All of us have been told that we should drink substantial amount of water everyday. Now researchers have claimed in a new study that drinking eight glasses a day is probably too much.
The new study has been published in the journal Science and titled 'Variation in human water turnover associated with environmental and lifestyle factors.' It emphasises how water requirements for human consumption may become more difficult to manage as changes occur in the Earth's climate and in human populations.
The study was done on more than 5,600 people of all ages from 26 countries around the world. Researchers gave participants 100 milliliters of water enriched with five percent 'doubly labeled water', a type of water in which some of the hydrogen molecules were replaced by a stable isotope of the element called deuterium. It is entirely safe and occurs naturally in the human body. The speed at which the excess deuterium is eliminated reveals how quickly the body is changing its water. A higher water turnover usually necessitates more water consumption.
Men aged 20 to 30 and women aged 20 to 55 had the highest water turnover, which dropped after the age 40 for men and after the age 65 for women. Of all the water in their bodies, newborns had the highest water turnover rate, replacing almost 28 percent of it each day. Men drink around half a litre more water per day than women do under similar circumstances.
"The current study clearly indicates that one size does not fit all for drinking water guidelines, and the common suggestion that we should drink eight 8-ounce glasses of water per day is not backed up by objective evidence," the researchers mentioned.
Persons in developed countries who lead sedentary lifestyles in climate-controlled indoor settings had lower water turnover than people in poor countries who worked as manual labourers or hunter-gatherers.
Commenting on the study further, the researchers remarked, "Improved guidelines are of increasing importance because of the explosive population growth and climate change the world currently faces, which will affect the availability of water for human consumption."
