Daily Peanuts May Support Memory and Brain Blood Flow

What did the peanut study find about memory?

Researchers at Maastricht University Medical Center compared unsalted peanuts roasted with their skins against a no-peanut period. Participants completed both conditions, separated by an eight-week break. Brain imaging showed increased blood flow, and participants recalled approximately 1.4 more words on a delayed memory test. Executive function and psychomotor speed did not improve. [Clinical Nutrition study](https://pubmed.ncbi.nlm.nih.gov/41205298/).

The distinction matters: a change on one laboratory task does not establish a noticeable improvement in everyday functioning. The small sample also limits generalizability. This was a study of healthy older adults, not a treatment trial in people with diagnosed dementia.

How might peanuts affect the brain's response to insulin?

An October report in Food & Function examined the same trial, rather than independently reproducing its results. Researchers administered insulin through the nose and measured changes in brain blood flow using MRI. After peanut consumption, one region showed a reduced blood-flow response, which the authors interpreted as potentially beneficial insulin responsiveness. Blood markers of glucose regulation, lipid metabolism and inflammation remained unchanged. [Food & Function analysis](https://pubmed.ncbi.nlm.nih.gov/42841520/).

This measurement differs from the resting brain blood-flow assessment: a smaller response to an insulin challenge does not simply mean poorer circulation. Nevertheless, the analysis does not prove that altered insulin signaling caused the memory finding. Larger independent trials should determine whether the effects persist and translate into meaningful cognitive benefits.