Association between dietary antioxidant vitamins intake/blood level and risk of gastric cancer
A partir d'une revue systématique de la littérature publiée jusqu'en avril 2013 (40 articles), cette méta-analyse évalue l'association entre la consommation ou le niveau sanguin de vitamines ou provitamines antioxydantes (vitamine C, vitamine E, β-carotène et α-carotène) et le risque de cancer gastrique
We aimed to systematically evaluate the association between dietary intake/blood levels of antioxidant vitamins (vitamin C, vitamin E, β-carotene, and α-carotene) and gastric cancer risk. Systematic literature searches were conducted until April 2013 in Pubmed and Embase to identify relevant studies. Either a fixed- or a random-effects model was adopted to estimate overall odds ratios (ORs). Dose–response, meta-regression, subgroup, and publication bias analyses were applied. Forty articles were finally included in the present study. Higher dietary intake of vitamin C, vitamin E, β-carotene, and α-carotene was inversely associated with gastric cancer risk (for vitamin C, pooled OR = 0.58, 95% CI 0.51–0.65; for vitamin E, pooled OR = 0.65, 95% CI 0.57–0.74; for β-carotene, pooled OR = 0.59, 95% CI 0.49–0.70; for α-carotene, pooled OR = 0.69, 95% CI 0.52–0.93). Subgroup analyses suggested the effects of these antioxidant vitamins were different in gastric cancer subtypes. As indicated by dose–response analysis, a 100 mg/day increment of vitamin C intake conferred an OR of 0.78 (95% CI 0.67–0.90); a 15 mg/day increment of vitamin E intake conferred an OR of 0.79 (95% CI 0.66–0.94); and a 5 mg/day increment in β-carotene intake conferred an OR of 0.80 (95% CI 0.60–1.04). No significant association was observed between blood vitamin C, α-tocopherol, γ- tocopherol, β-carotene and α-carotene levels and gastric cancer risk. In conclusion, dietary intake of vitamin C, vitamin E, β-carotene and α-carotene was inversely associated with gastric cancer risk while no such association was observed for blood levels of these antioxidant vitamins, thus the results should be interpreted cautiously.