137 Animal studies in the 1990s by researcher Phyllis Mullenix, at the Harvard-affiliated Forsyth Research Institute, showed that rats exposed to fluoride in the womb were much more likely to behave in a hyperactive manner later in life. This could be due to direct damage or alteration to the development of the brain. (Mullenix's adviser told her she was "jeopardizing the financial support" of her institution by "going against what dentists and everybody have been publishing for fifty years, that [fluoride] is safe and effective," and she was fired shortly after one of her seminal papers was accepted for publication,according to Grandjean and a book by investigative journalist Christopher Bryson called The Fluoride Deception.)
Multiple studies also suggest that kids with moderate and severe fluorosis—a staining and occasional mottling of the teeth caused by fluoride—score lower on measures of cognitive skills and IQ. According to a 2010 CDC report, a total of 41 percent of American youths ages 12 to 15 had some form of fluorosis. Another study showed structural abnormalities in aborted fetuses from women in an area of China with high naturally occurring levels of fluoride.
There have also been about 40 studies showing that children born in areas home to water with elevated levels of this chemical (higher than the concentrations used in U.S. water fluoridation) have lower-than-normal IQs. Grandjean and colleagues reviewed 27 such studies that were available in 2012, concluding that all but one of them showed a significant link; children in high fluoride areas had IQs that were, on average, seven points below those of children from areas with low concentrations of the substance.
120 Besides drinking water, Enagic's machines produce four other types of water. Enagic recommends using very acidic "sanitary water" for household disinfecting, such as sanitizing cutting boards and knives. "Beauty water" helps close facial pores after washing with it, the company says. Neutral water is intended for taking medications and making baby formula; and "strong" Kangen water, a very alkaline water, is intended for "cleansing power" in such tasks as removing toilet stains or floor stains.
, Some doctors and scientists say the companies' claims aren't backed by good high-quality studies. "Human evidence is lacking, safety profile is lacking and it's very expensive," says Catherine Ulbricht, co-founder of National Standard Research Collaboration, a Cambridge, Mass. scientist-owned group that evaluates natural therapies. "There is no basis for any health claims at all" for alkaline drinking water, adds Santa Barbara, Calif., gastroenterologist John Petrini, past president of the American Society for Gastrointestinal Endoscopy. After it is digested, food and water goes into the stomach and—no matter what pH it was when it entered—ends up leaving the stomach at a pH of about 6.8, Dr. Petrini says. And no matter what you eat, your body has effective mechanisms to keep your blood in a narrow range between 7.35 and 7.45, he adds. Chemists say it's logical that acidic or very alkaline water could be useful for cleaning, but there's no evidence that the pH of water has any specific effect on skin or pores, says Washington, D.C., dermatologist Tina Alster.