Polyphenol-rich diets improve glucose metabolism in people at high cardiometabolic risk: a controlled randomised intervention trial

What this study found

Overall, the polyphenol-rich diet improved glucose metabolism, whereas the LCn3-rich diet had mixed effects and did not clearly improve insulin sensitivity. In the high polyphenol group, the 8-week change in OGTT glucose AUC was favorable versus the other dietary patterns, with a significant polyphenol effect by two-factor ANOVA (p=0.036), and early-phase insulin secretion increased (p=0.048). LCn3 showed a significant effect on beta-cell function (p=0.031) and a strong effect on postprandial GLP-1 responses (p<0.0001), but these changes did not translate into clear improvement in insulin…

Study & population

Controlled randomized intervention trial in adults aged 35 to 70 years with overweight or obesity, high central adiposity, and metabolic syndrome/high cardiometabolic risk, recruited from an obesity outpatient clinic in Naples, Italy.

Intervention

Participants followed 8-week isoenergetic diets designed to be either polyphenol-rich, LCn3-rich, or rich in both components.

Key limitation

Small per-arm sample size and short 8-week duration limit inference about durability and clinical outcomes such as diabetes incidence.

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