabolism

Especially for gestational diabetes, studies have found that plant sterols can improve the blood lipids of pregnant women while also improving their insulin resistance and sugar metabolism, which is also beneficial for reducing the incidence of low birth weight and hypoglycemia in newborns.

3. Reduce the risk of cancer

A meta-analysis of plant sterol intake and cancer risk included 11 randomized controlled trials and enrolled 16,763 subjects from the United States, Europe, and Asia. The results showed that there was a significant nonlinear negative correlation between plant sterol intake and cancer risk. A total dietary plant sterol intake of 500 mg/d may reduce the risk of cancer, especially gastrointestinal tumors. This may be related to the fact that high plant sterol intake affects cholesterol and bile acid metabolism.

Epidemiological studies have also found that increasing the intake of plant sterols in the diet has an inhibitory effect on cancer cells such as breast cancer, prostate cancer, lung cancer, ovarian cancer, gastric cancer, and intestinal cancer.

4. Anti-oxidation and anti-inflammatory

Phytosterols contain double bonds and alcoholic hydroxyl groups in their structure, which have certain antioxidant properties. They also have anti-inflammatory activity, can reduce inflammatory responses, and have an improving effect on inflammation of the colon, prostate, liver, bones and joints, etc.

How to take plant sterols?

Since plant sterols have so many health benefits, is there a recommended intake?

In 2000, the U.S. Food and Drug Administration (FDA) approved plant sterols to make such functional claims: Foods containing at least 0.65g of plant sterol esters, consumed twice a day, equivalent to 1.3g per day, as part of a diet low in saturated fat and cholesterol, can reduce the risk of heart disease.

my country's "Dietary Reference Intakes for Chinese Residents 2023 Edition" also recommends that the specific recommended value (SPL) of plant sterols for Chinese residents is 0.8g/d (1.3g/d for plant sterol esters), and the maximum tolerable intake (UL) is 2.4g/d (the UL of plant sterol esters is 3.9g/d).

However, residents in our country do not need to worry about excessive intake of plant sterols. According to the data of the "my country Residents Nutrition and Health Status Monitoring Report (2010-2013)", it is estimated that the average intake of plant sterols in the diet of Chinese residents is about 392.3 mg/d. Although this amount has improved compared with 2007, it is still far from the recommended intake.

In addition, which foods can provide plant sterols?

As the name "phytosterol" suggests, this ingredient comes from plant foods, mainly edible vegetable oils, grains, nuts, vegetables, fruits, beans and bean products, and tubers. Among them, the phytosterol content in vegetable oils is the highest, and it is the main source of phytosterol intake in the diet of Chinese residents.

Among the staple foods we eat, the phytosterol content of flour is higher than that of rice, and the more processed the rice is, the lower its phytosterol content.

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Phytosterol Content in Some Foods

Summarize:

Phytosterols are beneficial to health and have many physiological functions. Adequate intake of phytosterols can help us improve blood lipid health, reduce bad cholesterol levels, have certain anti-cancer effects, and reduce the body's inflammatory response.

At present, the daily intake of plant sterols by Chinese residents is not enough, and more efforts are still needed. For people with dyslipidemia problems, they can also consider consulting a doctor and taking plant sterol supplements.

References

[1] Chinese Nutrition Society. Dietary Reference Intakes of Nutrients for Chinese Residents (2023 Edition) [M]. People's Medical Publishing House. 2023.8

[2] Dietary Guidelines for Adults with Hyperlipidemia (2023 Edition)

[3] Li Yan, Jiang Minjie, Liang Qiang, Zhao Ling, Xiong Wei, Xuan Pu, Yao Yingzheng. Physiological functions and influencing factors of rapeseed oil phytosterols[J]. Sichuan Agricultural Science and Technology, 2023(7):90-93

Author: Xue Qingxin, registered nutritionist

Reviewer: Ruan Guangfeng, Director of Science and Technology Department, Kexin Food and Nutrition Information Exchange Center