Dietary intake of selected micronutrients and gastric cancer risk: an Italian case-control study.

BACKGROUND: A high consumption of non-starchy vegetables and fruits likely decreases the risk of gastric cancer, but no specific constituent of plant foods has been consistently identified to explain this association. PATIENTS AND METHODS: We considered several micronutrients and minerals in an Italian case-control study conducted between 1997 and 2007, including 230 patients with incident, histologically confirmed gastric cancer and 547 matched controls, admitted with acute conditions. Micronutrients computation was based on a validated and reproducible food frequency questionnaire, through an Italian food composition database. We estimated odds ratios (ORs) using conditional logistic regression, adjusted for energy intake and selected covariates. RESULTS: We found decreased ORs for the highest versus lowest quartile of vitamin E (OR=0.50), alpha-carotene (OR=0.52) and beta-carotene (OR=0.42) intake. Gastric cancer was directly associated with sodium, with ORs of 2.22 for the second, 2.56 for the third and 2.46 for the fourth quartile of intake. No significant relation emerged with iron, calcium, potassium, zinc, vitamin C, thiamin, riboflavin, niacin, vitamin B6, folate, vitamin D, retinol, beta-cryptoxanthin, lycopene and lutein plus zeaxanthin. CONCLUSIONS: Our data support a favourable effect on gastric cancer of vitamin E and selected carotenoids and a detrimental effect of sodium even at intermediate levels of intake.