Antioxidant, anti-inflammatory and anti-obesity effects of onion and its by-products in high-fat fed rodents: a systematic review

Abstract The effects of onion and its by-products on metabolic changes induced by excessive consumption of a high fat diet have been the focus of many studies. The aim of this study was to systematically review the effects of onion and its by-products antioxidant, anti-inflammatory and anti-obesity in rats exposed to a high-fat diet. Five databases were used: Pubmed, EMBASE, Science Direct, Web of science and Scopus until June 2020 updated December 1, 2022. Research of the articles was carried out by two reviewers, searching and selecting studies after an initial reading of the titles and abstracts. In total, 2,448 papers were found and, after assessing against the inclusion and exclusion criteria, 18 papers were selected for this review. The findings of this review show the beneficial effects of onion and its by-products on inflammatory parameters, obesity, cardiovascular disease, thermogenesis and hepatic alterations generally associated with the consumption of a high-fat diet.