In a meta-analysis, researchers from Harvard School of Public Health (HSPH) and China Medical University in Shenyang for the first time combined 27 studies and found strong indications that fluoride may adversely affect cognitive development in children. Based on the findings, the authors say that this risk should not be ignored, and that more research on fluoride’s impact on the developing brain is warranted.
The study [click for abstract] was published online in Environmental Health Perspectives on July 20, 2012.
Environmental Health Perspectives is a publication of the United States National Institutes of Health’s National Institute of Environmental Health Sciences.
Harvard’s announcement continues:
The average loss in IQ was reported as a standardized weighted mean difference of 0.45, which would be approximately equivalent to seven IQ points for commonly used IQ scores with a standard deviation of 15. Some studies suggested that even slightly increased fluoride exposure could be toxic to the brain. Thus, children in high-fluoride areas had significantly lower IQ scores than those who lived in low-fluoride areas. The children studied were up to 14 years of age, but the investigators speculate that any toxic effect on brain development may have happened earlier, and that the brain may not be fully capable of compensating for the toxicity.“Fluoride seems to fit in with lead, mercury, and other poisons that cause chemical brain drain,” Grandjean says. “The effect of each toxicant may seem small, but the combined damage on a population scale can be serious, especially because the brain power of the next generation is crucial to all of us.”
Indeed, the above video interviewing National Research Council scientists, a Nobel laureate in medicine, a professor of dentistry and other professionals summarizes the evidence fairly succinctly … and makes the case that our understanding of the damage fluoride can cause to our brains is like our growing understanding in the 1970s of the dangers of lead.
[A] 2006 National Academy of Science [report ] reviews the scientific studies which have been performed on fluoride, and concludes:
It is apparent that fluorides have the ability to interfere with the functions of the brain and the body by direct and indirect means. (bottom of page 222).
The NAS report also notes that fluoride may actually impair intelligence, and that more testing should be done in this regard.
Indeed, studies from around the world continue to find that exposure to sodium fluoride – especially in the very young – lowers IQ. See this and this. The same is true for rats exposed to fluoride. See this and this. And see the studies listed here.
Dr. Vyvyan Howard – a PhD fetal pathologist, who is a professor of developmental toxico-pathology at the University of Liverpool and University of Ulster, president of the International Society of Doctors for the Environment and former president of the Royal Microscopical Society and the International Society for Stereology, and general editor of the Journal of Microscopy – said in a 2008 Canadian television interview (short, worthwhile video at the link) that studies done in several countries show that children’s IQ are likely to be lower in high natural water fluoride areas.
He said that these studies are plausible because fluoride is known to affect the thyroid hormone which affects intelligence and fluoride is also a known neurotoxicant. Such studies have not been conducted in countries that artificially fluoridate the water such as the US, UK and Canada, but should be, he said.
And as the International Business Times noted last month on the newest Chinese study on fluoride:
Exposure to fluoride may lower children’s intelligence, says a study published in Environmental Health Perspectives, a publication of the National Institute of Environmental Health Sciences. Fluoride is added to 70 percent of U.S. public drinking water supplies.
About 28 percent of the children in the low-fluoride area scored as bright, normal or higher intelligence compared to only 8 percent in the “high” fluoride area of Wamaio.
In the high-fluoride city, 15 percent had scores indicating mental retardation and only 6 percent in the low-fluoride city. The authors of the study eliminated both lead exposure and iodine deficiency as possible causes for the lowered IQs.
One scientist – Jennifer Luke – alleged in a 2001 scientific article that fluoride accumulates in the brain (specifically, in the structure of the pineal gland) more than it accumulates in our bones. In other words, she implies that fluoride may accumulate more in the brain than in the teeth, doing more harm than good (here’s Luke’s 1997 PhD dissertation on the topic.)
The 2006 National Academy of Sciences report corroborates some of Luke’s allegations:
As with other calcifying tissues, the pineal gland can accumulate fluoride (Luke 1997, 2001). Fluoride has been shown to be present in the pineal glands of older people (14-875 mg of fluoride per kg of gland in persons aged 72-100 years), with the fluoride concentrations being positively related to the calcium concentrations in the pineal gland, but not to the bone fluoride, suggesting that pineal fluoride is not necessarily a function of cumulative fluoride exposure of the individual (Luke 1997, 2001). Fluoride has not been measured in the pineal glands of children or young adults, nor has there been any investigation of the relationship between pineal fluoride concentrations and either recent or cumulative fluoride intakes.
