Sleep myths debunked, from swallowing spiders to drinking before bed – Metro.co.uk

Have you ever heard the old wives’ tale that you swallow eight spiders in your sleep over the course of your life?
Turns out you’re not alone, as a poll from US firm Mattress Advisor and OnePoll suggests.
They tested the knowledge of 2,000 Americans to see just how much they know about the science of sleep and whether certain myths hold truth, and found that a lot of people really believed many myths.
While the spider myth isn’t anything to worry about, those that focused on how much sleep you need and how to get there mean that people could actually be damaging their health.
Here, we go through the most common misconceptions around the land of nod.
Drinking alcohol before bed helps you sleep
A whopping 32% of those surveyed believed that a nightcap was the key to a good night’s sleep.
This is likely due to the fact that many of us have had a boozy night and slept like logs, struggling to wake up in the morning (except perhaps if tempted by a cooked breakfast).
However, just because you feel dead to the world, doesn’t mean you’re getting the quality sleep you need to regenerate, which contributes to your tiredness the next day.
Irshaad Ebrahim from The London Sleep Centre said: ‘Alcohol may seem to be helping you to sleep, as it helps induce sleep, but overall it is more disruptive to sleep, particularly in the second half of the night.
‘Alcohol also suppresses breathing and can precipitate sleep apnoea.’
Watching TV/using a smartphone/tablet/computer helps you fall asleep
Watching something boring on your laptop or phone might seem like a good way to lull yourself to sleep.
Almost a third of respondents (30%) believed so anyway, but they couldn’t be more wrong.
In fact, the blue light emitted by these devices actually has the opposite effect, as the blue light emitted from screens affect the brain’s ability to produce melatonin, which tells the body when it’s time to sleep.
Far better to read a book or simply be alone with your thoughts before bed.
The older you get, the less sleep you need
Just because your granny gets up at the crack of dawn doesn’t mean she needs less sleep. 29% of respondents believed this, however.
In trials, when older people were asked to sleep as much as they could, they averaged less than younger adults tasked with the same.
Those running the study were keen not to state that this meant that older people definitively needed less sleep, though, and instead concluded that there was no way to state whether it was a  decreased ability or need to sleep.
Essentially, sleep needs differ from person to person, and there’s no need to assume that you can stay up all night as soon as you hit pension age and not feel the effects.
Some people don’t dream at all
25% of those asked believed that some people simply have no dreams whatsoever, which may be due to the fact that they don’t remember them.
Studies show that, while not all people know they’ve had a dream, dreaming happens in all people during the REM (Rapid Eye Movement) period of deep sleep.
One that looked at people with RBD (a condition where they move and speak in their sleep) found ‘the observation of speeches, facial expressions and behaviours while sleeping, unbeknownst to the dreamers, suggests that dreaming production is universal, while dreaming recall is variable.’
You can train your body to function on less sleep than needed
In the age of the bio-hack, everybody’s trying to spend less time doing more things.
As if your body is simply a Rubik’s Cube that need to be solved, that has also moved into the sleep sphere, with almost a quarter believing they can train their body to need less sleep.
For most people (up to 99% according to some research), getting less than six hours a night can have consequences – from lower testosterone levels to insulin resistance to cardiovascular disease.
Those who ‘naturally’ need less sleep tend to have a mutated gene called hDEC2, which essentially predisposes them to being ‘short-sleepers’.
So, that’ll be all the entrepreneurs who do interviews saying they get three hours a night and everyone else is a lazy loser. Don’t worry, needing a full night every night is perfectly normal.
Working out at night makes it harder to fall asleep
‘Pumping iron’ or ‘feeling the burn’ hardly conjure images of rest and relaxation. This may be why 23% of people think exercise is bad for falling asleep.
It is actually true that over-training can lead to insomnia, but researchers agree that moderate exercise can work wonders for your sleep cycle, with those who do around 30 minutes of exercise finding that they sleep longer and better the same night.
Why this is isn’t completely clear, but it’s thought that it may have something to do with body temperature and endorphins released during exercise.
You can “make up” for lost sleep over the weekend
Having an early alarm in the week may mean that you’re keen to make up for lost time at the weekend with a big old lie-in. While we’re not going to stop you, it doesn’t actually help at all.
A study this year from the University of Colorado tested the theory that you could make up for sleep lost during the week, and found that it wasn’t the case.
Assistant Professor at the university, Christopher Depner, said: ‘Catch-up sleep does not appear to be an effective strategy to reverse sleep loss induced disruptions of metabolism.’
Falling asleep with wet hair will give you a cold
Given that colds are a virus, going to sleep with wet hair or dry hair will have no effect whatsoever on whether you get one.
Apologies to the older members of your family, who have definitely told you this at one point or another.
An hour of sleep before midnight is worth more than two after
A whopping 23% of people believe this myth, which probably came from parents who wanted their kids to go to sleep on time.
While those who are ‘early birds’ and go to bed earlier are shown to be more successful, there shouldn’t be a direct correlation between sleep times and quality of sleep.
There are caveats, in that you need to make sure you have some semblance of circadian rhythm. For example, you won’t get effective sleep in a light room, as your body assumes this is wake-up time.
It also only makes sense if you’re actually getting around eight hours of sleep (or less if you’re one of these mythological short-sleepers). You can’t simply go to bed at 3am, get up at 7am, then be confused at why you’re tired.
The brain is inactive during sleep
Those who sleep walk or sleep talk will know concretely that the brain is very much active at night.
Some things that your brain is doing in the night is logging the memories of the day before, clearing out toxins, and moving the more important short-term memories into the part of the brain that stores long-term memories.
One study even found that you’re able to make decisions in your sleep.
You swallow eight spiders per year while you sleep
This is probably the funniest one of all, and it’s even funnier that 20% of people really believe that spiders are queuing up waiting for you to drift off and claim your mouth as their home.
While we’re awake or asleep, we’re breathing and have a heartbeat, which creates vibrations alerting spiders of danger (at least the ones that live in the UK). The old adage is true that ‘they’re more scared of you than you are of them’.
Spider expert Dave Clarke told the BBC: ‘Most predators won’t tackle anything bigger than themselves because they are likely to come off worse
‘Spiders are highly sensitive to both vibrations and heat so are unlikely to stumble across a human unawares. They are just not interested in us at all really.’
Another flaw in the story includes the fact that there would really be no way to report having swallowed a spider in your sleep, given you’d be asleep when it happened. Wouldn’t it wake you while crawling on your face to get to the mouth?
Essentially, while it’s not impossible that someone might swallow a spider in their sleep, it’s a pretty rare event, and not anything to keep you awake.
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