You probably have a jar of peanuts somewhere in the kitchen.
They are cheap, easy to grab, and most people would never call them brain food. They are just a snack.
A new trial from Maastricht University Medical Center in the Netherlands puts that assumption to the test.
Daily peanut consumption for 16 weeks improved how the aging brain responds to insulin in regions tied to memory.
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The results were published in the journal Food & Function.
Insulin is best known as the blood-sugar hormone, but it also helps brain cells store and recall information.
As people age, the brain can become less responsive to insulin. That drop has been linked to cognitive decline and Alzheimer's disease, and the same Maastricht group has previously reported on how peanuts may help older brains respond to insulin again.
What the trial actually measured
Researchers at NUTRIM, Maastricht's institute for nutrition and metabolism, ran a randomized, controlled crossover trial.
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The participants were 31 healthy adults. All were aged 60 to 75.
For 16 weeks, each person ate unsalted, skin-roasted peanuts every day. The dose was 60 grams.
That is roughly two small handfuls. In the control phase, the same people avoided peanuts for 16 weeks.
MRI scans measured how brain blood flow changed when participants were given insulin as a nasal spray.
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During the peanut phase, insulin responsiveness improved in a cluster of right-hemisphere areas that includes the hippocampus, a region central to memory.
The team had already published memory and blood-flow results from the same trial.
In an earlier paper in Clinical Nutrition, they reported that the peanut period raised global brain blood flow by 3.6%. Verbal memory scores rose by 5.8%.
Why peanuts might help an aging brain
Peanuts contain unsaturated fats, fiber, several vitamins and minerals, and plant compounds known as polyphenols.
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According to the Maastricht team's statement via EurekAlert, this mix of nutrients, rather than any single one, is the likely driver of the brain effects.
The findings come with real caveats. Only 31 people took part, so the effects need confirming in larger groups before peanuts can be called a brain treatment.
The study was funded by the Peanut Institute Foundation.
The researchers say the funder had no role in designing or analyzing the trial. The memory gain, while measurable, was modest.
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What this means for your next snack
The practical takeaway is simple. Swapping an afternoon snack for a small handful of unsalted peanuts is cheap and easy.
The peanuts used in the trial were unsalted and skin-roasted.
The dose in the trial was 60 grams a day. Participants kept it up for 16 weeks before the brain changes showed up.
Smaller amounts, or shorter periods, were not tested.
People with diabetes, nut allergies, or kidney issues should talk to their doctor before adding daily peanuts to the plate.
This article is made and published by Ida-Marie Palm Varbæk, who may have used AI in the preparation.