The Shambhala Mountain Center sits nestled among the remote lakes and pastures of Colorado's Rocky Mountains, where for four decades it has offered instruction and retreat to serious students of meditation and yoga. Starting in February 2007, it became a scientific laboratory as well. The center began hosting the Shamatha Project, one of the most rigorous scientific examinations of meditation's effects ever undertaken. The Project is now beginning to yield its insights, and from early reports it appears that this ancient practice delivers benefits that go all the way down to the chromosomal level.

Many claims have been made over many years about the effects of meditation on health and well-being, but rarely have these claims been put to the test. Under the direction of Clifford Saron, a neuroscientist at the University of California at Davis, the Shamatha Project enrolled 60 experienced meditators in a three-month study. Half were randomly selected to receive intensive training and practice in meditation over the spring months of 2007, including two group training sessions and five or more hours of individual practice every day. Those who were wait-listed for the actual retreat served as controls -- an essential part of the rigorous experimental design that distinguishes the Project from previous meditation studies.

At three points in the three-month study -- before, halfway through, and at the end -- Saron and his many colleagues took a battery of behavioral and physiological measurements of both the meditators and the controls, who ranged from 21 to 70 years old. They have been crunching the data and analyzing the results, which are now emerging in peer-reviewed journals.

For example: Those who intensely practiced meditation got better at visual perception, and as a result their attention improved. UC Davis psychological scientist Katherine Maclean (now at Johns Hopkins) had all the volunteers perform a difficult visual discrimination task on a computer screen -- watching a parade of identical lines go by and spotting the slightly shorter lines that appeared occasionally. This 30-minute task is not only visually demanding; it's incredibly boring as well. But as reported recently in the journal Psychological Science, the meditators' increased visual acuity also freed up their limited cognitive firepower for vigilance; and their sharpened attention led to improved performance on the task. This improvement lasted for five months after the retreat was over.

That may not be all that surprising, since focus and attention are what meditation is all about. Less expected is the recent finding that intense meditation may also have anti-aging effects. Tonya Jacobs, a scientist at UC Davis's Center for Mind and Brain, has just reported (on-line in the journal Psychoneuroendocrinology) that meditators show improved psychological well-being, and that these improvements lead to biochemical changes associated with resistance to aging at the cellular level. Specifically, an analysis of meditators' white blood cells showed a 30 percent increase in an enzyme called telomerase, a chemical essential to the long-term health of the body's chromosomes and cells.

The scientists emphasize that meditation does not lead directly to cellular health and longevity. Instead, the practice appears to give people an increased sense of meaning and purpose in life, which in turn leads to an increased sense of control over their lives and to less negative emotion. This cascade of emotional and psychological changes is what regulates the levels of telomerase, the anti-aging enzyme.

Positivity appears to be the link between meditative practice and a variety of health benefits. In a study scheduled for publication in the journal Emotion, UC Davis psychological scientist Baljinder Sahdra is reporting that meditation leads to a decrease in impulsive reactions -- another health improvement linked to psychological positivity. Impulsivity has been tied to an array of health problems, including addictions and other risky behavior.