Too much napping could be a sign of dementia

Too much napping could be a sign of dementia

Older people who nap often during the day, take note: it may be a factor in developing dementia.

Those who sleep at least once or for more than an hour during the day are 40% more likely to develop Alzheimer’s disease than those who napped less often or for shorter periods. That’s what researchers at the University of California, San Francisco concluded after analyzing data spanning 14 years from more than 1,400 people between the ages of 74 and 88.

For 14 days each year, participants wore a watch-like device that tracked their movements. They underwent neuropsychological tests to evaluate cognition.

Since sleep quality declines with age, some increase in daytime napping is typical. But the researchers noted what it could portend: For those who didn’t develop cognitive impairment over the life of the study, daily nap time increased by an average of 11 minutes a year. Daytime napping rates doubled for those with mild cognitive impairment and nearly tripled after an Alzheimer’s disease diagnosis.

Among people who had normal cognition at the start of the study but later developed Alzheimer’s, those who slept more than an hour a day had a 40% higher risk of the disease.

The researchers believe daytime napping can be a hallmark of brain changes that are independent of nighttime sleep. They point to prior research suggesting the development of tau tangles — abnormal brain proteins and a classic sign of Alzheimer’s — may be affecting cells that keep people awake.

The researchers said the “drastic increase” in nap length and frequency seems to be a crucial signal.

For older people, the message is clear: Don’t sleep on the underlying causes of more daytime napping.

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