Antioxidant and anti-inflammatory activities of the Black Bean (Phaseolus vulgaris L.): A systematic review

The black bean (Phaseolus vulgaris L.), a nutrient-dense legume containing bioactive compounds, has proven to have excellent antioxidant and anti-anflammatory effects. However, the available literature data are diverse and needs summarizing. Therefore, we aimed to systematically review the studies on the antioxidant and anti-inflammatory activities of the black bean. A literature search following the PRISMA guidelines was carried out for in vitro, in vivo, and human studies assessing the antioxidant and anti-inflammatory effects of the black bean. For this, we used Boolean operators in the following databases: PUBMED, DOAJ, Google Scholar, and WHO’s International Clinical Trials Registry Platform. A total of 411 articles was screened, with 28 duplicate articles removed. Among the remaining 383 articles, only 38 matched the inclusion criteria. The risks of bias were evaluated using the QUIN tool for the in vitro studies and the OHAT tool for the in vivo and human studies. The seed coat of the black bean exhibited the strongest antioxidant and anti-inflammatory activities compared to the other parts of the seed. While thermal processing negatively impacted the beneficial effects, the retention of the cooking water improved the beans’ antioxidant and anti-inflammatory activities. Germinated and fermented black beans had higher potential than raw and cooked beans. Thus, the black bean can exert a protective effect against inflammatory cytokines. The antioxidant and anti-inflammatory activities of the black bean depend on which parts of the bean are used and how they are processed. There is a need for further studies and clinical trials to focus on the beneficial role of germinated and fermented black beans in human health.