Mice that ran on a treadmill a few times a week for five months fended off premature aging in nearly every organ of their bodies, according to a study published on February 21, 2011 in the Proceedings of the National Academy of Sciences. It's one of the strongest pieces of evidence ever produced showing the power of exercise as an anti-aging remedy.
What's ingenious about this study is how it was designed. Scientists at McMaster University took a group of mice that were genetically engineered to age faster than normal mice. Some of the mice ran on treadmills for 45 minutes at a time, three times a week. Others were sedentary. The scientists then examined their mitochondria -- power centers within cells that generate energy. They could clearly see that the mice who exercised had fewer mutations or signs of damage to their mitochondria.
And the scientists could tell just by looking at them that they were younger than the mice who didn't run on the treadmill. According to a statement released by the university, "those who had endurance exercise training three times a week looked as young as healthy mice while their sedentary siblings were balding, graying, physically inactive, socially isolated and less fertile." (In the photo, courtesy of McMaster University, the lazy mouse is the one on the right.)
Studies in humans who exercise have been equally impressive. In a 10-year project called the MacArthur Foundation Study of Aging in America, scientists discovered that exercise cut the risk of coronary artery disease, diabetes and colon cancer, and it slashed the chance of developing high blood pressure by half.
We're not talking about back-breaking workouts here. Running on a treadmill, or even just walking around the neighborhood for 30 minutes or so, a few times a week, is plenty.
The McMaster study generated considerably less fanfare than a 22-year study of Ecuadorian Dwarfs released just one week earlier. That study, conducted at the University of Southern California, suggested that a lack of growth hormone protects against diabetes and cancer. And one of the lead scientists, Valter Longo, declared that if drugs were developed to suppress growth hormone, they could be as ubiquitous as statins to lower cholesterol.
But the McMaster scientists seemed to have found an easier path to the fountain of youth --one that's not about popping a pill, but about putting down the remote control and getting active. Principal investigator Mark Tarnopolsky said it best in a statement accompanying the mouse study: "We have clearly shown that there is no substitute for the 'real thing' of exercise when it comes to protection from aging."