Lisa Mosconi, an Italian-born neuroscientist and nutritionist, had no idea how important the taste of water was to her until she moved to New York City and took a long sip from the tap.

"This is supposed to be the best water in America," she said, "but it tasted awful. It was disgusting."

She set off to the grocery store in search of the sort of good-tasting water that flowed from her tap in Italy, and was soon confronted by a confusing array of choices: purified, distilled, natural spring, seltzer, soda. Most were in the refrigerated section.

"No Italian puts water in the fridge," she said. "Water is actually more hydrating when it's warm."

It didn't take long for Mosconi, the associate director of the Alzheimer's Prevention Clinic at Weill Cornell Medical College in New York City, to conclude that Americans, with their affinities for coffees, Frappuccinos, sodas, juices and alcohol, are basically walking around in a state of dehydration, which can be devastating for the brain.

About 40% of Americans, she discovered, drink fewer than four glasses of water a day, including 7% who drink no water at all.

"This is incredibly dangerous," she told me during a phone interview on Thursday. "The rationale is 'I drink milk, juice, that's water right?' No, it's not."

In the brain, which is 80% water, even very mild dehydration — a 3% to 4% decrease in water — can cause neurological issues, Mosconi said. "Fatigue, brain fog, headaches, mood swings." More worrisome, it may contribute to serious brain problems.

"There are no studies that look specifically at water intake and Alzheimer's," she said. "But some look at the brains of people who are not drinking, and they show many parts of the brain get thinner and lose volume over time in people who are dehydrated. If you don't drink water, it looks like your brain is aging faster."

Mosconi has just published her first book, "Brain Food: The Surprising Science of Eating for Cognitive Power," a guide to the latest research on the links between nutrition and brain health. (This book will make caviar lovers very happy; Twinkie lovers, not so much.)

Mosconi, who has received a five-year grant from the NIH to study Alzheimer's and women's brains, mentioned onstage that she recommended people drink tap water, which I repeated probably a little too glibly, as I soon received a number of emails from people wondering why.

"Everybody is asking me about water too!" Mosconi emailed when I reached out to her for elaboration.

As it turns out, compared with, say, distilled water or purified water, tap water generally contains minerals the brain needs to keep itself hydrated. As long as water districts filter out harmful substances like asbestos, lead and benzene, tap water is better for your brain than water stripped of all substances.

"Purified and distilled waters are just fluids," Mosconi said. "There is nothing hydrating there."

For herself and her family, Mosconi buys bottled spring water or mineral water. Often, people complain about the expense. But the cases of Poland Spring water that she buys cost about the same as a case of Coca-Cola, and surely there is no question which is better for your brain. (Or your body.)

Also, she said, she drinks aloe water every morning because it makes her feel more alert than coffee does.

What makes aloe so beneficial? "Plant experts say it's nature's most potent hydrator," Mosconi said. "The aloe leaf is 99% water with more than 200 active compounds."

Now, a few words about food, including Twinkies and caviar.

Read more here

Via L.A. Times