N-3 polyunsaturated fatty acids intake and risk of colorectal cancer: meta-analysis of prospective studies
A partir d'une revue systématique de la littérature (14 études prospectives, 8 775 cas), cette méta-analyse évalue l'association entre une consommation d'acides gras oméga-3 et le risque de cancer colorectal
Background : Growing body of laboratory evidence supports the beneficial effects of n-3 polyunsaturated fatty acids (PUFAs) on colorectal cancer (CRC) prevention. Epidemiologic studies investigating the relationship between n-3 PUFAs intake and risk of CRC, however, have been inconsistent. We aimed to clarify the relation by conducting a meta-analysis of prospective studies. Methods : Eligible studies were identified by searching PubMed database and by carefully reviewing bibliographies of retrieved publications. Summary relative risks (RRs) with their 95 % confidence intervals (CIs) were computed with a random-effects model. Subgroup, meta-regression, and dose–response analyses were performed to explore potential sources of heterogeneity. Results : A total of 14 prospective studies involving 8,775 cancer cases were included in the final analysis. Overall, total n-3 or marine PUFAs intake was not associated with risk of CRC (RR 0.99 and 1.00). However, there was a trend toward reduced risk of proximal colon cancer (total n-3 PUFAs: RR 0.83, 95 % CI 0.66–1.05; marine PUFAs: RR 0.81, 95 % CI 0.59–1.10) and a significant increased risk of distal colon cancer (total n-3 PUFAs: RR 1.26, 95 % CI 1.06–1.50; marine PUFAs: RR 1.38, 95 % CI 1.11–1.71). Furthermore, marine PUFAs intake accessed longer before diagnosis was associated 21 % reduced risk of CRC (RR 0.79, 95 % CI 0.63–1.00). Conclusion : Overall, this meta-analysis finds no relation between n-3 PUFAs intake and risk of CRC. The observed subsite heterogeneity within colon cancer and the possible effect modification by latency time merit further studies.