Eating peanuts every day may offer surprising benefits for the aging brain. Researchers at Maastricht University Medical Center in the Netherlands have found that regularly consuming unsalted, skin-roasted peanuts can improve how certain brain regions respond to insulin in older adults. The findings come from the Institute of Nutrition and Translational Research in Metabolism (NUTRIM) and were published in the peer-reviewed journal Food & Function.
Although insulin is best known for regulating blood sugar, it also plays an essential role in the brain. It helps nerve cells grow, survive, and communicate with one another, supporting memory and other cognitive abilities. Healthy insulin signaling may also help protect against processes associated with Alzheimer’s disease.
After participants consumed peanuts daily for 16 weeks, researchers observed improved insulin responsiveness in a group of brain regions in the right hemisphere. These included portions of the lingual gyrus, hippocampus, parahippocampal gyrus, and posterior cingulate gyrus, all of which contribute to memory-related processes.
“The hormone insulin plays an important role in the brain, where it supports memory and other cognitive processes. As people age, the brain may become less responsive to insulin, which has been linked to age-related cognitive decline,” says Dr. Peter Joris, the study’s senior author and an associate professor in the Department of Nutrition and Movement Sciences, NUTRIM, Maastricht University Medical Center. “Our study found that daily peanut consumption beneficially affected insulin responsiveness in memory-related brain regions in older adults. These findings suggest that enhanced regional brain insulin responsiveness may contribute to the cognitive benefits of unsalted, skin-roasted peanut intake.”
Daily Peanuts Linked to Better Memory and Brain Blood Flow
The study included 31 healthy adults between the ages of 60 and 75. During the peanut consumption phase, participants ate 60 grams (approximately two servings) of peanuts each day for 16 weeks. Researchers used a randomized, controlled crossover trial, a rigorous study design that allowed them to compare the effects of eating peanuts with those of avoiding them.
The new findings build on earlier research by Joris published in 2025. That investigation found that consuming peanuts for 16 weeks increased overall cerebral blood flow (CBF) by 3.6% and improved verbal memory performance by 5.8%.
Cerebral blood flow measures how much blood circulates through the brain, carrying oxygen and nutrients that brain cells need to function properly. It is an important indicator of the health of the brain’s blood vessels. Those earlier results appeared in the peer-reviewed journal Clinical Nutrition.
How Scientists Measured the Effects of Peanuts on the Brain
One distinguishing feature of the NUTRIM research was its combination of a carefully controlled dietary intervention lasting several months with sophisticated brain imaging technology.
To examine changes in brain function, researchers used arterial spin labeling magnetic resonance imaging (ASL-MRI), a technique that measures blood flow in different regions of the brain. They evaluated insulin responsiveness by tracking changes in regional cerebral blood flow after insulin was administered through the nose.
The team also used abdominal MRI scans to measure fat accumulation in the liver, known as intrahepatic lipid (IHL) content. Cognitive abilities were assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB), a standardized collection of computerized tests.
Researchers believe several components of peanuts may contribute to their observed effects on brain health, rather than any single nutrient being responsible.
“Multiple nutrients present in peanuts, including unsaturated fats, dietary fiber, vitamins and minerals and bioactive phytochemicals, could potentially contribute to the observed brain benefits,” says Joris. “Peanuts are also a good source of plant-based protein and are especially rich in L-arginine. L-arginine is a key precursor of nitric oxide (NO), which has been reported to facilitate learning and memory performance.”
What Participants Ate During the 16-Week Study
To ensure participants consumed a consistent amount, researchers supplied premeasured packets of skin-roasted peanuts throughout the peanut intervention period.
Participants were instructed to eat their peanuts in the morning or afternoon, but they could choose how to incorporate them into their daily routine. They could consume the entire portion at once, divide it into smaller amounts throughout the day, or include the peanuts in their meals.
During the control phase, participants avoided peanuts entirely. After 16 weeks, they switched to the opposite study condition, allowing researchers to compare brain health measurements under both dietary approaches.
The study was led by principal investigator Associate Professor Dr. Peter J. Joris and conducted by Ph.D. candidate Lucia Kerkhof of the Department of Nutrition and Movement Sciences at Maastricht University Medical Center.
Funding was provided by The Peanut Institute Foundation. According to the researchers, the foundation had no involvement in designing or conducting the study, analyzing or interpreting the results, or preparing the manuscript.
