Dietary Branched Chain Amino Acids Association with Cancer and Mortality: A Systematic Review and Meta-Analysis of Observational Studies.

The present study aimed to investigate the association of dietary branched-chain amino acids (BCAAs) and its components with cancer, cancer mortality, and all-cause mortality in a meta-analysis of observational studies. A comprehensive search was conducted between electronic databases (PubMed, Scopus, and Web of Science) until September 2022. Odds ratios (OR), hazard ratios (HR), and relative risks (RR) were extracted. Eight articles (six studies on breast cancer (BC) and digestive cancers risk, and three studies on both BC and digestive cancers mortality, and all-cause mortality) were included. The present study showed no statistically significant association between dietary BCAAs and its components with BC and digestive cancers (RR_BCAA: 0.87, 95% CI: 0.68–1.10, RR_Leucine: 0.74, 95% CI: 0.52–1.04, RR_Isoleucine: 0.98, 95% CI: 0.93–1.04, RR_Valine: 0.76, 95% CI: 0.55–1.05). Also, no statistically significant relationship between dietary BCAAs and its components with both BC and digestive cancers mortality (RR_BCAA: 0.95, 95% CI: 0.68–1.33, RR_Leucine: 0.95, 95% CI: 0.79-1.15, RR_Isoleucine: 0.95, 95% CI: 0.79–1.14, RR_Valine: 1.01, 95% CI: 0.84–1.21) and all-cause mortality (RR_BCAA: 0.98, 95% CI: 0.73–1.32, RR_Leucine: 1.02, 95% CI: 0.81–1.29, RR_Isoleucine: 0.96, 95% CI: 0.73–1.27, RR_Valine: 1.02, 95% CI: 0.79–1.32) were observed. Our findings showed no significant association between dietary BCAAs and its components with BC and digestive cancers, BC and digestive cancers mortality, and all-cause mortality. [ABSTRACT FROM AUTHOR]