Excessive Napping During The Day Could Be An Early Sign Of Alzheimer’s, Study Shows
There’s nothing like a blissful midday nap when you’re sapped of energy. Children may fight them and retirees may be able to indulge in them daily, but for many adults, being able to squeeze in a nap is a delightful treat.
However, a small study has found that excessive napping may be a very early sign of Alzheimer’s. Tau proteins — long known to be a key player in Alzheimer’s development — are responsible for damaging key areas of our brains that keep us awake during daylight hours.
Keep in mind that excessive napping as a sign of Alzheimer’s applies only to a change in napping behavior, though. Plenty of people are able to regularly slip in naps (lucky ducks), and in some cultures, an afternoon snooze every day is pretty common.
Regularly napping in and of itself isn’t the issue — it’s when those sleepy stretches during the day becomes longer and more frequent.
The study was published in the journal Alzheimer’s and Dementia in August of 2019.
Researchers analyzed 13 postmortem brains belonging to people who had had Alzheimer’s and 7 brains of people without it, obtaining the brains from the UCSF Neurodegenerative Disease Brain Bank. They focused specifically on the three regions of the brain known to manage wakefulness: the locus coeruleus (LC), lateral hypothalamic area (LHA), and tuberomammillary nucleus (TMN).
During the course of their research, the team found that all three regions lost roughly 75% of their neurons.
“In this particular study, we were curious if a specific network within the brain stem and subcortical regions are affected in Alzheimer’s disease. We found that the network, which [promotes] wakefulness, is obliterated in Alzheimer’s disease,” the study’s lead author, Jun Oh, told Healthline. He’s a staff research associate in the Grinberg Lab Memory and Aging Center at the Weill Institute for Neurosciences at UCSF.
“It seems that the wakefulness-promoting network is particularly vulnerable in Alzheimer’s disease,” Oh said. “Crucially this means that the brain has no way to compensate because all of these functionally related cell types are being destroyed at the same time.”
Previous research from Grinberg’s lab and others have shown that these areas of the brain were “highly involved” in the development of the disease — yet they’re areas that have historically been overlooked in research.
An earlier Grinberg study found that the postmortem brain stems of people with increasingly disturbed sleep patterns had elevated tau protein levels. They’d also been undergoing mood changes like increased anxiety and depression when they died.
Increased levels of tau proteins in the brain stem is an indication of the earliest stage of Alzheimer’s. More research is pointing to tau protein build-up as being tightly linked to Alzheimer’s symptoms, even though the amyloid beta protein is much more widely studied.
Dr. Lea Grinberg, an associate professor of neurology and pathology at the Memory and Aging Center at the University of California, San Francisco (UCSF), was the study’s senior author.
“Our work shows definitive evidence that the brain areas promoting wakefulness degenerate due to accumulation of tau — not amyloid protein — from the very earliest stages of the disease,” Grinberg said.
“It suggests we need to be much more focused on understanding the early stages of tau accumulation in these brain areas in our ongoing search for Alzheimer’s treatments,” she said.