杏吧原创

A lack of sleep could help toxic plaques develop in the brain, accelerating the progression of Alzheimer鈥檚 disease.

looked at how sleep affected the levels of beta-amyloid protein in mice and humans. This protein causes plaques to build up in the brain, which some think cause Alzheimer鈥檚 disease by killing cells.

Holtzman鈥檚 group found that beta-amyloid levels were higher in mouse brains when the mice were awake than when they were sleeping.

Lack of sleep also had an effect on plaque levels: when the mice were sleep-deprived 鈥� forced to stay awake for 20 hours of the day 鈥� they developed more plaques in their brains.

Sleep therapy

Holtzman also tried sending the mice to sleep with a drug that is being trialled for insomnia, called . This reduced the amount of plaque-forming protein.

He suggests that sleeping for longer could limit the formation of plaques, and perhaps block it altogether.

The group also measured levels of beta-amyloid in the cerebrospinal fluid of 10 healthy men, both at night and during the day. Levels were lower at night, suggesting that sleep might also help keep levels of the plaque protein low in humans.

Holtzman reckons that when we鈥檙e awake, our brains are more active, and that this may cause us to produce more beta-amyloid protein.

Pills aren鈥檛 the answer

Neuroscientist of the University of Cambridge says that people with Alzheimer鈥檚 are known to suffer sleep abnormalities, but that whether these are a cause or a symptom of the disease is unknown.

He says the new results are interesting, but cautions against encouraging people with Alzheimer鈥檚 to take sleeping pills in the hope that sleep will mitigate the disease. Instead, he suggests exercise to induce sleep might be a good idea if later studies confirm a link between sleep and Alzheimer鈥檚 progression.

鈥淚t is interesting that there may be a link between sleep and the build-up of the protein associated with the development of Alzheimer鈥檚 disease,鈥� says Clive Ballard, director of research at the in London. 鈥淗owever, there are many other biological factors that may have an impact on the protein鈥檚 production, so further research in this area would be needed.鈥�

Recently, for example, several drugs that clear plaques failed to relieve the symptoms of Alzheimer鈥檚. And earlier this month, two studies suggested that disruptions of the immune system, the way cells metabolise fat and wear and tear on the circulatory system may be as much to blame for Alzheimer鈥檚 as plaques.

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