Fluoride Action Network

Fluoride Content of Bone Impairs Bone Quality

April 7th, 2012


Water Fluoridation Increases the Fluoride Content of Bone

“Fluoride analyses of the cadaver material from Kuopio revealed that fluoridation of drinking water increases the fluoride concentration in bone. In some individual cases the amount of fluoride in trabecular bone may rise to relatively high levels, notably in patients with impaired renal function.”
SOURCE: Arnala I, et al. (1985). Effects of fluoride on bone in Finland. Histomorphometry of cadaver bone from low and high fluoride areas. Acta Orthopaedica Scandinavica 56(2):161-6.

Bone-Fluoride Content in Fluoridated Areas Associated with Bone Defects in Kidney Patients

“Trace elements are known to influence bone metabolism; however, their effects may be exacerbated in renal failure because dialysis patients are unable to excrete excess elements properly. Our study correlated bone quality in dialysis patients with levels of bone fluoride, magnesium, and aluminum. A number of studies have linked trace elements, including fluoride, magnesium, and aluminum, to the development of renal osteodystrophy (ROD). However, little is known about the relationship between trace elements and changes in bone quality in ROD patients. The purpose of this study was to examinebone quality in ROD patients, and correlate differences in bone quality to trace element concentrations in bone. Bone quality encompasses parameters that contribute to the mechanical integrity of the bone. METHODS: One hundred fifty-three anterior iliac crest bone biopsies from patients with ROD were examined and subdivided into five groups based on the pathological features. Parameters contributing to bone quality, such as bone structure and remodeling, connectivity, mineralization, and microhardness, were assessed and correlated to bone chemical composition. In addition, clinical symptoms of ROD were assessed and correlated with bone composition. RESULTS AND CONCLUSIONS: There were no differences in bone architecture between the different ROD bone groups; however, differences in bone mineralization and microhardness were observed. Increase in bone fluoride was associated with increased osteoid parameters and decreased bone microhardness. Bone mineralization and microhardness decreased with increasing bone magnesium content and intact parathyroid hormone (PTH) level. Moreover, bone magnesium increased with intact PTH levels. The relationship between PTH, bone magnesium, mineralization, and microhardness was primarily observed in aplastic bone disorder. Furthermore, bone magnesium and aluminum contents were positively associated with bone pain and proximal myopathy in these patients. Most importantly, fluoride, magnesium, and aluminum showed significant correlations with one another. These results suggested that in ROD, bone fluoride may diminish bone microhardness by interfering with mineralization. Magnesium may be involved in the suppression of PTH secretion, lowering bone turnover thus leading to an increase in bone mineralization profile and microhardness in aplastic bone disorder. The effects of fluoride and magnesium onbone quality may be exacerbated by their interaction with aluminum.”
SOURCE: Ng AHM, et al. (2004). Association between fluoride, magnesium, aluminum and bone quality in renal osteodystrophy. Bone 34: 216-224.

Bone-Fluoride Content in Fluoridated Areas Associated with Reduced Bone Strength

“Epidemiological studies have failed to observe an effect of municipally fluoridated drinking water on bone, but the safety of long-term water fluoridation remains uncertain in public discussions. In this study, we measured the physical properties and fluoride content of the bone samples directly. . . . The differences observed between quartiles [bone with highest fluoride content versus bone with lowest fluoride content], are in contrast to the differences observed between cities. Between quartiles, the density is unaltered, but the strength of the bone is lower for the more fluoridated group, which is consistent with some previous animal studies. Between cities, the density is greater for the bones from the region with municipal fluoridation, but the strength of the bone is unchanged…”
SOURCE: Chachra D, et al. (2010). The long-term effects of water fluoridation on the human skeleton. Journal of Dental Research 89:1219-23.

“Radiographically normal vertebral bone cylinders from 80 male subjects were tested mechanically by static compression and analyzed for porosity, fluoride and ash content. As a group, they had low fluoride content, suggesting little prior intake, consonent with this geographic area (New Jersey). Nevertheless, increasing levels of fluoride were associated with bulkier bone, less porosity, and less mineral per unit of bone, which in direction though not degree suggested changes similar to those of osteomalacia and opposite from those of osteoporosis without apparent threshold. The higher fluoride hard tissue was weaker in static tests than that with less fluoride, but the increased bulk apparently offset this, resulting in bones of unchanged static strength. Hence, water fluoridation should not alter static bone strength. There has, however, been a recent report suggesting that increased mineralization of bone renders it more brittle and thus more likely to fracture on impact. . . .  Impact and torsion, occurring during falls and auto accidents, cause fractures of the long bones. Currey’s impact studies showed that the changes we associate with low fluoride content are in fact related to increased impact susceptibility. However, only when impact characteristics are tested in relationship to fluoride content will definitive judgments be possible.”
SOURCE: Stein ID, Granik G. (1980). Human vertebral bone: Relation of strength, porosity, and mineralization to fluoride content. Calcified Tissue International 32: 189-194.

Bone-Fluoride Content in Areas with 1.5 ppm Associated with Increased Osteoid Content

“The main histolological change induced by fluoride is the increase of osteoid volume… This increase in osteoid parameters was observed in our study already at fluoride concentrations above 1.5 ppm.”
SOURCE: Arnala I, et al. (1985). Effects of fluoride on bone in Finland. Histomorphometry of cadaver bone from low and high fluoride areas. Acta Orthopaedica Scandinavica 56(2):161-6.