UPDATES
Part
7
in a series
Demystified
Myth: Drink eight glasses of water daily to keep your body hydrated. Fact: There is no one right number; adequate hydration even varies for each person per day. With summer up ahead, this is the perfect time to debunk one of the most widely-accepted myths. Yup, about the fixed eight glasses of water. Many of us subconsciously ascribe to the misconception that eight is the magical number, but in truth, there’s no science to prove that eight it is. The advice to drink eight cups of water a day evolved after a 1945 recommendation from the Food and Nutrition Board of the National Research Council, which encouraged adults to consume about 64 ounces of water daily. The recommendation referred to a person’s total daily intake of water, including from all their foods and beverages, but it was widely misinterpreted to mean that people should drink eight 8-ounce glasses of water every day. Furthermore, some experts have argued that this widely-held belief is not even rooted in science. According to a study published in Science, for most healthy adults, drinking eight cups of water a day is completely unnecessary. The research found that our water needs vary greatly based on age, movement, and food con24
WELLSPRING / JUNE 2023
sumption. One study of 883 elderly adults, for example, found that there was no evidence of dehydration among the 227 people in the study who routinely drank less than six glasses of water daily. So how much water is just right? The answer is simple. It’s not about a particular amount, as our hydration needs vary from day to day depending on an array of variables, including temperature, level of activity, and the amount of food-derived hydration (and dehydration, such as after eating foods high in added sugar). Thus, the advice is to drink when you’re thirsty. “If you’re paying attention to your body and drinking when you feel like you need to, then you should be fine,” says Herman Pontzer, a professor of evolutionary anthropology and global health at Duke University and a co-author of an extensive analysis of water needs. Bear in mind that hydrating with foods that have a high water content is also important, so stock up on all those fruits and vegetables as the temperatures keep rising.
