Everyone ages at a different
That's why two 50-year-olds, despite living the same number of years, may have different biological ages — meaning that many intrinsic and extrinsic factors cause them to age at different rates and have different
risks of disease and early death.
Lifestyle choices, such as diet and smoking, as well as disease, can cause a person's biological age to age faster
In other words, your body is aging faster
For the first time, researchers have found that muscle weakness, marked by grip strength, is associated
with an acceleration of biological age.
Grip strength is a proxy for
overall strength capability.
Specifically, according to research published in the Journal of Cachexia, Sarcopenia and Muscle, the weaker your grip, the older your biology will be
Using three "age acceleration clocks" based on DNA methylation, researchers at Michigan Medical College modeled
the relationship between biological age and grip strength in 1,274 middle-aged and older adults.
These clocks were originally modeled
on various studies of diabetes, cardiovascular disease, cancer, physical disability, Alzheimer's, inflammation, and early death.
The results showed that both older men and women showed an association
between lower grip strength and biological age acceleration on the DNA methylation clock.
"We already knew that muscle strength was a predictor of longevity and that frailty was a strong indicator of disease and mortality, however, for the first time, we found strong evidence that there is a biological link between muscle weakness and the actual acceleration of biological age," said Mark Peterson, Ph.
, lead author of the study and associate professor of
physical medicine and rehabilitation at the University of Michigan.
"This suggests that if you maintain muscle strength throughout your life, you may be able to prevent many common age-related diseases
" For example, we know that smoking can be a powerful predictor of disease and mortality, but now we know that muscle weakness may be the new smoking
Study co-author Dr.
Jessica Fore, a research associate professor at the University of Michigan's Institute for Social Research, said the real strength of the study lies in 8 to 10 years of observation, during which lower grip strength predicted faster biological aging
Past studies have shown that low grip strength is a very strong predictor
of adverse health events.
One study even found that it was a better predictor of cardiovascular events, such as myocardial infarction
, than systolic blood pressure, which detects clinical markers of heart disease.
Peterson and his team have previously demonstrated a strong link
between frailty and chronic disease and mortality in populations.
Peterson said this evidence, combined with their recent findings, suggests that clinicians may be using grip strength as a way
to screen individuals for future functional decline, chronic disease and even early mortality risk.
"Screening for grip strength will give us the opportunity to design interventions to delay or prevent the onset or development
of these 'age-related' adverse health events," he said.
"We've been pushing clinicians to start using grip strength in their clinics, and it's only in geriatrics
However, not many people use this method, although we have seen hundreds of publications showing that grip strength is a good indicator
The researchers say future research needs to understand the link between grip strength and age acceleration, including how inflammation contributes to age-related weakness and death
Previous research has shown that chronic inflammation during aging — known as "inflammation" — is an important risk factor
for death in older adults.
This inflammation is also associated with lower grip strength and may be an important predictor
of pathways between lower grip strength and disability and chronic disease.
In addition, Peterson said, research must focus on how lifestyle and behavioral factors, such as physical activity and diet, affect grip strength and age acceleration
"Healthy eating habits are very important, but I think regular exercise is the most critical thing
people can do to stay healthy throughout their lives," he said.
"We can show it with biomarkers like DNA methylation age, and we can test it
with clinical features like grip strength.