Researchers say even small amounts of nuts may help protect the brain with age

Scientists behind an analysis published in the journal "Food & Function" have found that even a modest amount of nuts in the diet may be linked to better brain function in older age. The study drew on long-term data from 1,771 people with an average age of 61.

Participants completed detailed questionnaires about their dietary habits and took tests assessing memory, information processing speed and reasoning ability. Of all participants, 29 had previously suffered a stroke — a group the researchers focused on specifically, since it faces a higher risk of cognitive decline but has been relatively understudied in nutrition research.

Effects on memory and brain volume

Among participants without a history of stroke, those who ate more nuts scored better on tests of general cognitive ability and memory. This association held even after accounting for age, education, smoking, physical activity and overall diet quality. The link was strongest among those with less healthy diets overall and those who were least physically active. Nut consumption was also associated with greater total brain volume, though only among the most physically active participants.

Notably, the median nut intake among participants was just 1.3 grams per day — far below the standard recommendation of 20 grams daily, which fewer than 2% of participants met.

Possible relevance for stroke survivors

Among participants who had suffered a stroke, higher nut consumption was linked to higher blood levels of vascular endothelial growth factor (VEGF), a protein that promotes the formation of new blood vessels. Researchers noted that this finding is based on a small number of participants and needs confirmation in larger studies, but it offers a clue to a possible mechanism through which this food could aid recovery after a stroke.