Soy milk is a widely loved health drink and also enjoys the reputation of "plant milk". Many people eat it for breakfast, one cup a day. Some people are concerned about the rumors that "soy milk can cause precocious puberty" and "people with gout cannot drink soy milk." They love soy milk but dare not drink it... What effects does soy milk have on the body? Here’s the answer!
Health Benefits of Soy Milk
1. Supplement protein
The protein content of soy milk is similar to that of milk, and both are high-quality proteins. Although the amino acid pattern of soy protein is not as good as protein from animal sources such as meat, eggs, and milk, it is also much stronger than cereals and vegetables.
2. Improve cardiovascular health
Soybeans contain soy isoflavones, which can regulate lipoprotein levels and help us reduce low-density lipoprotein cholesterol (commonly known as bad cholesterol) levels in the body and lower blood lipids. Some studies have mentioned that soy isoflavones can effectively resist the formation of atherosclerosis and play an important role in preventing and treating cardiovascular diseases. [2] The intake of soybeans and their products can reduce the risk of cardiovascular disease. [3] In addition, the potassium content in soy milk is quite good, which is very helpful in controlling blood pressure.
3. Regulate hormone levels
Soy isoflavones, as phytoestrogens, play an important role in maintaining hormone balance in the body. It can bind to estrogen receptors instead of estrogen when the body lacks estrogen and play the role of estrogen. It can also interfere with the combination of estrogen and estrogen receptors to play an anti-estrogenic role when the body has excess estrogen. [2]
4. Reduce the risk of breast cancer
Studies have shown that the intake of soybeans and their products can reduce the risk of breast cancer in premenopausal women and can also reduce the risk of breast cancer in postmenopausal Asian women. Meta-analysis data shows that a daily intake of 26.3 mg of soy isoflavones (equivalent to 15 to 50 grams of soybeans) can reduce the risk of breast cancer. [3]
5. Good for gut health
Soy milk contains oligosaccharides, such as raffinose, stachyose, etc., which are all prebiotics and can promote the proliferation of beneficial bacteria in the intestines and are beneficial to intestinal health. But they can also ferment and produce gas under the action of intestinal bacteria, which can cause bloating. This may not be friendly to people with poor gastrointestinal function, so drink less.
6. Prevent osteoporosis
To ensure bone health, it is not only necessary to absorb sufficient calcium, but the intake of soy products is also very important to prevent osteoporosis. A meta-analysis shows that soy isoflavones can significantly improve the bone density of the lumbar spine, hip, and femoral neck in menopausal women. Studies have also shown that if you can consume 82 mg of soy isoflavones (equivalent to 47 to 150 grams of soybeans) every day for 6 to 12 months, you can significantly increase the lumbar bone density of menopausal women. [3]
How much soy milk is suitable to drink?
Soybeans are the main raw material of soy milk. The "Dietary Guidelines for Chinese Residents" recommends that the general population eat 15 to 25 grams of soybeans and soy products every day.If you plan to rely on soy milk to consume soy products throughout the day, you can use 15 to 25 grams of soybeans and add about 300 ml of water to make 1 cup of soy milk.
Drinking soy milk every day has many health benefits, but it should be noted thatDon’t expect to drink soy milk to supplement calcium.
When 15 to 25 grams of soybeans are used to make soy milk, the calcium content is 29 to 47 mg. Many people also filter out the bean dregs after making soy milk, which will lead to further loss of calcium. Data from the "Chinese Food Composition Table" shows that the calcium content in soy milk is only 5 mg/100 grams, which is far behind that of milk, only 4.6% of milk.
Rumors about soy milk
1. Will your breasts become bigger if you drink soy milk?
Won't. Soy milk contains phytoestrogens, soy isoflavones, which are not equivalent to real estrogen. They mainly help us maintain the balance of estrogen in the body and will not cause breast enlargement.
2. Will children develop precocious puberty if they drink soy milk?
Won't. Drinking soy milk will not cause precocious puberty in children. To prevent precocious puberty in children, the most important thing to do is to control the child's weight and avoid excessive obesity.
3. Can’t soy milk be eaten with eggs?
Eat with confidence. There has been a popular saying among the people that eggs and soy milk are incompatible. The reason is that the trypsin inhibitor in soy milk will inhibit the digestion and absorption of protein in eggs. In fact, most trypsin inhibitors have lost their activity after soy milk is cooked, so there is no need to worry about inhibiting the activity of proteases or affecting the digestion and absorption of protein in eggs. Moreover, eggs are animal protein and soy milk is plant protein. Eating them together can improve the absorption and utilization of protein.
4. Can’t you add brown sugar to soy milk?
It's possible, but not recommended. Rumor has it that the organic acids in brown sugar will denature the protein in soy milk, affecting digestion and absorption. In fact, the organic acid content in brown sugar is not much, and even if you do not add brown sugar, you will encounter gastric acid when drinking soy milk, and the protein will also be denatured. Moreover, adding brown sugar to soy milk does not look good in color and will also increase the intake of added sugar, which is not good for health. It is best not to add it.
5. Can gout patients drink soy milk?
You can drink it, but you have to pay attention to the concentration. Patients with gout and high uric acid are most concerned about the purine content of food. Foods with a purine content of less than 30 mg/100g are considered low-purine foods. [4]
Although the purine content of soybeans is not low, when they are made into soy products such as soy milk and tofu, the purine will be lost or diluted. The purine content of soy milk is related to the concentration. The lower the concentration, the lower the purine content.If you have gout or high uric acid, you can drink low-concentration soy milk, such as 10%, 5%, and 2.5% soy milk.
However, some people may induce gout after eating soy milk or soy products. This can be determined based on their actual physical condition.
Do not drink homemade soy milk if it is not fully cooked!
Homemade soy milk must be thoroughly cooked before drinking, otherwise it may cause food poisoning. This is because there is a "false boiling" phenomenon in the process of cooking soy milk. Soy milk contains saponin. This component will produce a large amount of foam when heated to 80°C, giving the impression that the soy milk is "boiling". But in fact, the soy milk at this time is not cooked, and it still contains some anti-nutritional factors, such as trypsin inhibitors, lipoxygenase, phytoerythrocyte agglutinin, etc.
If you drink incompletely cooked soy milk, poisoning symptoms will appear within a few minutes or an hour, leading to nausea, vomiting, abdominal pain, and diarrhea. The key step to prevent soy milk poisoning: Don't turn off the heat when the soy milk is "falsely boiling", continue to simmer for more than 5 minutes, and then boil again for a while after the foam disappears.
In general, 1 cup of soy milk a day can bring many benefits to the body. It is recommended that everyone drink soy milk without added sugar and try to reduce the intake of added sugar. If you like sweet food, you can add 2 red dates or a small handful of wolfberry to improve the taste. In addition, homemade soy milk must be thoroughly cooked before drinking!
References
[1] Yang Yuexin. Chinese Food Composition List 6th Edition Volume 1[M]. Peking University Medical Press, 2018
[2] Zhang Cuifen. Review of research on soy isoflavones on cardiovascular diseases [J]. Chinese Food Additives, 2018, 29(9): 210-213
[3] Chinese Nutrition Society. Dietary Guidelines for Chinese Residents[M]. People's Health Publishing House. 2022
[4] Yang Yuexin, Ge Keyou. Chinese Nutritional Science Encyclopedia 2nd Edition (Volume 2) [M]. People's Medical Publishing House, 2019
[5] Yang Yuexin. Chinese Food Composition List 6th Edition Volume 2[M]. Peking University Medical Press, 2019