The eagerly awaited results of the review of the safety of soy isoflavones have finally arrived. The European Food Safety Authority (EFSA) has found soy isoflavones at the levels typically found in food supplements are safe for post-menopausal women.
Dr Alicja Mortensen, Chair of the expert panel on Food Additives (ANS) commented on the results:
“The human data did not support the hypothesis of an increased risk of breast cancer – No effect was found on endometrial thickness and histopathological changes in the uterus when supplementing with 150mg/day of soy isoflavones for 30 months. After 60 months some non-malignant histopathological changes were reported. Thyroid hormone levels were not changed following intake of isoflavones from food supplements.”
“The evidence reviewed does not suggest there are harmful effects on the three organs considered for this assessment – mammary gland, uterus and thyroid gland. We considered studies testing doses of isoflavones that are typically found in food supplements targeted at menopausal women in the EU.”
The review also attempted to assess the safety of soy isoflavones for women during peri-menopause and also menopausal women with a history or family history of cancer, however there was not enough data available to assess this at the present time.
The EFSA found that most products recommended provide doses comparable to those the agency considered safe.
Isoflavones are naturally occurring substances found in soy, red clover and kudzu root among other sources. They are a class of natural compounds known as phytoestrogens (which are similar in shape to the oestrogen molecule and can bind to oestrogen receptors) that influence oestrogen receptor binding, and have antioxidants effects. Soy isoflavones can be considered an important supplement for those women seeking natural alternatives to HRT, as well as men and women of any age who want to enjoy the many health benefits.
Mortensen A et al. Risk assessment for peri- and post-menopausal women taking food supplements containing isolated isoflavones. EFSA Journal 2015; 13 (10): 4246 (342 pp). doi: 10.2903/j.efsa.2015.4246