International Vegetarian Day | Veganism is bad for your health

November 25th of every year is World Vegetarian Day. This festival originated from the "World Meatless Day" initiated by India in 1986 and gradually developed into a global festival. It is said that on this day, many slaughterhouses around the world will stop slaughtering, and canteens in hospitals and prisons will provide vegan food. With the hype of vegetarian lovers such as celebrities and Internet celebrities, copywriting recommending a vegan diet is overwhelming and has become a dietary guide for many people who want to lose weight or maintain health. Huang Yubin, deputy chief physician of the Department of Encephalopathy at Guangzhou Huangpu District Chinese Medicine Hospital, pointed out that it is desirable to eat a vegan diet occasionally, but a long-term vegan diet will be detrimental to your health.

Definition and classification of vegetarianism

"Vegetarianism generally refers to not eating meat. It has a specific term in nutrition or medicine, which is a diet habit that mainly relies on plant proteins such as cereals, fruits and vegetables, beans and nuts. It can be divided into full vegetarian and semi-vegetarian. Full vegetarianism is pure vegetarian, and semi-vegetarianism includes lacto-vegetarianism, ovo-vegetarianism, lacto-ovo-vegetarianism and pescatarianism, etc." Huang Yubin explained that some people do not eat red meat, but eat fish and other seafood, which is a semi-vegetarian.

"Another type is defined by time, whether it is continuous vegetarianism or intermittent vegetarianism." He said that now more people choose intermittent vegetarianism, such as normal diet for breakfast and lunch, and completely vegetarian dinner; or normal diet on Monday, Wednesday and Friday, and pure vegetarian diet on Tuesday, Thursday and Saturday. We can also call it flexible vegetarianism.

Vegetarianism is not the same as intermittent fasting

In the past decade, with the improvement of people's living standards and the continuous changes in dietary structure, the proportion of overweight/obese people has continued to increase, and has gradually developed towards younger people. At this stage, overweight/obesity has become a major public health problem that seriously affects the physical and mental health of the Chinese people. Therefore, many medical experts have proposed the light fasting method of weight loss. Are light fasting and vegetarianism the same thing? Huang Yubin denied it: "Vegetarianism and light fasting are not quite the same. Vegetarianism generally refers to not eating meat, but light fasting in nutrition refers to intermittent energy restriction, a diet pattern of fasting or restricting energy intake for a certain period of time." He said that weight loss is to control energy intake, and no medical expert would recommend a completely vegetarian method to lose weight. The scientific light fasting diet still pays attention to balanced nutrition and comprehensive food. It can be one meal a day or two or three days a week to eat less or fast.

Can you get a full nutritional balance by eating vegetables of different colors every day?

The reporter has seen some celebrities and internet celebrities say in videos or TV shows that they eat more than a dozen kinds of vegetables a day, and that if they eat six or seven kinds of vegetables of different colors every day, they can get enough nutrition. They also introduce daily vegetarian recipes and cooking methods online, and teach everyone how to make meat taste with vegetarian ingredients. Huang Yubin laughed at this statement. He said that nutrition pays attention to balanced diet, which includes cereals, vegetables, meat, milk and eggs, etc. It is impossible to achieve comprehensive nutrition by relying solely on plant foods such as fruits and vegetables.

"Humans are omnivores and need a variety of foods. A completely vegetarian diet will definitely have an impact on health. Not eating meat means missing the trace elements, vitamins and high-quality protein contained in meat." He said that protein is divided into high-quality protein and ordinary protein. High-quality protein generally refers to animal protein. Plants also have protein, but except for bean protein, other plant proteins are not as good as animal proteins in absorption and utilization. Similarly, for many trace elements such as calcium, zinc, iron, etc., there are also in vegetables and fruits, but in fact they are not well absorbed. There are also some vitamins such as vitamin B12, which are mainly derived from animal ingredients. Therefore, for long-term vegan people, they may lack vitamin B12, and vitamin B12 deficiency may lead to megaloblastic anemia, and iron deficiency may lead to iron deficiency anemia. In addition, it will lead to decreased resistance, susceptibility to colds, and may also cause endocrine disorders and other problems.

