One of the largest studies conducted on bone fractures and fluoride, reported in the British Medical Journal in 2000, was undertaken in the United States to determine whether, on an individual level, older women with long term exposure to fluoridated water had different bone mass and rates of fracture compared with women with no exposure. (1)

Nearly 10,000 white women aged 65 and over were recruited into the study in four different US States between 1986 and 1988.  In addition to having their bone density measured, they were interviewed about their level of physical activity, diet, smoking habits, coffee and alcohol consumption, medical history, and the number and types of bone fractures they had previously experienced.

To establish the degree to which they had or had not been exposed to fluoridated water, they were also asked to give their addresses and sources of water supply between 1950 and 1994.

Following their initial recruitment and examination, the women were contacted every four months to ascertain whether they had since suffered a fracture.  All fractures up to December 1995 were recorded and taken into account in the subsequent analysis.

Fluoridation may reduce older women’s hip and vertebral fracture risk, say the authors

In reporting the outcome of their study, the researchers wrote: “We found that exposure to fluoridation was associated with an increase in bone mass at the lumbar spine and proximal femur and a slight decrease in the risk of hip and vertebral fractures.”

They concluded: “Our results show that long-term exposure to fluoridation may reduce the risk of fractures of the hip and vertebrae in older white women.  Because the burden of osteoporosis is largely due to fractures of the hip, this finding may have enormous importance for public health.

“If fluoridation does reduce the risk of hip fracture it may be one of the most cost effective methods for reducing the incidence of fractures related to osteoporosis.  In addition, our results support the safety of fluoridation as a public health measure for the control of dental caries.”

1. Phipps KR, Orwoll ES, Mason JD, Cauley JA (2000):  Community water fluoridation, bone mineral density, and fractures: prospective study of effects in older women.  British Medical Journal, 321: 864-5.