New Research Reveals the Benefits of Peanuts & Their Effects on Brain Health

The Potential Impact of Peanuts on the Aging Brain

Peanuts may offer more than just a convenient source of protein and healthy fats. According to recent research, regularly consuming these foods may improve the elderly brain's ability to respond to insulin, a hormone crucial for communication between nerve cells, learning, and memory. A change that has been linked to cognitive decline in old age is the potential for our brains to become less sensitive to insulin as we age.

Researchers at Maastricht University Medical Center in the Netherlands found that consuming unsalted, skin-roasted peanuts daily for 16 weeks enhanced insulin responsiveness in brain regions associated with memory. The research, which was conducted by the Institute of Nutrition and Translational Research in Metabolism (NUTRIM), was published in Food & Function.

How Peanuts Affected The Aging Brain

"The hormone insulin is essential for the brain, as it aids in the development of memory and other cognitive functions." As individuals age, the brain may become less responsive to insulin, a phenomenon that has been linked to age-related cognitive decline, according to Dr. Peter Joris, the senior author of the study and an associate professor in the Department of Nutrition and Movement Sciences at NUTRIM, Maastricht University Medical Center.

The trial included 31 healthy adults aged 60 to 75. Each participant completed a 16-week period of eating peanuts and a control period without them. This randomized, controlled crossover design allowed researchers to compare each person’s results under both conditions.

Insulin induces changes in regional cerebral blood flow (CBF; mL/100 g/min). The peanut intervention resulted in a cluster in the right hemisphere that was positively impacted by CBF responses to intranasal insulin in comparison to the control period (-5.4 ± 5.4 mL/100 g tissue/min), as demonstrated by whole-brain analysis. Parts of the thalamus, posterior cingulate gyrus, hippocampus, parahippocampal gyrus, and lingual gyrus were included in this cluster. The Z-values are represented by the color map. Credit: Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University Medical Center, Netherlands

During the peanut period, participants ate 60 grams (approximately two servings), or about 2.1 ounces, daily. Premeasured packets helped them follow the prescribed amount, which they could eat in one sitting, divide throughout the day, or add to meals. They were instructed to consume the peanuts in the morning or afternoon.

The insulin responsiveness changes were observed in a cluster on the right side of the brain, which encompassed portions of the lingual gyrus, hippocampus, parahippocampal gyrus, and posterior cingulate gyrus. These regions facilitate memory.

Measuring Insulin’s Effects on the Brain

In order to evaluate the brain's response, researchers administered insulin via the nasal passage and monitored the subsequent fluctuations in regional cerebral blood flow (CBF). They employed arterial spin labeling magnetic resonance imaging (ASL-MRI), which involved a controlled dietary intervention that lasted for several months, in conjunction with advanced imaging.

Previous results from the 16-week peanut intervention published in Clinical Nutrition in 2025 showed a 3.6% increase in global cerebral blood flow, which delivers oxygen and nutrients to the brain, along with a 5.8% improvement in verbal memory.

The team also evaluated cognitive performance using the Cambridge Neuropsychological Test Automated Battery (CANTAB) and measured intrahepatic lipid (IHL) content, or liver fat, using abdominal magnetic resonance imaging (MRI).

“In our study we found that daily peanut consumption had a beneficial effect on insulin responsiveness in memory-related brain regions in older adults,” says Dr Peter Joris, the study’s senior author and associate professor at Maastricht University Medical Center. These results suggest that improved regional brain insulin sensitivity could explain the cognitive-enhancing effects of peanut consumption (unsalted, skin-roasted).

"Peanuts contain a number of nutrients, including unsaturated fats, dietary fiber, vitamins and minerals, and bioactive phytochemicals, which may contribute to the brain benefits observed," adds Joris. “Peanuts are also a good source of plant protein and are especially high in L-arginine. L-arginine is an important precursor of nitric oxide (NO), which has been shown to improve learning and memory performance.