Is your Michigan water fluoridated? Here’s what the research says about it

• Citing harm at high levels and consumers’ right to choose, opponents say it’s time to stop decades-old practice of fluoridating water
• A large body of research shows fluoride is crucial to dental health, although the benefits are dwindling
• Most Michiganders on public water systems — about 9 in 10 — get fluoride in their water

Dr. Margaret Gingrich’s strongest endorsement for fluoride happens at home, long after she closes her Big Rapids dental practice for the day.

That’s when 2½-year-old twins AJ and Ollie open wide for grape-flavored fluoride drops, carefully measured by Gingrich. A third-generation dentist,  Gingrich — along with leading dental organizations — say the mineral hardens tooth enamel, helping protect teeth against the acid produced by bacteria that cause decay.

“Fluoride in the water helps them be healthy, so they can be at school, so they can be educated,” Gingrich said of her boys and youngsters at her practice. 

But Gingrich and others are facing increasing questions and criticism about that stance.

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The debate over fluoride has taken center stage, with Robert F. Kennedy Jr., now President-elect Donald Trump's pick to head the US Department of Health and Human Services, calling for an end to fluoridation.

If successful, that could change the makeup of water of some 6.5 million in Michigan — the state where fluoridation got its start more than 75 years ago.

Just last week, Florida Surgeon General Joseph Ladapo advised local governments across the state to stop fluoridating water systems, citing “neuropsychiatric risk associated with fluoride exposure,” while Arkansas lawmakers introduced two bills that could ban the fluoridation of water. 

Those opposed to the practice are eschewing longstanding advice from leading health and dental organizations that endorse water fluoridation as a central player in preventing painful and expensive dental decay. They include the American Dental Association, the American Academy of Pediatric Dentistry and the American Academy of Pediatrics.

Opponents cite research that suggests fluoride might affect the nervous system or do damage to bones and kidneys and other organs. And they say adding the mineral to public drinking water supplies is government overreach.

“I should have a medical choice to choose whether I want this medication in my water or not,” said Dr. Dean Weber, of Grand Rapids, a now-retired dentist who said he spent 30 years supporting fluoride.

“I was part of the problem.”

Why fluoridate?

A naturally occurring mineral, fluoride is common in nature. Even some foods — coffee, raisins and potatoes — contain trace amounts of fluoride, according to the National Institutes of Health’s Office of Dietary Supplements.

Moreover, consumers now may get fluoride in their toothpastes, mouth rinses, and gels. Higher-strength topical fluoride varnishes are applied by dentists. Fluoride drops are prescribed. 

But too much can cause fluorosis, or dark brown, permanent stains on the teeth. 

In fact, it was a series of mysterious fluorosis cases that first called a dentist’s attention to fluoride in the early 1900s. In Colorado Springs, some residents’ teeth were stained so badly that their “entire teeth were splotched the color of chocolate candy,” according to the National Institutes of Health Dental and Craniofacial Research.

But importantly, the stained teeth sometimes were resistant to decay, too.

The key, scientists found, was to carefully control fluoridation levels — adding in enough to protect children against tooth decay, but not so much as to cause the brown stains or be toxic, said Dr. Jeffery Johnston, chief science officer of Delta Dental of Michigan, Ohio, and Indiana.

In 1945, Grand Rapids became the first US city to fluoridate water. After a decade of study, the risk of cavities had fallen 60-65%, according to results published in 1957 by the American Journal of Public Health and the Nation's Health.

Other cities began fluoridating, including Muskegon. Studies abounded, and dental organizations say the inexpensive addition to drinking water has dramatically improved dental health and saved billions in dental care costs.

“Fluoride has been one of the most well studied public health initiatives of all time. The efficacy and the safety is unquestioned,” Johnston said.

The US Centers for Disease Control and Prevention now names fluoridation among the top 10 greatest public health achievements of the last century.

Dwindling benefits

But even supporters acknowledge the benefits of fluoridated water have dwindled over the decades.

The mineral now likely reduces cavities by about 25% or so, said Johnston.

Fluoride these days is added to other sources such as toothpaste. Moreover, dental care overall has improved both at home and in dentists’ chairs.

“Fluoride alone is not the answer,” Johnston said.

In October, researchers from the Universities of Manchester, Dundee and Aberdeen released the results from their review of 157 studies in what is called the “Cochrane Review.” In it, the researchers compared communities that added fluoride to their water supplies with communities that did not. 

The benefit of fluoridation — reducing the risk of decayed, missing and filled teeth — has declined since the 1970s, likely the result of more widely available fluoride toothpaste, they found. Moreover, the Cochrane researchers said it remained unclear the extent to which fluoride protected adult teeth.

