Is fluoride really effective in preventing tooth decay, or could it be doing us more harm than good?

Most of us put our trust and faith in fluoride to help prevent tooth decay. It is a common ingredient in toothpaste and mouthwashes, and several countries, including parts of the UK, even add fluoride to the water supply. Even last month, a study was published which reported that adding fluoride to table salt had reduced dental decay in Jamaica. However, not all scientists are as enthusiastic about fluoride as you might imagine. Quite recent evidence suggests that fluoride is not as effective in preventing tooth decay (also known as dental caries) as was originally thought. In fact, it is now that fluoride treatment has the capacity to cause dental disease. There is also some evidence that fluoride may increase the risk of other health issues including weakened bones and thyroid disease. So, is fluoride really effective in preventing tooth decay, or could it be doing us more harm than good?

Fluoride is a by-product of certain manufacturing practises (primarily the phosphate fertiliser industry). Precisely what lay behind the decision to add it to water supplies is not clear. Fluoride is, after all, a potentially toxic waste product. Also, when fluoridation of water started some 60 years ago, there was no good evidence to suggest that fluoride might prevent tooth decay. However, partly as a result of later studies which suggested that fluoride might have some tooth-protecting qualities, fluoridation of water became accepted practice in several countries around the World. However, it is now recognised that the initial studies on fluoride and tooth decay were of poor quality from a scientific standpoint. More recently, the UK Government commissioned a review of the scientific literature on fluoride and dental caries. The results of this review, commonly referred to as the ‘York study’ was published last year in the British Medical Journal.

The York study has cast serious doubt on the usefulness of water fluoridation. As expected, the authors of the study concluded that the rationale behind the fluoridation of water is based on weak scientific evidence. In addition, the York study found that the protection offered by fluoride is much less than previously thought. In fact, just one in six people drinking fluoridated water benefits from this practice. Other studies show similarly poor results. In the largest dental health survey ever conducted in the United States, (as determined by the National Institute of Dental Research), fluoridation of water was found to protect less than 1 p.c. of the total tooth surfaces in a child’s mouth. What is more, studies conducted in Finland, East Germany, Cuba, and Canada have found that the rate of dental decay does not increase when communities stop fluoridation.

And while the benefits of fluoride appear to been grossly overrated, it seems that the hazards of this substance have been downplayed. For instance, the York study found that almost 50 p.c. of individuals drinking fluoridated water exhibit a condition known as ‘dental fluorosis’ ” a mottling of the teeth thought to be caused by the toxic effects of fluoride. So, while fluoridation of water may prevent dental disease in about 15 p.c. of the population, it seems to cause dental disease in about half those treated. And, because fluoride in water gets into the body, it is probably reasonable to assume that if toxic effects are seen in the teeth, damage is also done inside the body.

The authors of the York study stated that they could find no good evidence for the toxic effects of fluoride on the body. However, the reality is that there is at least some evidence to suggest that fluoride can have a range of undesirable effects on the body. More than one study shows that fluoride has the capacity to weaken the bones and increase the risk of fracture. There is also evidence that fluoride can accumulate in the pineal gland, a small gland in the brain which secretes the sleep-inducing hormone melatonin. Potentially, this could disrupt a range of body processes including sleep. Studies in animals show that fluoride may bring on premature puberty. Fluoride is also known to reduce the function of the thyroid gland (the organ responsible for regulating the speed of the metabolism).

One other question which hangs over the concept of fluoridation is whether this practice is ethical. After all, if fluoride does indeed reduce dental caries, should it not be classed as a medicine? If this is the case, then individuals who live in areas where the water is fluoridated are essentially being medicated without their consent. This, surely, is an infringement of human liberty. One might even question whether fluoridation of water is even legal. In English law, medical treatment without consent is only legally permitted for convicted criminals, the mentally ill, and children with the express permission of their guardians. It is interesting to note that in Scotland, fluoridation of water was deemed unlawful in 1983.

Fluoridation of water is essentially mass-medication without consent. When we as doctors prescribe drugs, we generally do so with knowledge of the patient’s sex, age, weight, medical history and current drug therapy. We also will attempt to make some judgement about whether a treatment is necessary. And even if we do suggest treatment, we will want to decide on an appropriate dosage, and monitor the effects, both good and bad. None of this is true in the case of water fluoridation. Bearing in mind the question marks over the usefulness and safety of fluoride, does adding fluoride to water really seem like good medicine?

