Researchers have identified four markers of bodily ageing, and people who change their lifestyles have reversed several of these, at least for a little while.
A research team from Stanford University School of Medicine reckon there are four biological pathways that regulate the ageing process: metabolic, immune system, hepatic (liver) and nephrotic (kidney).
They measured the pathways in 43 healthy men and women for two years and discovered that some of the participants weren't showing any signs of biological ageing, and some were seeing their markers reversing, even for a short time, when they changed their lifestyle, such as diet or exercise. Reversals were usually found in kidney functioning.
One of the biggest impacts on ageing was insulin resistance, the body's inability to properly break down blood sugars.
Lead researcher Michael Snyder said his own pathways were showing average ageing. "I was a bit disappointed to see that I was ageing at a pretty average rate, and so I started lifting weights. It'll be interesting to see if that influences my ageing pathways in another year's time."