Daily Serving of Peanuts May Boost Brain Blood Flow and Memory in Older Adults, Study Finds

A daily serving of peanuts could significantly improve brain blood flow and memory in older adults, according to new research published in Clinical Nutrition. The study, conducted by scientists at the NUTRIM Institute at Maastricht University Medical Center in the Netherlands, suggests that this simple dietary addition might offer cognitive benefits for aging populations.

Researchers recruited 31 healthy adults between 60 and 75 years old for the crossover trial. Participants consumed 60 grams of unsalted, skin-roasted peanuts daily for 16 weeks during one period of the study, while completely avoiding peanuts in another phase. The two periods were separated by an eight-week washout interval to prevent carryover effects.

Throughout the study, specialized MRI technology measured cerebral blood flow, while standardized cognitive assessments evaluated memory function. The results were promising: after the peanut consumption period, participants showed a 3.6% overall increase in brain blood flow, with particularly notable improvements in gray matter—the brain tissue responsible for memory, emotion, and decision-making.

“Cerebral blood flow is an important physiological marker, because having a strong flow of blood to the brain contributes to its health,” explained Peter Joris, Ph.D., the study’s author and an associate professor in the Department of Nutrition and Movement Sciences at Maastricht University Medical Center.

The most significant blood flow improvements occurred in the frontal and temporal lobes, areas critical for higher-level thinking and language processing. This enhanced blood flow appeared to translate into cognitive benefits, with participants demonstrating approximately 5.8% improvement in verbal memory tests following the peanut consumption period.

Beyond brain health, the study detected modest decreases in systolic blood pressure and pulse pressure, suggesting broader cardiovascular benefits. These findings align with previous research on nuts and cardiovascular health, reinforcing the connection between vascular function and cognitive performance.

The researchers attribute these benefits to peanuts’ rich nutritional profile. “Peanuts are especially rich in plant-based protein and contain high concentrations of L-arginine, an amino acid important for vascular health,” noted Joris. “They are also a valuable source of unsaturated fats and polyphenols, both known to support vascular function.”

The skin-roasted preparation method preserved additional antioxidants in the peanut skins, potentially enhancing the nutritional benefits. This combination of nutrients may work synergistically to improve blood vessel function throughout the body, including the brain.

The study represents an important contribution to understanding dietary approaches to cognitive health in aging populations. As dementia and cognitive decline become increasingly prevalent health concerns worldwide, identifying accessible and affordable interventions takes on greater significance. Peanuts, being widely available and relatively inexpensive compared to some other nuts, could represent a practical dietary addition for many older adults.

However, the research does have limitations. The small sample size of 31 healthy older adults makes it difficult to determine whether these effects would apply to larger populations or those with existing health conditions. Additionally, the study only tested unsalted, skin-roasted peanuts at a specific daily amount, so other forms or smaller portions might not yield identical results.

The trial’s duration of a few months cannot demonstrate whether these cognitive benefits persist long-term or meaningfully impact dementia risk. There’s also the possibility of a placebo effect, as participants were aware of whether they were consuming peanuts during the study period.

Nutritionists recommend choosing unsalted, lightly salted, dry-roasted or raw peanuts rather than heavily salted or oil-roasted varieties. As peanuts are calorie-dense, moderate portions should be integrated within a balanced diet rich in vegetables, fruits, healthy proteins, and whole grains.

While the study received funding from The Peanut Institute Foundation, the researchers noted that the foundation had no role in the study design, implementation, analysis, or interpretation of the results.