Biological age measures how old a person is physiologically. As a group, long-term meditators who had been practicing Transcendental Meditation for more than 5 years were physiologically 12 years younger than their chronological age, as measured by reduction of blood pressure, and better near-point vision and auditory discrimination.
Short-term meditators were physiologically 5 years younger than their chronological age. The study controlled for the effects of diet and exercise.
*Reference: The Effects of the Transcendental Meditation and TM-Sidhi programme on the Ageing process, International Journal of Neuroscience 16 (1): 5358, 1982.