This study used genetic variants as proxies for coffee consumption (i.e., Mendelian randomization) to examine cause-and-effect relationships with health markers of metabolic syndrome in men and women.

In women, coffee consumption was associated with 26% lower odds of elevated waist circumference. In men, genetically predicted higher coffee consumption was associated with 38% lower odds of elevated triglycerides but 64% higher odds of low HDL-C.

No associations were found for overall metabolic syndrome, high blood pressure, elevated fasting glucose, or other markers in either sex.

Can coffee improve metabolic health? Original paper