Eating a handful of peanuts each day might help keep your brain healthy as you get older. A new study from the Netherlands found that regularly eating unsalted, skin-roasted peanuts can improve how the brain responds to insulin in older adults.
Researchers at Maastricht University Medical Center ran a 16-week study with 31 healthy adults aged 60 to 75. Each person ate 60 grams of peanuts, or about two servings, every day.
With advanced brain scans, the team found that eating peanuts daily improved how the brain responds to insulin. Insulin is important in the brain because it helps nerve cells survive and communicate. This process is crucial for memory and is thought to help protect against Alzheimer’s disease.
“As people ge, the brain may become less responsive to insulin, which has been linked to age-related cognitive decline,” explained Dr. Peter Joris, the study’s lead author. “Our study found that eating peanuts every day helped the brain respond better to insulin in areas related to memory.”
The brain scans showed big improvements in the right side of the brain, especially in the hippocampus and other areas that help with memory.
This new study adds to the team’s earlier results from 2025, which showed that the same 16-week peanut diet increased blood flow in the brain by 3.6 percent and improved verbal memory scores by 5.8 percent.
Researchers say peanuts’ rich nutrition is behind these brain benefits. Peanuts have lots of healthy fats, fiber, and important minerals. They are also high in L-arginine, a plant protein that helps make nitric oxide, which supports learning and memory.
