Researchers from Monash University have discovered that a protein known as NOX4 plays a crucial role in preserving muscle mass and strength as the body ages. The findings were published on the preprint server bioRxiv.

Scientists believe NOX4 may be one of the key molecular links between physical activity and the slowing of biological aging — the gradual decline in the function of organs and tissues over time.

Regular exercise is widely regarded as one of the most effective ways to delay age-related deterioration. However, both physical activity levels and the natural activity of NOX4 tend to decrease with age. According to the researchers, this may partly explain why older individuals often derive fewer benefits from exercise than younger people. Experimental studies showed that low NOX4 levels were associated with muscle loss, reduced strength, and increased frailty. In contrast, restoring NOX4 activity improved metabolism, increased muscle mass, and enhanced muscle strength.

According to the study’s lead investigator, Tony Tiganis, the findings raise the possibility of developing alternative approaches that activate the same biological pathways triggered by exercise. If these mechanisms can be reproduced therapeutically, they could help older adults maintain strength, mobility, and overall health for longer.

The researchers propose that NOX4 functions as a signaling molecule within muscle tissue, stimulating the production of oxygen-containing molecules that help cells adapt to physical stress. These molecules appear to improve energy production, reduce cellular damage, and support normal tissue function.

The same research team previously demonstrated that NOX4 acts as an important mediator of the muscle adaptations induced by physical activity. They are now investigating the specific intracellular signaling pathways controlled by the protein in an effort to determine whether these effects can be replicated artificially.

One area of interest involves naturally occurring compounds found in cruciferous vegetables such as broccoli, cabbage, and Brussels sprouts. Scientists are exploring whether these compounds can influence the NOX4-related pathway and potentially mimic some of the beneficial effects of exercise during aging.

The researchers emphasize, however, that their findings do not suggest replacing physical activity with medications or dietary interventions. At this stage, the work represents a promising avenue of research that could eventually complement existing strategies for maintaining health in older age.