Simple exercise can actually delay aging, study finds
Published Monday, February 21, 2011 3:00PM EST
New Canadian research is showing that regular exercise may be the long-sought fountain of youth, not only helping to prevent an early death, but actually delaying aging.
The study, published in the prestigious science journal Proceedings of the National Academy of Science, used mice to compare the effects of a lifetime of regular exercise over a sedentary lifestyle.
The researchers from McMaster University in Hamilton, Ont. worked with a litter of mice that were genetically programmed to age quickly. The mice were engineered to have a defect in a gene that alters the repair system of their mitochondria – which are the cellular powerhouses responsible for generating energy for nearly every cell in the body.
The researchers forced some of the mice to exercise by putting them on a treadmill to jog at a brisk pace three times a week for 45 minutes.
After five months, they found that premature aging was prevented in nearly every organ in the mice that ran on the treadmill.
"We surprised at how effective [exercise] was," the study's lead researcher Dr. Mark Tarnopolsky told CTV News. "It turned out to be more effective than we thought."
The exercising mice looked as young as ever, while the sedentary mice were balding and going grey. They were also inactive, more socially isolated and less fertile. The muscle tissue of the inactive mice showed signs of damage, while those that exercised had muscle structure that was completely normal.
"What really shocked us was the gonads, the spleen, liver -- every tissue we looked at was made better with the exercise. It has a systemic effect and even prevented a slight shrinkage of the brain," said Tarnopolsky, who's a professor of pediatrics and medicine at McMaster's DeGroote School of Medicine.
Perhaps most surprising is what the scientists discovered in the mitochondria of the mice. Mitochondria are unique in that they have their own DNA. It's long been thought that accumulation of mitochondrial DNA mutations over our lifetimes leads to the progressive decline in tissue and organ function that results in aging.
But in the exercising mice, their mitochondria had gone from damaged to young and healthy.
So are the results seen in the mice applicable to humans? Absolutely, says Tarnopolsky, who hopes the mice inspire humans worldwide to get moving .
"When you see the video with the mice barely moving and their sisters moving around healthy, that may shock them into getting their buts off the couch and get some exercise," he says.
He notes that studies have shown that even those who have spent most of their lives sedentary can reap the benefits of exercise, with increased energy, more mobility and healthier organs.
"Get moving, get active and get your kids moving while they are young," he advises.
With a report from CTV medical specialist Avis Favaro and producer Elizabeth St. Philip