Key Findings - Fluoride & Bone Density; Epidemiology:

"These results suggest that excessive intake of fluoride may decrease bone mass, and that intake of fluoride from brick-tea may play an important role in this grassland area's low bone mass."
SOURCE: Zhang M, et al. (2003). Influence of fluoride concentration in drinking water and brick-tea water on bone mass in healthy Inner Mongolian Women. International Bone & Mineral Society/Japanese Society for Bone & Mineral Research Abstract:P389.

"The study demonstrated a significant age-related increase in fluoride content of trabecular and cortical bone resected from the proximal femur... The study also revealed an inverse relationship between bone fluoride content and bone mineral density."
SOURCE: Bohatyrewicz A. (2001). Bone fluoride in proximal femur fractures. Fluoride 34: 227-235.

"Depending upon which fluoride exposure method is used, two different sets of conclusions can be drawn from this study. If the ecologic measure (city of residence) is used, then exposure to higher levels of fluoride in community water systems increases lumbar spine and proximal femur BMD. If the individual level measure (daily fluoride intake) is used, then exposure to higher levels of fluoride in community water systems decreases forearm BMD."
SOURCE: Phipps KR, et al. (1998). The association between water-borne fluoride and bone mineral density in older adults. Journal of Dental Research 77:1739-1748.

"young women in the higher-fluoride community had significantly lower mean bone mass than did women in the control and higher-calcium communities. Furthermore, the mean loss of radial bone (primarily cortical), expressed as absolute difference or percentage of loss, was greater in women of the higher-fluoride community than in women of the control and higher-calcium communities... We could determine no reason, apart from the higher fluoride exposure, why women in the higher-fluoride community should have greater loss of bone mass than women in the other two communities."
SOURCE: Sowers MR, et al. (1991). A prospective study of bone mineral content and fracture in communities with differential fluoride exposure. American Journal of Epidemiology 133: 649-660.

"living in a community with high levels of water-borne fluoride was associated with decreased bone mass*... a Lordsburg woman (high-fluoride community, 3.5 ppm) had approximately 7% less bone mass than a Deming (low fluoride community) peer of similar weight and years since menopause... The negative association we found between fluoride exposure and bone mass was not an anticipated result, since this study was stimulated by the hypothesis that fluoride may actually prevent overall skeletal osteopenia by increasing cortical bone mass. However, we cannot attribute this result to bias or random error, since the other significant findings were consistent with theoretical considerations and prior research." (*"For this study, bone mass of the distal radius (75% cortical bone) was utilized as the measure of cortical bone osteopenia.")
SOURCE: Phipps KR, Burt BA. (1990). Water-borne fluoride and cortical bone mass: a comparison of two communities. Journal of Dental Research 69: 1256-1260.