Polyphenol-rich diet helps prevent type 2 diabetes
Diets rich in polyphenols, particularly flavonoids, provide a protective effect against type 2 diabetes (T2D), according to a recent meta-analysis.
“For most associations evidence for nonlinearity was found, suggesting a recommendable amount of intake associated with the lowest risk of T2D,” the investigators said.
A meta-analysis was conducted on prospective epidemiologic studies published before January 2018. A random-effects model combined log-transformed multivariable-adjusted hazard (HR) and odds ratios (OR). Comparisons between extreme quantiles of polyphenol exposure were further explored using linear and nonlinear dose-response meta-analyses.
A total of 18 studies investigating the relation between polyphenols (51 different compounds in total) and T2D were included.
In a comparison of extreme quantiles, T2D was inversely associated with intakes of polyphenols (HR, 0.56; 95 percent CI, 0.34–0.93), flavonoids (HR, 0.88; 0.81–0.96), flavonols (HR, 0.92; 0.85–0.98), flavan-3-ols (HR, 0.89; 0.81–0.99), catechins (HR, 0.86; 0.75–0.97), anthocyanidins (HR, 0.86; 0.81–0.91), isoflavones (HR, 0.92; 0.86–0.97), daidzein (HR, 0.89; 0.83–0.95), genistein (HR, 0.92; 0.66–0.99) and stilbenes (HR, 0.44; 0.26–0.72), as well as with biomarkers of daidzein (HR, 0.81; 0.66–0.99) and genistein (HR, 0.79; 0.62–0.99).
Dose-response meta-analysis revealed nonlinear associations of T2D with intakes of polyphenols, flavonoids, flavanones, anthocyanidins, anthocyanins and biomarkers of genistein. Additionally, there was a linear dose-response association for phenolic acids.
The investigators recommended further research on nonlinear associations.
“T2D is characterized by impaired glucose metabolism. Bioactive compounds in fruits and vegetables such as polyphenols have been suggested to influence glucose metabolism,” they noted.