Childhood fluoride exposure has no effect on IQ

About a year ago, the city of Portland, Oregon was in the news because of its water supply—and not because a teenager decided to relieve himself into a reservoir. Instead, the issue was fluoridation, the addition of trace amounts of fluorine to municipal drinking water. Fluoridation is widespread in the US, as copious evidence indicates it improves oral hygiene.

That evidence prompted the Oregon City Council to approve fluoridation—only to see voters reject that plan by a wide margin. While some of the opposition focused on the finances of the deal for the fluoridation process, concerns about the safety of fluoridation also played a major role in organizing the opposition.

It turns out that a similar drama had been playing out in New Zealand, where the city of Hamilton reversed course on water fluoridation several times over the past two years. Now, in response to the kerfuffle, some New Zealand researchers (combined with a ringer from Duke) have looked into one of the supposed health threats posed by fluoridation: it stunts the mental development of children. Their new report finds no evidence of this, however. In fact, children who grew up with fluoridated water had slightly higher IQs than their peers, though the difference wasn’t statistically significant.

Read 7 remaining paragraphs | Comments

from Ars Technica » Scientific Method


One thought on “Childhood fluoride exposure has no effect on IQ

  1. The NZ study is seriously flawed: Only about 10% of the kids the researchers Broadbent et al. reviewed were from the non-fluoridated areas (99). But 139 took fluoride tablets Since fluoride tablets are recommended for children who don’t live in fluoridated areas, it’s safe to assume that most of the 99 were the ones who took the fluoride tablets. Broadbent doesn’t provide the numbers. And he assumes that the kids in the fluoridated areas were drinking the tap water instead of bottled or tank water.

    A different Dunedin study shows that kids who take fluoride tablets actually have higher rates of fluoride ingestion than kids who live in fluoridated areas.

    Broadbent also doesn’t factor in the large amount of toothpaste toddlers studied ingest daily while brushing (once, twice or more times a day) because they can’t or won’t spit it out.

    Further Broadbent reports that critics of the Lancet fluoride/IQ studies didn’t adjust for lead, iodine, arsenic, nutrition, and fluoride from other sources. But the neither did he.

    Broadbent also based family income on occupation – not on actual income of the family

    Broadbent is one of NZ’s leading political promoters of fluoridation. He is a dentist not developmental neurotoxicologist
    His article is obviously politically motivated.

    Broadbent’s assertion that his study will put a nail in the coffin of fluoridation opposition is scientifically naive as over 100 animal studies and 38 human studies show a link to fluoride and brain deficits.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s