Losing sleep may lead to brain disease
Sleeping less as we age may contribute to a greater risk of brain disease, scientists have found.
It is well established that after they pass 30 most people not only take longer to drift off and wake up earlier, they also suffer from more broken sleep and do not sleep as deeply.
Some experts argue that we need less sleep as we age but researchers at the University of California, Berkeley, found that the changes could impair the consolidation of memories and exacerbate the disintegration associated with conditions such as Alzheimer’s disease.
The problem seems particularly acute for men, who spend on average 14 per cent of their nights in restorative “slow-wave” sleep in their twenties but 5 per cent when over 70.
This type of sleep is key for clearing out the poisonous amyloid-beta protein that leads to Alzheimer’s.
The scientists argue that troubled sleep is playing its part in a vicious circle of brain damage. “Those with greater initial levels of sleep fragmentation go on to suffer a more rapid subsequent rate of cognitive decline and a higher risk of developing Alzheimer’s,” they wrote in the journal Neuron.
Matthew Walker, one of the authors, said: “Sleep decline is one of the most dramatic physiological changes that occurs as we age, yet that demonstrable change is not part of the health conversation today. We need to recognise the causal contribution of sleep disruption in the physical and mental deterioration that underlies ageing and dementia. More attention needs to be paid to the diagnosis and treatment of sleep disturbance if we are going to extend healthspan, and not just lifespan.”