So, is soy good for you? Soy has become very popular and has been pushed as a health food. We are lead to believe that it is a major component of the Asian diet, but this is not true. In Asian countries, soy is used more as a condiment and only in quantity after fermentation which reduces the danger. Soy was initially grown as a nitrogen fixer in crop rotation and not used as a food.

In 1913, soy was listed in the US Department of Agriculture (USDA) handbook as an industrial product - not as a food.

Let’s look at some of the reasons why soy is bad for your health.

Phytic acid in soy

Soy contains high levels of phytic acid, which is not neutralized by the usual preparation methods. High levels of phytic acid in soy reduce assimilation of calcium, magnesium, copper, iron and zinc. Vegetarians who consume soy as a major source of protein risk serious mineral deficiencies.

Haemagglutinin

The haemagglutinin in soy is a clot-promoting substance that causes red blood cells to clump together.

Vitamin D

Soy foods increase the body’s need for vitamin D. This is serious given that many people are already vitamin D deficient. Vitamin D is need by the body to fight cancer.

Vitamin B12

Soy contains vitamin B12 analogs. These are not absorbed and can actually increase the body’s need for vitamin B12. This is especially a problem for vegetarians who need to be more diligent in obtaining vitamin B12.

Trypsin inhibitors in soy

The trypsin inhibitors in soy interfere with protein digestion and may cause pancreatic disorders. Animal based tests with soy containing trypsin inhibitors showed stunted growth.

Aluminium

Soy foods may contain high levels of aluminium which is toxic to both the nervous system and kidneys.

Accelerated brain aging

A study by Dr White of Japanese Americans living in Hawaii, showed a significant statistical relationship between two or more servings of tofu a week and “accelerated brain aging”. Those participants who consumed tofu in mid-life had lower cognitive function in late life and a greater incidence of Alzheimer’s disease and dementia.

Phytoestrogens

The phytoestrogens in soy can disrupt endocrine function and have the potential to cause infertility and breast cancer in women.

Infants fed exclusively soy-based formula have up to 22,000 times more estrogen compounds in their blood than babies fed milk-based formula. This is the equivalent of at least five birth control pills per day. Premature development of girls has been linked to the use of soy formula, as has the under development of males.

Soy and cancer

The soy industry pushes soy as a cancer preventing food. On the contrary, soy contains toxins such as lysinoalanine and nitrosamines. Nitrosamines are highly carcinogenic. Laboratory rats fed soy develop thyroid cancer, pancreatic cancer and digestive cancers. Note that cancer preventing compounds are found only in fermented soy not in tofu, soy milk and other soy products.

References:

Alarcon P. et. al. Clinical trial of home available, mixed diets versus a lactose-free soy-protein formula for the dietary management of acute childhood diarrhea. Journal of Pediatric and Gastroenterol Nutrition. v.12 (2), Feb 1991.

Berk Z. Technology of production of edible flours and protein products from soybeans. FAO Agricultural Services Bulletin 97, Food and Agriculture Organization of the United Nations 1992.

Chandra R K. Five-year follow-up of high risk infants with family history of allergy who were extensively breast-fed or fed partial whey hydrolase, soy and conventional cow’s milk formulas. Journal of Pediatric and Gastroenterol Nutrition. 1997.

Jensen K. Chemical substances harmful for the endocrine system. Report to the European Parliament, July 23, 1998.

Katz S H. Food and Biocultural Evolution: A Model for the Investigation of Modern Nutritional Problems. Nutritional Anthropology, Alan R. Liss Inc., 1987.

Lonnerdal B. et. al. The effect of individual components of soy formula and cows’ milk formula on zinc bioavailability American Journal of Clinical Nutrition. Nov 1984.

Palmer G. The Politics of Breastfeeding. Pandora Press, London, 1993.

Setchell K D R. Simmer-Nechemias L, Cai J, Helibi J E. Exposure of infants to phyto-oestrogens from soy-based infant formula. Lancet 1997.

White, L. Association of High Midlife Tofu Consumption with Accelerated Brain Aging. Plenary Session #8: Cognitive Function, The Third International Soy Symposium, November 1999.