This food is closely related to immunity, but many people may not eat enough

Many people have heard the saying "There is no life without protein". Protein is very important to our body, accounting for about 16% of body weight. From our hair to our heels, there is protein everywhere. It can be said that it is the material basis of all life, and all manifestations of life are essentially the manifestation of protein function.

If the protein intake in the diet is insufficient, it will lead to protein deficiency in the body, which will lead to a decline in health. Paying attention to changes in the body may help us judge our own protein situation and make up for it if it is deficient.

So, how do you tell if you are lacking in protein? What happens to your body when you lack protein? Which foods are rich in protein? This article will answer these questions one by one.

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Good immunity

Can't live without protein

The concept of "protein" was first proposed by a Dutch scientist in 1839. Protein is an important substance that constitutes our body's cells, skin, tissues, and organs. It can maintain the stability of the body's internal environment and provide energy for our body. The key is that it is closely related to the body's immune function and participates in the body's immune regulation.

Human antibodies include immunoglobulins, white blood cells, lymphocytes, macrophages, etc., which can help us resist the invasion of foreign microorganisms and other harmful substances. If the body lacks protein, it will affect the normal function of these antibodies, which will lead to a decrease in the body's immunity, and it will not be able to fight the "invading bad guys", and it will be easy to get sick.

Therefore, in order to maintain good immunity, everyone needs to eat enough protein. The "Chinese Residents' Dietary Nutrient Reference Intake 2023 Edition" recommends that the recommended daily protein intake for men and women aged 18 to 64 in China is 65 grams and 55 grams respectively; the protein demand for the elderly over 65 years old will be slightly higher, and the recommended daily protein intake for elderly men and women is 72 grams and 62 grams respectively.

Check yourself! If you have these 7 symptoms

Maybe you’re not eating enough protein.

Since protein is so important to health, how do you determine whether your body is lacking protein?

If you don't take in enough protein in your diet for a long time, it will cause protein deficiency in your body, which may lead to many discomfort symptoms. In addition to feeling that your immunity is weakened and you are prone to illness, if you have the following conditions, it may also be caused by protein deficiency in your body.

1

Poor hair quality, a lot of hair loss

Protein is the main component of hair, accounting for 60% to 95%, mainly keratin. When protein is deficient, hair will not only grow slowly, but also change color, become brittle and easy to fall off.

2

Dry skin, wrinkles

The skin contains a large amount of proteins, such as the well-known collagen, which combines with other extracellular matrix components such as hyaluronic acid, reticulin and elastin to form a fibrous network that maintains the overall integrity of the skin.

Protein supplementation plays a certain role in maintaining skin structure. Protein-energy deficiency can lead to dermal waste, reduced collagen density and tissue, which in turn can affect skin condition, causing dry skin, poor elasticity, and wrinkles.

3

Slow wound healing

Wound healing requires the participation of protein. Protein deficiency can lead to obstacles in capillary formation, fibroblast proliferation, proteoglycan synthesis, collagen synthesis and wound remodeling. At the same time, it will also affect the immune system, weaken the phagocytic function of leukocytes, and increase the risk of wound infection.

4

Muscle relaxation

Protein is the main component of muscle. Sufficient protein can ensure the body's muscle content. If protein intake is insufficient, it will inevitably affect the body's muscle synthesis, resulting in muscle loss, weakened physical strength and other problems. If it is severely deficient, it will also increase the risk of muscle atrophy.

5

Low mood

Protein is an important component of neurotransmitters and can affect brain function and mental health. Currently, more and more studies are beginning to focus on the relationship between dietary protein intake and the risk of depression. There is a negative correlation between protein intake and the risk of depression, which means that insufficient protein intake can easily make people feel low and depressed, especially for adult men under 45 years old.

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6

Excessive appetite

A study published in Obesity, the official journal of the Obesity Society, found that a strong appetite may be related to a lack of protein in the body. Researchers at the University of Sydney analyzed the nutrition and physical activity survey data of 9,341 adults with an average age of 46.3 years. The results showed that participants who consumed less protein during the day ate more food throughout the day, had a stronger appetite, and consumed more calories than those who consumed enough protein.

This may be because adequate protein can reduce hunger and takes a long time to digest, so the feeling of fullness is more lasting.

7

Body edema

Adequate protein can act as a buffer in the body, maintaining the osmotic pressure and acid-base balance of body fluids. If there is a severe lack of protein, it will cause edema in the body.

Protein Supplement Food Comparison

Collect these 10 best ingredients!

There are many common foods that contain protein, but the quality is different. They can be divided into complete protein, semi-complete protein and incomplete protein. Among them, complete protein is high-quality protein, which is highly absorbed and utilized by the human body. It contains a full range of essential amino acids, which can not only maintain the health of adults, but also promote the growth and development of children. This type of food is the most recommended food for protein supplementation.

The expert working group of the Chinese Nutrition Society conducted a nutritional evaluation of common foods in our daily lives in 2020. It mainly conducted a comprehensive evaluation based on two indicators: "protein content" and "protein amino acid score", and finally listed the top ten "top ten high-quality protein foods".

1

egg

Eggs are very nutritious. In addition to providing high-quality protein, one egg a day can also supplement us with B vitamins, vitamin A, vitamin E, lecithin, calcium, potassium, selenium and other nutrients, and most of the nutrients are found in the yolk. Therefore, it is best not to throw away the yolk when eating eggs!

