Introduction:
Worldwide, type 2 diabetes is a major health concern with numerous risk factors. In observational studies, cheese consumption has been linked to type 2 diabetes, however it is still unclear whether these relationships are causal. To ascertain these relationships, we performed a two-sample Mendelian randomization (MR) study.

Material and methods:
A summary of cheese intake statistics from UK Biobank and publicly available genome-wide association studies (GWAS) for type 2 diabetes from IEU OpenGWAS, FinnGen Biobank, EBI GWAS, and Biobank Japan, respectivel. The primary method was pooled meta-analysis with the inverse variance weighting method. The sensitivity analyses included MR-Egger regression, weighted median, weighted mode, and leave-one-out. MR estimations of causation were reported as odds ratios (OR) with 95% confidence intervals (CI).

Results:
In the pooled meta-analysis of the fixed and random effect model, the combined ORs for type 2 diabetes were 0.58 (95% CI: 0.50-0.68, P<0.001) and 0.50 (95%CI: 0.32-0.78, P=0.003) per standard deviation rise in the levels of cheese intake. Sensitivity analysis revealed no horizontal pleiotropy (all P>0.05) but heterogeneity (all P<0.05).

Conclusions:
We found that moderate consumption of beneficial cheese may reduce the risk of type 2 diabetes. These findings suggested that increasing cheese intake appropriate for humans may help prevent and control type 2 diabetes.