Consumption of garlic and risk of colorectal cancer:An updated meta-analysis of prospective studies

AIM:To conduct an updated meta-analysis of prospective studies addressing the association between garlic consumption and colorectal cancer.METHODS:Eligible cohort studies were identified by searching MEDLINE(PubMed) and screening the references of related articles published up to October 2013.Meta-analyses were conducted for colorectal cancer in relation to consumption of raw and cooked(RC) garlic and garlic supplements,separately.The summary relative risks(RR) with 95%CI were calculated using fixedeffects or random-effects model depending on the heterogeneity among studies.RESULTS:A total of 5 prospective cohort studies were identified.In contrast to the previous meta-analysis,no significant associations were found between consumption of RC garlic(RR:1.06; 95%CI:0.95-1.19) or garlic supplements(RR:1.12; 95%CI:0.96-1.31) and risk of colorectal cancer.A non-significant protective effect of garlic supplement intake against colorectal cancer was observed in females(RR:0.84; 95%CI:0.64-1.11),but the opposite was the case in males(RR:1.24; 95%CI:0.96-1.59).CONCLUSION:Consumption of RC garlic or garlic supplements is not significantly associated with reduced colorectal cancer risk.