Relationship between coffee intake and risk of stroke

Observational epidemiological studies have reported a relationship between coffee intake and risk of stroke. However, evidence for this association is inconsistent and it remains uncertain whether the association is causal or due to confounding or reverse causality.

In a new study the investigators try to find the answer.

A meta‐analysis of genome‐wide association studies (GWASs) including 91,462 coffee consumers was used to identify instruments for coffee consumption. Summary‐level data for stroke, intracerebral hemorrhage, ischemic stroke (IS) and IS subtypes were obtained from GWAS meta‐analyses conducted by the MEGASTROKE consortium. MR analyses were performed using the inverse‐variance‐weighted (IVW), weighted‐median, MR Pleiotropy RESidual Sum and Outlier (PRESSO) test and MR‐Egger regression.

Genetically predicted coffee consumption (high vs. infrequent/no) was not associated with risk of stroke. Similarly, among coffee consumers, MR analysis did not indicate causal associations between coffee consumption (cups/day) and risk of stroke. However, in the subgroup analysis, we found weak suggestive evidence for a potential protective effect of coffee consumption on risk of small vessel ischemic stroke (SV‐IS), though the association did not reach statistical significance after correction for multiple comparisons.