Highlights:

• Fluoridation results in only 2% fewer cavities

• No reductions in social inequalities

• No reductions in missing teeth

• Fluoridation a likely net economic loss when capital costs are included

A new study using dental insurance records of 6.4 million adults in England found essentially no reduction in tooth decay for those living in fluoridated areas. It’s the largest ever study of the effects of fluoridation on the dental health of adults.

The LOTUS study, funded by the UK Department of Health, was intended to inform policy-makers of what to expect for future dental and economic outcomes from the current plan to expand fluoridation to all of England. Currently, only 10% of England is fluoridated. The study found “exceedingly small” reductions in caries most people would not consider meaningful.

An economic cost-benefit analysis found individuals would only save about $1 a year in dental expenses, a savings that wouldn’t even pay for a cup of coffee. The authors cautioned, however, that their economic analysis did not take into account the capital costs of expanding fluoridation, which could easily tip their economic estimates of fluoridation to a net loss. Millions would be spent for virtually no benefit.

Far more important, but omitted from the economic analysis, are the costs from health harms caused by fluoridation. 70% of children in fluoridated parts of the U.S. now have dental fluorosis. The cost of cosmetic dentistry to correct what can be an unsightly condition even in its so-called “mild” stage, would exceed the marginal 2% cavity reduction found by the LOTUS study.

Fluoride’s neurotoxic effects were not mentioned in the study. Yet the scientific evidence is now strong that fluoridated water can harm the developing brain and cause reduced IQ in children. The economic cost of nation-wide “brain drain” would certainly dwarf the costs of filling a few cavities.

The LOTUS study comes hot on the heels of a companion study in children, the CATFISH study, that found fluoridation produced similarly minuscule benefits. That study found only 0.3 fewer cavities per child from fluoridation, and there was confounding in the study that might have caused even that small benefit to be exaggerated.

When fluoridation was first introduced 80 years ago in the U.S., it was touted as reducing tooth decay by 60% or more. By the beginning of this century, the U.S. CDC had tempered its claim of effectiveness to about 30%. Rigorous systematic reviews by the Cochrane Collaborative warned that even that claim was based on low-quality studies, almost all of which were from before the mid-1970s, when fluoridated toothpaste started to become widely used.

Tooth decay rates in all developed countries have dropped dramatically since the 1970s, but only a few of the countries are fluoridated, so fluoridation could not be the reason. Under today’s conditions, the LOTUS and CATFISH studies have found almost no reduction of tooth decay in fluoridated areas compared to non-fluoridated.

There is no need to continue fluoridation, let alone expand it. The economic argument for fluoridation has reversed: more money will be saved by stopping fluoridation than starting it. Setting aside the economic argument, the likely loss of IQ in children means it is doing more harm than good.

The LOTUS study should be the last nail in the coffin of fluoridation.