Fluoridation opponents say a growing body of research also has linked fluoride to a host of health problems, and those concerns outweigh any remaining benefits of fluoridated water.

One study, by a University of Florida College of Public Health and Health Professions researcher, came earlier this year. In it, epidemiologist Ashley Malin found that higher fluoride levels in pregnant women were linked to increased odds of neurobehavioral problems by the time they were 3 years old.

Opponents also point to the 2015 decision by the US Public Health Service decision to ratchet down the upper limit of fluoridation from a range of 0.7–1.2 milligrams per liter to simply 0.7 milligrams.

In August this year, the National Toxicology Program, part of the US Department of Health and Human Services, noted that — while research isn’t strong, there is “some evidence that fluoride exposure is associated with other neurodevelopmental and cognitive effects in children.”

The following month, a federal judge in California ordered the U.S. Environmental Protection Agency to reexamine regulations for fluoride in drinking water. US District Judge Edward Chen ruled the compound poses an unreasonable risk to children at the current levels.

“There are two people in this world right now. There are those who have realized that fluoridation is over, and those who haven't,” said Stuart Cooper, executive director of the New Hampshire-based Fluoride Action Network, which since 2000 has advocated for an end to “water fluoridation and other involuntary exposures to fluoride.”

Supporters of fluoridation say research that suggests links between fluoride and disease and lower cognitive functioning lacks scientific rigor or fails to account for other factors, such as access to health care or exposure to environmental toxins.

And some studies are done on animals, while others are conducted in countries in which fluoride levels are twice as high as those in US systems.

Weber, in Grand Rapids, said he spent his entire career supporting fluoride for teeth, then retired to Florida. 

“I made $50,000 on fluoride,” he said.

But when Weber turned to the research after hearing concerns in Florida, he said, he changed his mind.

“You can argue the toxicity issues all you want. You can find guys that say, ‘Oh, it's not a problem.’ And then you can find another 100 guys that will say, ‘Oh, it's very toxic,’” he said.

Bottom line: “I'm a human being, and I want to make my own choice, and as a professional, I want to give my patient that choice,” he said.

All this conflicting information also leaves patients and parents confused and frustrated, said Dr. Eric Knudsen, a dentist in Escanaba in Michigan’s Upper Peninsula.

“The research is a challenge,” he said. “It's tough as a parent to filter through that.”

Is it in my water?

In Michigan, likely yes.

These days, nearly all of Michigan’s residents on shared water systems get fluoridate water. Of the more than 6.5 million Michiganders served by public systems, about 9 in 10 receive fluoridated water, according to the CDC. Some of the water contains naturally occurring fluoride, too, so levels of added fluoride are adjusted.

In Michigan, local governments are in charge of decisions about fluoridation. 

And for the most part, there has been little change among communities in their preference for fluoride, said Sandy Sutton, community water fluoridation coordinator at the Michigan Department of Health and Human Services.

One city, Alpena, moved away from fluoridating its water in 2022 after it ran into supply chain issues, Sutton said. Ultimately, though, the decisions focused on conflicting research, said then-Mayor Matt Waligora, who at the time noted “I’m not a chemist, I’m not a doctor, and I’m not a scientist.”

It was almost a better-safe-than-sorry vote, he told Bridge Tuesday.

The research is “ridiculously unlimited,” he said. “There’s so much out there, and one piece of research leads to another.”

“Our responsibility is to provide clean water,” Waligora said. “I had people say ‘It’s not your responsibility to medicate us.”

Council voted 5-0 against continuing fluoridation.

But to the far west in Michigan’s Upper Peninsula, concrete will be poured on a new water treatment plant next month, said Paul Anderson, city manager of Ironwood.

In 2021, the city commission heard from the state and dental experts before moving forward with a plan to incorporate fluoridation in its new treatment system, which also will remove manganese and iron, he said.

“It seemed like a no-brainer that fluoride is a good thing,” he said.

Ironwood’s commission, also in a 5-0, agreed to begin fluoridating.

Making a choice

For her part, Gingrich in Big Rapids said she draws her expertise not only from her long dental career and the mentoring of her grandfather, uncle and father dentists, but also from her colleagues. She’s former president of the Michigan Dental Association and sits on the American Dental Association’s Council on Dental Practice, too.

Those who are confused about the research, she and others said, should talk to their dental provider.

Short of that, she notes the fluoride drops she received as a child, herself, and the nighttime routine for her toddlers, too.

If she were worried about it, she noted, “why would I be giving it to my own children?”