Whether or not your water supply is fluoridated depends on where you live. In the UK, Ireland is the most heavily country: About three-quarters of its water supply is treated with fluoride. Interestingly, while the Irish have generally good dental health, studies show lower dental disease in non-fluoridated areas. Wales and Scotland are non-fluoridated. In England, fluoridation depends very much on location. A full list of fluoridated areas can be obtained by logging on to

Certain steps can be taken to reduce exposure to fluoride. Those living in a fluoridated region may avoid tap water to drink, or filter their water. Jug and plumbed-in carbon filters can be quite effective in reducing the fluoride content of water. For those wanting to avoid fluoride in toothpaste, many natural alternatives exist. One particular brand based on aloe vera (called AloeDent) comes in several forms, one of which contains vitamin K. Vitamin K has been shown to be effective in preventing tooth decay. AloeDent can be found in health food stores.

12 Responses to Is fluoride really effective in preventing tooth decay, or could it be doing us more harm than good?

  1. Charles P Ringling 31 January 2008 at 9:07 pm #

    My dentist in the military was suprized I was from ohio because I had cavities and Ohio has high fluoridation so many people from there he saw had few or no dental problems. I have celiac disease (low teeth enamal) so I had many cavities. While traveling I seen some countries were the people had nasty blackend teeth with many cavities like Japan but they adopted fluorine many years ago so many young people had bright shiny teeth while the ones over 30 had horrible yellow or black teeth hense the habit of covering thier mouths while smiling or laughing.

  2. carolyn 12 September 2010 at 8:06 pm #

    I’m 56 years old and have always used floride, in water and toothpaste. I have osteoporosis now and hypothyroidism. I have since been using bottled water (floride 00.3 ppm) and make my own toothpaste. I’m even scared of baths now and take quick showers. I have nice teeth but certainly my share of cavities. I don’t allow the dentist to give me floride rinses anymore. This stuff should be illegal to put in water!!!

  3. Zahnarzt in Münster 30 November 2010 at 1:56 pm #

    Water fluoridation might be a health risk which can have side effects on health. More research should be focus on this subject matter.

  4. Jennifer wierschke 17 June 2011 at 1:00 am #

    I don’t want floride in my water and I’m sure if more people in my town knew of the risks they wouldn’t want it either. I think we should have a choice in the matter. I dont see how this is legal!

  5. Mae Newton 29 July 2011 at 10:22 am #

    There are so many products nowadays that contains fluoride. One of the most common among these is the toothpaste that we are using everyday. I never thought that this can be very harmful to all of us.

  6. vancouver wa dentist 12 April 2012 at 6:26 pm #

    Fluoride is also one that help us to prevent tooth decay but if we used it too much then it can also harm us. We need to balance everything

  7. ARlene Goetze 28 April 2012 at 12:54 am #

    Fluoride is now in hundreds of our foods as well as drugs, vaccines and tobacco.
    Go to USDA fluoride in food to see it 15 pages of hundreds of baby and normal foods with fluoride!
    We are all overdosed…and our skin absorbs fluoride from showers as well.

  8. Valerie 9 July 2012 at 10:21 pm #

    Please don’t advocate unfluoridated toothpaste. You might as well brush your teeth with shampoo for all the good it will do you.
    The primary way toothpaste works is as a means of topical application of fluoride.
    Like any other thing in the world , its efficacy is dose specific. Just because over ingestion is harmful does not mean that it’s harmful if used correctly .

  9. RTP 15 February 2013 at 2:12 am #

    Valerie, one day your going to have health problems but that’s OK because you’ll have healthy teeth right? Well maybe not…

    People should have the right to choose. If fluoride prevented cancer people still deserve the right to choose to consume it. Don’t buy into junk science!

  10. Mary Kay 24 May 2013 at 9:17 pm #

    Flouride is scary. How the heck would drinking it over our tongues missing the teeth going down to our stomach and bowels ward off cavities? Studies should be done on all the toothpaste brushing we do and how swallowing that affects our health and the health of our kids. Most kids eat sugary snacks, loads of bread and sugary drinks. This crap is where the cavities form – not whether or not there is flouride in your water. With the rise in colon cancers, bladder and liver diseases I wonder if flouride has some part in it. More studies need to be done. Would you drink something if it had arsenic right on the label?

  11. Archie Mey 20 December 2013 at 12:00 pm #

    As a homeopath I must warn against the side effects of fluoridation.
    Roger Morrison, MD, gives in his Desk Top Guide the following risk factors for overdosing:
    Head: falling of hair, discolored or breaking teeth & easy caries of teeth
    Extremeties: varicose veins, distortion and weakness of nails; osteomyelitis, caries of bones;
    Clinical: bone disorders.
    And this is only a short and incomplete overview,.
    Do I need to say more ?

  12. peace 12 February 2014 at 10:49 pm #

    Why does the USA government even put them in tap water anyway! They should know that there is horrible and toxic chemicals in fluoride. After all, they are the people leading the USA.

Leave a Reply