The incidence of colorectal cancer has been reported to be lower in Asians than in Caucasians, even though rapid increases in Asian countries, particularly in Japan, have been noticed [1,2]. Higher soy food consumption by Asians than by Caucasians has been thought to be one of the possible reasons for the difference. A recently published prospective cohort study  evaluated the relationship between soy food intake and colorectal cancer risk in women in Shanghai, China. The study examined 68,412 women 40–70 years of age by assessing their usual soy food intake at baseline (1977–2000) and again at follow-up (2000–2002) through in-person interview with a validated questionnaire. During a mean follow-up of 6.4 years, 321 colorectal cancer cases were identified. The results showed that total soy intake was inversely associated with colorectal cancer risk. Each 5-g/day increase in intake of soy foods was associated with 8% reduction in risk (95% confidence interval (CI) 3–14%). Women in the highest tertile of intake had a risk of 0.67 (95% CI 0.49–0.90) compared with those in the lowest tertile (p for trend = 0.008). This inverse association was primarily confined to postmenopausal women. The authors concluded that consumption of soy foods may reduce the risk of colorectal cancer in postmenopausal women.
Chang Gung Memorial Hospital, Kaohsiung Hsien, Taiwan
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