Zhang Wenhong: The most effective drug is immunity! Eat 3 types of food during the war epidemic, strong immunity

There are several high-frequency words in the COVID-19 epidemic: protection, isolation, immunity. Immunity is called "the best doctor in the world". Professor Zhang Wenhong, director of the Department of Infectious Diseases at Huashan Hospital Affiliated to Fudan University, once said: "The most effective drug is human immunity."

Why is it that someone who has been in contact with someone infected with the new coronavirus is infected, but some people are fine? This may be related to immunity.

Do you really understand immunity? During the epidemic, what can we eat to boost our immunity?

1. What is immunity?

We all know immunity, and boosting immunity can fight disease. However, what exactly is immunity, I am afraid few people can say clearly.

In fact, the so-called immunity is a physiological function of the human body. Relying on the immune system, the human body can identify "own" and "enemy". When it finds antigens such as viruses and bacteria from the outside that have entered the human body, or damaged cells and tumor cells produced by the body itself, the immune system will be dispatched to clear it .

The immune system has three lines of defense to achieve immune function. The first is the skin, mucous membranes and secretions, which play the first line of defense when invaders invade . The second line of defense is phagocytosis, inflammatory response, antibacterial proteins, temperature response, and strikes against invaders. The last line of defense is immune organs and immune cells that can play a more powerful role in repelling invaders quickly and violently.

The new coronavirus and immunity are two opposing sides. For a virus to invade and cause an infection, it needs to break through these three lines of defense.

2. Why do some people get infected when they come into contact with the virus, while others are fine?

In terms of immunity, different people have different immunity. Whether it is a high-risk infection group or an already infected group, people with strong immunity have an advantage. So, what are the factors that affect immunity?

1. Age

Age is related to immunity. With age, the body's immune system will continue to degenerate.

3-6 months after birth is the time when the human immune system is at its weakest, and then it begins to improve slowly, reaching a peak around the age of 25. After the age of 30, immunity begins to decline . After the age of 65, the trend of declining immunity will become more and more obvious.

2. Diet and nutrition

Dietary nutrition also has a certain impact on immunity. Boston immunologist Terry B. Strom has studied that the main reason for the decline of immunity may be malnutrition .

Because leptin secreted by fat cells enters the bloodstream, it travels through the brain and signals the brain about energy storage. If you are undernourished, leptin levels drop, possibly causing the brain to temporarily shut down the functioning of the immune system.

3. Sleep

Sleep not only affects the mental state, but also has an important impact on the immune system.

A study found that people who slept less than 5 hours a day had an 82% higher risk of being infected with the flu virus than those who slept 7-8 hours a day.

4. Smoking

During the epidemic, some people claimed that smoking can prevent the COVID-19 virus infection, which is not true.

Harmful substances in cigarettes can destroy the activity of immune cells and reduce immunity. Studies have shown that non-smokers have a five-fold lower risk of contracting the flu virus than smokers.

Since strong immunity can prevent viruses, does stronger immunity mean better for the body?

The answer is not absolute . Some rejection reactions, autoimmune diseases, hypersensitivity reactions, immunodeficiency diseases, etc. are actually related to abnormal or high immunity of the body. In this case, the immune system should be boosted with caution .

It should be emphasized that immunity is a systematic project and cannot be improved just by eating, and it cannot be improved all at once.

Gao Jian, director of the Nutrition Department of Zhongshan Hospital Affiliated to Fudan University, believes that the key to improving immunity is to achieve a balanced diet, healthy lifestyle, and scientific nutritional supplements.

3. Low immunity, there are these manifestations

Generally speaking, the immunity of the vast majority of people is normal. Yu Xinhua of the Borstel Research Center in Germany once said that instead of improving immunity, most people need to consider not reducing immunity.

However, how can we know whether our immune system is high or low? The direct consequence of low immunity is to increase the probability of infection, so in daily life, there are three obvious manifestations:

First, there is the common cold. Most colds are caused by viruses, the most common being rhinovirus. Under normal circumstances, the immune system can suppress the viruses that cause colds and prevent them from making waves. However, if the body is overtired, the temperature changes greatly, etc., the immune system may not be able to control the virus, causing a cold.

Second, the lips are foamy. Blisters at the corners of the mouth are mostly cold sores, caused by herpes simplex virus type I (HSV-I). Most people have this virus in their bodies, and most of the time it's suppressed by the immune system and won't mess up. However, in the case of weakened immunity, the herpes simplex virus can become active, get out of control, and multiply in the epithelial cells of the mucous membrane of the corner of the mouth, resulting in the occurrence of herpes.

Third, the wound is difficult to heal. Low immunity will affect the speed of wound healing, such as biting the lip, small skin wounds, etc., which have been difficult to heal.

If a person often has the above three phenomena, he may need to consider restoring his immunity. If you are a person with a weakened immune system, you need to improve your immune system.

4. During the war "epidemic", what to eat to improve immunity?

From the perspective of diet, the nutrients that are closely related to immunity are protein, vitamin A, vitamin C, vitamin E, iron, zinc and selenium. We can maintain or improve our immunity through dietary supplements and nutritional elements.

Specifically, what should be done?

First, get high-quality protein . Foods rich in high-quality protein are milk, beans and soy products.

The protein content of milk is about 3%, the digestibility is more than 90%, and it also contains calcium, phosphorus, magnesium, potassium and other minerals. It is recommended to consume 300 grams of milk or equivalent dairy products per day.

Beans such as soybeans, green beans, black beans, and soy products such as soy milk, tofu, and bean sprouts are also rich in high-quality protein. It is recommended to consume 30-50 grams of soybeans or an equivalent amount of soy products per day.

Second, supplement foods rich in vitamins A, E, and C.

Foods rich in vitamin A include animal liver , including sheep liver, pig liver, chicken liver, duck liver, etc.

Foods rich in vitamin E include vegetable oils, germs of plant seeds, nuts, beans and cereals .

Foods rich in vitamin C include green peppers, spinach, hawthorn, citrus, grapefruit, kiwi, strawberries , etc. Especially with fresh vegetables and fruits. It is recommended to consume an average of 300-500 grams of vegetables per day, half of which is fresh dark leafy vegetables, and an average of 200-350 grams of fruit per day .

Finally, eat foods rich in iron, zinc, and selenium in moderation .

Foods such as animal blood, liver, and red meat are rich in iron, and foods such as shellfish, red meat, and animal offal are rich in zinc, which can be eaten in moderation.

In the important stage of epidemic prevention and anti-epidemic, we need to cooperate actively, do a good job in protection, and at the same time improve our own immunity, reduce the risk of virus infection, and not cause chaos to the country.

References

[1] "I want to improve immunity, but do you know what immunity is? ". China Medical Tribune. 2021-10-08

[2] "Low immunity can easily lead to bacterial and viral infections, and even induce major diseases! 》.Human Health. 2020-11-08

[3] "National Nutrition Week | What to eat during the war epidemic to improve immunity? Experts tell you the answer". Healthy China. 2020-05-21

[4]Prather AA, et al. Association of Insufficient Sleep With Respiratory Infection Among Adults in the United States[J]. JAMA Intern Med. 2016;176(6):850–852.

[5]Lawrence H, et al. Cigarette smoking and the occurrence of influenza - Systematic review[J]. J Infect. 2019;79(5):401–406.

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