60 GRAMS OF PEANUTS A DAY MADE OLD BRAINS WORK BETTER

Researchers at Maastricht University Medical Center handed 31 healthy adults aged 60 to 75 premeasured packets of unsalted, skin-roasted peanuts and told them to eat 60 grams a day, roughly two servings, for 16 weeks. Then everyone got an MRI. Insulin responsiveness improved in a cluster of right-hemisphere regions including the hippocampus, which matters because the aging brain gets worse at responding to insulin and that slide tracks with cognitive decline. The same trial already produced the numbers that got everyone's attention. Global cerebral blood flow up 3.6%. Verbal memory up 5.8% on delayed recall. Systolic and pulse pressure both down. Decent résumé for a food that usually lives in a bar bowl under a dozen unwashed hands. Now the fine print, because there's a lot of it. Thirty-one people is a small room. Executive function and psychomotor speed didn't move at all, so your recall sharpens while your decision making stays exactly as dumb as it was Tuesday. The researchers said plainly they did not show that peanuts prevent cognitive decline or dementia. And the research was supported by the Peanut Institute Foundation, which is the least shocking funding disclosure in the history of nutrition science.

Why you should give a shit: Thirty-one Dutch retirees and a peanut lobby don't add up to a dementia cure, but a daily handful costs four bucks and it's the only thing in the snack aisle with actual brain scans behind it.