Soy Nutrition Institute
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Aug 01, 2013

Soyfood intake reduces lung cancer risk

Epidemiologic research has consistently shown soy intake to be inversely related to lung cancer risk. However, as noted by Wu and Liu, from Vanderbilt University School of Medicine, methods and results from these studies, especially the measurements of soyfood across studies/populations, have been variable. The measurements of soy intake varied from gram per day of soybean products consumption in Chinese, gram per day of tofu products consumption in Singaporean, to μg per day of isoflavone intake in U.S. populations. Furthermore, there was great variability among the studies in the definitions of high and low exposure. To improve comparability of these different exposure levels and investigate the association between soyfood intake and lung cancer risk, Wu and Liu conducted a meta-analysis to explore in detail the association of consumption of soyfoods, using estimated daily grams of soy protein consumption, with risk of lung cancer. Their meta-analysis included 11 epidemiologic studies. Overall, the inverse association between daily gram of soy protein intake and risk of lung cancer was borderline statistically significant (odds ratio = 0.98, 95% confidence interval = 0.96 to 1.00); the inverse association was statistically significant in nonsmokers (odds ratio = 0.96; 95% confidence interval = 0.93 to 0.99) and stronger than in smokers (P for difference <0.05). Their findings suggest that the consumption of regular tofu (100 g) could decrease risk of lung cancer by about 24%, 28%, and 13% among nonsmokers in Japan, China, and Singapore, respectively. Wu SH, Liu Z. Soy food consumption and lung cancer risk: a meta-analysis using a common measure across studies. Nutr Cancer 2013;65:625-32.