Potential of functional drink fortified with plant extract as anti-diabetic agent: a systematic review

Ready-to-drink beverages are becoming more popular among working people as alternative energy drinks. However, the glucose level of ready-to-drink beverages is high due to the refined sugar content and preservatives, leading to various health problems, especially diabetes mellitus. Therefore, many people are now choosing natural-based drinks as healthier alternatives to refined sugar. In addition, consumers are now searching for functional drinks that help to alleviate their diseases. Flavonoids are the main bioactive compounds in plants, with many beneficial effects towards non-communicable diseases (NCDs) and metabolic syndrome. Systematically, this study aims to discuss the potential of functional drinks incorporating plant extracts as an anti-diabetic agent. A search of the Web of Science (WoS), PubMed, Science Direct, and Scopus databases for articles published from 1996 to 2023 was performed using the keywords functional drink or beverages, plant extracts, phenolic compound, and antidiabetic. All identified articles were analysed, and data were extracted using standard forms. Twelve papers fit the inclusion criteria, detailing the presence of six articles containing bioactive compounds and six papers focusing on plant extracts with potential for anti-diabetic properties. These bioactive substances alter metabolic signalling pathways and biomarkers for glycaemic management, lipid profiles, renal function, liver enzymes, and antioxidant enzymes. Poor insulin sensitivity, which hinders efficient glucose absorption into cells, plays a pivotal role in the development of diabetes, with long-term consequences such as cardiovascular disease, kidney damage, and nerve-related issues. Thus, plant-extracted flavonoids could be a promising anti-diabetic agent; however, their anti-diabetic effects still need to be confirmed in future human studies.