Eating one egg can provide about 7 grams of protein.

2

milk

Milk contains protein and is a good source of calcium. In addition, milk also contains nutrients such as vitamin B2, potassium, zinc, and selenium.

Drinking 300~500 ml of milk can supplement about 10~17 grams of protein.

3

Fish

Fish is generally high in protein, low in fat, and rich in n-3 unsaturated fatty acids. Mackerel, salmon, yellow croaker, and sea bass are especially recommended. While supplementing protein, they can also intake more DHA, which is good for eye and cardiovascular health.

Eating 50 grams of fish can provide about 9 grams of protein.

4

Shrimp

Shrimp meat is low in calories, fat, and high in protein. It is also a good source of DHA and can be eaten safely even by people who are trying to lose weight.

Eating 50 grams of shrimp meat can provide about 8.5 grams of protein.

5

chicken

Chicken has a high protein content, especially chicken breast, which has a protein content of 24.6g/100g and a fat content of only 1.9g/100g. It is also rich in the mineral potassium. While supplementing protein, it is also friendly to blood pressure control.

Eating 50 grams of chicken breast can provide about 13 grams of protein.

6

duck

Although the protein content of duck meat is not as good as that of chicken, it is still good, and the content of polyunsaturated fatty acids is richer than that of chicken.

Eating 50 grams of duck breast can provide about 8 grams of protein.

7

Lean beef

Among livestock meats, beef has a lower fat content, especially beef tenderloin, which is more friendly to those who need to control their weight. In addition to protein, beef also contains B vitamins, iron, potassium, zinc and other nutrients.

Eating 50 grams of beef tenderloin can provide about 11 grams of protein.

8

Lean lamb

Mutton has a unique taste, and the mutton smell mainly comes from the short-chain fatty acids it contains. Removing as much fat as possible before cooking the mutton and blanching it before cooking can greatly reduce the mutton smell.

Eating 50 grams of lean lamb can provide about 10 grams of protein.

9

Lean pork

Lean pork is not only rich in protein, but also has a good potassium content, which is nearly twice that of lean beef and lean lamb. As long as you pay attention to the cooking method with less oil and salt, it is still helpful to stabilize blood pressure.

Eating 50 grams of lean pork can provide about 10 grams of protein.

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10

Soybean and its products

Soybeans include soybeans, black beans and green beans. Soy products made from soybeans are also good, such as tofu, dried tofu, tofu skin, dried tofu, soy milk, etc. This type of food not only provides high-quality protein, but also contains soy isoflavones, which are polyphenol compounds and a type of phytoestrogen, which helps maintain the stability of human estrogen.

Eating 15 to 25 grams of soybeans or corresponding soy products every day can supplement about 5 to 9 grams of protein.

The Dietary Guidelines for Chinese Residents recommends that Chinese residents eat one egg, 300-500 ml of milk, 15-25 grams of soybeans and their products, 40-75 grams of livestock and poultry meat or aquatic products such as fish and shrimp, and 10 grams of nuts, 200-300 grams of grains, and 50-100 grams of potatoes every day. Following this recommendation, the body's daily protein needs can be fully met.

Summarize

Lack of protein in the body will cause many health problems. If you want to be healthy, it is recommended that you get enough protein every day. Especially high-quality proteins such as meat, eggs, milk and beans, don't ignore them!

References

[1] Sun Changhao. Nutrition and Food Hygiene. 8th edition. People's Medical Publishing House. 2018

[2] Wu Xiaolin, Xu Ping, Zhang Yali, et al. Research progress on hair metabolomics and proteomics of human characteristics[J]. Chinese Journal of Biotechnology, 2022, 38(10): 3638-3647. DOI: 10.13345/j.cjb.220526

[3] Lin Lihong, Lu Tao. Research progress on the relationship between skin aging and nutrients[J]. Bulletin of Dermatology, 2023, 40(5): 533-538

[4] Yao Bo, Liu Wanhong, Fu Ya. Research progress on nutritional factors affecting wound healing[J]. Genomics and Applied Biology, 2012, 31(06): 640-643.

[5] Li Yan. Study on the relationship between protein intake and depressive symptoms in adults[D]. Qingdao University, 2020.DOI:10.27262/d.cnki.gqdau.2020.000241

[6]Grech, Amanda et al. "Macronutrient (im)balance drives energy intake in an obesogenic food environment: An ecological analysis." Obesity (Silver Spring, Md.) vol. 30,11 (2022): 2156-2166. doi:10.1002/oby.23578

[7] Yang Yuexin, Ge Keyou. Chinese Nutrition Science Encyclopedia 2nd Edition[M]. People's Medical Publishing House, 2019

[8]https://www.cnsoc.org/knowledge/9520102019.html

[9] Yang Yuexin. Chinese Food Composition Table 6th Edition Volume 2[M]. Peking University Medical Press, 2019

Planning and production

This article is a work of Science Popularization China-Starry Sky Project

Produced by: Science Popularization Department of China Association for Science and Technology

Producer｜China Science and Technology Press Co., Ltd., Beijing Zhongke Xinghe Culture Media Co., Ltd.

Author: Xue Qingxin, registered nutritionist

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

Planning丨Zhong Yanping

Editor: Zhong Yanping