Osteoarthritis, the number one cause of disability in the U.S., is a disease marked by a progressively debilitating stiffness and pain in the joints. The stiffness and pain results from degeneration in the joint cartilage, degeneration in the bone tissue underlying the joints, and bony overgrowth as well. (CDC 2011) The CDC estimates that over 27 million Americans have the condition.
It has long been observed that skeletal fluorosis (a bone disease caused by too much fluoride) can cause symptoms and degenerative changes that closely resemble osteoarthritis. While these arthritic effects were once considered to be confined to those with skeletal fluorosis, recent research shows that fluoride can cause osteoarthritis in the absence of traditionally defined fluorosis.
If conventional methods for detecting skeletal fluorosis continue to be used, many individuals with fluoride-induced osteoarthritis will not receive the correct diagnosis and treatment.
Symptoms and Bone Changes of Skeletal Fluorosis Can Closely Resemble Osteoarthritis
The symptoms of skeletal fluorosis (chronic joint pain and stiffness) mimic the symptoms of osteoarthritis. As an example of this, the following figure displays the findings from a recent Chinese study that investigated the prevalence of osteoarthritic symptoms in populations based on the level of fluoride in the drinking water:
It’s not just the symptoms of fluorosis that resemble osteoarthritis; the bone changes of fluorosis resemble osteoarthritis as well. Skeletal fluorosis causes bony outgrowths (i.e., osteophytes), degradation and calcification of cartilage, osteosclerosis, and reduced space between the joint — conditions common to osteoarthritis, including osteoarthritis of the spine (spondylosis). As noted in a recent study:
“because some of the early clinical symptoms resemble those of osteoarthritis, the first clinical phases of skeletal fluorosis could be easily misdiagnosed.” (Petrone 2011).
Fluoride Intake Can Cause Osteoarthritis
Not only can skeletal fluorosis produce bone changes that resemble osteoarthritis; it can cause osteoarthritis itself. (Luo 2012; Su 2012; Bao 2003; Savas 2001; Tartatovskaya 1995; Chen 1988; Xu 1987).
This fact was convincingly demonstrated in a recent, well-conducted study by a Chinese research group. (Bao 2003) In the study, the researchers x-rayed the right hands of adults living in a fluorosis area. They then compared these x-rays with the findings of a nearby non-fluorosis area and the findings of a nationwide study that they had previously conducted. The incidence of osteoarthritis in the fluorosis area was “remarkably higher” than in either the adjacent area or the nation as a whole. According to the researchers, “the osteoarthritis caused by fluorosis differs from ordinary osteoarthritis in severity rather than in nature.”
Fluoride Can Cause Osteoarthritis BEFORE Skeletal Fluorosis Is Evident
For years, U.S. health authorities have assumed that fluoride does not cause arthritic symptoms before the traditional bone changes of fluorosis are evident on x-ray. Recent research strongly suggests that this long-held assumption is in error.
Of particular significance is a study from Turkey which found strong evidence of a fluoride-osteoarthritis link in individuals who did not have telltale sign of skeletal fluorosis. (Savas 2001) According to the study, the most common radiological finding among the fluorosis patients was knee osteoarthritis — which was found in 66% of the 56 fluorosis patients examined. By contrast, only 3.6% of the fluorosis patients had axial osteosclerosis (i.e., hyperdense bone of the lower spine and pelvis), which is regarded by U.S. authorities to be the first radiological sign of fluorosis. Thus, many of the fluorosis patients had knee osteoarthritis without simultaneously showing the spinal bone changes that US authorities still deem necessary to warrant a diagnosis of skeletal fluorosis.
Consistent with this Turkish study, a team of Russian researchers have found that fluoride-exposed individuals suffer a significantly elevated rate of osteoarthritis in the absence of radiologically detectable fluorosis in the spine. (Tartatovskaya 1995). The researchers, who were interested in determining whether fluoride exposure can exacerbate the wear and tear on joints from physical stress, examined two groups of mine workers with job activities that exposed them to significant vibration stress (e.g., drilling). Workers who were exposed to fluoride dusts were found to have a significantly higher rate of elbow osteoarthritis (48.7% vs. 12.9%) and spondylosis (83.3% vs. 41.1%) than the mine workers not exposed to fluoride dusts.
To test the veracity of these findings, the Russian researchers conducted animal studies where they subjected mice to the isolated and combined effects of vibration and fluoride exposure. As with the mine workers, the mice exposed to both vibration stress and fluoride experienced a greater frequency and earlier onset of degenerative joint changes than the mice exposed to either factor alone. The Russian researchers thus concluded that fluoride exposure can exacerbate the degenerative effect of physical stress on joints with or without the presence of radiologically detectable skeletal fluorosis.
Consistent with the Turkish and Russian studies, a team of Polish researchers examined 2,258 fluoride-exposed workers in the aluminum industry and found high rates of arthritic effects in the absence of fluorosis bone changes. (Czerwinski 1988). Although the researchers could only detect fluorosis by x-ray in 1% of the workers, they found high rates of joint pain in the knee, hip, elbow, shoulder and lumbar spine, with the pains correlating to the duration of fluoride exposure. According to the researchers, “the only characteristic feature” of fluorosis is “multiple-joint involvement,” which “would differentiate fluorosis from monoarticular osteoarthritis, but unfortunately not from multiple-joint osteoarthritis or rheumatoid arthritis.”
Even among patients with crippling forms of fluorosis, degenerative joint damage can be the primary radiological finding, not osteosclerosis. In one study, for example, Chinese researchers found that 5 of 19 patients with crippling skeletal fluorosis “presented with mainly articular injury but relatively mild bone pathology.” (Cao 2003). The researchers termed this condition “fluorosis arthropathy.”
The Misdiagnosis Problem
The fact that fluoride can cause osteoarthritis in the joints prior to, and in the absence of, detectable osteosclerosis in the spine, highlights the difficulty of diagnosing fluorosis. Since many doctors continue to consider spinal osteosclerosis necessary for a diagnosis of skeletal fluorosis, many cases of fluoride-induced osteoarthritis (“secondary osteoarthritis”) will be misdiagnosed as “primary osteoarthritis,” thus depriving patients of the most effective treatment for the condition (reduction in fluoride exposure).
The difficulty of differentiating between osteoarthritis and early stage skeletal fluorosis was highlighted in a 1995 study by a team of Austrian doctors. (Roschger 1995). In the study, the doctors conducted x-rays of a woman who received high-dose fluoride treatment for 6 years as an experimental treatment for osteoporosis. After the woman sustained multiple spontaneous fractures, the doctors x-rayed her skeleton and measured her bone density. According to the doctors, “radiographs of the skeleton and bone scintigraphy showed degenerative osteoarthritis,” but none of the traditional signs of skeletal fluorosis. It wasn’t until the doctors performed a bone biopsy that the doctors were able to detect the presence of fluorosis. As the doctors noted, “Without bone biopsy we would have failed the correct diagnosis.” Based on this experience, the doctors concluded that “invasive investigation of the skeleton (bone biopsy, histomorphometry, BSEI plus SAXS) is the only diagnostic tool, when skeletal fluorosis is suspected.”
The problem with relying on x-rays to detect and prevent joint pathologies caused by fluoride is yet further demonstrated in the following figure. The figure presents the findings of a study from one of China’s most pre-eminent experts (Changqing Huang) on the diagnosis of skeletal fluorosis. As can be seen, many individuals diagnosed with fluorosis (based on detailed clinical examinations) did not have radiologically detectable fluorosis on x-ray.