Regular consumption of peanuts may offer measurable benefits for brain health in older adults, according to a new study from Maastricht University Medical Center in the Netherlands. The research, published in the journal Food & Function, demonstrates that daily intake of unsalted, skin-roasted peanuts improves how specific brain regions respond to insulin.
Insulin is widely recognized for its role in regulating blood sugar, but it also functions as a critical signaling molecule in the central nervous system. It supports the growth, survival, and communication of nerve cells, which are essential for memory and other cognitive functions. As people age, the brain often becomes less responsive to insulin, a condition linked to age-related cognitive decline and an increased risk of Alzheimer’s disease.
Improved Insulin Sensitivity in Memory Centers
The study involved 31 healthy adults aged 60 to 75. Participants followed a randomized, controlled crossover design, meaning they underwent two distinct phases. During the intervention phase, they consumed 60 grams of peanuts daily for 16 weeks. In the control phase, they avoided peanuts entirely. After the first 16 weeks, the groups switched conditions to allow for direct comparison.
Researchers used arterial spin labeling magnetic resonance imaging, or ASL-MRI, to track changes in regional cerebral blood flow. This technique allowed them to measure brain activity in real time. To assess insulin responsiveness, the team administered insulin via a nasal spray and monitored how blood flow changed in different parts of the brain.
After the 16-week peanut consumption period, participants showed improved insulin responsiveness in the right hemisphere of the brain. Key areas affected included the lingual gyrus, hippocampus, parahippocampal gyrus, and posterior cingulate gyrus. These regions are heavily involved in memory processing and are often among the first to show signs of decline in neurodegenerative conditions.
Dr. Peter Joris, the study’s senior author and an associate professor in the Department of Nutrition and Movement Sciences at NUTRIM, emphasized the connection between the dietary intervention and the observed neurological changes. He noted that the findings suggest enhanced regional brain insulin responsiveness may be a primary mechanism behind the cognitive benefits of peanut intake.
Nutritional Components and Previous Findings
The researchers attribute the positive effects to a combination of nutrients found in peanuts rather than a single compound. Peanuts are rich in unsaturated fats, dietary fiber, vitamins, minerals, and bioactive phytochemicals. They are also a significant source of plant-based protein and L-arginine. L-arginine serves as a precursor for nitric oxide, a molecule known to facilitate learning and memory performance by improving blood vessel function.
These results build upon earlier work by the same research team. A 2025 study published in Clinical Nutrition found that the same 16-week peanut intervention increased overall cerebral blood flow by 3.6 percent and improved verbal memory performance by 5.8 percent. The new study adds a layer of mechanistic detail, showing that the improved blood flow is associated with better insulin signaling in memory-critical areas.
To ensure consistency, the study provided participants with premeasured packets of skin-roasted peanuts. Participants were free to consume the nuts at any time during the day, either as a snack or incorporated into meals. The control phase required complete avoidance of peanuts and peanut products.
The study was led by Principal Investigator Dr. Peter J. Joris and conducted by Ph.D. candidate Lucia Kerkhof. Funding was provided by The Peanut Institute Foundation, which stated it had no role in the study design, data analysis, or manuscript preparation. The findings highlight the potential of simple dietary adjustments to support brain health in aging populations.
Source: ScienceDaily
