Fluoride has been added to municipal water systems since the 1940s. The practice has been widely shown in numerous medical studies to reduce tooth decay in people from all walks of life, regardless of economic or ethnic background. On Wednesday, Denver Water will decide whether to continue adding fluoride to the drinking water of its 1.3 million customers.

The state’s largest water utility adds enough fluoride at its treatment plants to meet a target level recommended by public health officials of 0.7 milligrams per liter. That amounts to less than a drop per 55 gallons of water. But even that amount is too much for opponents of fluoridation, who believe that fluoride’s risks far outweigh its benefits and who don’t want to be forced to consume it.

“We don’t want it in there,” said nutritionist Greg Gillette, who produces an Internet show from his bedroom in a Denver apartment. “You could say it’s like pouring Vitamin C in the water. It may help, but maybe I don’t want it in there.”

Gillette is a part of the push to drop fluoride that includes local group We Are Change Colorado, and the national Fluoride Action Network, a non-profit based in Binghamton, New York. He said there are plenty of places, other than the community water supply, to get fluoride.

“Go buy fluoridated toothpaste,” he said. “You can get fluoridated water at big stores, fluoridated tablets. We just don’t want it mass produced for everyone.”

The Fluoride Action Network’s director, Paul Connett, a retired chemistry professor, calls public water fluoridation a “sham,” and says a variety of studies, mostly international, show fluoride can damage bones, the brain, thyroid function and is linked to arthritis.

“If it was so clear cut, why do so few countries actually fluoridate their water?” Connett asked, claiming that more than 200 cities across the world, including Snowmass and Montrose in Colorado, have rejected fluoride.

Public health officials in Colorado say that in many parts of the world people can get fluoride in other ways. For example, in some countries, salt is fluoridated. Many European countries have school-based health care where dentists apply fluoride to children’s teeth. The World Health Organization encourages the use of fluoride, especially to “disadvantaged and under-served population groups” — though it says too much of it can lead to unwanted health effects.

Connett calls public health officials who back fluoridation in the U.S. “propagandists” who treat opponents as “the crazies, the John Birchers, the Dr. Strangelove and so on.”

Public health officials push back

Colorado’s chief medical officer, Dr. Larry Wolk, a pediatrician, likens the fluoride debate to the contentious public health fight over vaccines. He and Gov. John Hickenlooper recently issued a joint statement saying community water fluoridation is a “safe, effective and inexpensive method” to improve oral health. Wolk said the board should look at the evidence “and not to speculation, or to rumor or to fear.”

He points to recommendations from the Centers for Disease Control and Prevention, which named drinking water fluoridation one of 10 “great public health achievements” of the last century. The CDC cites a National Research Council report finding no substantial evidence fluoridation, even at higher than recommended concentrations, caused “unwanted health effects.”

Dr. Bill Bailey, a professor at the University of Colorado School of Dental Medicine and a former assistant U.S. surgeon general, said the impact of fluoride on teeth was first discovered in Manitou Springs, Colorado, in the early 20th Century. Residents there had brownish teeth, but almost no cavities, and researchers determined the condition was caused by fluoride found in their water.

Water districts began adding fluoride to their supplies in the 1940s. The practice became more widespread in the 1950s and has grown dramatically since then. Now, the number of Americans consuming fluoridated water from public systems is 200 million and growing. The latest figures, from 2012, show nearly 3.8 million Colorado residents, 72 percent of the state’s population, receive fluoride-treated water, according to Bailey.

“It is a major discovery that has helped so many millions of people over decades of time and has really improved the health of teeth,” said Bailey.

Lower-income patients affected most

Denver Health pediatrician Dr. Patty Braun said a decision to drop fluoride from Denver Water’s supply would hurt low-income children who don’t get enough fluoride elsewhere.

“We are fearful that it would increase the rates of dental disease that are already high in the populations that we serve,” Braun said.

And at Aurora’s Cavity Free SAt Three clinic, hygienist Valerie Haustein said she and other dentists and hygienists believe that dropping fluoride from public water would be bad for the mostly low-income kids they serve.

“Fluoride in the community water system is something that will reach every child regardless of their socio-economic status,” Haustein said.

That’s a position backed by the clinic’s Dr. Scott Hamilton, who says many children who go to the operating room at Children’s Hospital have entire mouthfuls of teeth removed due to tooth decay.

“Last week we saw a one-year, one-month-old that already needs 12 teeth crowned or extracted. It’s really sad,” said Hamilton. “It’s because they’re drinking the wrong things and because they’re not getting enough [fluoride],” and eliminating the added fluoride from the community’s water would be a “nightmare disaster.”

By the numbers

The Denver Water board received more than 1,000 public comments on fluoride. Here’s how they break down, according to the utility:

• Number of comments in favor of fluoridation: 101
• Organizations in favor of fluoridation:
  Denver Public Health Department
  Denver Health
  Denver Environmental Health
  Tri-County Health Department (Adams, Arapahoe, Douglas)
  Jefferson County Public Health
  Colorado Department of Public Health and Environment
  Colorado Dental Association
  American Dental Association
  Colorado Academy of Pediatric Dentistry
  Colorado Medical Society
  Colorado Academy of Family Physicians
  Deans of the University of Colorado Dental, Medical and Public Health Schools
  Various community organizations
• Number of comments opposed to fluoridation: 1,078
• Organizations opposed to Fluoridation:
  Fluoride Action Network
  New York State Coalition Opposed to Fluoridation
  Concerned Residents of Peel to End Fluoridation
  We Are Change Colorado