Your sleeping habits could predict if you are at risk of developing Alzheimer’s.

Napping is less common among younger people, but as we age it becomes a more frequent daily event.

But recent research has found a link between daytime napping and Alzheimer’s and other dementias.

The study also found that once dementia, or mild cognitive impairment, are diagnosed naps become more frequent and longer.

Research led by UC San Francisco and Harvard Medical School together with Brigham and Women’s Hospital, goes against the old theory that daytime napping in older people is to make up for poor sleep.

Instead, it found developing dementia might actually affect the neurons in the brain that tell people when to wake up.

Co-senior author Yue Leng, MD, PhD, of the UCSF Department of Psychiatry and Behavioral Sciences, said: “We found the association between excessive daytime napping and dementia remained after adjusting for nighttime quantity and quality of sleep.

“This suggested that the role of daytime napping is important itself and is independent of nighttime sleep.”  

In the study, the researchers tracked data from 1,401 seniors, who wore a watch-like device that monitored their movement in the day.

When researchers looked at the 24 percent who had normal cognition at the start of the study but developed Alzheimer’s six years later, and compared them with those whose cognition remained stable, they found differences in napping habits.

Participants who napped more than an hour a day had a 40 percent higher risk of developing Alzheimer’s than those who napped less than an hour a day.

And participants who napped at least once a day had a 40 percent higher risk of developing Alzheimer’s than those who napped less than once a day.

The authors wrote: “It is plausible that our observed associations of excessive daytime napping at baseline, and increased risk for Alzheimer’s disease during follow-up, may reflect the effect of Alzheimer’s disease pathology at preclinical stages.

“It would be very interesting for future studies to explore whether intervention of naps may help slow down age-related cognitive decline.”

Alzheimer’s affects one in six people over the age of 80 and it is thought that around 850,000 people in total are suffering in the UK alone.

A hallmark of the disease is the build-up of amyloid beta proteins in the brain, which causes plaques.

The plaques then result in the loss of connections between nerve cells in the brain – and ultimately the death of those cells and a loss of brain tissue.

Those with Alzheimer’s also have a shortage of key chemicals in the brain, which help transmit messages.

A lack of these chemicals means the brain is unable to process certain messages in the way it would have previously, which causes confusion and memory loss.

This story originally appeared on The Sun and was reproduced here with permission.