I have seen in several places estimates that 75% of older Americans are continuously dehydrated. Part of the problem is that there is no clear standard or method for measuring hydration, so far as I have found. The book by Cohen and Bria looks at the subjection and emphasizes that much of the body's water supply comes from water in consumed food rather than from drinking water. Many sources agree that "8 oz. 8 times a day" is not accurate. Bria founded the Hydration Foundation and has studied Bedouin and other desert people to see how they survive. Several of my friends want to avoid stressing their kidneys and avoid having to urinate too many bothersome times a day. I reported that a nurse practitioner asked me about my hydration and advised me to "aim for 50 oz. a day". I have read that coffee and tea only function as dehydration agents at high levels of consumption and matter as hydrators at low levels. That was more than a year ago and since then, I have worked at consuming two 16 oz. mugs of water, first thing in the morning and about 3 PM. I usually have some water at dinner and afterwards when reading aloud. I have seen an article in Mozilla's daily collection of suggested reading that some scientists feel that human longevity is approaching a limit but I wouldn't be surprised if better hydration increases years lived. Part of the problem is that most people lose quite a bit of their ability to feel thirst as they age.
