Endurance Exercise Prevents Premature Aging In Animals Genetically Engineered To Age Faster

Endurance exercise may stop you looking and feeling old, it may even help you live longer, a study by McMaster University researchers has found. The study, published today in the prestigious science journal Proceedings of the National Academy of Sciences (PNAS), found that premature aging in nearly every organ in the body was completely prevented in mice that ran on a treadmill three times a week for five months.

These mice were genetically engineered to age faster due to a defect in a gene for polymerase gamma (POLG1) that alters the repair system of their mitochondria – the cellular powerhouses responsible for generating energy for nearly every cell in the body.

“Many people falsely believe that the benefits of exercise will be found in a pill,” said Mark Tarnopolsky, principal investigator of the study and a professor of pediatrics and medicine of the Michael G. DeGroote School of Medicine. “We have clearly shown that there is no substitute for the “real thing” of exercise when it comes to protection from aging.”

Aging mice pair – Both mice were genetically engineered to age more quickly. The mouse on the left exercised, while the one on the right was sedentary.

Mitochondria are unique in that they have their own DNA. It has been thought that lifelong accumulation of mitochondrial DNA mutations lead to energy crisis that result in a progressive decline in tissue and organ function, ultimately resulting in aging. But the study on genetically-disadvantaged mice found 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.

“Others have tried to treat these animals with “exercise pill” drugs and have even tried to reduce their caloric intake, a strategy felt to be the most effective for slowing aging, and these were met with limited success,” said Tarnopolsky.

Adeel Safdar, lead author and PhD candidate with Dr. Tarnopolsky, and a sedentary aging mouse

Adeel Safdar, lead author and a senior PhD student working with Tarnopolsky said: “I believe that we have very compelling evidence that clearly show that endurance exercise is a lifestyle approach that improves whole body mitochondrial function which is critical for reducing morbidity and mortality. Exercise truly is the fountain of youth.”

Co-author Jacqueline Bourgeois said: “The recipe for healthy aging is very simple, and that’s exercise. The problem is that it is most people find it a difficult recipe to follow.” She is an associate professor of pathology and molecular medicine at McMaster.

Tarnopolsky said he hopes that this research will motive children and adults to adopt a healthier lifestyle and for government agencies to promote health and sport.

Funders of the study included the Canadian Institutes of Health Research (CIHR). As well, Adeel Safdar holds a CIHR – Institute of Aging doctoral research scholarship.

Material adapted from McMaster University.