- Sarcopenia describes the muscle loss that often occurs in older age.
- Individuals with higher levels of muscle loss are more at risk of adverse Health outcomes, including falls and fractures.
- The latest study concludes that sarcopenia is also linked to an increased risk of cognitive decline and dementia.
A new study involving researchers at multiple Johns Hopkins Medical Institutions investigated muscle loss and dementia risk.
They found that the relative size of one specific muscle — which they used as a proxy for sarcopenia — was associated with increased dementia risk and cognitive decline.
The results will be presented at this year’s Radiology Conference and Annual Meeting in Chicago, IL.
As we age, our overall muscle mass tends to decline. After age 50, we lose an average of
This downward trend makes it more difficult to navigate daily life and can impact an individual’s ability to care for themselves.
Sarcopenia also significantly increases the risk of falls and fractures. Aside from issues of strength and balance, muscle loss can also impact other body systems. Skeletal muscle is an endocrine organ, meaning that it releases hormones. These hormones — called myokines — enter the blood and have wide-ranging effects.
For instance, they can influence how glucose is metabolized in the liver, how insulin-producing cells in the pancreas function, and how well nerve cells work.
Myokines also help keep inflammation in check, which is important: As people age, they tend to experience long-term inflammation, which can start to damage cells and tissues. Inflammaging is the term experts use to describe this persistent low-level inflammation with age.
There are a few factors that increase the risk of sarcopenia, which include:
- Physical inactivity.
- Inadequate protein intake.
- Ongoing medical conditions, like cancer or diabetes.
- The natural process of aging.
Diagnosing sarcopenia is not straightforward, but may involve physical tests. These can include testing hand grip strength, measuring walking speed, or using the chair stand test, in which the individual stands up and sits down as many times as possible within 30 seconds.
In the latest study, the scientists utilized a relatively new approach. They used magnetic resonance imagery (MRI) scans to measure the size of a muscle in the head called the temporalis muscle.
This muscle is responsible for closing the jaw, and earlier studies have found that its size strongly correlates with sarcopenia — people with a smaller temporalis tend to have reduced muscle mass throughout their entire body.
The study’s lead author, Kamyar Moradi, MD, explains why this approach is useful:
“Measuring temporalis muscle size as a potential indicator for generalized skeletal muscle status offers an opportunity for skeletal muscle quantification without additional cost or burden in older adults who already have brain MRIs for any neurological condition, such as mild dementia.”
In the latest study, the researchers recruited 621 participants without dementia with an average age of 77.3 years.
Using MRI scans, they measured participants’ temporalis muscles and split them into either large or small. In total, 131 had a large and 488 participants had a small temporalis.
In their analysis, the researchers accounted for other variables that can play a role in dementia risk. This included age, sex, education level, marital status, brain size, and APOE-E4 status — a gene associated with dementia.
During an average follow-up of 5.8 years, they found that those with a smaller temporalis had an increased risk of developing dementia.
Further analyses showed that having a smaller temporalis was associated with poorer performance on cognitive tests. Also, this group had greater decreases in overall brain size, and the size of certain brain regions important for memory, like the hippocampus and entorhinal cortex.
“We found that older adults with smaller skeletal muscles are about 60% more likely to develop dementia when adjusted for other known risk factors,” explains co-senior author Prof. Marilyn Albert, Ph.D.
The good news is that there are ways to manage sarcopenia. So, by intervening during the aging process, medical professionals may be able to reduce dementia risk.
As co-author Prof. Shadpour Demehri explains, “These interventions may help prevent or slow down muscle loss and subsequently reduce the risk of cognitive decline and dementia.”
Medical News Today contacted Kaleigh Ray, an exercise physiologist with a Masters in biomechanics, who has worked as a personal trainer for many years. We asked what exercises older adults can do to help maintain muscle mass.
“I am a huge fan of chair workouts for older adults trying to build muscle at home,” she said. “These exercises are great for older adults because they can be done with no other equipment besides a chair and provide extra support for adults with balance issues.”
“My favorite chair exercises include chair rises, seated leg lifts, and side bends.” For instructions on how to complete these exercises, MNT has an in-depth guide to chair exercises for older adults.
“With a pair of lightweight dumbbells, senior adults can also do bicep curls, shoulder presses, front to lateral raises, and more,” continues Ray.
Alongside physical activity, it is important to consume enough protein — the building blocks of muscle.
Most adults in the United States meet the
MNT contacted Maddie Gallivan, a registered dietitian about the importance of protein intake.
“Our appetite naturally declines as we age, so meeting these higher protein needs can be more challenging. But there are lots of ways to incorporate protein as part of a balanced meal or snack,” she told Medical News Today.
“When we think of rich protein sources, people typically think of meat, fish, dairy, and eggs, but it is possible to get all the essential amino acids you need from a plant-based diet,” she said.
Gallivan advocates a food-first approach, “focusing on nourishing, high quality protein sources like lentils, chickpeas, beans, whole grains, such as quinoa and barley, and a variety of nuts and seeds. These are not only fantastic protein sources but they’re also rich in fiber — a nutrient most of us could benefit from consuming more of.”
Gallivan also said that the texture of high protein foods can sometimes be challenging for older adults, particularly those with dentures, but there are many ways to adapt meals.
“For example,” she told MNT, “stirring a spoonful of ground nuts and seeds into porridge is an excellent way to boost protein at breakfast while keeping the meal easy to eat, and yogurt is another great option.”
