A new study published in the British Medical Journal suggests that developing lean muscle mass may offer some protection against Alzheimer's disease. Researchers from the University of California San Francisco found that individuals with higher levels of lean muscle mass had a 12% reduction in Alzheimer's risk.
Previous studies have explored the role of obesity and body mass index (BMI) in Alzheimer's development, but this study aimed to examine body composition more closely. Using data from hundreds of thousands of individuals, the researchers used gene variations as proxies for certain risk factors and estimated individuals' lean muscle and fat mass using bioimpedance measures.
The study found that participants with greater levels of lean muscle mass had a statistically significant lower risk of developing Alzheimer's. Interestingly, the analysis did not find a link between body fat and Alzheimer's risk once adjusted for lean mass.
While the findings support a cause-and-effect association between muscle mass and Alzheimer's risk, there are still unanswered questions. For example, it is unclear whether lean muscle must be built before a certain age to positively influence Alzheimer's development, or if it only impacts certain Alzheimer's pathologies. Additionally, the study does not directly address whether factors behind DNA, such as proactively building muscle mass, benefit from the association.
The mechanisms behind the relationship between lean muscle and Alzheimer's also remain unclear. The researchers speculated on potential links, such as cardiovascular disease and the release of proteins known as myokines by muscles that positively influence brain function. However, more research is needed to confirm these speculations.
While there is no foolproof measure to prevent Alzheimer's, experts believe that maintaining a healthy lifestyle, including regular physical activity, can help reduce the risk. Increasing lean muscle mass can be achieved through resistance training, and proper nutrition and recovery are also important factors.
Overall, this study provides hopeful findings that give individuals agency in their neurologic health. However, more research is needed to confirm the effect of lean muscle on Alzheimer's and understand the underlying mechanisms.