Is soy dangerous?
THE news surrounding soy or soy substitutes has for the most part been positive. But though it is promoted as a healthy alternative to milk, soy has been claimed to be higher in phytoestrogens — plant-derived compounds that can be bad for your health. Research indicates that soy has the potential to cause adverse effects on the body: It can increase the risk of developing breast cancer, it can damage your thyroid, it blocks mineral absorption in the human digestive tract, and is loaded with trypsin inhibitors, which will lead to stomach cramps, diarrhoea, bleeding and pancreatic problems.
However, Kirk Bolton, public relations officer at Jamaica Association of Professionals in Nutrition and Dietetics (JAPINAD), says it is difficult to validate the dangers of soy because most of the studies related to it are inconclusive.
“Soy has received negative reviews because sufficient research work wasn’t done to elucidate the evidence to support or oppose past claims of soy increasing the risk for cancers or having a negative effect on sexual development, especially concerning the male reproductive system. It was once held that the male child should not consume high quantities of soy due to the presence of isoflavones or phytoestrogens — oestrogen-mimicking compounds which could possibly affect the male characteristics. Isoflavones are chemically similar to oestrogen, but this type of oestrogen-mimicking compound is considered to be a weak form,” he explained.
Bolton said new studies suggest the following:
1. Soy consumption neither causes early sexual development nor has a negative effect on the male reproductive system.
2. Soy consumption does not increase the risk of developing breast cancer. On the contrary, it is suggested that it may help to prevent breast cancer and is associated with reduced risk of mortality and recurrence of cancer in patients with cancer.
3. It is the position of the American Cancer Association that the risk of developing breast, prostate and uterine cancers (and possibly other cancers) may be reduced by consumption of traditional soy foods such as tofu.
On the other hand, Bolton said that a study conducted in 2014, according to a published issue of the Journal of the National Cancer Institute, concluded that several genes that encouraged cancer cell growth were turned on in women who were given soy protein.
“This suggests that soy consumption may increase the growth of existing cancer cells in comparison to those who didn’t consume soy. This study involves women who were recently diagnosed with stage one or stage two breast cancer between 2003 and 2007. Biopsy of the breast tissues before and after the removal of the breast was compared, and it showed that several genes that encouraged cell growth were turned on in the women who had consumed soy protein,” he said.
Bolton further pointed out that the study did not look at whether soy does or does not reduce the risk of breast cancer, or whether consuming soy had any effects on the women who did not have breast cancer or those with non-cancerous lesions.
Moreover, he said the conclusion of such research did not recommend that women should avoid soy, but that soy should be consumed in moderation, like any other food items.
Bolton added that it would also be prudent for women to limit their intake of soy if any members of their family have cancer or if they themselves are currently diagnosed with cancer.
“The recommended intake of soy is one to three servings daily, with one serving being approximately a half-cup,” he said.
Bolton advised that it is best to consult a nutritionist or dietitian if you have concerns about soy products.
“These practitioners are the experts in the science of nutrition and dietetics; they are qualified to advise you on how to eat properly, and they teach you how to use your foods to meet your health objectives,” he declared.
