(Integrative Medicine) - Soy has received much publicity as a food that can prevent or conversely, promote breast cancer, and consequently many women are unsure about whether to consume or avoid soy products. Numerous in vitro, animal, epidemiologic, and clinical trials have been conducted, but according to a review of soy and breast cancer studies published in the Journal of Nutrition, the data are conflicting and show both positive and negative results. Soy is considered a plant estrogen and there has been concern that higher estrogen levels may increase breast cancer risk. But Messina and Loprinzi point out that the role of estrogen in breast cancer is still unclear, and that the action of soy on breast cancer cells is complex. After evaluating the existing evidence, Messina and Loprinzi conclude that "no convincing data supports either claim" for soy's protective or harmful effects, and that women (both with and without breast cancer) who enjoy soy products should feel comfortable consuming them in moderation.

References

Messina MJ, Loprinzi CL. Soy for breast cancer survivors: a critical review of the literature. J Nutr. 2001;131:3095S-3108S.