How Not to Die: Discover the Foods Scientifically Proven to Prevent and Reverse Disease

by Michael Greger

Based on the best evidence to date, authorities from Europe, the U.S. Institute of Medicine, and the World Health Organization recommend about eight to eleven cups of water a day for women and ten to fifteen cups a day for men.13 These recommendations include water from all sources, though, not solely beverages. You get about four cups from the food you eat and the water your body actually produces on its own,14 so these guidelines roughly translate into a daily recommendation for drinking four to seven cups of water for women and six to eleven cups for men (assuming only moderate physical activity at moderate ambient temperatures).15 You can also get water from all the other drinks you consume, including caffeinated beverages, with the exception of stronger alcoholic drinks like wines and spirits. Coffee,16 tea,17 and beer can leave you with more water than you started with, but wine actively dehydrates you.18 Note, though, in the cancer and heart disease studies mentioned earlier, the health benefits were almost exclusively associated with increased consumption of water, not other beverages.