Scientists discover a surprising brain benefit of eating peanuts every day
A surprising new study suggests that eating peanuts every day could help support brain health and memory in older adults. Researchers found that consuming about two servings of unsalted, skin-roasted peanuts daily for 16 weeks improved insulin responsiveness in brain regions important for memory, a function that often weakens with age and has been linked to Alzheimer's disease.
Key points
- Daily unsalted skin-roasted peanuts improved insulin responsiveness in memory-related brain regions of adults aged 60 to 75.
- The 16-week randomized crossover trial involved 31 healthy participants who ate 60 grams of peanuts daily.
- Earlier research by the same team found peanuts increased cerebral blood flow by 3.6% and verbal memory by 5.8%.
Researchers at Maastricht University Medical Center in the Netherlands have found that eating unsalted, skin-roasted peanuts daily may improve how certain brain regions respond to insulin in older adults. The findings, from the Institute of Nutrition and Translational Research in Metabolism (NUTRIM), were published in the peer-reviewed journal Food & Function.
The study included 31 healthy adults aged 60 to 75. In a randomized, controlled crossover trial, participants ate 60 grams of peanuts daily for 16 weeks and then avoided peanuts for a control period. Researchers observed improved insulin responsiveness in several right-hemisphere brain regions involved in memory, including parts of the lingual gyrus, hippocampus, parahippocampal gyrus and posterior cingulate gyrus.
How the brain was measured
The team used arterial spin labeling magnetic resonance imaging (ASL-MRI) to measure blood flow in different brain regions. Insulin responsiveness was assessed by tracking changes in regional cerebral blood flow after insulin was administered through the nose. Abdominal MRI scans measured liver fat, and cognitive abilities were tested with the Cambridge Neuropsychological Test Automated Battery (CANTAB).
The new results build on earlier research by the same team, published in 2025 in Clinical Nutrition, which found that 16 weeks of peanut consumption increased overall cerebral blood flow by 3.6% and improved verbal memory performance by 5.8%.
Our study found that daily peanut consumption beneficially affected insulin responsiveness in memory-related brain regions in older adults.
— Dr. Peter Joris
What the lead author said
Dr. Peter Joris, the study's senior author and an associate professor at Maastricht University Medical Center, said the brain may become less responsive to insulin with age, which has been linked to cognitive decline. He said the study found that daily peanut consumption beneficially affected insulin responsiveness in memory-related brain regions.
Joris said multiple nutrients in peanuts, including unsaturated fats, dietary fiber, vitamins, minerals and bioactive phytochemicals, could contribute to the observed benefits. He also noted that peanuts are rich in L-arginine, a precursor of nitric oxide, which has been reported to support learning and memory.
