November 10, 2022. A recent INC-funded study, published in the Journal of Nutrition showed that after 4 weeks of consumption of nuts in a healthy non-elderly sample, there are positive effects on cognitive function as well as modulation of microbial taxa associated with gut health.
The goal of this clinical study was to examine the effects of daily consumption of tree nuts on cognitive function, mood, metabolomics, and gut microbial species in healthy adults, aged between 18 and 49. Researchers from Northumbria University in the UK conducted a randomized, placebo-controlled, double-blind, counterbalanced crossover study and examined the outcomes of daily tree nut consumption following a 4-week intervention.
The study’s participants were split into two groups, one was supplemented with 30 grams/day of mixed tree nuts (15 g walnuts, 7.5 g almonds, 7.5 g hazelnuts) for 4-weeks before switching to a placebo intervention for 4-weeks, the other received placebo before switching to nut consumption. To be able to examine the effects of tree nut consumption, metabolic responses were monitored, as well as gut bacterial community structure and the potential for these to impact cognition.
Results demonstrated that nut consumption significantly improved accuracy and speed of response on a picture recognition task. And while the study did not yield any significant changes to bacterial community alpha or beta diversity, there was a Lachnospiraceae amplicon sequence variant (ASV) that was found to be enriched in those who consumed the mixed tree nuts daily.
Lead researcher, Prof. Crystal Haskell-Ramsay commented, “This study provides exciting evidence for improvements to cognition following only 4-weeks’ consumption of tree nuts. Since the study participants were healthy, non-elderly adults, it’s possible that more profound effects may be shown in those at increased risk for cognitive decline or in those with poor gut health.”
The study was supported by the INC International Nut and Dried Fruit Council.