Exercise may reduce plaque and tangles in the brain associated with Alzheimer’s.

Exercise may reduce plaque and tangles in the brain associated with Alzheimer's.

Exercise Hormone Irisin Could Help Prevent Alzheimer’s Disease

Weightlifting is one of the exercises recommended for brain health in older adults.

Researchers from Massachusetts General Hospital have found compelling evidence suggesting that exercise plays a crucial role in preventing Alzheimer’s disease. They discovered that exercise helps produce a hormone called irisin, which has the potential to combat the brain-damaging abnormal protein, amyloid beta. The team’s groundbreaking study, published in the journal Neuron, offers valuable insights into the mechanisms behind the link between exercise and reduced amyloid beta levels.

Irisin is a muscle-derived hormone that increases in the body following exercise. It regulates glucose and lipid metabolism in fat tissues and boosts energy expenditure by promoting the browning of white fat tissue. While studies have shown the presence of irisin in human and mouse brains, individuals with Alzheimer’s and mouse models of the disease exhibit reduced levels of this hormone.

To investigate the connection between exercise-induced irisin production and amyloid beta pathology, the researchers developed 3D human cell culture models of Alzheimer’s. These models demonstrated the characteristic generation of amyloid beta plaques and neurofibrillary degeneration of the protein tau, both observed in Alzheimer’s patients.

The research team then applied irisin to their 3D cell culture model to determine whether the hormone played a causal role in reducing amyloid beta levels. The results were striking: irisin treatment led to a remarkable reduction in amyloid beta pathology. The researchers further discovered that this effect of irisin was attributed to increased neprilysin activity, a crucial enzyme responsible for degrading amyloid beta.

Delving deeper into the mechanisms, the researchers identified a receptor that irisin binds to, triggering an increase in neprilysin levels. Additionally, the binding of irisin to this receptor resulted in reduced signaling of pathways involving two key proteins, extracellular signal-regulated kinase (ERK) and signal activator of transcription 3 (STAT3). The reduction in ERK and STAT3 signaling is critical for irisin to enhance neprilysin’s ability to combat amyloid beta.

Previous studies have shown that irisin injected into the bloodstream of mice can penetrate the brain, paving the way for targeted therapies. This exciting finding opens up a new pathway for potential treatments and interventions for Alzheimer’s disease.

While the research is still in its early stages, experts believe that further studies are needed to fully understand the mechanisms behind irisin’s role in preventing Alzheimer’s. Ryan Glatt, a senior brain health coach, emphasizes the necessity of human research. Comparisons between different growth factors, such as insulin-like growth factor-1 (IGF-1) and brain-derived neurotrophic factor (BDNF), could provide valuable insights into the mediating effects of irisin.

The research also raises questions about the specific modes, intensities, and durations of exercise that lead to significant concentrations of irisin. Additionally, understanding how irisin expression and other myokines affect cognitive outcomes is crucial, particularly when comparing cognitively healthy individuals with those with existing cognitive impairment.

Nick Voci, a doctor of physical therapy, believes that this research reinforces the importance of promoting physical therapy, activity, and exercise in general. While the study’s findings offer promising results, more research is needed to determine the impact exercise could have on people with Alzheimer’s and whether medications could replicate the effects of exercise without physical activity. Nonetheless, it is clear that exercise serves as a powerful preventative tool, and Voci emphasizes that exercise is medicine.

In conclusion, the discovery of the hormone irisin and its potential in combatting Alzheimer’s disease marks a significant breakthrough. The study conducted by researchers at Massachusetts General Hospital sheds light on the mechanisms behind the positive effects of exercise on reducing amyloid beta levels. With further research, irisin-based therapies may pave the way for the prevention and treatment of Alzheimer’s, giving hope to millions of individuals affected by this debilitating disease.

References: – Medical News TodayNeuron (Journal)