Fluoride in your water

In the 1930s, dental researchers in the US noted that people living in areas with higher natural levels of fluoride in their spring water had much less tooth decay than others. Experiments during the 1940s and 50s confirmed that fluoride helps protect teeth from decay by encouraging extra-tough modified enamel to form.

In 1945 fluoride was first added to municipal drinking water (in Michigan), and Hastings became the first New Zealand town to get fluoride in 1954. Today about 50 per cent of New Zealanders consume water which has had fluoride added at a concentration of about 1 mg/litre or one part per million – meaning each fluoride ion is diluted by a million water molecules. Fluoride is naturally present in sea water at a similar concentration, and in some freshwater springs it can reach ten times this level since it’s common in some soils and rocks. It is also added to many toothpastes.

The US Centre for Disease Control considers water fluoridation to be one of the 10 most important public health advances of the twentieth century. In New Zealand, our Ministry of Health and dental associations unequivocally favour water fluoridation as an inexpensive and effective health measure that benefits rich and poor alike. Fluoridation is said to reduce dental decay and tooth loss by 25–70 per cent at little cost.

Realistically, because the fluoride in many toothpastes is an effective way of preventing decay, fluoridation of water in this country is the government’s way of preventing tooth decay in children who aren’t taught to brush their teeth. Often these are children in poorer families.

Despite official support for fluoridation, a vocal minority, including the Fluoride Action Network, vigorously opposes fluoridation of drinking water. In New Zealand the decision to add fluoride to water is made at a local council level, and anti-fluoride groups are active in pressuring local communities against the practice.

Perhaps the best argument against fluoridation is that it amounts to compulsory mass medication where consent hasn’t been gained from everyone being treated.

However, it’s also claimed by these groups that the fluoride used is contaminated with heavy metals, and that it causes a variety of adverse health effects including neurological damage to infants, bone weakening in the elderly, cancer, retinal damage, soft tissue accumulation, decreasing thyroid activity and more.

Should we worry?

The evidence that fluoride combats tooth decay is strong, and it is also true that excessive fluoride can lead to brown staining of teeth. However evidence for any serious adverse effects is unconvincing.

With water in Auckland fluoridated and water in Christchurch unfluoridated any serious health effects would quickly show up in this county’s carefully examined medical statistics. So the fact that the Ministry of Health currently supports fluoridation of drinking water as “a safe and effective means of improving oral health” lends serious weight to the pro-fluoride argument.

The verdict

After weighing the evidence Green Ideas believes fluoridation of water is safe and worthwhile and those not receiving fluoridated water should brush with fluoride toothpaste.

However,. anyone who wishes to avoid fluoride could harvest rainwater for drinking, or use a special filter from suppliers such as www.nzfilterwarehouse.com or www.seychelle.co.nz.

Handy links

A survey of the New Zealand situation by the Ministry of Health
Home of the Fluoride Action Network (NZ)