Muscle Weakness is biologically linked to negative health outcomes related to ageing

We have known for some time now that muscle weakness (measure in the form of grip strength) is associated with age related negative health outcomes. For example, several studies have implicated weaker grip strength with cognitive decline (Duchowny et al, 2022), diabetes (Peterson et al, 2016) and all-cause mortality (García-Hermoso et al, 2018). This remarkable new study conducted by Peterson and colleagues has found a biomarker to further enhance our knowledge of the association between grip strength and negative health consequences.

Researchers studied a diverse sample of 1,274 middle aged men and women and modeled the relationship between biological age and grip strength by using ageing biomarkers known as “DNA methylation age acceleration” (DNAm). DNAm is an epigenetic-based biological timekeeping machine. Researchers in the aging field argue that epigenetic-based biological clocks are more robust and holistic, as they are modifiable by environmental and lifestyle factors, and these clocks more accurately measure the true biological age (Hannum et al, 2013).

The results of the study showed that participants with lower grip strength also showed DNA methylation acceleration across “several clocks". Researchers also found that having higher grip strength has protective effects against DNAm age acceleration. Overall, the findings imply that there is a strong biological link between muscle weakness and negative health outcomes related to ageing.

Keep in mind that this study does not show the causal link between weaker grip strength and age-related negative health outcomes. The process of ageing is highly complex and multi-faceted. This study simply shows that in a big cohort of people, there is a strong biological link between those who have weaker grip strength (a proxy measure of general muscle weakness) and negative age-related health consequences.

Certainly though, muscle weakness can be treated effectively via strength training.  You need to engage in strength training to enjoy living a prosperous, long life. Strength training is vital for your metabolic health and for preventing many chronic diseases. Your bones and muscles are tightly intertwined and having weak muscles puts more stress and unwanted forces on your bones and joints. If you are new to strength training, start out small and stay consistent. Your body will respond positively, and you will feel more motivated the more times you do. Starting out with body weight exercises such a push-ups, squats (or half squats), glut bridges, planks, side planks, jumping up and down etc. are a good way to start. If you are a healthy person and you are not sure where to begin, find a personal trainer that works with diverse populations and start simple but stick to the program. If you have health issues and you are not sure where to begin, consult with your physiotherapist or doctor before you start a strength training routine. Two to three times a week is recommended but there are certainly benefits to strength training when done even once/week.

References

Peterson, M. D., Collins, S., Meier, H. C., Brahmsteadt, A., & Faul, J. D. (2022). Grip strength is inversely associated with DNA methylation age acceleration. Journal of Cachexia, Sarcopenia and Muscle.

Duchowny K, Ackley S, Brenowitz W, Wang J, Zimmerman SC, Caunca MR, et al. Associ[1]ations between handgrip strength and de[1]mentia risk, cognition, and neuroimaging outcomes in the UK biobank cohort study. JAMA Open Netw 2022;5:e221831

Peterson MD, Zhang P, Choksi P, Markides KS, al Snih S. Muscle weakness thresholds for prediction of diabetes in adults. Sports Med 2016;46:619–628.

García-Hermoso A, Cavero-Redondo I, Ramírez-Vélez R, Ruiz JR, Ortega FB, Lee DC, et al. Muscular strength as a pre[1]dictor of all-cause mortality in an appar[1]ently healthy population: A systematic review and meta-analysis of data from approximately 2 million men and women. Arch Phys Med Rehabil 2018;99: 2100–2113.e5.

Hannum G, Guinney J, Zhao L, Zhang L, Hughes G, Sadda SV, et al. Genome-wide methylation profiles reveal quantitative views of human aging rates. Mol Cell 2013;49:359–367