Peanut trial finds altered insulin responsiveness in memory-related brain regions

Researchers at Maastricht University Medical Center studied 31 healthy adults aged 60–75 in a randomized, controlled crossover trial. Participants ate 60 g of unsalted, skin-roasted peanuts daily for 16 weeks and avoided peanuts during the comparison phase. Brain insulin responsiveness was assessed by measuring regional cerebral blood flow with arterial spin labeling MRI after insulin was administered intranasally; cognition and liver fat were also assessed.

After the peanut phase, insulin responsiveness improved in a group of right-hemisphere regions, including parts of the lingual gyrus, hippocampus, parahippocampal gyrus and posterior cingulate gyrus. The source does not report numerical results for these changes or cognitive outcomes from the current study. It cites earlier research by the same investigator, which reported a 3.6% increase in overall cerebral blood flow and a 5.8% improvement in verbal memory after a similar intervention.

The findings concern a brain-imaging measure, not demonstrated prevention of cognitive decline or Alzheimer’s disease. The small study involved healthy older adults, and the Peanut Institute Foundation funded the research; the investigators reported that it had no role in the study’s conduct or reporting. The results do not establish that peanut consumption improves clinical cognitive outcomes.