Undoubtedly, clean water plays an important role. But is it worth to drink two to three liters of water a day? According to the National Academy of Sciences of the United States, the vast majority of healthy people adequately meet their daily hydration needs, focusing on the feeling of thirst. 80% of the required volume of liquid we get drinking pure water and other drinks, including caffeine drinks, which, contrary to popular belief, affect total fluid intake. 20% of food – vegetables, fruits, berries, dairy products, writes likar.info.
Whether the theory of “eight glasses” a scientific justification
In a review published in the American journal of physiology, Dr Heinz Valtin of Dartmouth medical school says about the origins of the famous rule of “eight glasses”. As it turned out, it’s just taken out of context review of the influential nutritionist Frederick J. Steyr.
The newspaper “new York times” calls the source of the myth of eight glasses is the recommendation of the Council on food and nutrition, composed in 1945. It was argued that people should drink 2.5 litres of water a day, and this is equivalent to approximately eight glasses. However, the second part of the recommendation has successfully ignored most of the rules of the water are the finished products.
How much water should you drink a day? Usually this process is automatically regulated by various physiological mechanisms, but for the average adult takes about six to eight glasses a day. Water can be ingested in the form of coffee, tea, milk, soft drinks, beer, etc. Fruits and vegetables are also good sources of fluid.
Many things about the use of the water is greatly exaggerated
After careful analysis of the literature and discussions with experts, including nutritionists and other doctors, Waltin not been able to find any serious justification of this theory. Interestingly, he also refuted the assertion that “man is on the verge of dehydration thirst”. In fact, the physiological mechanism of thirst is triggered before dehydration. In fact, thirst is so sensitive, rapid and accurate process that it is difficult to believe that evolutionary development left us with a chronic water deficit that needs to be compensated by forcing fluid intake.
Valtin destroyed the myth that dark urine is a sign of dehydration.
Dr. Timothy Noakes, Professor of sports medicine at the University of Cape town, wrote perhaps the most popular in this area book: “Dehydration during exercise: myths and facts”. It says that gipergidratace does not improve the results, but rather worsen them. Drink before thirst, according to Noxa, it is impossible. It impairs physical activity. In his book he uses the example of African hunters who could pursue an antelope under the scorching sun for four to six hours without ever taking a SIP.
Excessive use of water not only reduces athletic performance, but also increases the risk of hyponatremia. When hyponatremia cells in the body, including brain cells, “swell”, which leads to fatal consequences.
It turns out that the appeal to the high fluid intake may lead to fluid overload and potentially serious consequences not only in the elderly but also among healthy young people.
The benefits of drinking water
Water is from 50% to 70% of our total body. Blood 85% water, muscles take 80%, the brain 75%. Even the bones are 25% water.
According to some, a high fluid intake is associated with a lower risk of developing certain types of cancer, such as bladder cancer and colorectal cancer. The risk of dying of coronary heart disease is also associated with the consumption of water, and women who drank five or more glasses of water a day could reduce the risk by 41%. In addition, water plays an important role in blood circulation, the metabolism, regulating body temperature and removing waste.
During dehydration worsens mood and cognitive function. According to a study published in the journal “Physiology and behavior” dehydrated drivers made two times more road accidents.
How much water you should drink actually
Eight glasses of pure water a day may not cause harm to your body. At the same time, there is no evidence that this magic number is ideal for everyone.
Water demand varies depending on your age, activity level, climate, and other factors. Do not waste time trying to find out how many liters per day are needed to your body or keep track of how many glasses were consumed. Just listen to your body. Thirst is your guide.