“There’s something magical about socializing,” Fotuhi said. “It releases endorphins in the brain. It’s hard to know whether it's through religion or a gathering of friends, but it improves brain health in the long term. And it’s also been shown that people who are introverted and don’t participate are more likely to get Alzheimer’s.”
Listening to sermons and reading religious works like the Bible may also invoke a cognitive benefit, Koenig said.
“You’re exercising your higher cortical function, thinking about complex concepts that require some imagination.”
And while a 2011 study found a shrinking of the hippocampus among people of certain religions, Koenig, a co-author of the study, points out that no one has replicated that work yet.
So where does that leave non-believers?
“Out of luck, I guess,” Koenig joked. “Actually, I would suspect that people doing the types of things like religious people do -- socializing, doing similarly complex cognitive tasks, would have similar benefits. But it is interesting that religion provides that whole package of things that people can adopt and pursue over time.”
While a January study published in the journal Brain Connectivity identified specific networks of the brain used to contemplate religious beliefs, suggesting that some people may be “hard-wired” to be religious, the opposite -- that religious belief begets a healthier brain -- has not been shown. Research has instead focused on long-term religious activity, not belief.
“My personal belief is that having a strong belief is key to getting the benefits,” Fotuhi said. “It’s hard to study these things; it’s why research has stayed away from them. But there does seem to be a strong link between spirituality and better brain health.”