Daily Peanut Consumption Linked to Improved Brain Insulin Response in Older Adults

Scientists at Maastricht University Medical Center in the Netherlands have discovered that regularly eating unsalted, skin-roasted peanuts can significantly improve how certain brain regions respond to insulin in older adults. This surprising finding, from the Institute of Nutrition and Translational Research in Metabolism (NUTRIM), was published in the peer-reviewed journal Food & Function. The research suggests a novel pathway through which daily peanut intake could support brain health and memory, functions often compromised with age and linked to conditions like Alzheimer's disease.

Insulin, while primarily known for blood sugar regulation, also plays a crucial role in the brain, supporting nerve cell growth, survival, and communication, all vital for memory and other cognitive abilities. Healthy insulin signaling in the brain may also offer protection against processes associated with Alzheimer's. After participants consumed approximately two servings (60 grams) of peanuts daily for 16 weeks, researchers observed enhanced insulin responsiveness in specific memory-related brain regions within the right hemisphere, including portions of the lingual gyrus, hippocampus, parahippocampal gyrus, and posterior cingulate gyrus.

Dr. Peter Joris, the study’s senior author and an associate professor at NUTRIM, highlighted that the aging brain can become less responsive to insulin, contributing to age-related cognitive decline. He stated that their findings suggest this enhanced regional brain insulin responsiveness directly contributes to the cognitive benefits seen from consuming unsalted, skin-roasted peanuts. This study, which involved 31 healthy adults aged between 60 and 75, utilized a rigorous randomized, controlled crossover trial design to compare the effects of peanut consumption versus avoidance.

These new findings build upon earlier research by Dr. Joris, published in 2025 in Clinical Nutrition, which found that 16 weeks of peanut consumption increased overall cerebral blood flow (CBF) by 3.6% and improved verbal memory performance by 5.8%. Cerebral blood flow is a key indicator of brain vascular health, delivering oxygen and nutrients essential for proper brain cell function. To measure these effects, the NUTRIM team employed sophisticated brain imaging technologies, including arterial spin labeling magnetic resonance imaging (ASL-MRI) to track blood flow changes, and evaluated insulin responsiveness by observing regional CBF shifts after nasal insulin administration.

Researchers believe that the observed benefits stem from multiple components within peanuts rather than a single nutrient. These include unsaturated fats, dietary fiber, various vitamins and minerals, and bioactive phytochemicals. Peanuts are also a good source of plant-based protein and are particularly rich in L-arginine, which is a key precursor of nitric oxide (NO), a molecule reported to facilitate learning and memory performance. The study was led by Dr. Peter J. Joris and Ph.D. candidate Lucia Kerkhof, with funding provided by The Peanut Institute Foundation, which had no involvement in the study's design, execution, analysis, or manuscript preparation.

What to watch: Further research into specific peanut components and their long-term cognitive impact.

Editor's note: The article effectively synthesizes the study's methodology, findings, and the specific brain regions involved, while maintaining accurate attribution.