Meat consumption and the risk of type 2 diabetes: a systematic review and meta-analysis of cohort studies

Aims/hypothesis Diet is thought to play an important role in the aetiology of type 2 diabetes. Previous studies have found positive associations between meat consumption and the risk of type 2 diabetes, but the results have been inconsistent. We conducted a systematic review and meta-analysis of cohort studies of meat consumption and type 2 diabetes risk. Methods We searched several databases for cohort studies on meat consumption and type 2 diabetes risk, up to December 2008. Summary relative risks were estimated by use of a random-effects model. Results We identified 12 cohort studies. The estimated summary RR and 95% confidence interval of type 2 diabetes comparing high vs low intake was 1.17 (95% CI 0.92-1.48) for total meat, 1.21 (95% CI 1.07-1.38) for red meat and 1.41 (95% CI 1.25-1.60) for processed meat. There was heterogeneity amongst the studies of total, red and processed meat which, to some degree, was explained by the study characteristics. Conclusions/interpretation These results suggest that meat consumption increases the risk of type 2 diabetes. However, the possibility that residual confounding could explain this association cannot be excluded.