Not getting enough sleep could increase your risk of Alzheimer's

The study was based on an admittedly small group of people, just 17 healthy adults aged between 35 and 65. On one night, when they drifted into deep (known as slow-wave) sleep, the headphones played a tone at increasing volume until they reverted to lighter sleep. However there were no changes to levels of tau, another protein linked to Alzheimer's. "We found that the worse the sleep quality in the preceding week, the higher the tau".

Another week of poor sleep can then subsequently increase a protein called tau, which has been linked to brain damage in Alzheimer's and other neurological diseases.

The results, published in the online issue of Neurology, the medical journal of the American Academy of Neurology, showed that those who reported worse sleep quality, more sleep problems and daytime sleepiness had more biological markers for Alzheimer's disease in their spinal fluid than people who did not have sleep problems.

Have you ever slept all night - only to wake up in the morning feeling exhausted?

"Because brain cells release amyloid beta during activity, we think if the brain cells can't rest the way they're supposed to and get that deep sleep, they produce a relative excess of amyloid", Ju said. "We think that not getting good sleep chronically over the years would increase the risk of the amyloid and tau clumping up and causing Alzheimer's disease".

Lead scientist Prof David Holtzman, from Washington University School of Medicine in Missouri, US, said: "We showed that poor sleep is associated with higher levels of two Alzheimer's-associated proteins".

The study doesn't prove whether or how disrupted sleep contributes to the risk of developing Alzheimer's disease.

Co-author Dr Yo-El Ju added that the team "were not surprised to find that tau levels didn't budge after just one night of disrupted sleep" while amyloid levels did. "These are good sleepers", Ju says. Both plaques and tangles are found in the brains of people with Alzheimer's disease.

At the end of the period, they spent a night asleep in the laboratory where they had their brain-waves tracked and, the following morning, they each had a lumbar puncture taken.

Certain illnesses can cause sleepless nights like depression, restless leg syndrome and sleep apnea.

  • Rogelio Becker