A study spearheaded by the National Institute on Aging (NIA) reveals that elderly individuals grappling with obesity and metabolic dilemmas could bolster their cognitive health through wholesome dietary practices. This revelation emerged from the team’s analysis of cerebral alterations in seniors who adhered to either a regimen of intermittent fasting or a balanced diet endorsed by the U.S. Department of Agriculture (USDA) over an eight-week period. Published in the journal Cell Metabolism, this research offers insightful methodologies to assess the impact of nutritious diets on the neurological well-being of the aging populace.
Current research posits a connection between the onset of Alzheimer’s disease or related dementias and insulin resistance—a metabolic impairment characterized by the body’s cells failing to effectively clear glucose from the bloodstream, thereby heightening dementia risk. The investigative team intended to determine if making healthful dietary alterations could enhance both general wellness and cognitive function.
In the course of the clinical examination, 40 participants, averaging 63 years in age and all contending with insulin resistance, were selected at random to follow either a 5:2 intermittent fasting regimen—limiting caloric intake to a mere 25% of the daily recommended amount for two days each week—or to adopt the USDA’s prescribed regimen for healthy living. This latter diet emphasized the consumption of fruits, vegetables, whole grains, lean protein sources, and low-fat dairy products while reducing added sugars, saturated fats, and sodium levels.
At the outset, in the fourth week, and at the conclusion of the study’s eighth week, the research team procured plasma samples from participants through blood collections. These samples were essential for extracting neuron-derived extracellular vesicles (NDEVs) – microscopic fragments or sacs emitted into the bloodstream from neuronal cells. Utilizing NDEVs presented a minimally invasive method to investigate neuronal insulin utilization. Cognitive function was evaluated, and advanced imaging techniques, including magnetic resonance imaging and spectroscopy, were employed to assess the rate of cerebral aging and the brain’s glucose consumption. The exploration extended to analyzing NDEVs and cerebrospinal fluid for indicators of Alzheimer’s disease.
The outcomes revealed that both dietary approaches – intermittent fasting and adherence to a USDA healthy living diet – tempered the progression of brain aging, while also enhancing cognitive function and insulin resistance. Notably, intermittent fasting yielded superior gains in executive function and fostered more significant weight loss. However, markers signaling Alzheimer’s disease remained unaltered by either dietary intervention.
Although the alterations in diet did not seem to influence dementia risk, the findings indicate that nutritional adjustments can augment brain health in older individuals with metabolic complications. This research provides a valuable foundation for broader clinical trials aimed at dietary interventions.