Most of us have spent our lives feeling pressured by the notion that we need to drink at least eight glasses of water a day in order to avoid dehydration and stay healthy. Every summer we are inundated with news, media warnings that dehydration is dangerous and it is necessary to keep our body hydrated. But Aaron E Caroll, American pediatrician from Indiana University says there’s no real scientific proof behind this to support it.
Caroll has already co-written a widely cited research paper and book debunking common health myths – primarily the idea that all humans need to drink eight 8-ounce (237 mL) glasses of water a day – but the rumour just won’t go away, with an onslaught of media this year alleging that dehydration is on the rise due to children not drinking enough water. So Caroll took to the New York Times to clear things up once and (hopefully) for all.
So where did the great water myth come from? It’s generally believed that the source is a 1945 Food and Nutrition Board Recommendation that declared, a suitable allowance of water for adults is 2.5 liters daily in most instances. An ordinary standard for diverse persons is 1 milliliter for each calorie of food. As you might have guessed, 2.5 litres more or less works out to be around eight glasses. But what’s usually ignored from that report is the crucial next sentence: “Most of this quantity is contained in prepared foods.”
Water is universally present in various food consumptions like fruits, vegetables, juice, and beverages. Water is not the only source of hydration. Drinking extra water has no health benefits. Reviews have failed to find evidences that more water consumption makes skin look healthier. Before another objection pops up that tea, coffee dehydrates, again there’s no proof for it too. Human body is finely tuned to signal you to drink long before you are actually dehydrated.
In a recent study in the American Journal Of Public Health, researchers used data from the National Health and Nutrition Examination Survey from 2009 to 2012 to examine 4,134 children aged six to 19. Specifically, they calculated their mean urine osmolality, which is a measure of urine concentration. They found that more than half of the children had a urine osmolality of 800 mOsm/kg or higher. And children who drank eight ounces (236.5ml) or more of water a day had, on average, a urine osmolality about 8 mOsm less than those who did not. After detailed study, it is concluded that children who have a spot-urine measurement of 800 mOsm/kg need not be worried or consider dehydrated.
There is no formal recommendation for a daily amount of water people need. That amount differs by what a person eats, where he lives, how big he is and what he does.
Water is essential for good health, yet needs vary by individual.