The Good and Bad of Fluoridated Drinking Water

A recent study done by researchers from University of Adelaide, Australia and the University of North Carolina at Chapel Hill has brought light to strong evidence that mixing fluoride in drinking water brings about certain benefits to adult dental health, even to those who have not practiced drinking fluoridated water while growing up.

Spearheaded by Gary Slade, a faculty member of the UNC School of Dentistry, the study explores new evidence with regard to fluoridation dental health benefits. Proudly the first population-level study of its type, the water study has shown that tooth decay prevention in adults may be attained more easily with fluoridated drinking water, regardless of age and previous fluoridated water intake.

Slade stated that the previous belief was that only children who consumed fluoridated drinking water from birth benefited from it. The study shows that fluoridated water consumed even as adults reduces tooth decay, prompting Slade to state that more people actually benefit from consuming fluoridated water than it was previously thought. The team of researchers rounded up results from 3,799 adults (15 years old and above), randomly selecting them from the population of Australia between the years 2004 and 2006. The examiners of the research team measured the levels of decay, basing it partly on the residential location of the participants since the year 1964. The histories of the study participants were then compared to the community fluoride levels in the local water supply of their respective residences. The participants’ lifetime percentages in which fluoridated water was ingested were then determined. As published in the Journal of Dental education research online, results show that adults who have lived in communities where the water supply was fluoridated for more than 75% of their lifetime had up to 30% less tooth decay, as opposed to adults who have resided in fluoridated communities for less than 25% of their lifetime. A co-author of the study, Kaye Roberts-Thomson, pointed out that “the evidence is stacked in favor of long-term exposure to fluoride in drinking water," which is a finding that must be widely shared especially at a time when Australia is seeing more communities that are considering fluoridation. Roberts-Thomson emphasized that fluoridated water indeed has a significant impact as a benefit on dental health. Not all recipients of the study findings agree with it, however, such as medical journalist Anne-Lose Gotzche, who has written extensively on the hazards of fluoride.

According to Gotzche, about 10% of the population in UK and 50% of the population in US have turned to mixing water with fluoride, an agent that has previously been associated with brittle bones, genetic disorders, cancers and mottled teeth. While fluoride has been widely regarded over decades as a preventative mineral against tooth decay, more and more voices have been clamoring for a validation of this claim all over the world.

Initial figures of tooth decay reduction due to fluoridation were at 60%, however recent studies showed that the number is more accurately somewhere between the range of 20% - 40%. Gotzche also pointed out that new evidence in Canada and New Zealand has shown a possibility that tooth decay incidences may actually be higher in areas that have been fluoridated. John Colquhoun, former chief dental health officer of New Zealand resonates this in a statement released in 1984, saying that unfluoridated areas have a consistently higher percentage of tooth decay-free children as compared to fluoridated areas that are of roughly similar income levels, and that filling levels are most likely relative to income levels rather than fluoride levels.

Gotzche also says that while the dispute is not about how too much fluoride can be harmful to the teeth, but rather how much is enough and what effects over-fluoridation may bring. Excess fluoride, whether in the form of water, tablets or toothpaste may lead to fluorosis, or the condition where the teeth become mottled. She also claims that one in every four people is at a risk of overconsuming fluoride, even when the water isn't the source.

Gotzche then points out the fluoridating water is making the assumption that all people require the same amount of fluoride, which ignores the fact that the same amount of fluoride is assumed to be needed by children when compared to adults, who are roughly about four times the size of children on average. There are also other sources of daily fluoride intake such as tea, cooking wares, industrial air emissions, as well as food that is grown, managed or cooked in areas that are fluoridated.

In 1991 Lincolnshire-based Dr Peter Mansfield set up the UK's first laboratory to test individual fluoride levels. According to results from the first 100 people he has tested - most of whom come from areas where the water is not fluoridated - one in four people in the UK is in danger of overconsuming fluoride.

In a study done in 1991 by Dr. Peter Mansfield, results show that 25% of the participants, most of whom resided in non-fluoridated areas, are in danger of overconsuming fluoride merely from sources apart from drinking water. He then concluded that the British public was at risk for consuming too much.

“The great problem with overconsumption of fluoride is that only around half of that ingested is excreted by the body in healthy adults,” Gotzche pointed out, “Children, diabetics or those with kidney problems may retain up to two-thirds of the fluoride they take in.”

Mansfield calls this fluoride build-up in the body as "a poison - full stop", which is associated with a variation of health problems, including cancer. A previous US study claims that rats and mice exposed to low levels of fluoride showed evidence of cancer. Other finding included evidence in the formation of bone-related or bone cancer, oral lesions, liver or bile cancer, metaplasias, or the replacement of a certain tissue type with another, abnormal cell changes, and weakening of the immune system. While the association of cancer and fluoride is relatively new, brittle bones and fluoride have been long established, putting into question why fluoride is still prescribed to people suffering from osteoporosis.

Karen McDonagh is a proud contributing author and writes articles on several subjects including Dental CPD Australia. She is passionate for Eden Education and always looking for better ways to educate people.