Juneau fluoridation study: more hype than evidence

NEW YORK, Jan. 17, 2019 /PRNewswire/ -- Juneau, Alaska, stopped adding fluoride to drinking water in 2007. In December 2018, a study by Meyer blamed this fact for increased dental decay in the city, reports the Fluoride Action Network (FAN).

Paul Connett, PhD, FAN executive director described the Meyer study as "a very poorly controlled and unblinded study that can neither rule out or rule in that tooth decay went up after fluoridation ended." He cited seven weaknesses:

1)  The Juneau study looked at a single city at two times separated by 9 years. There is no information on what happened before, between, or after the two study years.

2)  There is no control information from comparison populations who did not have a change in fluoridation status.

3)  This study design was even weaker than the debunked Calgary cessation study where omitted information revealed decay increased at the same rate while the city was fluoridated as after cessation.

4)  Decay rates in Calgary and its comparison city Edmonton rose rapidly while both were fluoridated, demonstrating that factors other than fluoridation were causing a general increase. The same may have occurred in Juneau but Meyer's study was unable to control for such a background rise.

5)  The Juneau study failed to account for an increase in Medicaid reimbursement rates between the pre-cessation and post-cessation study years. Higher reimbursement often increases number of patients treated, number of teeth treated, and cost of treatment.

6)  The study was not blinded. The dentists in Juneau knew that fluoridation had ceased. They may have altered their treatment practices to compensate for what they expected would be an increase in decay. For example, placing more prophylactic fillings or more aggressively treating early stages of decay.

7)  From this study, it is not possible to make any strong conclusions about the actual effect of fluoridation cessation in Juneau.

Connett added, "The media is hyping these weak studies about dental decay (Juneau and Calgary), at the same time they are ignoring very strong studies on fluoride's impact on the brain. Two recent mother-offspring studies funded by the US government found a strong association between a pregnant mothers' exposure to fluoride and lowered IQ in their offspring as well as increased symptoms of ADHD. The science is stronger that fluoridation lowered children's IQ in Juneau than that fluoridation lowered tooth decay."

SOURCE Fluoride Action Network