Religion: Religious Affiliation and Brain Shrinkage

Intrigued by previous research that linked smaller hippocampus volume with hyper-religiosity in some epileptics — as well as research on the effect of meditation on the hippocampus — the researchers decided to conduct a wider study of religious belief and brain shrinkage. The participants were 268 residents of the American Southeast, all of whom were at least 58 years old when the project got underway. All were involved on an ongoing basis for two to eight years.

MRI scans of their brains were performed every two years; data on their spiritual life and psychological state (including levels of stress and depression) was collected annually. Religion-oriented questions included their specific affiliation (or lack thereof); how often they worship publicly and pray privately; and whether they consider themselves born again, or have had any other religious experience that changed their life.

Significantly greater hippocampal atrophy was observed from baseline to final assessment among born-again Protestants, Catholics, and those with no religious affiliation, compared with Protestants not identifying as born-again, the researchers report.

The reason, the researchers speculate, is the cumulative stress that comes with being a member of a religious minority.

For more, see Religious Affiliation and Brain Shrinkage by Tom Jacobs, May 10, 2011 at Miller-McCune.