Discussion
cognitive impairment
MINOR
Nut consumption led to improved picture recognition in terms of increased accuracy and faster reaction time in this sample of healthy nonelderly adults. Metabolomic analysis indicated only minor changes to the urinary metabolome following nut consumption. In terms of bacterial communities, an unclassified The finding of improved picture recognition adds to a growing body of literature showing positive effects of nuts on cognition. Previous studies have largely focused on adults aged 50+ y and shown positive effects in those with mild cognitive impairment following Brazil nut (Nut consumption for 4 wk increased the abundance of an ASV belonging to the Importantly, no association between changes in picture recognition outcomes and changes in Supplementation with mixed nuts failed to evince effects on mood in the current study. A previous study showed no effects of walnut on mood (Overall, the observed changes to the urinary metabolome were minor and supervised models were poor although some differences did exist. As the top identification matches did not relate to metabolic pathways perturbed by the intervention, these metabolomic changes were not investigated further. None of the discriminatory metabolites that were significantly increased in intensity had the same mass as that for known biomarkers of nut intake (for example, M-H m/z 227 for urolithin a, and urolithins were not measured in the current study). Urolithins appear to be the major urinary biomarkers of nut consumption (The current study explored the effects of nuts in addition to the diet rather than comparing to “unhealthy snacks”. Potential increases in body weight associated with this approach were not observed and meta-analysis indicates no increase in body weight, BMI, or waist circumference following nut consumption (In summary, the consumption of mixed tree nuts for 4 wk led to improvements on a picture recognition task in healthy nonelderly adults. This was accompanied by enrichment of an unclassified 