Beneficial effects of polyphenols in metabolic syndrome—a review

INTRODUCTION: Polyphenols (PPs) are plant-derived chemical compounds bearing one or more phenolic rings. The most commonly presented dietary PPs include anthocyanins, flavonols, flavanols and phenolic acids. Studies have shown that polyphenols exert a variety of actions including antioxidant, anti-inflammatory, antimicrobial, antiproliferative, cancer protective, cardioprotective, lipid-lowering, and glucose-lowering. Metabolic syndrome (MetS) is a global health issue associated with an increased risk of cardiovascular diseases, type 2 diabetes, and certain types of cancer. AIM: The purpose of this paper is to summarize the current knowledge about the beneficial effects of different polyphenols on the clinical manifestations of metabolic syndrome. MATERIALS AND METHODS: Literature in PubMed, Google Scholar and ScienceDirect has been studied and analyzed. RESULTS: Most data about the beneficial effects of polyphenols is derived from preclinical studies. The clinical trials involving polyphenolic compounds in subjects with MetS are limited, comprise a small number of participants, and the duration is short. CONCLUSION: Numerous studies show promising effects of polyphenols in improving the biochemical and clinical abnormalities associated with metabolic syndrome but larger, more precise, better controlled clinical trials are necessary to reveal their benefits in clinical practice.