American scholars conducted a study pointing out that an important component of soy sauce is the isoflavones contained in soybeans, which can lower cholesterol levels in the human body and reduce the risk of cardiovascular diseases. The study also found that the proportion of soy sauce consumption in Asian countries is 30-50 times higher than in European and American countries, and the incidence of breast cancer and uterine cancer is relatively low, which may be related to adding a few drops of soy sauce in daily diets.
Interestingly, not long after, the UK also published a research report on soy sauce. This report pointed out that among more than 40 tested soy sauce products, about 10 contained excessive amounts of the carcinogen 3-MCPD. Researchers proved through experiments on rats that long-term intake of 3-MCPD can cause cancer, but it does not pose harm to humans.
Soy sauce is indispensable in the Japanese daily diet. In the past, soy sauce was considered one of the main factors contributing to stomach cancer in Japanese people, but two years ago, the University of Wisconsin in the United States overturned this claim. Researchers fed rats with both nitrosamines (a carcinogenic substance) and soy sauce, and the results showed that the more soy sauce consumed, the lower the chance of developing stomach cancer.
Soy sauce is mainly made from defatted soybeans, starch, wheat, and salt through fermentation and other processes. Soybeans are highly nutritious, and earlier studies have shown that soybeans and their products all have anti-cancer effects. High levels of estrogen in the human body can lead to breast cancer, while the plant-based estrogen contained in soybeans can effectively suppress the production of human estrogen, thereby having anti-cancer properties. Studies have also found that components such as lecithin in soybeans have certain therapeutic effects on preventing and treating cancer, especially breast cancer.