ADA – Fl Does Not Cause Bone Cancer – FAN Disagrees

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The ADA says that Douglass has disproved the connection between fluoridation and osteosarcoma. Read the comment on the ADA report below.

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ADA President Raymond Gist, D.D.S., Comments on Harvard Study Examining Fluoride Levels in Bone

By American Dental Association

Published: Thursday, Jul. 28, 2011 – 2:11 pm

CHICAGO, July 28, 2011 — /PRNewswire-

USNewswire/ — A new study in the Journal of Dental Research finds bone fluoride levels are not associated with osteosarcoma, a rare bone cancer more prevalent in males.A team of researchers from Harvard University, the Medical College of Georgia and the National Cancer Institute analyzed hundreds of bone samples from nine hospitals over an eight-year period from patients with osteosarcoma and a control group to measure fluoride levels in the bone.Considered the most extensive study to date that examines a potential association between fluoride levels in bone and osteosarcoma, the results indicated no correlation. Three branches of the National Institutes of Health were involved in the study. The National Cancer Institute (NCI) approved the design of the study, and funding for the research was provided by the NCI, the National Institute of Environmental Health Sciences, and the National Institute of Dental and Craniofacial Research.”As a science-based profession, we must always examine new evidence and consider it along with existing science in order to evaluate guidelines and recommendations for patient care,” states Raymond Gist, D.D.S., president of the American Dental Association (ADA).”This new study adds to an already strong base of scientific evidence that fluoride is safe and effective at preventing cavities,” Dr. Gist states.An inconclusive animal study conducted 20 years ago first raised the question of an association between fluoride and osteosarcoma. Since that time, other studies have examined the issue; however, this new study, using actual bone to measure fluoride levels in individuals with and without osteosarcoma, is considered by researchers to be the best science to date because a more accurate and reliable scientific method was used to measure exposure from all sources of fluoride.

“Tooth decay rates have declined dramatically over the past several decades, thanks in part to the use of fluoride,” Dr. Gist states. “To help prevent cavities, the ADA continues to recommend brushing twice a day with fluoride toothpaste, flossing daily, eating a balanced diet and visiting your dentist regularly.”

Read more: http://www.sacbee.com/2011/07/28/3801401/ada-president-raymond-gist-dds.html#ixzz1Td0d26DZ

Read an abstract of the Douglass study at: http://jdr.sagepub.com/content/early/2011/07/23/0022034511418828.abstract.

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The Bassin study on fluoride and osteosarcoma came out in 2006, and it did find a correlation. The 2006 NRC Report on fluoride cited the Bassin study.

Dr.  Douglass was Dr. Bassin’s supervisor in her doctoral program. Douglass repudiated the study he had previously approved as a dissertation. Douglass promised that his own new study would come out soon which would disprove Bassin’s conclusions. After six years, this is it.
Note however that Bassin’s study was published in a respected cancer prevention journal. Douglass published his in the Journal of Dental Research. Was he unable to get a cancer journal to publish it?

The new study by Dr. Douglass finds no correlation but does not prove there is no correlation.

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New Study Fails to Refute Fluoride-Osteosarcoma Link

NEW YORK, Aug. 2, 2011 /PRNewswire-USNewswire/ — A paper in the Journal of Dental Research by dentist Chester Douglass and colleagues, “An Assessment of Bone Fluoride and Osteosarcoma,” (7/28/11) claims to show no association between fluoride bone levels and osteosarcoma, a form of bone cancer. However, Douglass’ study has serious scientific flaws and is incapable of disproving a previous study (Bassin et al., 2006) which linked water fluoridation to osteosarcoma, reports the Fluoride Action Network (FAN).

Bassin found a 500% to 600% increased risk for young boys, exposed to fluoride in their 6th to 8th years, of later developing osteosarcoma. Douglass’ study does not address exposure during this critical period because it measured the level of fluoride in bone, which accumulates fluoride over a lifetime. These bone levels provide no information about when the person was exposed to fluoride.

Not only does Douglass’ study fail to refute Bassin’s main finding, it suffers from other serious weaknesses:

1) Douglass’ study was much smaller and weaker than Bassin’s. It had only 20 control subjects under age 30, a fifth of Bassin’s. For this key age group, Douglass’ study was so small it could provide no reliable conclusions. Even Douglass admitted this serious limitation.

2) Douglass’ choice of comparison group is suspect. Douglass compared the bone fluoride level of patients with osteosarcoma to “controls” with other forms of bone cancer. If fluoride also causes these other bone cancer types, then one would not expect to find any difference in bone fluoride between these groups. It is biologically plausible that fluoride could cause other bone cancers because it reaches such high concentrations in bone. One of the only studies of fluoride and non-osteosarcoma bone cancers did find a link, but this evidence was never mentioned by Douglass.

3) The controls were severely mismatched to the cases. Controls were much older (median 41 yrs) than the cases (18 yrs). The risk of osteosarcoma is highly age-dependent. Also, fluoride builds up in bone with age. Given Douglass’ small sample size, it is unlikely he could have adequately compensated for the gross mismatch in age, especially because of these two simultaneous age dependencies. The groups were also mismatched on sex ratio, and osteosarcoma risk is well known to be sex dependent. Properly adjusting for sex and age would be virtually impossible.

In 2001, Douglass signed off on Elise Bassin’s Ph.D. dissertation which found the strong association between fluoride and osteosarcoma. When it was later published in a peer-reviewed scientific journal in 2006, Cancer Causes and Control, an accompanying letter from Douglass claimed that his “larger” study would eventually refute Bassin’s findings. But Douglass also told a Fox News reporter that Bassin “… did a good job. She had a good group of people advising her. And it’s a nice—it’s a nice analysis. There’s nothing wrong with that analysis.”

Now that Douglass’ study is finally published, it is clearly incapable of refuting Bassin’s work. According to FAN director, Paul Connett, Ph.D., “Bassin’s study was a high quality product, Douglass’ study was not.”

Chris Neurath, FAN’s Research Director, points out “Even though Douglass collected extensive fluoride exposure histories from hundreds of other controls, that data was ignored in this paper. FAN is calling for the release of all of the Douglass data. The only way to get to the bottom of Douglass’ two decade’s study is to make the data available for any independent researcher to check and do the analyses which Douglass has failed to provide. The public has paid millions for this data, why is most of it still behind locked doors?”

One reason is suggested in Douglass’ conflict-of-interest declaration where he says he has “… written reviews of the literature for several companies that sell, reimburse for, or do research on preventive dentistry products, most notably GlaxoSmithKline, Colgate-Palmolive, Dentsply, Quintile, Delta Dental Plans….”

Omitted was his paid editorship of Colgate’s promotional dental newsletter, which regularly contains advertisements for Colgate’s fluoride products.

The International Association of Dental Research (IADR), publishers of The Journal of Dental Research, has a history of promoting fluoridation.

Connett says, “In my opinion, it seems that Douglass is more interested in protecting fluoride than investigating this issue objectively. Bassin’s work suggests fluoridation may be causing a frequently fatal cancer in teenage boys. Douglass, after five years of trying, has failed to refute this disturbing evidence. How long will fluoridation promoters be allowed to continue to spin this issue?”

“Why are dentists – especially those who have shown a strong interest in protecting the water fluoridation program – conducting and publishing cancer research, anyway?” asks Connett.

A more detailed critique of Douglass’ paper will be posted soon at http://www.FluorideAction.Net

Contact Paul Connett, PhD, 315-379-9200pconnett@gmail.com

SOURCE: Fluoride Action Network

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I will be updating this post as new information comes in.

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