Effects of the Treatment with Flavonoids on Metabolic Syndrome Components in Humans: A Systematic Review Focusing on Mechanisms of Action.

Henrique J C B Gouveia, Mercedes V Urquiza-Martínez, Raul Manhães-de-Castro, Bárbara J R Costa-de-Santana, José Pérez Villarreal, Rosalío Mercado-Camargo, Luz Torner, Jailane de Souza Aquino, Ana E Toscano, Omar Guzmán-Quevedo

Journal: International journal of molecular sciences 2022;23(15):8344

PMID: 35955475

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Plain Language Summary

Metabolic syndrome is a condition characterised by at least three of the five risk factors, such as abdominal obesity, elevated fasting glucose, blood pressure and triglycerides and reduced high-density lipoprotein cholesterol (HDL-c). There is a strong link between metabolic syndrome and the development of cardiovascular disease and Type 2 diabetes. Research suggests that increasing consumption of flavonoid-rich foods can be beneficial in reducing cardiovascular morbidity and mortality. Flavonoids are bioactive compounds that possess antioxidative, anti-inflammatory, anti-cancerous, anti-mutagenic, and enzymatic properties. This systematic review of 29 randomised controlled trials evaluated the beneficial effects of long-term flavonoid supplementation in reducing the risk factors of metabolic syndrome. This review included a variety of flavonoid supplements, such as anthocyanin, hesperidin, quercetin, epigallocatechin gallate (egcg), genistein, theaflavin, catechin, and eriocitrin. Additionally, this research investigated the mechanisms behind the beneficial effects of flavonoid supplementation. Results showed that flavonoid supplementation for at least three weeks improved metabolic parameters and inflammatory markers, with hesperidin showing the greatest improvements in metabolic parameters. Healthcare professionals can use these findings to understand the potential benefits of long-term flavonoid supplementation in improving metabolic parameters. However, more robust studies are needed to determine the therapeutic dosages of different flavonoids.

Abstract

Diets high in bioactive compounds, such as polyphenols, have been used to mitigate metabolic syndrome (MetS). Polyphenols are a large group of naturally occurring bioactive compounds, classified into two main classes: non-flavonoids and flavonoids. Flavonoids are distributed in foods, such as fruits, vegetables, tea, red wine, and cocoa. Studies have already demonstrated the benefits of flavonoids on the cardiovascular and nervous systems, as well as cancer cells. The present review summarizes the results of clinical studies that evaluated the effects of flavonoids on the components of the MetS and associated complications when offered as supplements over the long term. The results show that flavonoids can significantly modulate several metabolic parameters, such as lipid profile, blood pressure, and blood glucose. Only theaflavin and catechin were unable to affect metabolic parameters. Moreover, only body weight and body mass index were unaltered. Thus, the evidence presented in this systematic review offers bases in support of a flavonoid supplementation, held for at least 3 weeks, as a strategy to improve several metabolic parameters and, consequently, reduce the risk of diseases associated with MetS. This fact becomes stronger due to the rare side effects reported with flavonoids.

Address: Postgraduate Program in Nutrition, Health Sciences Center, Federal University of Pernambuco, Recife 50670-901, PE, Brazil.; Studies in Nutrition and Phenotypic Plasticity Unit, Department of Nutrition, Federal University of Pernambuco, Recife 50670-901, PE, Brazil.; Laboratory of Neuronutrition and Food Engineering, Instituto Tecnológico Superior de Tacámbaro, Tacámbaro 61650, Michoacán, Mexico.; Centro de Investigación Biomédica de Michoacán, Instituto Mexicano del Seguro Social, Morelia 58330, Michoacán, Mexico.; Department of Nutrition, Federal University of Pernambuco, Recife 50670-901, PE, Brazil.; Postgraduate Program in Neuropsychiatry and Behavioral Sciences, Federal University of Pernambuco, Recife 50740-600, PE, Brazil.; Instituto Tecnológico Superior de Uruapan, Uruapan 60015, Michoacán, Mexico.; Facultad de Químico Farmacobiología, Universidad Michoacana de San Nicolás de Hidalgo, Morelia 58000, Michoacán, Mexico.; Laboratory of Experimental Nutrition, Department of Nutrition, Federal University of Paraiba, João Pessoa 58051-900, PB, Brazil.; Department of Nursing, CAV, Federal University of Pernambuco, Recife 55608-680, PE, Brazil.

DOI: 10.3390/ijms23158344