Saturday, December 26, 2009

Don't swallow your gum

Came across a book at the library the other day called, Don't Swallow Your Gum! - myths, half-truths and outright lies about your body and health. It's by Aaron Carroll and Rachel Vreeman.

It's basically disputing a number of the commonly-held 'beliefs' about things many of us now take for granted as being true, or have had foisted upon us by the health community. One that I was particularly pleased to see downgraded from medical 'truth' to basic twaddle was the idea that you should drink eight glasses of water each day. This has been hammered home for a couple of decades now, but has no basis in fact at all. The authors give reasons for all their conclusions, which are too detailed to go into here, but frequently ideas such as this come out of a small piece of study, or an article, or even from urban mythology, and take hold. You will not get dehydrated if you fail to sip water constantly; furthermore, too much water in your system is actually bad for you!

So all those who carry water-bottles from A to B and back again - forget it. You can blame the bottled water industry for much of this myth.

'You only use ten percent of your brain' gets the works - it's twaddle. 'Your urine should be almost clear' is untrue (it's quite normal for it to vary from yellow to clear - though obviously constant dark brown or darker is worth mentioning to the doctor). 'Men think about sex every seven seconds' - I've never heard it being reckoned as quite so frequently, but whatever the supposed frequency is, it's untrue. As the authors point out, if men thought about sex as often as they're supposed to, they'd never get anything else done in life, such as building bridges, making road, putting up houses, writing books, making movies, composing symphones and painting Sistine Chapels.

There's a great deal more, but these were the particular ones that appealed to me.

PS Just came across another review of this book - seemingly in Chinglish


bethyada said...

Sounds like an interesting read. The source of the 2 L of water (originally fluid) myth has been hard to track down. But there is evidence of protein loss from the kidney at that level, and therefore possibly kidney damage. Drink to thirst.

Mike Crowl said...

Happy Christmas to you!
The authors say the first recorded instance is when the National Research Council back in 1945 recommended 2.5 litres of water a day - but most of this is contained in the food we already eat.
A few years later a nutritionist called Frederick Stare recommended a similar thing, but again said that most of the water we need is already contained in drinks we drink normally: milk, tea, coffee etc, as well as being in fruits.
As you mention, drinking too much water can be harmful to the system: it dilutes the normal level of sodium in the blood. In a serious case this can cause brain cells to swell and die. While most of us wouldn't go down that track, drinking too much water just does what drinking too much of anything does: send it out the other end!