New research points to a practical way to protect the brain: tweak the Mediterranean diet to favor plant power and specific polyphenol-rich foods. Scientists tracked people over 18 months and found measurable changes in blood proteins linked to brain aging. The results suggest diet can nudge biological markers long before symptoms show.
The green Mediterranean diet keeps the core of the traditional plan—lots of fruits, vegetables, whole grains, nuts, seeds, and olive oil—but leans harder into plants and polyphenol-rich foods. It reduces red and processed meats and adds items like green tea, walnuts, and a plant protein called Mankai. The aim is to concentrate anti-inflammatory and antioxidant compounds that may protect heart and brain health.
Researchers in Israel wanted to test whether this version does more for the brain than a regular Mediterranean approach. “We have ways to influence brain age, and that was the purpose of the trial: to examine how diet affects markers involved in this process.” The study tracked changes in over 80 blood protein biomarkers while also measuring brain age with MRI scans.
The trial enrolled nearly 300 participants and randomly assigned them to one of three diets for 18 months: a standard healthy diet, a traditional Mediterranean diet with walnuts, or the green Mediterranean diet low in red and processed meat. MRIs gave each participant a so-called brain age and researchers compared that to chronological age to see who was aging faster or slower. Blood tests measured proteins that might help explain why some brains age more quickly than others.
Two proteins stood out: galectin-9 (Gal-9) and decorin (DCN). Higher levels of those proteins were linked to accelerated brain aging, and participants on the green Mediterranean diet showed reductions in those proteins over the study period. That pattern suggests the diet may influence biological processes tied to brain health.
“This approach offers a dynamic view of brain health, allowing us to detect biological changes long before symptoms appear. By mapping these protein signatures, we gain valuable insights into how interventions like diet may help maintain cognitive function as we age.” These were the researchers’ words about why measuring proteins matters. The protein shifts give a window into mechanisms, not just outcomes.
Lead authors and dietitians emphasize that the green version is a refinement rather than a radical replacement of the Mediterranean pattern. One nutrition expert called this way of eating “is one of the most powerful tools we have for protecting both heart and brain health.” The green tweaks are intended to amplify benefits already seen with Mediterranean-style eating.
Past work from the same group supports these findings. A previous trial reported both traditional and green Mediterranean diets slowed age-related brain shrinkage by roughly half over 18 months. Additional studies linked these diets to better blood sugar control and neuroprotective effects that line up with the new biomarker data.
Putting it together, the new study suggests that concentrating polyphenol-rich foods—think green tea, berries, herbs, and walnuts—may shift protein signals in ways consistent with slower brain aging. Researchers caution the effect size and exact pathways still need more study, but the pattern is consistent and biologically plausible. Diet seems to act on inflammation and oxidative stress pathways tied to brain health.
The study has limits worth noting. The trial primarily included men, Pachter says, “so applicability to women requires confirmation.” The team used MRIs to determine each participant’s so-called brain age, which provides a “robust biomarker,” Pachter says, but it’s not a clinical diagnosis or direct pre- or post-intervention cognitive measure.
Researchers plan to expand the work by validating additional early indicators that could flag risk before symptoms appear. If those markers hold up, clinicians might be able to recommend personalized diet changes as a preventive step. The aim is intervention well ahead of noticeable decline.
For people wondering how to apply the findings, the study offers practical, achievable tips rather than strict rules. Add green tea to your day and snack on a handful of walnuts most days. Swap some red meat for fish, poultry, or plant proteins like lentils, beans, tofu, and Mankai.
Increase leafy greens, berries, olive oil, and herbs to boost polyphenols without dramatic calorie counting. Focus on whole foods and simple swaps: more plants, fewer processed items, and modest portions of animal products. Small, consistent changes are the point—those tweaks were enough to change blood proteins in this trial.
These results don’t promise prevention of every case of cognitive decline, but they reinforce a simple truth: diet matters for the brain. The green Mediterranean diet is a low-risk, low-cost strategy that aligns with heart-healthy advice and now shows promise for brain aging markers too. If you’re looking for a practical, evidence-based way to support long-term cognitive health, greening your Mediterranean-style plate is a smart place to start.
