Daily Peanut Consumption Boosts Brain Insulin Sensitivity in Older Adults
A 16‑week trial found that eating 60 g of unsalted, skin‑roasted peanuts each day improves insulin responsiveness in memory‑related brain regions of seniors.
Eating peanuts daily may help the aging brain respond better to insulin, a hormone important for memory and cognition.
Study Design and Participants
The investigation was conducted at Maastricht University Medical Center’s Institute of Nutrition and Translational Research in Metabolism (NUTRIM). Thirty‑one healthy adults between 60 and 75 years old took part in a randomized, controlled crossover trial lasting 16 weeks.
During the intervention phase, each participant consumed 60 grams of unsalted, skin‑roasted peanuts each day—approximately two servings. The crossover design allowed researchers to compare brain outcomes when participants ate peanuts versus when they avoided them.
Brain Imaging and Insulin Responsiveness
To assess changes in brain function, the team employed arterial spin labeling magnetic resonance imaging (ASL‑MRI), which measures regional cerebral blood flow. Insulin responsiveness was evaluated by tracking blood‑flow changes after intranasal insulin administration.
After the 16‑week peanut period, improved insulin‑driven blood‑flow responses were observed in several right‑hemisphere regions, including the lingual gyrus, hippocampus, parahippocampal gyrus, and posterior cingulate gyrus—areas known to support memory processes.
Related Findings on Blood Flow and Memory
These results extend earlier work by the same senior author, Dr. Peter Joris, published in 2025. That earlier study reported a 3.6 % increase in overall cerebral blood flow and a 5.8 % improvement in verbal memory after a similar 16‑week peanut regimen.
Measurement of Additional Outcomes
Researchers also performed abdominal MRI scans to quantify intrahepatic lipid (IHL) content and used the Cambridge Neuropsychological Test Automated Battery (CANTAB) to evaluate cognitive performance.
Potential Nutrient Contributors
Dr. Joris noted that peanuts contain a blend of nutrients—unsaturated fats, dietary fiber, vitamins, minerals, phytochemicals, plant‑based protein, and notably L‑arginine, a precursor to nitric oxide that has been linked to learning and memory.
Implications
The findings suggest that regular consumption of unsalted, skin‑roasted peanuts may enhance regional brain insulin responsiveness, which could contribute to the cognitive benefits observed in older adults.
Continued research will clarify how these dietary effects translate into long‑term protection against age‑related cognitive decline.
