In 2018, nearly 5.7 million Americans 65 and over had Alzheimer’s dementia. By and large, poor sleep is a common factor among those with Alzheimer’s.
Firstly, observational studies found reduced slow-wave sleep as a common factor amongst adults, over age 65, who had amyloid plaques in their brain. Yet these adults did not show signs of Alzheimer’s, like memory loss and cognitive decline.
Indeed, amyloid beta proteins accumulate in the brain every day. And, they are thought to be a waste product from the energy used when brain cells communicate. However, while you are in slow-wave sleep, the excess amyloid beta proteins are cleared by the brain. In addition, memory consolidation occurs in the deep sleep phase of slow-wave sleep.
Regrettably, some studies suggest that, when your sleep is interrupted during the slow-wave phase, amyloid beta proteins build up to form plaque in brain tissue. Incidentally, scientists believe this is the first stage in the development of Alzheimer’s. Indeed, plaque can accumulate for years before symptoms appear.
Next, there is the 2015 study in Nature Neuroscience. And, this study, imaged the brains of 26 adults, between the ages of 65 to 81, who had not been diagnosed with dementia nor did they report any sleep problems. First, PET scans were done on the adults to measure levels of amyloid beta in their brains. The adults, then, memorized 120 pairs of words. Next, the adults were tested to see how well they remembered some portion of these words.
The adults, then, went to sleep for eight hours. Meanwhile, during this sleep time, their brain wave measurements were used to find sleep disruptions. And to find out if they woke up during the slow-wave phase. The following morning, while the adults tried to recall the memorized words, their brains were scanned.
Over all, adults with the highest levels of amyloid beta in their brain had the poorest quality of sleep and performed worst on the memory test. In fact, some of the adults forgot more than half the words. In conclusion, then improving the quality of your sleep would result in least level of amyloids in the brain.
Next, in another study, scientists looked at 119 adults over the age of 60. Incidentally, 80% of these adults had no memory or thinking problems. While, others had only mild memory or thinking problems.
Among these adults, those with less slow-wave sleep (deep sleep) had higher levels of the brain protein tau. Incidentally, these elevated levels of tau are a sign of Alzheimer’s and have been linked to brain damage and mental decline. Therefore, older adults with decreased slow wave sleep is another warning sign of Alzheimer’s.
In the meantime, other studies show that aerobic exercise helps you get better sleep quality. Lastly, losing weight is needed as overweight people tend to have more sleep problems.
Therefore, exercising, losing weight, and practicing good sleeping habits together help you improve your sleep and protect you from both amyloid plaques as well as tau proteins, both of which lead to Alzheimer’s.
Finally, practicing good sleeping habits also helps you avoid other problems with sleep deprivation (see infographic).