In general, I trust our government. I trust it to use my taxes wisely, protect the less fortunate among us, and enact policies based on sound research and reasoning.
If scientists from the government tell me that the scientific consensus is such-and-such, I generally believe them. Sample topics: climate change, vaccines, evolution.
Thus, when I heard that citizens’ groups were opposing the fluoridation of public drinking water, in contrast to the official position of the Centers for Disease Control and Prevention (CDC), I was initially skeptical. It sounded like a variation on the tragically misguided “vaccines are dangerous” movement.
But now that I’ve done some more reading and thinking about fluoridation, I think the anti-government fringe groups might be right!
Admittedly, a few hours of reading does not make me an expert on fluoridation. (So far, I’ve looked at the websites of the American Dental Association [ADA], CDC, Fluoride Action Network [FAN], and Rutland Fluoride Action, and followed links from these sites to other files such as the National Research Council’s 2006 report on fluoride in drinking water.) But, as someone with a Ph.D. in Physiology & Biophysics plus 14 years of postdoctoral research and teaching experience, I am qualified to comment on the issue.
It’s a challenging issue to tackle because there is a huge body of research on the biological effects of fluoride, which the two sides filter quite differently. For example, a thorough 2015 meta-analysis of the issue conducted by the independent, rigorous Cochrane Database group is touted by the FAN as showing “no valid evidence exists to prove fluoridation works,” while the ADA and CDC complain that the Cochrane analysis excluded valid studies that indicate benefits of fluoridation.
It’s hard for a neutral, semi-informed observer to know what to make of such debates.
Still, amidst the fog of disputed data and accusations of bias, the anti-fluoridation crowd does have a simple argument that I find compelling. Here it is:
1. Fluoride is a drug, not a nutrient.
2. Mass-administering a drug to entire communities, without individuals’ consent, can only be justified if we are extremely confident that the benefits-to-risks ratio is extremely high.
3. The available evidence does not warrant such extreme confidence.
Of these, claim #1 may be the most contentious. The ADA seems to disagree, as its 5 Reasons Why Fluoride in Water is Good for Communities include “It’s natural.”
“Fluoride is naturally present in groundwater and the oceans,” the ADA reassures us. Well, yes — but so is uranium-238. Should we be adding that to our water too?
The ADA continues, “[Fluoridation of water is] similar to fortifying other foods and beverages, like fortifying salt with iodine, milk with vitamin D, orange juice with calcium and bread with folic acid.”
The FAN rebuts this effectively.
It is now well established that fluoride is not an essential nutrient. This means that no human disease -– including tooth decay -– will result from a “deficiency” of fluoride. Fluoridating water supplies is therefore different than adding iodine to salt. Unlike fluoride, iodine is an essential nutrient (the body needs iodine to ensure the proper functioning of the thyroid gland). No such necessity exists for fluoride.
If fluoride is not a nutrient, then what is it? I find the FAN’s stance completely reasonable:
All water treatment chemicals, with the exception of fluoride, are added to make drinking water safe and pleasant to consume. Fluoride is the only chemical added to treat people who consume the water, rather than the water itself. Fluoridating water supplies can thus fairly be described as a form of mass medication, which is why most European countries have rejected the practice.
This classification of fluoride as a drug is consistent with official definitions from the Food and Drug Administration (FDA).
People usually are prescribed specific dosages of drugs according to their age, weight, medical history, etc. For fluoride in water, however, doses will vary wildly, not based on individuals’ “needs,” but based on how thirsty they are. It’s a bit unsettling, at the least.
Claim #2 concerns informed consent. I have some relevant professional experience, having conducted laboratory research and educational research that required approval from my university’s Institutional Review Board (IRB) as well as the consent of the research subjects themselves.
It’s a lot of tedious paperwork. In my own proposals, for example, I’ve spent many paragraphs explaining why students will not be harmed if they anonymously complete a survey, and guaranteeing that the students can nonetheless skip the survey, without being punished, if they have any objections to it. Still, I’m grateful that my institution has a serious review process that reflects its firm commitment to respecting individuals’ autonomy. This respect is a bedrock value of civilized society in general, and infringements upon it must be well-justified.
So is it OK to force-feed a drug to populations at haphazard levels related to individuals’ thirst? Sure — but only if the drug has obvious, important benefits and is extremely safe.
So — claim #3 — what does the evidence look like for benefits and risks?
Regarding benefits, the above-mentioned Cochrane study basically says that there IS evidence that fluoridated water reduces tooth decay, but that this evidence is not nearly as strong as we would like.
Regarding risks, the above-mentioned NRC report devotes over 200 pages to reviewing fluoride’s effects on the musculoskeletal, reproductive, nervous, endocrine, digestive, renal, and immune systems. For most of these systems, the NRC concluded that more research was needed, which is not particularly helpful because scientists always say that about everything (thus justifying our existence).
Still, based on data showing that high fluoride levels can compromise teeth and bones, the NRC concluded that the Maximum Level Contaminant Goal (MLCG) be altered downward from the previously established standard of 4 milligrams per liter (mg/L). More recently, the Department of Health and Human Services (HHS) has lowered its recommended level of fluoride in the water to 0.7 mg/L (down from a previous recommended range of 0.7-1.2 mg/L). These changes can be taken as an acknowledgment by experts that greater caution regarding fluoride exposure is warranted. Throw in some journal articles and government grant proposals that have made it through the peer review process, and you don’t need to be a conspiracy theorist to think that mass fluoridation has been enacted prematurely.
In a subsequent post, I will address the issue of “topical” versus “systemic” delivery of fluoride.