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Longer-term mixed nut consumption improves brain vascular function and memory: A randomized, controlled crossover trial in older adults
Consuming nuts may slow the cognitive deterioration of getting older, but the underlying mechanisms are unknown. Nijssen et al. (2023) looked into the longer-term effects of eating mixed nuts on brain vascular function in older persons, which may be the reason for improvements in cognitive function, through their randomized, single-blinded, cross-over trial. Across a 16-week intervention where 28 participants (age [mean SD]: 65 3 years; BMI: 27.9 2.3 kg/m2) received 60 g/d of mixed nuts (pistachio, walnuts, hazelnuts, and cashews), followed by a control period (no nuts), separated by eight weeks of washout. Using arterial spin labeling magnetic resonance imaging, cerebral blood flow (CBF), a measure of brain vascular function, was calculated after each phase. Cognitive ability was evaluated via the Cambridge Neuropsychological Test Automated Battery. In addition, the effects on retinal microvasculature, arterial stiffness, and endothelial function were evaluated. Analysis of the results revealed that body weight remained constant throughout the experiment. The mixed nut intervention led to a greater regional CBF than the control period in the right frontal and parietal lobes, left frontal lobe, and bilateral prefrontal cortex. Retinal arteriolar calibers were larger, brachial flow-mediated vasodilation was more pronounced, and carotid-to-femoral pulse wave velocity was slower. Executive function and psychomotor speed remained the same, while verbal and visuospatial memory were enhanced. The authors conclude that consuming mixed nuts regularly as part of a healthy diet positively impacts peripheral vasculature and brain vascular function, which may be related to the positive benefits of memory seen in older persons. [NPID: Brain, cardiometabolic risk, cognition, nut consumption, older adults, vascular function]
Year: 2023
