Peanuts may improve regional brain insulin response

A randomized crossover trial found changes in insulin-induced cerebral blood flow following 16 weeks of daily peanut consumption, although the connection to improved memory remains unclear.

By
Andrea Surnit
October 16, 2026
4 min

MDSpire News

At a Glance

Category	Detail
Condition	Regional brain insulin responsiveness in older adults
Key Mechanisms	Insulin-induced cerebral blood flow was measured before and after intranasal insulin; the study found a region-specific reduction in response after peanut consumption.
Target Population	Adults aged 60 to 75 years; 31 participants completed the study.
Care Setting	Controlled crossover research study using intranasal insulin and arterial spin labeling MRI; no clinical care setting was specified.

Key Highlights

Participants consumed 60 g of unsalted, skin-roasted peanuts daily for 16 weeks and completed a 16-week control period, separated by an 8-week washout.
Peanut consumption was associated with a statistically significant reduction in insulin-induced cerebral blood flow in one right-hemisphere cluster involving memory-related regions.
No significant differences were found in global, gray matter, cortical, or subcortical insulin-induced cerebral blood flow responses.
Regional brain response changes were not significantly associated with previously reported improvements in verbal recognition memory.
Fasting glucose, insulin, insulin resistance, liver fat, cholesterol measures, and high-sensitivity C-reactive protein did not significantly change.
Triglyceride concentrations were lower after 8 weeks of peanut consumption, but the difference was no longer evident at 16 weeks.

Guideline-Based Recommendations

Diagnosis

The study assessed brain insulin responsiveness by measuring cerebral blood flow before and 30 minutes after 160 IU of intranasal insulin using arterial spin labeling MRI.

Management

The study evaluated daily consumption of 60 g of unsalted, skin-roasted peanuts for 16 weeks; it did not establish a clinical treatment recommendation.

Monitoring & Follow-up

Researchers assessed cerebral blood flow, liver fat, glucose homeostasis, lipid measures, inflammation markers, and verbal recognition memory.

Risks

One participant withdrew because of gastrointestinal discomfort; no study-related serious adverse events were reported.
Peanuts increased total energy intake, while waist circumference and body fat percentage remained unchanged during the study.

Patient & Prescribing Data

Adults aged 60 to 75 years; 31 completed the randomized, single-blind, controlled crossover trial, with a mean age of 67 years and 15 women.

Participants consumed 60 g of unsalted, skin-roasted peanuts daily for 16 weeks. Median adherence was 100%. The study did not prescribe food replacement, and it lacked an energy- and macronutrient-matched control.

Clinical Best Practices

Interpret the regional cerebral blood flow finding as an indirect measure of insulin-related neuronal activity; the study did not directly measure neuronal insulin signaling.
Do not infer that the regional response change caused improved verbal recognition memory; no significant association was found.
Consider the study limitations when interpreting results, including its small sample, absence of an energy- and macronutrient-matched control, and addition of peanuts to participants’ habitual diets.