Association of pepper intake with all-cause and specific cause mortality - A systematic review and meta-analysis

Objective: To conduct a comprehensive systematic review and meta-analysis to compare mortality and other clinical outcomes associated with chili pepper (CP) consumption versus no/rare consumption of CP. Methods: A comprehensive search was performed using Ovid, Cochrane, Medline, EMBASE, and Scopus from inception till January 16, 2020. Observational studies and randomized controlled trials were included, while pediatric/animal studies, letters/case reports, reviews, abstracts, and book chapters were excluded. All-cause mortality was studied as the primary outcome. Cardiovascular mortality, cancer-related deaths and cerebrovascular accidents were studied as secondary outcomes. Results: From 4729 studies, four studies met the inclusion criteria. Random effects pooled analysis showed that all-cause mortality among CP consumers was lower, compared to rare/non-consumers, with a hazard ratio (HR) of 0.87 [95% CI: 0.85-0.90; p <0.0001; I-2 = 1%]. HR for cardiovascular mortality was 0.83 [95% CI: 0.74-0.95; p = 0.005, I-2= 66%] and for cancer-related mortality as 0.92 [95% CI: 0.87-0.97; p = 0.001; I-2 = 0%]. However, the HR for CVA was 0.78 [95% CI: 0.56-1.09; p = 0.26; I-2= 60%]. The mode and amount of CP consumption varied across the studies, and data were insufficient to design an optimal strategy guiding its intake. Conclusion: Regular CP consumption was associated with significantly lower all-cause, cardiovascular, and cancer-related mortalities. However, based on current literature, it is difficult to derive a standardized approach to guide the optimal mode and amount of CP consumption. This warrants well-designed prospective studies to further investigate the potential health benefits of CP consumption.