Consider this study, reasonably well reported by the Daily Mail:

First author Professor Brendan Lucey, director of the Washington University Sleep Medicine Center in St Louis, said: ‘The key is it wasn’t the total amount of sleep that was linked to tau.

‘It was the slow-wave sleep – which reflects quality of sleep.

‘The people with increased tau were actually sleeping more at night and napping more in the day – but they weren’t getting as good quality sleep.’

The finding published in Science Translational Medicine adds to a growing body of evidence linking poor sleep to Alzheimer’s and other forms of dementia.

Daytime napping alone was significantly associated with high levels of tau.

It means doctors could identify patients who could benefit from further testing simply by asking: ‘How much do you nap during the day?’

Last year a similar study by another US team found those who napped during the day – when they should have been awake – had almost three times as much amyloid beta.

This is another damaging protein that can trigger dementia by clumping together in grey matter and forming plaques.

Dr Lucey said fewer slow brain waves that occur during the most refreshing part of the sleep cycle is associated with high levels of the other toxic brain protein tau.

He said: ‘What’s interesting is we saw this inverse relationship between decreased slow-wave sleep and more tau protein in people who were either cognitively normal or very mildly impaired – meaning reduced slow-wave activity may be a marker for the transition between normal and impaired.

So researchers are using whether or not people require a day time nap as a metric for tau levels, and correlating that with Alzheimer’s. The journalist has done a pretty good job of passing on the important points.

Then it goes to their social media team…

The comments are full of derision by people who have seemingly not read the article, to the effect that scientists constantly change their minds, one minute saying lack of sleep causes Alzheimer’s and the next saying these naps cause Alzheimer’s etc.

These little decisions in presentation can make a big difference, and when it is done poorly it can just make people switch off to useful info.

BREAKING NEWS: Daily Mail social media team are DUMDUMS who can BARELY READ

Hang on though…what about all those countries that traditionally siesta every day? Do they have high levels of dementia? Or do they know how to do the right sort of sleep after lunch?

(I’ll find the research link)

OK, from the paper…

_Sleep monitoring

Sleep was assessed longitudinally in all participants using three separate measures over six nights at home: (i) sleep logs, (ii) actigraphy (Actiwatch 2, Philips Respironics), and (iii) a single-channel EEG device worn on the forehead (Sleep Profiler, Advanced Brain Monitoring). Sleep logs and actigraphy were scored as previously reported (18). Single-channel EEG sleep studies were visually scored by registered polysomnographic technologists using criteria adapted from the standard American Academy of Sleep Medicine (AASM) criteria (56). Sleep parameters for time in each sleep stage, sleep latency, sleep efficiency, WASO, and TST were calculated. Nights were excluded if >10% of the recording was artifactual or if the bed and rise times did not match the sleep log and/or actigraphy. All participants needed at least two nights from the single-channel EEG device that met these criteria to be included in this analysis._

So that is night time sleep. No mention of daytime napping there.

The paper is at: http://stm.sciencemag.org/content/11/474/eaau6550

And the abstract:

—————————————————————————————-

Abstract

In Alzheimer’s disease (AD), deposition of insoluble amyloid-β (Aβ) is followed by intracellular aggregation of tau in the neocortex and subsequent neuronal cell loss, synaptic loss, brain atrophy, and cognitive impairment. By the time even the earliest clinical symptoms are detectable, Aβ accumulation is close to reaching its peak and neocortical tau pathology is frequently already present. The period in which AD pathology is accumulating in the absence of cognitive symptoms represents a clinically relevant time window for therapeutic intervention. Sleep is increasingly recognized as a potential marker for AD pathology and future risk of cognitive impairment. Previous studies in animal models and humans have associated decreased non–rapid eye movement (NREM) sleep slow wave activity (SWA) with Aβ deposition. In this study, we analyzed cognitive performance, brain imaging, and cerebrospinal fluid (CSF) AD biomarkers in participants enrolled in longitudinal studies of aging. In addition, we monitored their sleep using a single-channel electroencephalography (EEG) device worn on the forehead. After adjusting for multiple covariates such as age and sex, we found that NREM SWA showed an inverse relationship with AD pathology, particularly tauopathy, and that this association was most evident at the lowest frequencies of NREM SWA. Given that our study participants were predominantly cognitively normal, this suggested that changes in NREM SWA, especially at 1 to 2 Hz, might be able to discriminate tau pathology and cognitive impairment either before or at the earliest stages of symptomatic AD.

