Dietary patterns and gastric cancer risk : a sistematic review and meta-analysis

To assess the role of diet and the risk of gastric cancer (GC), we conducted a systemic review of the literature through Medline and Embase databases, and a meta-analysis of epidemiological studies evaluating the association between dietary patterns and gastric cancer risk. Of the 16 papers identified, 9 derived dietary patterns through an a posteriori method, 5 through a priori scores, and 2 used both approaches. Among the studies based on a posteriori dietary patterns, the RRs for overall GC ranged from 0.4 to 0.6 for the favorable ones, and from 1.7 to 3.0 for the unfavorable ones; among the studies based on a priori dietary patterns, the RRs for overall GC ranged from 0.2 to 0.7 for favorable ones, and from 1.8 to 6.9, plus an outlier RR of 41.2, for the unfavorable ones, for the highest versus the lowest category. Of these studies, 8 were included in our meta-analysis, as they provide a similar method to derive dietary patterns. A favourable role on GC emerged for the “Prudent/healthy”, with an odds ratio (OR) of 0.75 (95% confidence intervals, CI: 0.63-0.90), for the highest versus the lowest category. Similar results emerged by anatomical subtype. An unfavourable role on GC emerged for the “Western/unhealthy” dietary pattern, with an OR=1.51 (95% CI: 1.21-1.89). This association was weaker for the distal/NOS (not otherwise specified) category (OR=1.36) compared to the cardia GC (OR=2.05)