Overview

• The randomized DIRECT PLUS study followed about 300 adults assigned to a healthy diet, a calorie‑restricted Mediterranean diet, or a polyphenol‑enhanced variant for 18 months.
• Participants on the green‑Mediterranean plan showed larger drops in blood Galectin‑9 and Decorin, proteins associated with an accelerated brain‑aging signature, versus comparison diets.
• The regimen emphasized polyphenol‑rich foods such as green tea, Mankai and walnuts, with reported associations between three to four daily green teas or roughly seven weekly walnut servings and lower protein levels.
• The authors propose anti‑inflammatory effects as a plausible mechanism but note the trial assessed biomarkers rather than cognitive outcomes.
• Investigators and outside experts urge larger, longer, and more diverse trials and recommend studying how diet interacts with sleep, exercise and other lifestyle factors.