As an aside, I am reading a book called About Time which mentions something I knew about, the two sleeps that were the norm before electric light. When lighting was expensive and inefficient people would go to bed with the sun going down, wake midway through the night, have a snack and a stretch, stoke the fire then back to bed for another sleep.

Modern sleep patterns, evolutionarily, are very new.

So the nap bit comes from one of the references, not this actual research (I think). Here:

https://jamanetwork.com/journals/jamaneurology/fullarticle/1663363

Anyway, it’s not really the main point of the research in the paper referenced by the news report.

I had a nap today after sleeping about 12 hours last night, but that’s hangover-related.

Poor quality sleep at night is often strongly associated with the need to get up for urinary tract problems. Did they take that into account?

So they’re saying napping is partially correlated with harmful brain proteins because some of the people who nap, do so because they have poor quality sleep in general, and might be trying to make up for it?

Kothos said:

So they’re saying napping is partially correlated with harmful brain proteins because some of the people who nap, do so because they have poor quality sleep in general, and might be trying to make up for it?

Tick

dv said:

Kothos said:

So they’re saying napping is partially correlated with harmful brain proteins because some of the people who nap, do so because they have poor quality sleep in general, and might be trying to make up for it?

Tick

But…but… the headline says if i stop having naps i can avoid dementia. Doesn’t it?

captain_spalding said:

dv said:

Kothos said:

So they’re saying napping is partially correlated with harmful brain proteins because some of the people who nap, do so because they have poor quality sleep in general, and might be trying to make up for it?

Tick

But…but… the headline says if i stop having naps i can avoid dementia. Doesn’t it?

Read the OP of this thread.

dv said:

captain_spalding said:

dv said:

Tick

But…but… the headline says if i stop having naps i can avoid dementia. Doesn’t it?

Read the OP of this thread.

I did. I was just trying to play the part of the ingénue.

buffy said:

Hang on though…what about all those countries that traditionally siesta every day? Do they have high levels of dementia? Or do they know how to do the right sort of sleep after lunch?

(I’ll find the research link)

They drink lots of Tequila till after midnight and sleep like rocks.

AwesomeO said:

As an aside, I am reading a book called About Time which mentions something I knew about, the two sleeps that were the norm before electric light. When lighting was expensive and inefficient people would go to bed with the sun going down, wake midway through the night, have a snack and a stretch, stoke the fire then back to bed for another sleep.

Modern sleep patterns, evolutionarily, are very new.

Yes. This is true.

roughbarked said:

AwesomeO said:

As an aside, I am reading a book called About Time which mentions something I knew about, the two sleeps that were the norm before electric light. When lighting was expensive and inefficient people would go to bed with the sun going down, wake midway through the night, have a snack and a stretch, stoke the fire then back to bed for another sleep.

Modern sleep patterns, evolutionarily, are very new.

Yes. This is true.

Bubblecar still does this

captain_spalding said:

dv said:

captain_spalding said:

But…but… the headline says if i stop having naps i can avoid dementia. Doesn’t it?

Read the OP of this thread.

I did. I was just trying to play the part of the ingénue.

Needs work…

Kothos said:

So they’re saying napping is partially correlated with harmful brain proteins because some of the people who nap, do so because they have poor quality sleep in general, and might be trying to make up for it?

I was thinking that as well, day time napping is needed as you didn’t sleep well at night or not enough

roughbarked said:

AwesomeO said:

As an aside, I am reading a book called About Time which mentions something I knew about, the two sleeps that were the norm before electric light. When lighting was expensive and inefficient people would go to bed with the sun going down, wake midway through the night, have a snack and a stretch, stoke the fire then back to bed for another sleep.

Modern sleep patterns, evolutionarily, are very new.

Yes. This is true.

You could add in even newer sleep pattern disruption due to using computers/phones, etc at night