Featured Research

from universities, journals, and other organizations

Fluoridating water does not lower IQ, study concludes

Date:
May 19, 2014
Source:
University of Otago
Summary:
Fluoridating water does not adversely affects children's mental development and adult IQ, new research concludes. The researchers were testing the contentious claim that exposure to levels of fluoride used in community water fluoridation is toxic to the developing brain and can cause IQ deficits. "Our findings will hopefully help to put another nail in the coffin of the complete canard that fluoridating water is somehow harmful to children's development," researchers noted.

New University of Otago research out of the world-renowned Dunedin Multidisciplinary Study does not support claims that fluoridating water adversely affects children's mental development and adult IQ.

Related Articles


The researchers were testing the contentious claim that exposure to levels of fluoride used in community water fluoridation is toxic to the developing brain and can cause IQ deficits. Their findings are newly published in the American Journal of Public Health.

The Dunedin Study has followed nearly all aspects of the health and development of around 1000 people born in Dunedin in 1972-1973 up to age 38.

Lead author Dr Jonathan Broadbent says the new research focused on Study members' fluoride exposure during the first five years of their lives, as this is a critical period in brain development, after which IQ is known to be relatively stable.

Dr Broadbent and colleagues compared IQs of Study members who grew up in Dunedin suburbs with and without fluoridated water. Use of fluoride toothpaste and tablets was also taken into account.

They examined average IQ scores between the ages of 7-13 years and at age 38, as well as subtest scores for verbal comprehension, perceptual reasoning, working memory and processing speed. Data on IQ were available for 992 and 942 study members in childhood and adulthood, respectively.

Dr Broadbent says the team controlled for childhood factors associated with IQ variation, such as socio-economic status of parents, birth weight and breastfeeding, and secondary and tertiary educational achievement, which is associated with adult IQ.

"Our analysis showed no significant differences in IQ by fluoride exposure, even before controlling for the other factors that might influence scores. In line with other studies, we found breastfeeding was associated with higher child IQ, and this was regardless of whether children grew up in fluoridated or non-fluoridated areas."

Dr Broadbent says that studies that fluoridation opponents say show that fluoride in water can cause IQ deficits, and which they heavily relied on in city council submissions and hearings, have been reviewed and found to have used poor research methodology and have a high risk of bias.

"In comparison, the Dunedin Multidisciplinary Study is world-renowned for the quality of its data and rigor of its analysis," he says.

"Our findings will hopefully help to put another nail in the coffin of the complete canard that fluoridating water is somehow harmful to children's development. In reality, the total opposite is true, as it helps reduce the tooth decay blighting the childhood of far too many New Zealanders."


Story Source:

The above story is based on materials provided by University of Otago. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jonathan M. Broadbent, W. Murray Thomson, Sandhya Ramrakha, Terrie E. Moffitt, Jiaxu Zeng, Lyndie A. Foster Page, Richie Poulton. Community Water Fluoridation and Intelligence: Prospective Study in New Zealand. American Journal of Public Health, 2014; e1 DOI: 10.2105/AJPH.2013.301857

Cite This Page:

University of Otago. "Fluoridating water does not lower IQ, study concludes." ScienceDaily. ScienceDaily, 19 May 2014. <www.sciencedaily.com/releases/2014/05/140519110154.htm>.
University of Otago. (2014, May 19). Fluoridating water does not lower IQ, study concludes. ScienceDaily. Retrieved January 28, 2015 from www.sciencedaily.com/releases/2014/05/140519110154.htm
University of Otago. "Fluoridating water does not lower IQ, study concludes." ScienceDaily. www.sciencedaily.com/releases/2014/05/140519110154.htm (accessed January 28, 2015).

Share This


More From ScienceDaily



More Mind & Brain News

Wednesday, January 28, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

City Divided: A Look at Model Schools in the TDSB

City Divided: A Look at Model Schools in the TDSB

The Toronto Star (Jan. 27, 2015) Model schools are rethinking how they engage with the community to help enhance the lives of the students and their parents. Video provided by The Toronto Star
Powered by NewsLook.com
Man Saves Pennies For 65 Years

Man Saves Pennies For 65 Years

Rooftop Comedy (Jan. 26, 2015) A man in Texas saved every penny he found for 65 years, and this week he finally cashed them in. Bank tellers at Prosperity Bank in Slaton, Texas were shocked when Ira Keys arrived at their bank with over 500 pounds of loose pennies stored in coffee cans. After more than an hour of sorting and counting, it turned out the 81 year-old was in possession of 81,600 pennies, or $816. And he&apos;s got more at home! Video provided by Rooftop Comedy
Powered by NewsLook.com
How Technology Is Ruining Snow Days For Students

How Technology Is Ruining Snow Days For Students

Newsy (Jan. 25, 2015) More schools are using online classes to keep from losing time to snow days, but it only works if students have Internet access at home. Video provided by Newsy
Powered by NewsLook.com
Weird Things Couples Do When They Lose Their Phone

Weird Things Couples Do When They Lose Their Phone

BuzzFeed (Jan. 24, 2015) Did you back it up? Do you even know how to do that? Video provided by BuzzFeed
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins