Posted : 01.15.2015 | by AMRA

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The human brain starts atrophying in the third decade of life, losing an average of 5% of its volume in each succeeding decade. Any technique that can slow or reverse that trajectory might have important benefits in terms of maintaining brain structural integrity across the lifespan. Luders et al. [Frontiers in Psychology] compared magnetic resonance imaging (MRI) scans of the brains of long-term meditators and a control group to determine if the correlations between age and gray matter volume differed between groups. Gray matter is the part of the brain consisting primarily of neuronal cell bodies, dendrites, and glial cells, in contrast to cerebral white matter, which consists mostly of myelinated axons.

The authors measured the volume of whole-brain gray matter and specific region gray matter in the MRI scans of 50 meditators (mean age = 50) with an average of 19 years of Zen, Vipassana, or Shamatha meditation experience – practices similar to those used in mindfulness based interventions. They then compared the gray matter volumes of the meditators with those of 50 age-matched controls drawn from a MRI database of normal adults.

Age was significantly negatively correlated with whole brain gray matter volume for both controls (r = -0.77) and meditators (r = -0.58), but the slope was significantly steeper for controls, with meditators showing less of a relationship between age and atrophy. Differences between controls and meditators were apparent in the frontal, parietal, and temporal lobes, the midbrain, and the cerebellum.

There are a range of possible explanations for these results including enhanced dendritic and synaptic growth or reduced stress-related degradation in meditators, and pre-existing differences between people who choose to become long-term meditators and those who don’t.

The findings of the study support previous results suggesting that meditation may slow normal brain atrophy associated with aging, but there was a lack of evidence to suggest that meditation might actually reverse such atrophy. Longitudinal research is needed to examine if these differences are actually caused by rather than correlated with meditation. Research is also needed to determine whether these brain differences are associated with meaningful differences in psychological functioning.

Reference:

Luders, E., Cherbuin, N., & Kurth, F. (2014). Forever young (er): Potential age-defying effects of long-term meditation on gray matter atrophy. Frontiers in Psychology, 5, 1551.

[Link to abstract]