WashPo Warns Readers: 'Excessive Brain Activity Linked to a Shorter Life'

Something to ponder, but not too hard https://t.co/SWqZfFNxZr

¡ª carolyn johnson (@Carolynyjohnson) October 17, 2019

One key to a longer life could be a quieter brain without too much neural activity, according to a new study that examined postmortem brain tissue from extremely long-lived people for clues about what made them different from people who died in their 60s and 70s.

¡°Use it or lose it¡± has dominated thinking on how to protect the aging brain, and extensive research shows there are many benefits to remaining physically and mentally active as people get older. But the study, published in the journal Nature, suggests more isn¡¯t always better. Excessive activity ¡ª at least at the level of brain cells ¡ª could be harmful.

¡°The completely shocking and puzzling thing about this new paper is ¡­ [brain activity] is what you think of as keeping you cognitively normal. There¡¯s the idea that you want to keep your brain active in later life,¡± said Michael McConnell, a neuroscientist at the Lieber Institute for Brain Development, who was not involved in the study. ¡°The thing that is super unexpected is ¡­ limiting neural activity is a good thing in healthy aging. It¡¯s very counterintuitive.¡±

Researchers at Harvard Medical School analyzed brain tissue donated to human brain banks by people ranging in age from their 60s and 70s to centenarians who lived to be 100 or older. They found people who died before their mid-80s had lower levels in their brains of a protein called REST that tamps down genes involved in sparking brain activity, compared to the very oldest people. REST had already been shown to be protective against Alzheimer¡¯s disease. But they weren¡¯t sure whether REST somehow protected people from death or was just a sign of further aging.

Since it is not currently possible to measure REST in the brains of living people, the scientists began experiments in roundworms and mice to test whether it plays a role in life span. When researchers increased the activity of a worm version of REST, the worms¡¯ brain activity decreased and they lived longer. The opposite happened when scientists disabled the REST-like gene in ¡°Methuselah¡± roundworms that have very long life spans; the worms¡¯ neural activity increased ¡ª and their lives were dramatically shortened. Mice lacking REST were also more likely to have busier brains, including seizure-like bursts of activity.

It¡¯s not yet clear how these differences in brain activity at the level of cells could translate to differences in cognition or behavior in people.