Dietary polyunsaturated fatty acids and gastric cancer

Polyunsaturated fatty acids (PUFAs) are fatty acids, containing more than one double bond and have both anti-inflammatory properties and inhibit tumor progression effects as well as carcinogenic properties. There is inconclusive evidence regarding the effect of PUFA intake on gastric cancer in diverse populations. We, therefore, aimed to determine the association between PUFA intake and risk of gastric cancer in a hospital-based case-control study comprising 1182 incident cases of gastric cancer and 2965 controls in Vietnam. A semiquantitative validated food frequency questionnaire was used to derive PUFA intake. Unconditional logistic regression model was applied to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for the risk of gastric cancer in relation to PUFA intake. Overall, there was a dose-response inverse association between PUFA intake and gastric cancer risk (OR_{per-SD increment}=0.72, 95% CI: 0.65-0.79; P_trend<0.001). Compared with quintile 1 (the lowest quintile), the ORs and respective 95% CIs of gastric cancer for quintiles 2, 3, 4, and 5 of the PUFA intake were 0.65 (0.52-0.80), 0.51 (0.41-0.64), 0.47 (0.37-0.59), and 0.37 (0.28-0.48), respectively. A similar pattern was observed in both sexes and individuals aged <60 years and those aged 60 years or older. In summary, we found a risk reduction of gastric cancer in individuals with a higher intake of PUFA in the Vietnamese population, regardless of sex or age. Our findings have great implications for the prevention and control programs against gastric cancer in low-middle-income countries and similar limited-resource settings.