“Drink eight glasses of water a day for good health,” this saying has been used by many as a scientific fact in their daily lives. However, a study by American scientists shows that there is currently insufficient scientific evidence to prove that drinking eight glasses of water (about 1.6 liters) daily is beneficial to human health. It is unclear where this saying originated.
Supporters of the "eight glasses of water a day" theory claim that drinking eight glasses of water daily (about 200 ml per glass) helps the body flush out toxins, control weight, and improve skin condition.
On the 3rd, the British "Daily Telegraph" cited research findings from Dr. Dan Negoianu and Stanley Goldfarb of the University of Pennsylvania, stating that no research has proven that an average healthy person should drink 1.6 liters of water per day.
"In fact, we are not even sure of the origin of this saying," Negoianu and Goldfarb wrote in their research report published in an American nephrology journal. The report said that researchers found that people living in hot, dry climates and athletes need to increase their water intake. Some studies have also found that drinking large amounts of water helps the body expel excess salt and urea. However, to date, no studies have shown that increasing water intake is beneficial to human organs. Insufficient Evidence
Supporters of this theory believe that drinking large amounts of water can create a feeling of fullness, thereby suppressing appetite, achieving the effect of controlling weight and preventing obesity.
However, Negoianu and Goldfarb said that the evidence supporting this claim is not "conclusive" because to date, no rigorous clinical trials have quantified the effect of water intake on maintaining weight.
Some also believe that headaches are often caused by insufficient water intake. Negoianu and Goldfarb refuted this, saying there is almost no scientific basis for this claim.
Although results from small clinical trials showed that subjects who drank more water had a lower chance of getting headaches than those who did not increase their water intake, the difference in the incidence of headaches between the two groups was very small.
In addition, water has long been regarded as a good remedy for improving skin conditions. However, scientists have stated that while some studies have shown that dehydrated skin has reduced hardness, no clinical trial results have proven that drinking more water can improve skin condition. Daily Water Requirement: 1-1.5 Liters
In their article, Negoianu and Goldfarb stated that to date, it cannot be proven that increasing water intake is beneficial to the health of ordinary people, but there is also no evidence that drinking more water is harmful. "Overall, it's a lack of evidence," they said.
Under normal circumstances, a person needs to drink 1 to 1.5 liters of water per day, and more water is needed in high temperatures and immediately after exercise.
In addition to pure water and beverages, a large number of foods, including vegetables, fruits, and dairy products, are also rich in water. Therefore, people do not need to specifically drink large amounts of water to replenish fluids.
Negoianu and Goldfarb also pointed out that excessive drinking can disrupt the body's water and electrolyte balance and cause "water intoxication," which can potentially lead to death.