DIETARY HABITS AND STOMACH-CANCER IN SHANGHAI, CHINA

Stomach cancer remains the second leading cancer in incidence in Shang hai, China, despite its decline over the past 2 decades. To clarify ri sk factors for this common malignancy, we conducted a population-based case-control study in Shanghai, China. Included in the study were 1,1 24 stomach cancer patients (age 20-69) newly diagnosed in 1988-1989 an d 1,451 controls randomly selected among Shanghai residents. Usual adu lt dietary intake was assessed using a comprehensive food frequency qu estionnaire. Adjusted odds ratios (ORs) and 95% confidence intervals ( CIs) were estimated using logistic regression models. Risks of stomach cancer were inversely associated with high consumption of several foo d groups, including fresh vegetables and fruits, poultry, eggs, plant oil, and some nutrients, such as protein, fat, fiber and antioxidant v itamins. By contrast, risks increased with increasing consumption of d ietary carbohydrates, with odds ratios (ORs) of 1.5 (95% confidence in terval [CI] 1.1-2.1) and 1.9 (95% CI 1.3-2.9) in the highest quartile of intake among men (p for trend = 0.02) and women (p = 0.0007), respe ctively. Similar increases in risk were associated with frequent intak e of noodles and bread in both men (p = 0.07) and women (p = 0.05) aft er further adjustment for fiber consumption. In addition, elevated ris ks were associated with frequent consumption of preserved, salty. or f ried foods, and hot soup/porridge, and with irregular meals, speed eat ing and binge eating. No major differences in risk were seen according to subsite (cardia vs. non-cardia). Our findings add to the evidence that diet plays a major role in stomach cancer risk and suggest the ne ed for further evaluation of risks associated with carbohydrates and s tarchy foods as well as the mechanisms involved. (C) 1998 Wiley-Liss, Inc.