"One interpretation of our finding -- that members of majority religious groups seem to have less atrophy compared with minority religious groups -- is that when you feel your beliefs and values are somewhat at odds with those of society as a whole, it may contribute to long-term stress that could have implications for the brain," Amy Owen, lead author of the study and a research associate at Duke University Medical Center, said in a Duke news release.
The study authors also suggested that life-changing religious experiences could challenge a person's established religious beliefs, triggering stress.
"Other studies have led us to think that whether a new experience you consider spiritual is interpreted as comforting or stressful may depend on whether or not it fits in with your existing religious beliefs and those of the people around you," David Hayward, research associate at Duke University Medical Center, added. "Especially for older adults, these unexpected new experiences may lead to doubts about long-held religious beliefs, or to disagreements with friends and family."