Proper hydration is a critical factor in maintaining and improving your mind as you age. “Your brain is 80 percent water,” says Daniel Amen, MD, a clinical neuroscientist and author of Use Your Brain to Change Your Age: Secrets to Look, Feel, and Think Younger Every Day (Crown, 2012). “Even slight dehydration increases the body’s stress hormones, which can decrease your ability to think clearly. Over time, increased levels of stress hormones are associated with memory problems.”
While the amount of hydration you need day-to-day depends on several factors, including activity level, relative humidity and eating habits (to name only a few), the oft-repeated advice to drink 64 ounces — or eight 8-ounce glasses — of water a day isn’t a bad general rule to follow. Keep in mind, however, that you can account for those ounces in several different ways. If you’re eating a lot of vegetables and fruits, for example, you may need to drink less water. Most fresh plant foods have a high water content and will help keep you hydrated.
While the feeling of thirst is a good indicator you need to hydrate, if the only time you grab a glass of water is when you’re noticeably thirsty, you may not be drinking enough for optimal health. That’s because that “thirsty feeling” kicks in only when your body is already a bit dehydrated. The best approach to hydration is a conscious, proactive one. So, drink up! (For more on proper hydration, see Drink to Your Health.)