New research reveals that both an intermittent fasting (IF) diet and a standard healthy living (HL) diet can lead to significant cognitive improvements and slowed brain aging in older overweight adults with insulin resistance (IR). The findings, published in Cell Metabolism on June 19, highlight the potential of dietary interventions to enhance brain health, although neither diet affected Alzheimer’s disease (AD) biomarkers.
The study, led by Dr. Dimitrios Kapogiannis, MD, chief of the human neuroscience section at the National Institute on Aging, involved 40 cognitively intact overweight participants with IR, with a mean age of 63.2 years. The participants were randomly assigned to follow either the IF diet or the HL diet for eight weeks.
Key Findings:
- Cognitive Outcomes:
- Both diets improved executive function and memory.
- The IF diet showed more robust benefits in areas such as strategic planning and task switching.
- Brain Aging:
- MRI assessments revealed a decrease in brain age by 2.63 years with the IF diet and 2.42 years with the HL diet.
- Insulin Resistance and Metabolic Health:
- Both diets reduced neuronal IR and improved insulin signaling biomarkers.
- There were comparable reductions in brain glucose and improvements in blood biomarkers of carbohydrate and lipid metabolism.
- Body Composition:
- BMI decreased by 1.41 kg/m² with the IF diet and by 0.80 kg/m² with the HL diet.
- Both diets led to significant weight loss and reductions in waist circumference.
Despite these promising outcomes, the study found no changes in AD biomarkers such as amyloid beta 42, amyloid beta 40, and plasma phosphorylated-tau181, potentially due to the study’s short duration. Both diets were generally well tolerated, although gastrointestinal issues were more common with the IF diet.
Conclusion: This research provides a valuable framework for evaluating the impact of dietary interventions on brain health and underscores the need for further studies on intermittent fasting and continuous diets. The findings support the role of diet in promoting cognitive health and slowing brain aging, offering hope for dietary strategies to combat cognitive decline in older adults.
Funding and Disclosure: The study was supported by the National Institutes of Health’s National Institute on Aging. The authors reported no competing interests.
The study emphasizes the importance of healthy eating patterns in maintaining cognitive function and delaying brain aging, marking a significant step forward in nutritional neuroscience.