There are countless pieces of health advice which are widely believed but which are in fact totally wrong, as these experts point out
Swallowed chewing gum stays in your stomach for seven years
TRUTH: ”It’s true your digestive tract cannot break down the synthetic resin in chewing gum, but it’s very efficient at moving the contents of your stomach along and passing it out of your body.
Leave cuts open for faster healing
TRUTH: Research has found that rather than leaving wounds exposed to dry air to heal, the opposite is true.
Creating moist wound conditions allows cells to grow, divide and migrate at an increased rate.
Wounds that are left to dry in air will always create scabs, which makes it hard for new skin tissue to form.
”Covering a wound also reduces the risk of it becoming infected,” adds Dr Hicks. “And it lessens the chance of the wound suffering further injury, which would slow healing.”
Coughing up green mucus means you need antibiotics
TRUTH : Antibiotics are no longer prescribed according to the colour of sputum, explains Dr Hicks.
“The colour doesn’t help distinguish between a viral and a bacterial infection. Most infections associated with lots of phlegm are caused by viruses and, as antibiotics only treat bacterial infections, they have no effect.”
Cracking your knuckles causes arthritis
TRUTH: There have been studies about this and there is no evidence to back it up, says Arthritis Research UK.
A study from the University of Alberta suggested that when muscle joints are pulled apart it forms a tiny cavity filled with gas which then collapses, creating a popping noise.
Eating late at night results in weight gain
TRUTH: It’s a myth that if we do this, calories deposit themselves more readily into fat cells than calories eaten earlier in the day.
“It’s not when – but what you eat,” says Dr Jebb. “Your basic metabolism is fairly consistent over a 24-hour period and does not slow down when the sun sets, though of course you burn off fewer calories when you are sleeping.”
Sugar causes hyperactivity in kids
TRUTH: Numerous double-blind, randomised controlled trials have been done specifically looking at this claim and have found no evidence to show that sugary foods or drinks have any real effect on children’s behaviour.
In one study, parents were told their child had been given sugar when they hadn’t, and reported their child was more hyperactive anyway!
There is some evidence, however, to suggest certain additives (E numbers) used in sugary drinks and sweets can cause hyperactivity in some children.
Tilt your head back to stop a nosebleed
TRUTH: This doesn’t help. Instead: “Pinch the soft part of the nose beneath the bony bridge, lean forward, and breathe through the mouth to treat a nosebleed,” says Dr Hicks.
“Leaning forwards helps the blood come out of the nose rather than down the back of the throat where it might irritate the stomach.”
Microwaving kills the nutrients in food
TRUTH: Studies have found that microwaving food often retains more nutrients than conventional cooking.
That’s because the cooking time is shorter (vitamins and minerals are heat-sensitive) and you’re less likely to use water (nutrients leach into water).
The healthiest way to cook veg is to steam them, but microwaving won’t do them any harm. The exception is breast milk for babies – microwaving it decreases the potency of its enzymes.
Waking sleepwalkers can give them a heart attack
TRUTH: “It may leave them a bit disorientated but will not cause them any harm,” explains Dr Hicks.
“But it’s best not to wake a sleepwalker, just make sure they remain safe as you guide them back to bed.”