Coffee and tea intake and stroke events among West Africans: findings from the SIREN Study

Coffee and tea intake is rising in parts of Africa, but evidence on associations with stroke is limited. This study examined the relationship of coffee and tea intake with stroke among Africans recruited in the matched case-control Stroke Investigative Research and Educational Network (SIREN) study in West Africa.

Using data of 7,368 case-control pairs (1:1 matched for age, sex and ethnicity) from the SIREN study from multiple sites in Nigeria and Ghana, we evaluated the adjusted odds ratio (aOR) and 95% confidence intervals (CIs) for stroke (verified based on cranial computed tomography or magnetic resonance imaging) by level of coffee or tea intake (in cups per day) in a multivariable adjusted conditional logistic regression models at a two-sided P < 0.05.

Overall, 2,263 (30.7%) and 3,201 (43.4%) of participants reported coffee or tea intake of ≥ one cup per day, respectively. In the multivariate-adjusted model, coffee intake showed a statistically insignificant, suggestive inverse association with stroke among those consuming 4-5 cups/day (aOR: 0.99; 95% CI: 0.35-2.79) and ≥ 6 cups/day (aOR: 0.71; 95% CI: 0.29-1.76), P for trend = 0.77 compared to non-coffee consumers. Similarly, higher tea intake was linked with statistically insignificant, suggestive lower odds of stroke; aOR: 0.90 (95% CI: 0.51-1.60) for 4-5 cups/day, and aOR: 0.81 (95% CI: 0.51-1.28) for ≥ 6 cups/day, P for trend = 0.03. The direction of associations was consistent, independent of stratification by stroke subtype, age group, and sex, for tea intake but not for coffee intake.

We observed a statistically insignificant but suggestively inverse association between coffee and tea intake and stroke, with generally lower intake levels in this sample of indigenous Africans. However, prospective studies would be necessary to clarify these associations.