Want to know how old you are? Check your grip strength. That is, how hard you are able to grip something, physically.
A recent study of 1,275 men and women found that people with relatively weak handgrip strength, a reliable marker of overall muscle quality and strength, showed signs of accelerated aging of their DNA. Their genes seemed to age faster than those of more powerful people.
Although preliminary, the research raises the possibility that hitting the gym or doing a few push-ups in our living rooms may help turn back the clock, making our cells and bodies biologically younger, no matter what our current age.
Plenty of research has already revealed that physical strength is good for us. People who lift weights are significantly less likely to develop heart disease, high blood pressure and many other chronic diseases than those who skip exercise.
Physical strength can also be a marker of how long we will live. In a 2015 study of nearly 140,000 adults in high-, middle-, and low-income countries, reduced handgrip strength was strongly associated with mortality in people of all income levels, predicting the risks of early death better than blood pressure, often considered one of the best indicators of life expectancy. . “Grip strength is a simple but powerful predictor of future disability, morbidity, and mortality,” concluded the authors of an accompanying editorial, and its effects hold “not only in older people, but also in middle-aged and young people.”
But how might a firm grip today affect our well-being tomorrow?
“Grip strength is often called a biomarker of aging,” said Mark Peterson, a professor of physical medicine and rehabilitation at the University of Michigan in Ann Arbor, who led the new study. “But the biological context for why it so well predicts positive and negative outcomes during aging was not really clear.” Epigenetics, Dr. Peterson and his colleagues suggested, may be the key. Epigenetics involves changes in the number and actions of certain tiny molecules that cling like clams to the outer surface of a gene and affect how and when that gene turns on. Epigenetic changes occur in response to our diet, exercise habits, and aspects many others of our lives, affecting our DNA and health.
Epigenetics may also signal how fast we age. About a decade ago, researchers began analyzing huge datasets of people’s epigenomes, which are the epigenetic changes unique to each of us, and using that data to develop so-called “epigenetic clocks” that estimate our biological age.
Chronological age is, of course, how old we are, according to our birth certificates. Biological age indicates the age, function and health of our cells, and in fact – the age of our body. The two numbers can be substantially different.
Epigenetic clocks use algorithms to estimate biological age, based on the different patterns of molecules on genes. If the clock indicates that your biological age exceeds your chronological age, you are aging faster than normal, and to be blunt, approaching frailty and death at a higher rate than someone whose biological age is lower.
Aware of the latest epigenetic clock research, Peterson and his colleagues wondered whether physical strength might be related to epigenetic age, for better or for worse. They began collecting records for 1,275 participants of an ongoing study on aging for whom they had already given blood and used a pressure device called a hand dynamometer to measure their grip strength. The researchers then determined the approximate epigenetic age of each of their blood cells, using three different clocks (several labs have developed proprietary epigenetic clocks, which vary slightly). They also looked at death records for up to 10 years after people joined the study and finally, cross-referenced that data against people’s grip strength.
They found that, in general, the weaker someone’s grip strength, the higher their epigenetic age. Their DNA appears less youthful than that of their more robust peers, leaving them more vulnerable to disease or increasing their chances of dying earlier. “Overall, this study lends further support to the link between epigenetic age and frailty,” said Guillaume Parra, professor and director of the Laboratory of Genetic and Molecular Epidemiology at McMaster University in Hamilton, Ontario. Parra studied epigenetics but was not involved in the new research.
However, the study raises new issues. “A key question that remains to be addressed is the causality of these relationships,” said Parra. Although the study shows that people with weaker muscles are also people with higher epigenetic age, it cannot prove that weakness directly caused someone to age faster. Other factors may be involved, such as income, diet, medical history, or other aspects of a person’s lifestyle.
But even with its limitations, the study’s results are provocative, Peterson said, suggesting that the quality of our muscles may affect our epigenomes, and consequently how quickly and in what way we age.
If you’re wondering about your current physical strength, many gyms have hand dynamometers that you can use to test your grip strength. If the results show that your grip is leaning towards the weaker side, you should not focus only on strengthening your hands. You can strengthen the grip by strengthening the body, in general.
In fact, most of us don’t need to analyze our exact grip strength to realize that we can benefit from additional strength training. “The common physical activity pyramids, which indicate the amount and types of activity we need, put strength training at the end of the pyramid,” said Peterson, “as if it’s the part we need the least. But in my opinion, strengthening our physical strength should be at the base. It’s the foundation of health “.
So use the gym membership you bought this month. Try a body-weight workout or complete some sit-ups. You may eventually change your epigenome age. And along the way maybe also strengthen the biceps muscle.