Don’t crack your knuckles, you’ll get arthritis!
The verdict
An American doctor cracked the knuckles of only one hand for 60 years and then compared the two: no difference. He won an Ig Nobel Prize for his trouble. Larger studies have found no link to arthritis either.
On the wall
Don’t keep your mobile in your pocket, the radiation will give you a brain tumour!
Verdict: A large review commissioned by the WHO in 2024 found no link between mobile phones and brain tumours, even though almost everyone has had a mobile for decades.
Don’t swim straight after eating, you’ll get cramp and drown!
Verdict: No research has shown that people drown from swimming on a full stomach. A gentle swim after lunch is perfectly fine.
Don’t swallow the apple pips, a tree will grow in your tummy!
Verdict: The stomach is far too dark and acidic for anything to sprout. The pips come out again, usually quite unbothered.
Verdict: There is no evidence that coffee stunts growth. Children still shouldn’t have much caffeine – but for other reasons.