Donald Miller – cardiac surgeon and Professor of Surgery at the University of Washington – alleges:
Fluoride … inhibits the enzyme acetylcholinesterase in the brain, which is involved in transmitting signals along nerve cells.
Fluoride also damages the brain, both directly and indirectly. Rats given fluoridated water at a dose of 4 ppm develop symptoms resembling attention deficit-hyperactivity disorder. High concentrations of fluoride accumulate in the pineal gland, which produces serotonin and melatonin.
People with Alzheimer’s disease have high levels of aluminum in their brains. Fluoride combines with aluminum in drinking water and takes it through the blood-brain barrier into the brain. Dr. Russell Blaylock, MD, a neurosurgeon, spells out in chilling detail the danger fluoride poses to one’s brain and health in general in his book Health and Nutrition Secrets that can Save Your Life (2002).
Time Magazine notes:
What has also changed is how much toxicologists know about the harmful effects of fluoride compounds. Ingested in high doses, fluoride is indisputably toxic; it was once commonly used in rat poison. Hydrogen fluoride is regulated as a hazardous pollutant in emissions from chemical plants and has been linked to respiratory illness. Even in toothpaste, sodium fluoride is a health concern. In 1997 the Food and Drug Administration toughened the warning on every tube to read, “If more than used for brushing is accidentally swallowed, get medical help or contact a poison-control center right away.”
ABC News from Raleigh-Durham reports:
Study after study dating back to the 80s from respected academic and scientific institutions that connect fluoride to health dangers. Some of the studies were funded by the government. They suggest fluoride can be linked to brain, blood and bone deficiencies in humans.
“EPA’s drinking water standards are supposed to protect all persons against anticipated adverse health effects of the contaminant in question,” explained Kathleen Thiessen – one of the scientists who worked on the 400-page study. “And we concluded after three years worth of work that the drinking water standard for fluoride was not protected and cannot be assumed to be safe for humans.”
Thiessen said the EPA was warned about potential fluoride health dangers by one of its own chemists more than a decade ago. Dr. William Hirzy testified before a Senate subcommittee in 2000. He was representing the views of EPA scientists and staff who analyze hazards in the environment.
“In 1997, we voted to oppose fluoridation, and our opposition has grown stronger as more adverse data on the practice has come in,” said Hirzy.
“The CDC and others say whatever beneficial effect there is from fluoride is from topical use. It’s not from swallowing it. It never has been from swallowing it,” said Thiessen.
The I-Team discovered most western countries do not fluoridate their water. Dental records kept by the World Health Organization show tooth decay in those countries has declined at the same rate as here in the United States – where we do fluoridate our water.
Indeed, an overwhelming number of scientific studies conclude that cavity levels are falling worldwide … even in countries which don’t fluoridate water. Specifically, the scientific literature shows that – when fluoridation of water supplies is stopped – cavities do not increase (but may in some cases actually decrease). See this, this, this, this, this and this.
World Health Organization Data (2004) -
Tooth Decay Trends (12 year olds) in Fluoridated vs. Unfluoridated Countries:
No wonder more and more countries are stopping fluoridation.
In fact, many prominent leaders of the pro-water fluoridation movement have recently admitted publicly that they were wrong. That includes:
- John Colquhoun, DDS, Principal Dental Officer for Auckland, New Zealand and chair of that country’s Fluoridation Promotion Committee, reviewed New Zealand’s dental statistics in an effort to convince skeptics that fluoridation was beneficial and found that tooth decay rates were the same in fluoridated and nonfluoridated places, which prompted him to re-examine the classic fluoridation studies. He withdrew his support for it in “Why I Changed my Mind About Water Fluoridation” (Perspectives in Biology and Medicine 1997;41:29—44).
- Richard G. Foulkes, MD, a health care administrator and former assistant professor in the Department of Health Care and Epidemiology at the University of British Columbia also switched from pro to anti-water fluoridation after studying the issue.
- And Dr. Hardy Limeback PhD, DDS – one of the 12 scientists who served on the 2006 National Academy of Sciences review of fluoride, and Head of Preventive Dentistry at University of Toronto – wrote “Why I am Now Officially Opposed to Adding Fluoride to Drinking Water”