Naked Science Forum
Life Sciences => Physiology & Medicine => Topic started by: thedoc on 19/07/2012 12:30:01
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Bert Hunt asked the Naked Scientists:
Back in the 70s I worked on building site when very hot we had a salt drink and it worked it stoped us feeling ill compare to those that never tried it. But now salt is bad for us?
What do you think?
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Salt is essential for good health, and you lose salt through sweat while doing heavy work in hot weather (or running a marathon, or suffering diarrhea).
- Drinking pure water doesn't restore the salt, and you can start to suffer from Hyponatremia http://en.wikipedia.org/wiki/Hyponatremia
- Cows are given "salt licks" in their field (a lump of salt) - but they obviously know when to stop!
- In 1930, in a move of defiance against British rule, Ghandi led a march for people to collect their own salt from the seashore
- So you need to restore your salt balance, and a rehydration solution can do this.
Humans like salt in their diet - it disguises bitter flavours, and over time we have become used to salt in all areas of our diet - to the point where even a strict salt-controlled diet can't get down to anywhere near the recommended daily intake.
Our kidneys have to work harder to get rid of the excess salt, which pushes up blood pressure, with impacts on heart disease, kidney problems and stroke...
It's a matter of salt balance.
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The primary method of treating cholera, which triggers diarrhoea and can lead to severe dehydration, is Oral Rehydration Therapy. This is basically salt/sugar water, with the salt and sugar at a certain ratio to best counter-act the causes of the diarrhoea. Diarrhoea is caused by an electrolyte imbalance, and particularly chloride, potassium and sodium ions moving out into the lumen of your gut. This in turn causes water to move out of the cells lining the gut, and into the lumen itself, by osmosis. This leads to the *obvious effects*.
By taking the salt/sugar water as part of oral rehydration therapy you help rectify this electrolyte imbalance, by supplying the cells lining the gut with more sodium and chloride ions. This then stops water being drawn out of the cells and prevents diarrhoea.
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Years ago, my dad worked in a "sweat shop" kind of factory, and they had salt tablets on hand in case anyone needed them to replenish electrolytes lost through too much sweating. However, here's an article (http://www.hammernutrition.com/knowledge/electrolyte-replenishment.1274.html) about electrolyte replenishment that cautions against using salt tablets.