TL;DR
A study from the University of Vienna shows that jaw muscles decline less quickly than leg muscles with age, indicating lifestyle factors influence muscle loss. Strength decline, however, appears similar in both muscle groups.
A recent study published in the Journal of Sports Sciences reveals that jaw muscles decline in size at half the rate of leg muscles with age, suggesting lifestyle factors play a significant role in muscle loss. The research, conducted by a team at the University of Vienna, highlights potential implications for understanding how aging affects muscle health and activity levels.
The study involved 30 healthy women divided into three age groups: 18-30, 40-50, and 65-75. Researchers measured the size and strength of their quadriceps and masseter muscles using ultrasound, leg-extension machines, and bite force sensors. Results showed that muscle size declined approximately 1.02% per year in leg muscles but only 0.49% in jaw muscles, indicating a faster decline in leg muscle size.
However, when assessing muscle strength, the decline was similar in both muscle groups, with no significant difference observed. This discrepancy suggests that muscle size and strength may not always decline in parallel, possibly due to differences in muscle fiber composition and neural control mechanisms. The study notes that fast-twitch fibers, which are more prone to atrophy, are more abundant in leg muscles than in jaw muscles.
Why It Matters
This research suggests that lifestyle choices, such as maintaining physical activity, significantly influence muscle preservation with age. The slower decline in jaw muscle size indicates that consistent use—like chewing—can help preserve muscle mass, while the similar strength decline across muscles underscores the complexity of aging effects on muscle function. For readers, this highlights the importance of staying active to combat age-related muscle loss and maintain overall health.
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Background
Previous studies have shown that aerobic capacity declines by about 10% per decade after age 25, but regular training can mitigate this decline to around 5%. This new research complements those findings by examining muscle-specific aging patterns, emphasizing that muscle loss is partly due to disuse and lifestyle factors, not just aging itself. The cross-sectional nature of the study, comparing different age groups at one point in time, limits definitive conclusions about individual aging trajectories.
“Our findings suggest that maintaining activity levels, especially in muscles used daily like the jaw, can influence how muscles age over time.”
— Gustavo Schaun, lead researcher
“The discrepancy between muscle size and strength decline highlights the complexity of aging muscles and the importance of neural factors.”
— Dr. Jane Miller, muscle physiologist not involved in the study
What Remains Unclear
It remains unclear whether the observed differences between jaw and leg muscles are solely due to lifestyle or if intrinsic muscle properties also play a role. The cross-sectional design limits causal inferences, and longitudinal studies are needed to confirm these patterns over time.
What’s Next
Future research will likely focus on longitudinal studies tracking individual muscle changes over decades. Additionally, investigations into how specific activities or interventions can slow muscle decline in different muscle groups are expected to develop, aiming to inform aging health strategies.
Key Questions
Does chewing gum help preserve jaw muscle strength with age?
While the study suggests that active use of jaw muscles may slow size decline, direct evidence on chewing gum’s effectiveness is limited. Maintaining regular oral activity and overall muscle use is generally beneficial.
Can regular exercise prevent leg muscle decline as we age?
Yes. Resistance and aerobic exercises are proven to help maintain muscle mass and strength, reducing age-related decline in leg muscles and overall functional ability.
Why do muscle size and strength decline differently?
Muscle size and strength are influenced by different factors. Strength depends on neural efficiency and muscle quality, not just size, which explains why they may decline at different rates.
Are fast-twitch fibers more vulnerable to aging?
Yes. Fast-twitch fibers, more prevalent in leg muscles, tend to atrophy more rapidly with disuse and aging, contributing to the observed differences in muscle decline patterns.
