Soy Foods & Cancer Survival

Previously reporting an inverse association between soy food intake and lung cancer risk among nonsmoking women, Gong Yang, MD, Vanderbilt University School of Medicine (Tennessee, USA), and colleagues investigated the role of soy foods to beneficially impact the overall survival of patients with lung cancer.  In the present study, the researchers included 444 women with incident lung cancer identified from the Shanghai Women’s Health Study, which tracked the incidence of cancer in about 75,000 women. Women were surveyed at enrollment and reassessed 2 years later, for their dietary habits – including what types, and how much, soy foods they ate.   The women who were diagnosed with lung cancer during the study were divided into three groups according to the amount of soy food they had eaten before their lung cancer diagnosis. The highest intake levels of tofu were equal to about 4 ounces a day, while the lowest soy consumers ate less than 2 ounces daily.  During the study, more than 300 of the lung cancer patients died, with data revealing that 60% of the women in the highest soy-eating group and 50% in the low soy consumer group were alive twelve months after diagnosis. A patient’s risk of death decreased with increasing soy intake, but leveled off at 4 ounces of daily tofu consumption.  The study investigators conclude that: “this study suggests, to the best of our knowledge for the first time, that, among women with lung cancer, prediagnosis intake of soy food is associated with better overall survival.”