Is Soy Good or Bad for You?

There are several controversies concerning soy and its safety which has led many individuals to avoid soy-based foods. Let’s discuss the good and bad effect of soy on our health.

            The soybean is a species of legume native to east Asia, widely grown for its edible bean, which has numerous uses. Traditional unfermented food uses of soybeans include soy milk from which tofu is made. Fermented soy foods include soy sauce, fermented bean paste and tempeh. Soy is abundant in protein, vitamins and minerals. Most vegetarians, to some extent, rely on soya as a major source of protein.

            Soy is good for the prevention of cardiovascular diseases. In 2017 a meta-study was published that revealed increase in soy intake can decease strokes, coronary heart disease and coronary vascular disease.

            Soy appears to be beneficial in the prevention and treatment of cancer.  A 2018 meta-analysis on the correlation between soy and prostate cancer reveals that soy intake has an inverse relationship to prostate cancer. Another research study conducted in 2017 involving 11,169 breast cancer patients concluded soy as a protective factor against breast cancer. One type of phytoestrogen called formononetin, a subtype of isoflavone found in soy does show evidence of increased risk. However, when taken as a whole product, the overall effect appears protective.

            Studies almost universally support the use of soy for the management of perimenopausal and menopausal symptoms. It contains phytoestrogens that can help reduce the hot flashes and other physical and psychological symptoms associated with menopause. Research was published in the Journal of Menopausal Medicine in 2017 that supported the beneficial effect of phytoestrogens on depression and anxiety in menopausal women. 

            Meanwhile, some studies point to soy milk intake prior to puberty leading to nutritional and developmental deficiencies. Soy milk is not recommended for infants and caution should be used in pre-pubescent children as it has an endocrine disrupting quality that may affect male reproductive development. However, it did not show a similar effect in human adult men.

            In conclusion, soy consumption can be a healthy choice with little or no risk to the health of the adults. Caution should be used in pre-pubescent children.  To maximize the overall health benefits, you need to eat soy in the natural way and avoid processed soy-based products. The best sources of natural soy would be edamame, tempeh and tofu. If you don’t eat soy, adding a small amount of it as a substitute for meat can be beneficial for your health.