Busted: five myths about the human body, from larger private parts in men with big feet to only using 10 per cent of your brain
- Many misconceptions and inaccuracies regarding the human body exist, such as the idea that a flatlining heart can be restarted again with a defibrillator
- That eating carrots can help you see in the dark and that your appendix serves no purpose are two other medical fallacies that have been accepted as fact
Of all the myths propagated about the properties of the human body, those about our brains are the ones most in need of being dispelled, says British children’s book author Paul Mason, whose most recent title is Hair-raising Human Body Facts.,
“I still hear people saying, ‘You only use 10 per cent of your brain, you know?’” says Mason. The 2014 Hollywood film Lucy starring Scarlett Johansson is among media productions to have touted this false idea.
He is not the only writer to have published books that separate the real from the ridiculous, the facts from the falsities. Dr Sarah Schenker wrote Myth-busting Your Body: The Scientific Facts Behind the Headlines, Drs Aaron Carroll and Rachel Vreeman published Don’t Cross Your Eyes … They’ll Get Stuck That Way!: And 75 Other Health Myths Debunked, and Bill Bryson’s latest chart-topper, The Body: A Guide for Occupants, takes us on a tour of everything that makes us human.
Understanding the very essence of our physical selves has long captivated writers – which isn’t surprising given how astonishing our physiological composition is. As Bryson notes, people’s belly buttons have been found to contain 2,368 species of bacteria; over a lifetime our hearts exert the equivalent energy in their daily pumping to that needed to force a one-tonne weight 240km (150 miles) into the air, and; if you strung a single person’s DNA end to end, it would stretch beyond the planet Pluto.
Our bodies are such incredible vessels that it is perhaps not surprising that sometimes our imaginations run a little wild and we get caught up in myth and legend and forget to separate what’s real from what’s not.
Here are five common body myths busted; they are outed in a number of books, including the succinctly titled Everything You Know About the Human Body is Wrong, by science writer Matt Brown and illustrator Sara Mulvanny.
1. We only use 10 per cent of our brains
As Mason observes, this is nonsense. It is clear from scans and imaging that we engage all regions of our brains at some point during the day.
The myth dates back to at least the early 20th century – long before brain scans and MRIs were available – so it seems the figure was plucked from thin air.
2. A flatlining heart can be restarted with a defibrillator
No, it can’t – even though every medical drama show you’ve ever watched has led you to believe otherwise.
3. The appendix has no known function
Microbes that help us fight disease are stored there. During childhood, the appendix also makes white blood cells and antibodies to fight infections. And even when it’s removed it can serve a useful purpose as a spare part: surgeons have adapted it as a replacement for diseased urine ducts.
4. Carrots improve your night vision
“Eat your carrots. They’ll help you see in the dark.” Who wasn’t told that by their parents as a child, in a bid to get them to eat more veg? Carrots do, indeed, contain high levels of vitamin A, which helps to support night vision, but it will not improve eyesight.
The carrot eating/eyesight myth apparently originated during the second world war. The success of British pilots who intercepted enemy planes was explained away by the Royal Air Force as their having better night vision – on account of a healthy diet of carrots. It wasn’t, of course; the RAF relied on superior, secretive radar technology. But that in itself may be another legend.
5. Men with big feet have larger genitals
Men with large feet, so the myth goes, have big you-know-whats, too.
London hospital urologists have done studies on this and discovered that the theory does not stand up. In a study published in 2002 in the journal BJU International, they measured the stretched penile length of 104 men and compared it with their shoe size.
They found no correlation. What they did discover was that the average stretched penile length is 13cm (five inches), while the average male UK shoe size is nine.