As individuals age, a common physiological change observed is the gradual reduction in muscle mass, termed sarcopenia. From the age of 50 onwards, there is typically a yearly decline of 1-2% in muscle mass. Studies suggest that between 5-13% of individuals aged 60-70 experience sarcopenia, and the prevalence sharply rises to 11-50% in those aged 80 and above. This reduction contributes not only to physical challenges but also increases the likelihood of falls and fractures.
Beyond the mechanical effects, sarcopenia affects various physiological systems. For instance, skeletal muscles function as endocrine organs by releasing hormones known as myokines. These hormones are vital in managing glucose metabolism, insulin function, and nerve cell performance. Additionally, myokines are crucial in controlling inflammation, which tends to persist in older age and can harm cells and tissues, a phenomenon referred to as ‘inflammaging’.
The risk factors for sarcopenia are diverse, encompassing physical inactivity, insufficient protein intake, and chronic medical conditions like cancer or diabetes. Age-related changes also play a significant role. Diagnosing sarcopenia can be complex, often involving tests such as grip strength, walking speed, or the chair stand test.
The latest study utilized a novel approach by measuring the size of the temporalis muscle via MRI scans as a proxy for generalized muscle health. This muscle size correlates strongly with overall muscle mass, providing an indirect yet effective measure for assessing sarcopenia. Dr. Kamyar Moradi, the lead author, highlights the value of this method as it leverages existing MRI scans for neurological assessments without additional costs.
The study examined 621 participants, average age 77.3, who did not have dementia at the outset. Researchers found that individuals with smaller temporalis muscles exhibited a higher risk of dementia over a 5.8-year follow-up period. Smaller muscle size was associated with poorer cognitive test outcomes and larger reductions in brain volume, particularly in regions critical for memory, such as the hippocampus and entorhinal cortex. Prof. Marilyn Albert noted that adjusting for other dementia risk factors, smaller muscle size still posed a 60% increased risk.
Interventions focusing on mitigating sarcopenia could potentially help reduce the risk of cognitive decline and dementia. Exercise physiologist Kaleigh Ray advocates for simple yet effective workouts, such as chair exercises, which are accessible and supportive for older adults. These exercises, combined with lightweight dumbbell routines, can help maintain muscle mass.
Maintaining adequate protein intake is equally important in preserving muscle health. Many older adults in the U.S. meet standard protein recommendations, but some require more. Registered dietitian Maddie Gallivan suggests incorporating high-quality protein sources, including plant-based options, into daily diets. Innovative preparations, such as integrating ground nuts into breakfast porridges or using yogurt, can help meet protein needs even for those facing chewing difficulties.
The association between sarcopenia and dementia underscores the importance of proactive measures in aging populations. Both physical activity and nutritional strategies play essential roles in maintaining muscle health and potentially safeguarding cognitive function. These findings highlight the need for further attention to muscle health as a component of comprehensive elderly care strategies.
Source: MedicalNewsToday
