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(Updated) The image of the ancient but youthful-looking sage meditating on a mountaintop might be closer to reality than you think, according to a new study that found that after a three-month stay at a meditation retreat, people showed higher levels of an enzyme associated with longevity.

The study is preliminary and didn’t show that meditation actually extends life, but the findings suggest a possible means by which it could.

Researchers led by Tonya Jacobs of the University of California-Davis compared 30 participants at a meditation retreat held at the Shambhala Mountain Center in Colorado with matched controls on a waiting list for the retreat. Participants meditated six hours per day for three months. Their meditation centered on mindfulness — for instance, focusing solely on breathing, in the moment — and on lovingkindness and enhancing compassion towards others. (More on Time.com: Empathy Beats Bullies)

After the three-month intervention, researchers found that the meditators had on average about 30% more activity of the enzyme telomerase than the controls did. Telomerase is responsible for repairing telomeres, the structures located on the ends chromosomes, which, like the plastic aglets at the tips of shoelaces, prevent the chromosome from unraveling. Each time a cell reproduces, its telomeres become shorter and less effective at protecting the chromosome — this, researchers believe, is a cause of aging. As the chromosome becomes more and more vulnerable, cell copying becomes sloppier and eventually stops when the telomeres disintegrate completely. Telomerase can mitigate — and possibly stop — cell aging.

“Something about being on a retreat for three months changed the [amount of] telomerase in the retreat group,” says Elizabeth Blackburn, a study author who has won a Nobel Prize for her previous work on telomerase. “We didn’t prove that it was meditation [that caused the change]. A lot of things happened during the retreat. But the interesting thing was that the changes we saw tracked quantifiably with the change in people’s psychological well-being and outlook.” (More on Time.com: Can Meditation Ease Pain?)

In other words, people with higher levels of telomerase also showed more increases in psychological improvement. In retreat participants who showed no psychological change, telomerase levels were not any higher than in controls. (Researchers were unable to compare telomerase levels in the groups both before and after the retreat for logistical reasons.)

“It’s a very good study with interesting results in terms of health implications,” says Alan Marlatt, a professor of psychology at the University of Washington who has studied meditation for decades but was not associated with this research.

Of course, the relationship between health and telomerase is complex. In a recent study in mice by Harvard researchers, they found that boosting levels of telomerase reversed signs of aging, restoring graying fur and fertility, increasing brain size and sharpening scent perception. Too much telomerase activity can also be a problem, however. A cell that reproduces endlessly sounds like a good thing at first — that cell would be immortal. But this is exactly what happens with cancer cells — infinite replication. “If telomerase levels go too far up, that’s [associated with] cancer,” says Clifford Saron, associate research scientist at the University of California-Davis Center for Mind and Brain and a co-author of the new paper. He notes, however, that the difference is one that is orders of magnitude higher — so that meditation could not possibly cause cancer. (More on Time.com: Want to Eat Less? Imagine Eating More)

So how does meditation affect the machinery of cellular reproduction? Probably by reducing stress, research suggests. Severe psychological stress — particularly early in life and in the absence of social support — has been linked with poorer health, increasing risk for heart disease, stroke and some cancers. This is likely due to the negative effects of high levels of stress hormones on the brain and body. By reducing stress hormones, perhaps meditation contributes to healthier telomeres.

In a study published a few years ago in Lancet Oncology, researchers compared 30 men before and after adopting lifestyle changes following a diagnosis of low-risk prostate cancer. The patients started meditating, switched to a healthy plant-based diet, exercised and attended a support group. Like the new study, the Lancet Oncology paper found increases in telomerase linked with reduced psychological distress.

“The mind has a big influence on the body. If you get anxious, your heart beats faster and your stomach churns,” says Blackburn. “But we don’t know yet [if meditation is linked to] a reduction in stress hormones. The physiology is very complex.”

Recent evidence supports a connection: a study published this month in the Archives of General Psychiatry showed that mindfulness meditation can reduce relapse in patients who recovered from depression just as well as antidepressants. (More on Time.com: Is a Wandering Mind an Unhappy One?)

Of course, the increases in telomerase seen in the current study could be due to some other unknown factor that separates the meditators from the controls. That’s another reason why it’s too early to suggest that stress-reducing mind-body interventions like meditation be prescribed as a treatment for any diseases or disorders. The study also did not show that meditation actually extends life, only that it may increase the activity of an enzyme that is associated with longevity.

Still, research on meditation is expanding dramatically, with studies finding it helpful for pain, depression, addiction and many other conditions. “There’s a very exciting dialogue going on,” Marlatt says of the research. “It works for many different kinds of clinical problems. It’s very promising.”

That noise you hear in the background? Millions of new meditators chanting, “Om.”

Correction [Dec. 23, 2010]: The original version of this story misstated that after their three-month stay at a meditation retreat, meditators had on average about 40% more activity of the enzyme telomerase than controls did. That figure should be 30%.

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