We recently published a list of the 10 Biggest Junk Science Stories of 2013. At #5, was the rejection of water fluoridation by the citizens of Portland.

The left-wing alternative newspaper Willamette Week was particularly unhappy with the placement, calling RealClearScience a "national lab-rat news aggregator." Our editorial team thinks that was meant to be an insult, but nobody is quite certain. We like lab rats.

No matter. The science is on our side.

The story of water fluoridation goes back all the way to 1901. (See this NIH article for a longer version of this story.) The residents of Colorado Springs once had nasty brown teeth. In fact, their plight was so strange that the condition even got its own name: Colorado Brown Stain. The upside of having this condition is that their teeth were resistant to decay. Because tooth decay was so widespread in the early 1900s, these people could be considered lucky for just being able to keep their teeth, but apparently some found living with poop-colored chompers not entirely endearing.

In 1931, a breakthrough occurred when investigators discovered another town in Arkansas with the exact same problem. A local chemist who worked for Alcoa, an aluminum company, analyzed the water and found a very high level of fluoride. As it turns out, fluoride is a waste product from making aluminum. The local water supply was contaminated with excess fluoride.

Thus, the mystery was solved: Fluoride causes teeth to be both strong and brown. But people don't like brown teeth. Is there a way to have strong, non-brown teeth?

Epidemiologists set about answering that question. Because fluoride is naturally occurring, they measured the fluoride levels in drinking water in various parts of the country. They came to the conclusion that 1 part per million of fluoride is the ideal concentration for preventing the browning of teeth. (Today, the EPA recommends no more than 2 ppm.) The "slam dunk" evidence for the benefit of fluoride came in 1945, when Grand Rapids, Michigan volunteered to add fluoride to its water supply. It ended up being a great decision: Tooth decay among children dropped by 60 percent.

Considering that tooth decay is the most common chronic disease of kids aged 6-19, adding fluoride to drinking water is a very smart public health policy. It also benefits minorities and the poor, both of whom are disproportionately affected by tooth decay.

So, what does that mean for Portland? It means that the people cheering over the defeat of water fluoridation in this photograph are unwittingly celebrating the fact that poor people will continue to receive inadequate dental care. For a city that prides itself on progressive values, this is one of the most regressive things the city could have done.

In their article, the Willamette Weekly chided us for taking "one more kick at Portland." We kick because we care. Sadly, we appear to care more about the poor people of Portland than the majority of the city's own residents.

In retrospect, the only mistake we made in placing Portland's rejection of water fluoridation on the list is that the ranking was far too low. It should have been #1.

Source: NIH