The fountain of youth may simply be a healthy diet and reduced stress after all, not a magic pill or expensive cosmetics.

Comprehensive lifestyle changes, including more fruit and vegetables as well as meditation and yoga, were shown to reverse signs of aging at the cellular level for the first time in a study published today.

Adopting a diet rich in unprocessed foods combined with moderate exercise and stress management over five years increased the length of telomeres, the ends of chromosomes linked to aging, according to a study of 35 men published in the Lancet medical journal. No previous study has shown the effect of lifestyle changes on telomere length, the authors said.

The research, led by Dean Ornish, founder of the Preventive Medicine Research Institute, adds to evidence of the benefits of healthy habits. Ornish's Lifestyle Heart Trial, published in 1998, showed a reversal of coronary heart disease over five years. Patients who receive 72 hours of training from medical professionals on Ornish's program for reversing heart disease have beenreimbursed by Medicare since January 2011.

"So often, people think it has to be a new drug or laser, something really high-tech and expensive, to be powerful," Ornish said in a telephone interview. "Our studies are showing that simple changes in our lifestyle have powerful impacts in ways that we can measure."

Ornish collaborated on the study with Elizabeth Blackburn, who shared the Nobel Prize in medicine in 2009 with Carol Greider and Jack Szostak for research on the telomerase "immortality enzyme," which prevents telomeres from being shaved off.

David Fuller's view As a self-confessed foodie who loved meat, I have surprised myself by preferring the healthiest diet I have ever had. Although I like the flavour of good meat, I went off salty, fatty foods and most desserts some time ago. I prefer fish, lots of fresh vegetables and interesting salads. For dessert, I much prefer fresh fruit to puddings and pastries. I firmly believe that we are what we eat, and never more so than as we get older.

I do not practice yoga or meditation, recommended in the article above, but I am well aware of their worth. We are all different, and I prefer a good workout in the home gym most days, and find that exercise is one of the most therapeutic things that I do. So is music and especially quiet time with friends and a three-generation family.