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A small, everyday snack may deliver an outsized lift to brain circulation and memory. A controlled trial out of the Netherlands found that eating a modest daily portion of peanuts improved blood flow to key brain regions and lowered blood pressure in older adults. The results offer a simple dietary avenue to support thinking skills as we age.
Study setup: who ate the peanuts and how the trial ran
Researchers at Maastricht University enrolled 31 healthy volunteers aged 60 to 75. Participants followed a 16-week plan that included a daily portion of 60 grams of unsalted, skin‑roasted peanuts.
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- Portion size equaled roughly two small servings or under half a cup.
- Participants were asked not to crush or reheat the peanuts to preserve nutrients.
- Measurements were taken at baseline, week 8, and week 16.
Brain circulation measured by imaging and cognitive checks
The team used advanced imaging to track cerebral blood flow and ran cognitive tests late in the study. Results showed measurable changes in vascular function and memory.
- Global cerebral blood flow rose by 3.6% after 16 weeks versus the control period.
- Blood flow in gray matter increased by 4.5%.
- Specific regions saw larger gains: the frontal lobes went up 6.6%, and the temporal lobes rose 4.9%.
Those regional improvements matter because the frontal and temporal lobes help with memory, language, decision-making and emotional control. On memory tests, participants recognized more words from a short list seen 20 minutes earlier during the peanut period.
Not all functions shifted. Tests for executive skills and reaction speed did not show significant changes in this sample.
What in peanuts could drive better blood flow
Scientists point to several nutrients that benefit blood vessels and circulation.
- L‑arginine: an amino acid that helps make nitric oxide, a compound that relaxes blood vessels.
- Unsaturated fats: support healthy cholesterol and vessel function.
- Polyphenols and antioxidants: especially in the peanut skin, which also adds fiber.
These components likely work together to improve how blood vessels widen and constrict, a property known as vascular responsiveness.
Heart effects tied to brain health
The trial also recorded cardiovascular gains. Average systolic blood pressure dropped by about 5 mmHg, while pulse pressure fell by roughly 4 mmHg. Lower blood pressure reduces damage to tiny vessels in the brain and heart. That matters because poor circulation in midlife raises the risk of later cognitive decline.
How participants managed calories and weight
The additional peanuts added about 340 calories per day. Yet most volunteers did not gain significant weight over the study period. The researchers had participants fold the snack into their normal diet rather than adding it on top of existing intake.
Practical tips and next questions from the researchers
For those curious to try this approach, researchers emphasize specific choices and next steps.
- Pick unsalted, skin‑roasted peanuts to keep the beneficial compounds intact.
- Avoid crushing or additional heating, which can change nutrient profiles.
- Stick to portion control — about 60 grams daily in the study.
The team plans follow-up studies to test peanut butter and smaller servings. They will also investigate whether similar effects appear in larger, more diverse groups and over longer periods.
