In the last two decades we have learned that the brain is not a static structure of nerve cells; it is an organ that is continuously growing and changing in response to our genetic code and our personal experiences.
Recent research has revealed that regular practice of meditation has been associated with thickening of the brain and strengthening of connections between brain cells, specifically in areas dealing with sensory, cognitive and emotional processing.
Evidence also suggests that meditation may slow down age-related degeneration of brain structure, keeping your brain sharp as you age. Participants involved in the study were experienced Buddhist Insight meditation practitioners. They incorporated approximately 40 minutes of meditation into their daily routine, typically involving career, family, friends and outside interests.
Source: http://www.ncbi.nlm.nih.gov.ezproxy.cmcc.ca/pmc/articles/PMC1361002/?tool=pubmed