Abstract
Diabetes is one of the major non-communicable diseases whose physiological
complications are linked with a higher risk of mortality amongst the adult age group of
people living globally. This review article documents updated pharmacological evidence
and insights into the antidiabetic mechanisms of green, black, white, oolong, and pu-erh
teas via reported experimental and clinical models toward encouraging their use as a
complementary nutraceutical in managing the biochemical alterations found in the onset
and progression of diabetes. Peer-reviewed articles published in “PubMed”, “Google
Scholar”, and “ScienceDirect” from 2010 and beyond that reported the antidiabetic,
antilipidemic, and digestive enzyme inhibitory effects of the selected tea types were
identified. The keywords used for the literature search comprise the common or scientific
names of the tea and their corresponding bioactivity. Although teas portrayed different
antidiabetic pharmacological properties linked to their bioactive components, including
polyphenols, polysaccharides, and amino acids, the type of phytochemical found in each
tea type depends on their processing. Green tea’s strong carbohydrate digestive enzyme
inhibitory effect was linked with Ellagitannins and catechins, whereas theaflavin, a main
ingredient in black tea, increases insulin sensitivity via enhancing GLUT4 translocation.
Theabrownin in pu-erh tea improves FBG and lipid metabolism, while chemical
components in white tea attenuate prediabetes-mediated reproductive dysfunctions by
improving testicular tissue antioxidant capabilities. Based on the body of findings
presented in this article, it is evident that integrating tea intake into daily food
consumption routines could offer a promising practical solution to support human health
and well-being against diabetes disease.