Yet there’s a danger that comes from another bad habit that’s not well known. It’s not something people do, it something people don’t do…
I’m talking about exercising to maintain muscle strength.
Non-exercisers could claim there’s nothing to directly link muscle weakness with biological aging. But that’s not true. Scientists have discovered more new research that links weak muscles to faster aging.
The Weak Muscle Link to Aging
An abundance of evidence links muscular weakness - as determined by low grip strength - to a host of aging-related problems including heart disorders and heart attacks, diabetes, cognitive decline (including Alzheimer's disease), physical disability, and premature death.Lower grip strength is also linked to inflammation, which is a significant risk factor for mortality among older adults.
For these reasons grip strength has been labelled a “biomarker of aging.” However, up until now, no direct mechanism has been found to link muscle weakness with these health problems of aging.
Epigenetic Clocks
Our biological age is a more useful measure in predicting how our body is aging than our chronological age—or age since birth. One method of measuring our biological age is called epigenetics. Epigenetic processes affect gene expression without changing the DNA sequence itself.One epigenetic process is called DNA methylation, where chemical structures called methyl groups are added and removed along the length of the DNA to turn genes on and off. With aging, changes in methylation happen in a predictable way – like clockwork, but the speed of the clock will vary slightly in every person. This depends on a person’s individual genetics and lifestyle.
DNA methylation is strongly linked with the development of disease. The good news is that methylation profiles are thought to be modifiable by lifestyle and other environmental factors, so it’s possible to turn back the aging clock.
Researchers at the University of Michigan carried out a study that measured grip strength and tied it to biological aging clocks.
Grip Strength is the “New Smoking”
Several clocks have been generated for measuring an individual's epigenetic age and whether biological age is accelerating or decelerating.For their study the scientists used three DNA methylation “age acceleration clocks.” The clocks were used to model the relationship between grip strength and biological age in 1,274 men and women aged between 51 and 70 who took part in the Health and Retirement Study, which is the longest running longitudinal study of older adults in the USA. It includes full sociodemographic information, extensive questionnaire reports, physical and cognitive measures, and biological samples.
The results of their extensive analysis and eight to ten years of observation revealed a robust association between lower grip strength and biological age acceleration - the first time this has even been demonstrated.
Mark Peterson, lead author of the study, explained, saying, “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.”
Screening Important
Dr. Peterson believes that screening for grip strength is an important strategy because it “would allow for the opportunity to design interventions to delay or prevent the onset or progression of these adverse ‘age-related’ health events.”He explained the interventions he had in mind, saying, “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. We can show it with a biomarker like DNA methylation age, and we can also test it with a clinical feature like grip strength.”
