Lifestyle changes including an improved diet, exercise and stress management may help reverse the aging process on a cellular level, a new study suggests.

The study, published Monday in The Lancet Oncology, found that lifestyle changes including adopting a plant-based diet, moderate exercise and stress reduction were associated with a significant increase in relative telomere length – the part of chromosomes that affects cell aging.

Telomeres are found at the end of chromosomes and are believed to provide protection to these stranded molecules of DNA. Much like the tips of shoelaces that protect them from fraying, telomeres protect the ends of chromosomes and help them remain stable.

As telomeres become shorter their structure becomes weaker, which is believed to cause cells to age and die more quickly.

The length of a person's telomeres is typically determined by their age. A shorter length is associated with increased risk of premature death and chronic diseases such as cancer, heart disease, obesity, stroke and diabetes.

In the study comparing two groups of men with low-risk prostate cancer, researchers found that healthy lifestyle changes may have a beneficial effect on telomere length.

"It's not the fountain of youth, but it certainly is a step in the right direction. Until now we thought that only telomeres could get shorter,” Dr. Dean Ornish, the study's lead author, said. “Now we found that they actually can get longer."

The study was done by the Preventive Medicine Research Institute at the University of California, San Francisco, which was founded by diet and lifestyle guru Ornish.

"Our genes, and our telomeres, are not necessarily our fate," he added. "These findings indicate that telomeres may lengthen to the degree that people change how they live."

While past research has shown that lifestyle change can have many health benefits, Ornish's small study is the first to show that an intervention may affect telomere length over time.

The study measured telomere length in two groups of men, one group who were asked to make a number of lifestyle changes and a group who were not. Telomere length was measured five years after the men entered the study and were compared to baseline measurements.

Participants were asked to make four types of lifestyle changes including:

Eating a diet that's high in plant-based protein, fruits, vegetables, unrefined grains and low in fat and refined carbohydrates Doing moderate aerobic exercise for 30 minutes per day, six days per week Taking part in stress management activities such as yoga-based stretching and meditation Attending weekly social support group sessions

After five years, telomere length increased by an average of 10 per cent in the group of men who followed the lifestyle changes. By comparison, in the group that didn't follow the lifestyle changes, telomere length decreased by an average of three per cent.

The study followed 35 participants five years after their initial entry into two separate studies: the GEMINAL study and UCSF MENS study. Ten of the participants had been asked to make lifestyle changes and 25 had not.

The study also found that the more people positively changed their lifestyles, the longer their telomeres got at any age.

"That is a very empowering finding," Ornish said.

He added that the study builds on over 30 years of research showing that with low-tech interventions, our bodies can start to heal themselves.

"Our bodies often have a remarkable capacity to begin healing themselves, and much more quickly than we did once realize, if we simply make the lifestyle changes that are really the primary determinants of our health and well-being," he said.

While the study was conducted on men with low-risk prostate cancer, the researchers say the results are likely relevant to the broader population. The study was not designed to detect the effects of lifestyle changes on the participants' prostate cancer.

Ornish said the results of the small pilot study should be further investigated in large randomized clinical trials.

Test your telomeres?

Dr. Elaine Chin, chief medical officer of the Executive Health Centre, told CTV News that she hopes that Monday's "groundbreaking" study will encourage people to lead healthier lives to maintain telomere health.

The Executive Health Centre offers telomere testing, and Chin said the results of testing are usually a reflection of patients' past lifestyles and not a predictor of their futures.

"Our clients who have been smokers, who have been heavy drinkers, who don't exercise and who are overweight truly have shorter telomeres than the folks who are eating well, sleeping well and maintaining a healthy weight," she said. "So there is truth in telomere biology."

Chin stresses, however, that it isn't too late for clients to improve their health. "I have always believed that nurture trumps nature. We understand that our DNA increases our risk for disease, but it's up to us and how we interact with our environment that will determine our lifespan and health span," she said.

With a report by CTV's Medical Correspondent Avis Favaro and producer Elizabeth St. Philip