"For semi-vegetarians who just don't eat red meat, the situation is much better. Because fish and other seafood are white meat, they are rich in animal protein and various trace elements and vitamins, and they can also achieve a relatively balanced diet nutrition," Huang Yubin added.

Vegans are advised to supplement with high-quality protein and vitamins

Huang Yubin suggested that among plant proteins, soy protein is a relatively high-quality protein. Vegans can eat more soy products to supplement high-quality protein. There are some fortified flours on the market that are specially added with a variety of trace elements and vitamins. Such ingredients can be used. You can eat some tofu in moderation because tofu contains gypsum, which is rich in calcium. In addition, you should eat some dark-colored vegetables that are rich in iron. "Because the trace elements in vegetables are not easy to absorb, you can use some tricks to help absorption. For example, the absorption of iron can be enhanced under the action of acidic substances. Therefore, you can eat more fruits rich in vitamin C to help absorption, such as citrus, strawberries, kiwis, etc."

As a doctor at a traditional Chinese medicine hospital, Huang Yubin pointed out that many Chinese medicinal materials are plant-based and contain a variety of trace elements, but it is not recommended to use Chinese medicinal materials to supplement the nutritional deficiencies of vegans. This is unscientific and difficult to do.

Vegan diet may affect brain health

"A completely vegetarian diet will lead to nutritional imbalance. Even if you supplement it through various means and drugs, it is still different from a normal diet, so it is inevitable that it will affect brain health." Huang Yubin told reporters that eating too much meat can easily lead to cardiovascular and cerebrovascular diseases. Eating more vegetables can reduce the risk of disease because cholesterol and fat intake are reduced. However, excessive vegetarianism can also lead to cardiovascular and cerebrovascular diseases, because vitamin B12 deficiency can lead to hyperhomocysteinemia, which can easily lead to stroke. In addition, insufficient intake of vitamin B12 and iron can also lead to anemia, which can cause mental disorders, depression, anxiety, memory loss and other symptoms.

Since the elderly are a high-risk group for the three highs, many online articles recommend that they eat vegetarian food. However, Huang Yubin, who often goes to the senior citizen university to teach the elderly, believes that the elderly should eat healthy and balanced nutrition, and exercise properly to lower the three highs. They cannot adopt a completely vegetarian diet, otherwise it is easy to induce diseases such as stroke.

In the latest "Dietary Guidelines for Chinese Residents (2022)", eight principles for a balanced diet are proposed: Principle 1: Diverse foods and reasonable combinations; Principle 2: Balance eating and moving, and maintain a healthy weight; Principle 3: Eat more fruits and vegetables, milk, whole grains, and soy; Principle 4: Eat fish, poultry, eggs, and lean meat in moderation; Principle 5: Less salt and oil, control sugar and limit alcohol; Principle 6: Eat regularly and drink enough water; Principle 7: Know how to cook, choose, and read labels; Principle 8: Share meals with serving chopsticks to prevent waste. Among them, in Principle 4, it is recommended to consume eggs and lean meat in moderation, an average of 120 grams to 200 grams per day; it is best to eat fish twice a week or 300 grams to 500 grams, eggs 300 grams to 350 grams, and livestock and poultry meat 300 grams to 500 grams; eat less deeply processed meat products; eggs are rich in nutrients, and the yolk should not be discarded when eating eggs; fish should be given priority, and fatty, smoked, and pickled meat products should be eaten less. Huang Yubin emphasized: "We should establish a correct diet concept. Now that living conditions are better, we should reduce the intake of high-fat, high-cholesterol and other animal foods, and focus on increasing the consumption of plant foods. We must not go from one extreme to another. A vegan diet is not advisable!"

Produced by Guangdong Science and Technology Newspaper Media Center

Gatekeeper expert | Huang Yubin, deputy chief physician of the Department of Encephalopathy, Guangzhou Huangpu District Hospital of Traditional Chinese Medicine

Text | Mai Bo

Correspondent | Li Na