Healthful sleep may help prevent Alzheimer’s

According to a National Public Radio article (, adequate sleep may be even more important than previously thought. It seems that while you sleep the brain is hard at work!

A team of scientists led by Dr. Maiken Nedergaard, professor of neurosurgery at the University of Rochester, found that while mice were sleeping the flow of cerebrospinal fluid increased dramatically, washing away harmful waste proteins that build up between the brain cells during waking hours.

When the mice were asleep, the brain cells actually shrank, allowing the fluid to circulate “like a dishwasher,” said Dr. Nedergaard. When they awoke, the brain cells enlarged.

One of the waste products that is removed during sleep is beta amyloid, a substance that forms sticky plaques that are associated with brain diseases such as Alzheimer’s and dementia. “What’s getting washed away during sleep are waste proteins that are toxic to brain cells,” Dr. Nedergaard said. “This is the best explanation yet of why sleep is so important to animals and people.”

Scientists have long known that there is a mysterious association between sleep disorders and brain diseases.

So why does brain cell detoxifying only occur during sleep? Dr. Nedergaard believes that cleaning takes a lot of energy and it’s probably not possible for the brain to both clean itself and at the same time be aware of its surroundings and talk and move and so on.

Perhaps the mice study is a first step in solving the mystery.

What wasn’t addressed in the article is why Alzheimer’s disease and other brain problems are so much more prevalent today (and increasing) than they were in the past and only a couple of decades ago. A primary reason may be that in the past people were active all day and slept soundly at night. Today there is endless noise and distraction, and sleep deprivation has become a worrisome modern health issue.

There are many other factors in modern society that no doubt contribute to disturbed sleep, but for now each of us would likely benefit by removing what distractions we can and seek peaceful sleep.

After all, this may be the most important ‘cleaning’ of our lives!