Vegetarians need to know: Nutritional value of soybeans

This is an automatically translated article.

The article was written by Dr. BS Phan Nguyen Thanh Binh - Head of the Department of Nutrition - Dietetics, Department of Pediatrics - Neonatology, Vinmec Central Park International General Hospital
Although many studies on the benefits of soy have shown that soy isoflavones, specifically genistein and daidzein, reduce the risk of cardiovascular disease, osteoporosis, breast cancer, and prostate cancer, the reality is that In fact, the processing of tofu and soy milk has largely eliminated the anti-cancer effects of genistein and daidzein - the main factors that make soybeans famous. And even using unprocessed soybeans, there's no reason to believe that soy alone has those benefits.
Many studies show that other legumes have similar chemical properties and health effects as soybeans. Only thing, the soybean processing industry has made soybeans stand out above all in the legume family.

1. Benefits of soybeans

Soybean products have been considered a part of typical diets in China, Japan, Indonesia,... and also in our country for many decades, because experience has shown a protective effect on the body. can avoid diseases of soybeans. Women after 45 years of age, using soy to replace meat and poultry can still provide enough protein and low fat, and can relieve symptoms of menopause: mood changes, thinning bone, low risk of cardiovascular disease,...
>>> Soy milk - "Viagra" for menopausal women

This is because soy is the main source of dietary isoflavones - a complex that has been studied to be associated with alleviation of postmenopausal symptoms (because of its structural similarity to endogenous estrogen and its effects from 1 /1,000 to 1/100,000 endogenous estrogens), cancer prevention (because soy contains 5 anti-cancer substances phytosterols, phytates, saponins, protease inhibitors, and isoflavones), slows down the process of osteoporosis (by increasing the bone density). mineral content in bones and increase bone density) and reduce the risk of cardiovascular disease (by reducing LDL - cholesterol in the blood),... Particularly, soybean oil contains about 61% polyunsaturated fatty acids, 24 % monounsaturated fatty acids, and less than 15% saturated fatty acids, can lower LDL - cholesterol in the blood and reduce the risk of cardiovascular disease.
Daily use of 25 grams of soy protein (containing 50 - 70mg isoflavones) helps lower blood cholesterol. Just 45 mg of isoflavones in perimenopause is sufficient to produce a biological effect. It is estimated that 100g of soy protein provides the same amount of natural estrogen as 1 pill.
Soybeans can reduce the secretion of endogenous estrogen, and suppress the strong hormone secretion. Therefore, soy is considered a protective factor for the development of breast cancer, which is considered to be related to hormonal effects.
Genistein in soy has the effect of preventing blood vessel formation, thus, limiting the proliferation of cancer cells, especially prostate and breast cancer cells.

2. Soybean: Outstanding anti-nutritional factor

Soybeans contain a large amount of substances harmful to the body, first of all, phytic acid, or phytates, found in the bran coat of nuts and beans, most commonly soybeans. Phytic acid blocks the absorption of certain minerals, including magnesium, calcium, iron, and zinc. In addition to their high content, soybeans are also very resistant to phytate degradation techniques such as long and slow cooking.

Soy also contains many enzyme inhibitors such as inhibiting the absorption of trypsin, and other enzymes necessary for protein digestion, making the stomach work exhausted, reducing protein absorption in the body, which can lead to deficiency chronic amino acid deficiency, and physical retardation.
In addition, soybeans contain hemagglutinin, a substance that causes red blood cells to stick together, leading to a decrease in oxygen absorption to distribute to cell tissues, leading to decreased heart function.
Conventional processing cannot completely neutralize these harmful antinutrients. Only soybean fermentation can neutralize both hemagglutinin and trypsin inhibitors.
Not to mention the possibility of being contaminated with some pesticides during cultivation, so the processing of soybeans must go through many complicated stages to remove anti-nutrients from the final product. Finally, soy protein in particular has become a key ingredient in most soy products, when soy is used to replace meat, milk and dairy products.
Thyroid function is also affected by soy consumption. Genistein and daidzein are recognized as anti-thyroid agents because they block the enzyme thyroid peroxidase during the synthesis of thyroid-stimulating hormone. The spread of goiter and hypothyroidism occurred in some subjects and there were many signs such as constipation, lethargy, and fatigue, even when dietary iodine intake was adequate.

3. Soy products should be eaten in moderation

The traditional Japanese diet, through centuries of trial and error, has found a way to use soybeans and still enjoy good health. They never ate whole soybeans or isolated soy protein, but mostly fermented soy products. Fermentation reduces the activity of trypsin and hemagglutinin inhibitors, whereas conventional cooking does not.
Currently, the food industry has produced many soybean derivatives such as: soybean meal, soy protein, partially hydrogenated soybean oil, ... in many product forms: cheese , milk, margarine, vegetable oil, butter, hotdogs, formula milk, soybean meal, etc. Soy derivatives have become a major ingredient in fast food and packaged foods.
However, soy should only be one ingredient in a diet rich in foods rich in minerals, vitamins, and other essential nutrients. If you have to be a vegetarian, you should eat soybeans a few times a week, you can use fried tofu covered with sesame sauce, and green vegetables.
It is obvious that soy milk cannot be the main food for babies. Many countries restrict the use of soy for children and pregnant women, except in cases of allergy to cow's milk (accounting for 3-4% of the population), soy-based formula is the savior.

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