by Marion Nestle
Apr 15 2024

Industry-funded study of the week: Nuts

The study: Mixed nut consumption improves brain insulin sensitivity: a randomized, single-blinded, controlled, crossover trial in older adults with overweight or obesity.  American Journal of Clinical Nutrition.

Objective: “This study aimed to investigate longer-term effects of mixed nuts on brain insulin sensitivity in older individuals with overweight/obesity.”

Methods: “In a randomized, single-blinded, controlled, crossover trial, twenty-eight healthy adults (mean±SD; 65±3 years; BMI: 27.9±2.3 kg/m2) received either daily 60 g mixed nuts (15 g of walnuts, pistachio, cashew, and hazelnuts) or no nuts (control) for 16 weeks, separated by an 8-week washout period.”

Results: “Compared with control, mixed nut consumption improved regional brain insulin action in five clusters located in the left…and right occipital lobe.

Conclusions: “Longer-term mixed nut consumption affected insulin action in brain regions involved in the modulation of metabolic and cognitive processes in older adults with overweight/obesity.”

Funding: “This study was supported by a grant obtained from the International Nuts and Dried Fruit Council (INC). The INC had no role in the study design, data collection or analysis, decision to publish, or preparation of the manuscript.”

Comment: Does this study have any clinical significance?  Body weight and composition did not change. I’m all for nut-eating—love them—but for this reason?  Hardly.  Despite what this study implies, nuts have calories and they most definitely count.