Key Highlights
- Exercise Improves Brain Insulin Sensitivity
- Enhanced Glucose Tolerence and Fat Oxidation
- Neuroprotective benefits of exercise
The authors in this new study in Rutgers University discovered that exercise increased brain insulin sensitivity, which could enhance cognition and lessen the risk for dementia in older adults with prediabetes. This study shows how exercise induces the brain cells associated with insulin, opens a new avenue for preventive strategies against Alzheimer’s disease and other dementias that come under the category of ADRD.
The Association of Insulin Activity and Brain
Insulin is an important factor in the functioning of the brain, in addition to its action mainly as a sugar regulator in the body. It acts on both prefrontal cortex and the hypothalamus, which are related to memory and cognition. Thus, reduction of insulin trafficking into the brain along with age, prediabetes, and other factors has also been very much related to insulin resistance.
Neuronal extracellular vesicles released by neurons crossing the blood-brain barrier have opened a new frontier in research when it comes to how the brain responds to insulin. In exercise-based research, previous studies had shown increased gray matter volume, increased blood flow in the brain, and reduced neuroinflammation associated with better cognition.
The Study and Findings
There were 21 sedentary older adults with mean age being 60 years and mean BMI 33.5 kg/m². Participants were prediabetic and did not have any comorbid conditions, nor were on any glucose lowering medications. For this study participants, a supervised exercise program consisting of two weeks duration was offered, divided into sessions as follows:
Continuous exercise group: at 70% HRpeak
Interval exercise group: Periodic at 90% and 50% HRpeak
Each exercise session lasted for 60 minutes, and it had one rest day per week. Before and after the program, the measured outcomes were aerobic fitness, body weight, glucose tolerance, and insulin sensitivity.
The following are the results of the program outcome:
- Improved insulin sensitivity and glucose tolerance post-exercise
- Body weight reduction and increase in fat oxidation
- Higher peak oxygen consumption (VO₂ peak) that indicated improved aerobic fitness.
- Modulations in nEV-associated proteins, which were involved with exercise and insulin signaling, but might point towards improved sensitivity of the brain to insulin
Pro-BDNF was repressed post-fasting but not following glucose infusion. This would mean that exercise is a way to stimulate insulin signaling, which should, therefore, not damage all proteins that have brain origins.
Conclusion about Cognitive Health
Such studies further document the neuroprotective effects of exercise in older populations, at risk of declining faculties in view of prediabetes. As exercise enhances the insulin sensitivity of the brain, it may therefore serve as a preventive measure against dementia and thus holds forth promise for an even healthier course of aging.
