An umbrella review of meta-analysis to understand the effect of coffee consumption and the relationship between stroke, cardiovascular heart disease, and dementia among its global users

Coffee has long been popular worldwide. The rise in lifestyle-related diseases such as cardiovascular disease, diabetes, stroke, dementia, and others has motivated coffee usage and illness prevalence studies. Some studies show coffee consumers are at risk for such diseases, whereas others show its active components protect them. Policymakers and the public need a comprehensive umbrella review to make healthy choices and enjoy coffee. Coffee consumption and stroke, CHD, and dementia outcomes have been distinguished using the PICO search strategy in PubMed with a filter for meta-analysis. We included 10 years of investigations until October 2023. MeSH terms "coffee intake," "stroke, dementia," and "transient ischemic attack," comparing stroke risk with coffee consumption were used. The study excluded case reports and non-human, non-English observational research. The stroke risk of coffee was examined using RevMan software. Coffee consumption's stroke risk ratio (RR), 95% CI, and I2 were estimated. Forest plots with P values ≤ 0.05 are significant. The umbrella review includes 11 meta-analyses from 457052 papers, totalling 11.96 million individuals. Drinking up to 4 cups of coffee daily reduced stroke risk by 12% compared with not drinking any coffee (0.88 (CI of 0.84-0.92, I2 of 13%, P < 0.00001)). Coffee drinkers had a 1.19 risk ratio for cardiovascular diseases compared to non-coffee drinkers (CI: 0.99-1.38, I2 = 84%, P < 0.00001). The dementia risk ratio for caffeine users was 0.90 (95% CI: 0.82-0.97, I2 = 46%, P < 0.00001) compared with non-consumers. Our analysis covering 5.42 million individuals found that 4 cups of coffee consumed a day reduced stroke risk by 12%. Coffee may reduce ischemic and haemorrhagic strokes by preserving endothelium and antioxidants. Coffee may lessen dementia risk, according to our study's 0.94 pooled risk ratio after sensitivity analysis. Heavy coffee drinkers had a greater CHD risk, as per our findings. Heavy coffee drinkers were more at risk.