Have you heard the one about…
From cheese causing nightmares to the five-second rule, Michele O’Connor busts some common health myths
Gum takes seven years to digest
According to a recent poll, a third of Brits believe that swallowed chewing gum takes seven years to digest.
But there’s little truth to the tale, which is probably designed to encourage children to be careful with their gum.
Dr Deborah Lee (doctorfox.co.uk) says: “While chewing gum is not meant to be eaten because the human body cannot actually digest it at all, that doesn’t mean if you do swallow it, it will stick to the stomach or intestinal walls. It will simply travel through the gut unchanged and pass out of your body the next time you have a bowel motion.”
Sitting too close to the TV will ruin your eyesight
There is no evidence that sitting close to a TV for short periods will cause damage, says Dr Lee. “However, it does mean your eye muscles have to work harder to focus on the images and this can result in eye strain – meaning sore, tired, eyes.”
What’s more important is the amount of time you spend in front of any type of screen – mobile phone, iPad, computer or TV, she warns. That’s because they all emit blue light, which may cause digital eye strain (DES) – with symptoms such as headaches, dry eyes, blurred vision and pains in the neck and shoulders – and may also contribute to macular degeneration in later life. “Consider using anti-blue light filters for your TV and computer screen,” she advises.
Waking a sleepwalker is dangerous
“There is no evidence that waking a sleepwalker could cause them a fatal heart attack from shock, as many seem to believe,” says Dr Lee. In fact, you are more likely to suffer harm, she warns. A psychiatric medical study reported 20 murders and 30 other serious events occurring as a result of incomplete arousal from sleep. “They may be confused, angry and even violent, so it’s generally best to just gently coax them back to bed,” she says.
As most sleepwalkers tend to walk at the same time every night, it might be worth waking them up shortly before sleepwalking is likely to happen to try and avoid it, say sleep experts.
Never mix grape and grain
“Grape or grain, but never the twain” runs the old folk wisdom that advises against drinking wine and beer on the same night. Alas, it’s another myth. And drinking beer before wine won’t necessarily mean you’ll end up “feeling fine” either. “It doesn’t matter what you drink, it’s the amount of alcohol you consume, and how quickly you drink it that governs the extent of the hangover,” explains Dr Lee. However, there are some factors that will affect how quickly you start to feel the effects of alcohol, such as drinking on an empty stomach and not staying hydrated, she says.
“Darker coloured drinks, such as red wine, rum and whisky contain additives called congeners, which can contribute to hangover symptoms.”
Sitting on cold surfaces will give you piles
There is no plausible biological explanation as to why sitting on a cold surface could cause haemorrhoids (enlarged blood vessels that develop inside or around your anus), says Dr Lee.
Common causes can include pregnancy, constipation and spending a long time straining on the loo – but not sitting on cold surfaces. “In fact, sitting on an ice pack can help relieve the pain of protruding, painful piles,” adds Dr Lee.
Eating cheese before bed causes nightmares
“This myth is said to have originated from Mr Ebenezer Scrooge, who laid the blame for his ghostly night-time apparitions on his ‘crumb of cheese’ before bedtime,” says Dr Lee. So cheese lovers will be pleased to hear that there is no link whatsoever.
A Cheese and Dreams study involving 200 volunteers who ate various cheeses before bed found that 72 per cent slept well every night, and while 67 per cent were able to recall their dreams, none reported any nightmares. In fact, Dr Lee adds: “the investigators said that because cheese contains an amino acid called tryptophan, which is known to reduce stress, eating cheese before bedtime may actually help you to get a better night’s sleep.”
Drinking beer before wine won’t necessarily mean you’ll feel fine
The five-second rule
A 2016 study set out to investigate the belief that food that has been dropped on the floor for less than five seconds is safe to eat.
Scientists examined four different foods (watermelon, gummy candy, bread and bread with butter), four different floor surfaces (stainless steel, ceramic tile, wood and carpet) and four different contact times ( from one to 300 seconds).
“They found that some bacterial transfer occurs instantly at all sites, disproving the five-second rule,” says Dr Lee. “Micro-organisms including E. coli, salmonella, shigella, campylobacter, norovirus and hepatitis A are brought into our homes on the soles of your shoes.”