© 2025 American Dental Association l 51
Fluoridation Facts
Bone Fractures Risk Study
A study published in 2001233 examined the risk of bone fractures, including hip fractures, associated with
long-term exposure to fluoridated water in six Chinese samples. The water fluoride concentrations ranged
from 0.25 to 7.97 mg/L. A total of 8,266 male and female subjects, all of whom were 50 years old or older,
participated in the study. The results showed an interesting and potentially important finding regarding
overall bone fractures. The lowest overall fracture rates were observed at fluoride concentrations of 1–1.06
ppm, forming a U-shaped pattern where both lower and higher fluoride levels increased fracture risk.
High fluoride levels (above 4.32 ppm) were associated with a significant increase in hip fractures. The study
emphasized that fluoride exposure at optimal levels for dental health may also reduce overall fracture
risk, but excessive levels lead to adverse effects. These findings highlight the importance of maintaining
balanced fluoride levels to protect bone health.233 (Note that 4.32 mg/L is more than six times the
fluoride level currently recommended for community water fluoridation in the Unites States.)
Hillier and Phipps Studies
While a number of studies reported findings at a population level, both the Hillier234 and Phipps235
studies published in 2000 examined risk on an individual basis, rather than a community basis.
Using this more rigorous study design, these two studies reported no effect on the risk of hip fracture234
and no increase in the risk of hip fracture in those drinking fluoridated water,235 respectively.
Hillier et al. (2000)234 conducted a case-control study in the United Kingdom that examined the
potential link between fluoride in drinking water and hip fracture risk among adults aged 50 years and
older. The study included 914 cases of hip fracture and 1,196 controls. The estimated lifetime fluoride
exposure ranged from 0.15 to 1.79 ppm, with Hartlepool residents having the highest exposure. After
adjusting for confounders such as body mass index (BMI) and physical activity, no increased risk of hip
fractures was found for fluoride levels at or above 0.9 ppm.234
Phipps et al. (2000)235 investigated whether long-term exposure to fluoridated drinking water affects
bone mineral density (BMD) and fracture risk in older women. Among 7,129 participants, women with
20 years of continuous fluoride exposure had a slightly higher BMD at the femoral neck (2.6%) and
lumbar spine (2.5%), but a slightly lower BMD at the distal radius (1.9%). Continuous fluoride exposure
was associated with a reduced risk of hip fractures (risk ratio 0.69) and vertebral fractures (0.73), though
there was a non-significant trend toward an increased risk of wrist fractures (1.32). No difference in
humerus fracture risk was observed. Overall, the findings indicate that long-term fluoridation does
not increase fracture risk and may provide some protective effects for certain bones.235
In summary, according to the best available science, drinking water that has been fluoridated at the
recommended level does not have an adverse effect on bone health.
Fluoridation Facts
Bone Fractures Risk Study
A study published in 2001233 examined the risk of bone fractures, including hip fractures, associated with
long-term exposure to fluoridated water in six Chinese samples. The water fluoride concentrations ranged
from 0.25 to 7.97 mg/L. A total of 8,266 male and female subjects, all of whom were 50 years old or older,
participated in the study. The results showed an interesting and potentially important finding regarding
overall bone fractures. The lowest overall fracture rates were observed at fluoride concentrations of 1–1.06
ppm, forming a U-shaped pattern where both lower and higher fluoride levels increased fracture risk.
High fluoride levels (above 4.32 ppm) were associated with a significant increase in hip fractures. The study
emphasized that fluoride exposure at optimal levels for dental health may also reduce overall fracture
risk, but excessive levels lead to adverse effects. These findings highlight the importance of maintaining
balanced fluoride levels to protect bone health.233 (Note that 4.32 mg/L is more than six times the
fluoride level currently recommended for community water fluoridation in the Unites States.)
Hillier and Phipps Studies
While a number of studies reported findings at a population level, both the Hillier234 and Phipps235
studies published in 2000 examined risk on an individual basis, rather than a community basis.
Using this more rigorous study design, these two studies reported no effect on the risk of hip fracture234
and no increase in the risk of hip fracture in those drinking fluoridated water,235 respectively.
Hillier et al. (2000)234 conducted a case-control study in the United Kingdom that examined the
potential link between fluoride in drinking water and hip fracture risk among adults aged 50 years and
older. The study included 914 cases of hip fracture and 1,196 controls. The estimated lifetime fluoride
exposure ranged from 0.15 to 1.79 ppm, with Hartlepool residents having the highest exposure. After
adjusting for confounders such as body mass index (BMI) and physical activity, no increased risk of hip
fractures was found for fluoride levels at or above 0.9 ppm.234
Phipps et al. (2000)235 investigated whether long-term exposure to fluoridated drinking water affects
bone mineral density (BMD) and fracture risk in older women. Among 7,129 participants, women with
20 years of continuous fluoride exposure had a slightly higher BMD at the femoral neck (2.6%) and
lumbar spine (2.5%), but a slightly lower BMD at the distal radius (1.9%). Continuous fluoride exposure
was associated with a reduced risk of hip fractures (risk ratio 0.69) and vertebral fractures (0.73), though
there was a non-significant trend toward an increased risk of wrist fractures (1.32). No difference in
humerus fracture risk was observed. Overall, the findings indicate that long-term fluoridation does
not increase fracture risk and may provide some protective effects for certain bones.235
In summary, according to the best available science, drinking water that has been fluoridated at the
recommended level does not have an adverse effect on bone health.
