Throughout the 1990s, Robert O. Young and his wife, Shelley, sold products through a multilevel marketing company called Innerlight, Inc. Their product line included supplements like Prime pH and Supergreens; both offerings supposedly reduced the acidity of water and worked wonders by alkalizing your body. The couple eventually launched Young Naturals, but, after learning that a pornographic website owned that domain name, quickly rebranded as pH Miracle Living. Online they hawked water machines, mini exercise trampolines, books, and the Young pHorever Head pHirst alkalizing shampoo. 

In the early 2000s, Robert Young opened a clinic in Valley Center, California, called pH Miracle Center, where he offered IV infusions that included baking soda. He saw several patients who had been diagnosed with cancer. Young, who had no medical training but called himself a doctor, believed that germs did not cause illness, acid did. All sickness and disease, he wrote in the International Journal of Complementary and Alternative Medicine in 2017, was rooted in the overacidification of the blood and tissues. The simplicity of his vision was distilled in the company logo: a jaunty-looking cartoon fish inside a glass bowl, with a tagline that read, “When the fish is SICK Change the WATER!” 

Today, as bottled alkaline beverages move into the mainstream, more and more people are treading into these murky waters. The online retailer Boxed recently scored a three-month exclusive on selling Coca-Cola’s Smartwater Alkaline, which is billed as “hydration for daily fitness.” In March, Gwyneth Paltrow announced a partnership with Flow, an alkaline water that promises to “balance your body with healthy minerals” and calls its product “the organic avocado of hydration.” At many supermarkets, you can find brand-name alkaline waters like Alkaline88, Alkawonder, and Essentia. (You can also make your own by adding baking soda to regular water.) Since 2013, alkaline water sales in North America have grown more than 40 percent annually, according to consultancy firm Zenith Global. Market reports project that the category could soon break the $1 billion mark globally. 

Early alkaline evangelists said the stuff could hydrate the body more efficiently, as well as cure diabetes, high blood pressure, and cancer. But even alternative health gurus Andrew Weil and Joseph Mercola, who frequently traffic in unverified claims, warned people on their websites to be wary of the fad. Today most bottled-water brands stick with vague declarations about improving hydration and health—or misleading ones, like labeling their products “chemical-free.” (Water is a chemical substance.) Social-media influencers seem to imply that alkaline water helps no matter what you’re doing, whether that’s hitting the pool or sitting at a desk. (As one athlete cryptically explained to GQ: “Stick to alkaline waters with a higher pH. Trust me.”) But its popularity in wellness circles stands in especially sharp contrast to the fate of one of the trend’s leading proponents. 

In 2017, Robert O. Young was sentenced to more than three years in custody for practicing medicine without a license. In November, a jury awarded a $105 million judgement for negligence and fraud in a suit brought by Dawn Kali, a former patient diagnosed with breast cancer. Young contested the ruling and received a reduced judgement. He’s also still promoting himself as an expert on cancer, although, as part of his guilty plea, Young admitted that he did not have any post-high school educational degrees from any accredited schools—he was not a trained scientist, microbiologist, hematologist, medical doctor, or even a naturopathic doctor. The headwaters of the trend seemed to flow from a source as vaporous as the fabled Fountain of Youth.  

The concept of alkalinity itself, of course, is grounded in real science. Chemists and water-quality experts use the term alkaline, or basic, to describe substances that have a pH greater than pure water, which is a neutral 7 on the pH scale. Because the scale is logarithmic, a liquid with a pH of 8 is ten times more alkaline than pure water. Tap water frequently contains minerals, making it slightly alkaline. Our blood requires a tightly controlled pH level to survive (a 7.4, suggesting we’re all pretty basic). The pH of our urine and, to a lesser extent, our blood, responds to changes in dietary supplementation. Researchers are still trying to sort out how altering the acid-base balance affects health and disease. 

One notable example of tweaking pH is supplementing with baking soda, or soda loading, which is among the most widely studied supplements in sports, says Lewis Gough, a researcher at Birmingham City University in England who works with Huub Wattbike, a team of some of the world’s fastest track cyclists. Dissolve sodium bicarbonate—200 to 300 milligrams per kilogram of body weight—and the water becomes more alkaline. “In fluid form,” Gough says, “it tastes absolutely disgusting, almost like drinking seawater.” In studies on trained athletes, he’s shown that supplementing with large doses of baking soda about 90 minutes prior to competition resulted in faster time trials, probably due to increases in power and decreases in fatigue. Additional research has also led to broader adoption in some athletic circles.

Soda loading appears to be most effective for high-intensity, one-to-ten-minute pushes—“all-out blasts on the bike,” as Gough put it—but he’s seeing positive results on 16K time trials as well. (Due to the unpleasant side effects, supplementation is better suited for sprints, he says, since running jostles your gut. Among rugby players and others with larger body masses, it also means consuming uncomfortably large doses.) 

For those calling baking soda a miracle cure, Gough says, “There just isn’t really anything there.” However, some credible scientific research suggests that shifting one’s pH balance could help treat disease, including kidney disorders and muscle wasting. Gough thinks it’s a shame that so many people are overselling the potential benefits with false or misleading claims. “I think it’s ruined it for everybody in a way,” he says. 

Read the fine print and you’ll find that most commercially available alkaline waters have only modest amounts of sodium bicarbonate and other minerals, and it’s unclear if those doses meet the thresholds for beneficial effect. Alkaline water can also be ionized, lowering the pH without increasing mineral content, which has been shown to have such a marginal effect (in so few studies) that it’s practically indistinguishable from regular water. While the recent revival and rebranding of alkaline water seems to have arrived under the banner of science, its marketing and promotion taps into our misguided instinct that rigorous physical activity requires extraordinary forms of fluid replenishment. 

Unless you’re supplementing with high doses, though, there’s little evidence and, so far, that data suggests the effects will likely be minimal or nonexistent. Gough says, “I don’t think everybody jumping out of their chairs and going to buy alkaline water is the answer.” The best advice for hydration? Don’t overthink it, and don’t waste your money: stick with plain old tap water.