ANN ARBOR, Mich. — Want to feel younger? New research from the University of Michigan suggests you may want to invest in some weights and begin a strength training course. According to a recent study, weak muscles could be just as influential on your longterm health as smoking cigarettes!
Not everyone ages at the same rate. Consider two adults, both 60 years old. While those two people may share the same chronological age, one may be far younger from a biological aging perspective. Aging is influenced by far more than days crossed off on the calendar; genetic, environmental, and behavioral factors all play a major role as well. Poor lifestyle choices like avoiding exercise, unhealthy diet, and smoking are all believed to accelerate biological aging processes. Dealing with a serious illness can also age the body at an accelerated rate.
In short, your body may be aging at a much faster rate than the birthdate on your driver’s license suggests. Now, for the first time ever, the team at UM reports that muscle weakness marked by grip strength, a proxy for overall strength capacity, is connected with accelerated biological age. According to the findings, the weaker your grip strength, the older your biological age.
‘Strong evidence of link between muscle weakness and acceleration in biological age’
The team at Michigan Medicine modeled the relationship between biological age and grip strength among 1,274 participants, all of whom were either middle aged or older adults. This was accomplished via three “age acceleration clocks” based on DNA methylation, a process that provides a molecular biomarker and estimator of the pace of aging. Those clocks were originally crafted from earlier studies focusing on a variety of ailments including diabetes, cardiovascular disease, cancer, physical disability, Alzheimer’s disease, inflammation, and early mortality.
The ensuing results revealed both older men and women display an association between lower grip strength and biological age acceleration across DNA methylation clocks.
“We’ve known that muscular strength is a predictor of longevity, and that weakness is a powerful indicator of disease and mortality, but, for the first time, we have found strong evidence of a biological link between muscle weakness and actual acceleration in biological age,” says lead study author Mark Peterson, associate professor of physical medicine and rehabilitation at University of Michigan, in a university release. “This suggests that if you maintain your muscle strength across the lifespan, you may be able to protect against many common age-related diseases. We know that smoking, for example, can be a powerful predictor of disease and mortality, but now we know that muscle weakness could be the new smoking.”
One of this project’s biggest strengths was the eight to 10 years of observation performed. Results show that lower grip strength indeed predicted faster biological aging measured up to a decade later, according to study co-author Jessica Faul, a research associate professor at the UM Institute for Social Research.
Prior studies have suggested that low grip strength appears to be a strong predictor of negative health events in general. One project reported it is a better predictor of cardiovascular events, such as myocardial infarction, than systolic blood pressure, which is considered the clinical hallmark for detecting heart disorders. Prof. Peterson and his team have even previously uncovered a strong association between muscle weakness and chronic disease / mortality across population samples.
This prior work, in combination with these latest findings, suggests there is serious potential for clinicians to adopt the use of grip strength as a means of screening for accelerated biological aging. This can help identify those who may be at an elevated future risk of functional decline, chronic disease, and even early mortality.
“Screening for grip strength would allow for the opportunity to design interventions to delay or prevent the onset or progression of these adverse ‘age-related’ health events,” he adds. “We have been pushing for clinicians to start using grip strength in their clinics and only in geriatrics has this sort of been incorporated. However, not many people are using this, even though we’ve seen hundreds of publications showing that grip strength is a really good measure of health.”
Strength training could prevent ‘inflammaging?’
Moving forward, more research is needed to form a stronger understanding of the association between grip strength and age acceleration, such as how inflammatory conditions may contribute to age-related weakness and mortality. Prior studies tell us that chronic inflammation in aging, or “inflammaging,” is a strong risk factor for mortality in older adults. That same type of inflammation is also linked to lower grip strength, and may serve as a significant predictor on the pathway between lower grip strength and both disability/chronic disease multi-morbidity.
Also, future studies should focus more on how lifestyle and behavioral factors like exercise and diet may influence both grip strength and age acceleration, Prof. Peterson adds.
“Healthy dietary habits are very important, but I think regular exercise is the most critical thing that somebody can do to preserve health across the lifespan,” he concludes. “We can show it with a biomarker like DNA methylation age, and we can also test it with a clinical feature like grip strength.”
The study is published in the Journal of Cachexia Sarcopenia and Muscle.