The green-Mediterranean diet may protect against brain aging by reducing protein markers linked to cognitive decline.
Adopting a green-Mediterranean diet, which incorporates green tea and the aquatic plant Mankai, has been linked to slower brain aging, according to recent research.
The study, published in the journal Clinical Nutrition, was conducted by scientists from Ben-Gurion University, the Harvard T.H. Chan School of Public Health, and the University of Leipzig.
Investigating diet and brain age
Neurological disorders such as mild cognitive impairment and Alzheimer’s disease are often associated with an increased brain age gap, meaning the brain appears biologically older than a person’s actual age. To explore whether diet could influence this process, researchers examined data from nearly 300 participants in the DIRECT PLUS trial, one of the most extensive long-term studies on diet and brain health.
Over an 18-month period, participants followed one of three diets: a standard healthy diet; a traditional calorie-restricted Mediterranean diet, which limited simple carbohydrates, emphasized vegetables, and replaced red meat with poultry and fish; or the green-Mediterranean diet, which included all of the above along with green tea and Mankai.
When the researchers measured protein levels in the participants’ blood, they found that higher levels of certain proteins were associated with accelerated brain aging. Further, they found that those protein levels decreased in participants who followed the green-Mediterranean diet. The researchers hypothesized that the protective effect of the diet could be a result of the anti-inflammatory molecules contained in green tea and Mankai.
A dynamic view of brain health
“Studying the circulating proteins in blood allows us to observe, in a real-life setting, how the brain’s aging processes are influenced by lifestyle and dietary changes,” said Anat Meir, postdoctoral research fellow at Harvard Chan School, who co-led the study. “This approach gives us a dynamic window into brain health, helping to reveal biological changes long before symptoms may appear. By mapping these protein signatures, we gain powerful new insight into how interventions, such as diet, may help preserve cognitive function as we age.”
Reference: “Serum Galectin-9 and Decorin in relation to brain aging and the green-Mediterranean diet: A secondary analysis of the DIRECT PLUS randomized trial” by Dafna Pachter, Anat Yaskolka Meir, Alon Kaplan, Gal Tsaban, Hila Zelicha, Ehud Rinott, Gidon Levakov, Ofek Finkelstein, Ilan Shelef, Moti Salti, Frauke Beyer, Veronica Witte, Nora Klöting, Berend Isermann, Uta Ceglarek, Tammy Riklin Raviv, Matthias Blüher, Michael Stumvoll, Dong D. Wang, Frank B. Hu and Iris Shai, 23 August 2025, Clinical Nutrition.
DOI: 10.1016/j.clnu.2025.08.021
This study was supported by the German Research Foundation (DFG) project number 209933838 (SFB 1052; B11) (to I Shai); the Israel Ministry of Health grant 87472511 (to I Shai); the Israel Ministry of Science and Technology grant 3-13604 (to I Shai); and the California Walnut Commission (to I Shai).
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