November 1st, 2021
What do we know about the state of fluoride need in humans? Do we need it for adequate teeth mineralization? Can we do well without it?
Fluoride is a form of the element fluorine on the periodic table of elements. It is found naturally in rock that over time leaches into water as the primary source of our exposure.
Let us first look at the deficiency state: "In humans, the only clear effect of inadequate fluoride intake is an increased risk of dental caries (tooth decay) for
individuals of all ages. Epidemiological investigations of patterns of water consumption and the prevalence of dental caries across various US regions with different water fluoride concentrations led to the development of a recommended optimum range of fluoride concentration of 0.7-1.2 milligrams/liter (mg/L) or parts per million (ppm); the lower concentration was recommended for warmer climates where water consumption is higher, and the higher concentration was recommended for colder climates. Recently, the US Department of Health and Human Services recommended that all community water systems adjust the fluoride concentration to 0.7 mg/L, as more "recent data do not show a convincing relationship between fluid intake and ambient air temperature" (5). This recommendation was made in an effort to reduce the risk of dental fluorosis and in light of the widespread availability of fluoride from other sources, including fluoride-containing oral-care products (6). A number of studies conducted prior to the introduction of fluoride-containing toothpastes demonstrated that the prevalence of dental caries was 40% to 60% lower in communities with optimal water fluoride concentrations than in communities with low water fluoride concentrations (7)." (Linus Pauling Link)
I think that humans living in the natural world would have evolved to obtain fluoride that is readily attainable, i.e. in water and/or food naturally, if it was profoundly necessary or essential for all of us. Otherwise, we would have evolved to not need it through some biochemical mechanism. Thus, it makes me wonder if the fluoride need is now an artificial human construct to compensate for our lifestyle choices that affect tooth enamalization, i.e. the excess consumption of sugar. (hypothesis) Sort of like the need for statins to prevent diet induced heart disease.
How does fluoride work to prevent caries? Fluoride acidifies the oral cavity through the formation of hydrogen fluoride bonds which enter the bacterial cytoplasm which inhibits bacterial metabolism by inhibiting vital bacterial enzyme. The hydrogen fluoride lowers the local pH making bacteria consume more energy to maintain a balanced acid base status thus leaving less resources for replication and growth. There inefficiency in growing thus allows for less consumption of sugars that we consume causing the reduction in bacterial acid production that directly damages tooth enamel. (Aoun et. al.2018 ) The bacteria that are allowed to thrive on the tooth and gingiva in the absence of quality oral food consumption and/or fluoride will form a biofilm that is dynamic and capable of producing copious amounts of carbohydrate metabolized acid that slowly degrades the tooth enamel over time.
The big issue with fluoride remains a two tired problem of risk and need. 1) If a child is allowed to consume large volumes of sugar based beverages, including milk, as well as sugar based foods, then fluoride topical and paste needs will climb rapidly. 2) conversely, a child that has none of these antecedent risk caries promoters is unlikely to have significant need for fluoride.
Fluorinated water has significantly less appeal for me now that children are receiving frequent dental fluoride varnish applications at our office and also at the dentist as they age. As a population health based initiative, topical fluoride applications appear to be the best decision moving forward by reducing any risk of toxic ingestion and/or chronic exposure via water that is very hard to control intake quantity. This thought is not in line with current recommendations for water fluoridation, however, we have not been applying fluoride topically to a child's oral cavity for decades thus making the dynamic change in thought based on current events.
Flouride appears very safe unless young children use fluorinated toothpaste and swallow the contents either directly or while brushing. The other issues comes when drinking water has excess levels of fluoride in it which is very rare or when people over consume fluorinated water. Most of the industrialized world does not put fluoride in the water system and some are removing excess levels when naturally found. The US has fluoride in over 50% of municipal water systems. See below for toxicity.
If you have a well, levels of 0.7 mg/liter are associated with good tooth health. If your level is above 4 mg/L multiple times, it behooves you to install a water filter capable of removing the fluoride back down to tolerable levels.
However, getting back to my earlier statement above about evolution. It makes dramatically more sense to me that direct fluoride applications to the tooth for those that abuse their teeth via excess carbohydrate consumption , especially while young, should be our policy. It is highly likely that all kids should receive this therapy, although, I am unconvinced that most healthy eaters and drinkers need it. Gross fluoridation of all water sources is less sensical to me as we evolve to provide better medical care for the more marginalized Americans among us.
For more on dental care see this newsletter from a few months ago: Link
Clean teeth are a good thing,