Water is the number one healthiest beverage to drink.
That is the (perhaps unsurprising) finding from The Beverage Guidance Panel, a group of five of the world’s foremost nutrition experts.
The panel did extensive research on the health benefits and costs of each beverage, and ranked them on a six-tier scale from best to worst.
Water emerged as the clear winner.
But how much water should we drink?
You have undoubtedly heard the popular recommendation to drink eight glasses of water a day, but that guidance is based on little scientific evidence. The eight-glasses-a-day prescription traces back to a 1921 paper, based on just one person’s urine and sweat analysis.
So what are more broadly-applicable guidelines for water intake?
After reviewing all of the best evidence to date, authorities from Europe, the U.S. Institute of Medicine, and the World Health Organization recommend 8–11 cups of water per day for women and 10–15 cups a day for men.
However, this guidance includes water from all sources, including food and water produced naturally by the body. Those sources account for about 4 cups of water per day, and therefore the daily recommended water consumption becomes 4–7 cups for women and 6–11 cups for men.
Complicating things further, we also get water from other beverages, and certain drinks can actually increase the water in your body (even surprising ones like coffee, tea, and beer), whereas others actively dehydrate you (wine).
Accounting for all of these variables, what should we do?
He says, “Unless you have a condition like heart or kidney failure or your physician advises you to restrict your fluid intake, I recommend you drink five glasses of tap water a day.” One glass equals 12 ounces, so that translates to 60 ounces of water consumption per day.
Dr. Greger prefers tap water because it may have less microbial and chemical contamination than bottled water, and has less environmental and economic impact.
Why is water so beneficial anyway?
In his book, Dr. Greger cites studies showing that drinking water (at the levels he recommends) significantly reduces the risk of dying from heart disease, protects against certain cancers, increases brain functioning, and improves mood (whereas water restriction can cause the opposite effects).
If you find it challenging to drink five 12 oz. glasses of water per day, try spicing it up a bit.
Dr. Greger recommends adding fresh fruit (like strawberries or blackberries), veggies, and other enhancements (cucumber slices, mint leaves, sage, basil, cinnamon sticks, ginger shavings). He also points out that drinking carbonated water may help alleviate gastrointestinal symptoms.
For even more nutritional bang for your buck, try adding coffee beans or tea leaves to your water. Coffee and tea are tied as the number-two healthiest beverages, so adding them to your water provides additional nutrients without caloric expense (a cup of black coffee or tea only has two calories).
Summing it all up, Dr. Greger says it best: “Drink five glasses of water a day, be they plain tap water or flavored with fruit, tea leaves, or herbs. Keeping hydrated may elevate your mood (and vigor!), improve your thinking, and even help cut your risk for heart disease, bladder cancer, and other diseases. Bottoms up!”