A randomized trial from Maastricht University's NUTRIM institute found that eating about 60 grams of unsalted, skin-roasted peanuts daily — roughly two servings — for 16 weeks improved insulin responsiveness in brain regions tied to memory, compared with avoiding peanuts entirely.
The crossover study enrolled 31 healthy adults aged 60 to 75 and used arterial spin labeling MRI alongside an intranasal insulin challenge to measure blood flow in the lingual gyrus, hippocampus, parahippocampal gyrus and posterior cingulate gyrus — regions associated with memory and other cognitive functions. Researchers, writing in Food & Function, say the finding builds on the same group's 2025 report that 16 weeks of peanut consumption raised cerebral blood flow by 3.6 percent and verbal memory scores by 5.8 percent.
Insulin plays an important role in the brain, where it supports memory and other cognitive processes.
Dr. Peter J. Joris, senior author, Maastricht University
The study, led by PhD candidate Lucia Kerkhof with Joris as senior author, was funded by the Peanut Institute Foundation, a U.S. peanut-industry group. The authors state the funder had no role in designing the study or analyzing its results, but the funding source is worth weighing before drawing broad conclusions — industry-sponsored nutrition research has a track record of findings that are directionally favorable to the funder's product, even when individual studies are conducted rigorously. The sample size, 31 participants, is also small, and the researchers describe the work as supporting, rather than proving, a protective role for peanuts in brain aging.
