Exposure to Natural Fluoride in Well Water and Hip Fracture: A Cohort Analysis in Finland

Abstract

In the retrospective cohort study based on record linkage, the authors studied a cohort of persons born in 1900-1930 (n = 144,627), who had lived in the same rural location at least from 1967 to 1980. Estimates for fluoride concentrations (median, 0.1 mg/liter; maximum, 2.4 mg/liter) in well water in each member of the cohort were obtained by a weighted median smoothing method based on ground water measurements. Information on hip fractures was obtained from the Hospital Discharge Registry for 1981-1994. No association was observed between hip fractures and estimated fluoride concentration in the well water in either men or women when all age groups were analyzed together. However, the association was modified by age and sex so that among younger women, those aged 50-64 years, higher fluoride levels increased the risk of hip fractures. Among older men and women and younger men, no consistent association was seen. The adjusted rate ratio was 2.09 (95% confidence interval: 1.16, 3.76) for younger women who were the most exposed (>1.5 mg/liter) when compared with those who were the least exposed (< or =0.1 mg/liter). The results suggest that fluoride increases the risk of hip fractures only among women.

Fluoride Exposure May Accelerate the Osteoporotic Change in Postmenopausal Women: Animal Model of Fluoride-induced Osteoporosis

“…In both the soft X-ray radiograph of the calvaria and light microscopy of the tibia (Figures 1 and 4), the osteoporotic changes observed in this study were similar to those resulting from the combined effects of Es deficiency and Cd exposure, Cd-induced osteoporosis [13]. The finding supports the epidemiological results that water fluoridation might be responsible for the increasing rate of osteoporosis in postmenopausal women [20][21][22][23]. In general, using animal models of postmenopausal osteoporosis, many researchers tend to assume that the development of osteoporosis in the ovariectomized animals is primarily due to bone mineral loss resulting from an increase in bone resorption relative to bone formation.…”

“…Statistical analyses carried out between the late 1950s and early 1990s reported the exponential increase of osteoporotic fracture after F schemes for caries prevention were adopted around the 1940s [18,19]. This tendency is not simply explained by the increase in the proportion of elderly individuals in the population, suggesting a causal relationship between water fluoridation and the risk of bone mineral loss and fractures [20][21][22][23]. However, conflicting results have been reported [24][25][26][27], leaving the matter unsettled.…”

Prevalence of Dental Fluorosis and Its Association With Fluoride Content of Drinking Water in the Rural Area of Dharmapuri District, Tamilnadu

“…[9] Fluorides can be beneficial in preventing dental caries at water concentration 1 mg/dL, but it has also been shown to cause dental mottling and adverse effects in bones including increased risk of fracture at concentration in excess of 1.5 mg/dL with the risk gradually increasing with total intake of fluorides. [22][23][24] Apart from these, there are reports that excess consumption causes hip fracture, leads to still births and detrimental neurological effects. [25] Sadly, the harmful effects of fluorides not only just alter the aesthetic appearance of teeth but also affect the other body organs.…”

Finnish health and social welfare registers in epidemiological research

“…Another example is the study on relationships between natural well fluoride and hip fracture in Finland (Kurttio et al 1999). They combined data from the Population Census of Statistics Finland, the Central Population Register, and the Hospital Discharge Register to form a data set for a population cohort correlating with hip fracture cases.…”