Fluoride Action Network

Fluoride & Arthritis

FAN | August 2012 | By Michael Connett

Excessive ingestion of fluoride can cause symptoms (joint stiffness and pain) that closely mimic common forms of arthritis, including osteoarthritis and rheumatoid arthritis. In the United States, health authorities claim that fluoride can only cause arthritic pains when the hallmark bone changes of skeletal fluorosis (i.e., increased bone density in the spine) are detectable by x-ray. (DHHS 1991). This claim, however, is at odds with numerous studies that have found fluoride can cause widespread joint pain, and overt osteoarthritis, in the absence of detectable fluorosis in the spine.

In Savas (2001), for example, Turkish researchers found that the most common x-ray finding among skeletal fluorosis patients was knee osteoarthritis. Of the 56 fluorosis patients examined, 66% had osteoarthritis in the knee, while only 3.6% had hyper-dense bone in the spine. Thus, many of the fluorosis patients had knee osteoarthritis without simultaneously showing the bone change in the spine that U.S. health authorities claim is necessary to make a diagnosis of skeletal fluorosis.

Previous research has demonstrated that the earliest, and most severe, bone changes in skeletal fluorosis occur in the joints of the body that receive the most repetitive stress. Thus, some individuals with fluorosis may have x-ray evidence of fluorosis (along with significant arthritic pain) in their wrist, knee, and/or elbow, while showing little, or no, evidence of fluorosis in their spine.

Even when fluoride-induced athritis co-exists with detectable fluorosis in the spine, doctors have still been found to misdiagnose the disease. This owes, in part, to the similarity in radiological appearance of skeletal fluorosis and other bone diseases, including osteoarthritis, spondylosis, and DISH. Thus, whether one has “pre-skeletal” fluorosis, or overt x-ray detectable fluorosis, fluoride-induced joint damage will often be diagnosed as another, more commonly known, condition.

Since reduction in fluoride intake is the only known way to relieve the symptoms of fluoride-related joint pain, the failure to make a correct diagnosis will result in years of unnecessary and ineffective treatments.

Americans Ingest Daily Doses of Fluoride that Overlap Doses That Cause Joint Pain

Although there has been a lack of systematic research to determine the dose that causes early fluorosis, one of the few studies to examine the subject found that doses as low as 6 to 9 mg/day were sufficient to cause debilitating arthritis in a middle-aged English woman. (Cook 1971). The study, which was published in The Lancet, estimated that the woman was ingesting 6 to 9 mg of fluoride per day, mostly from tea. Within 3 months of quitting tea at her doctor’s suspicion of fluorosis, the woman reported major improvements in her arthritis and within 6 months “she was virtually free of pain” and “could do without drugs.” Based on these findings, the author concluded that “some cases of pain diagnosed as rheumatism or arthritis may be due to subclinical fluorosis which is not radiologically demonstrable.”

The Lancet study is consistent with more recent findings from China where surveys of daily fluoride intake have found that crippling fluorosis occurs at daily intakes as low as 9 mg/day, (Cao 2003) while the first clinical stage of the disease (where osteosclerosis is evident in the spine) occurs at daily intakes of 6.2 to 6.6 mg/day. (Experts Group 2000). Similarly, research from India has found that radiologically detectable skeletal fluorosis occurs in populations with typical exposures of 8 mg/day. (Jolly 1970). As already noted, fluoride can cause chronic joint pain prior to causing x-ray detectable fluorosis. Thus, for some individuals, the doses that can cause arthritic pain will be less than the 6 to 8 mg/day dose that causes radiologically detectable bone changes.

To put this in perspective, the U.S. Department of Health and Human Services has estimated that adults living in fluoridated communities routinely ingest between 1.6 and 6.6 mg of fluoride per day. (DHHS 1991). Thus, the doses that American adults now routinely ingest overlap the doses that may cause chronic joint pain.

Joint Problems Occur In Early Stages of Skeletal Fluorosis

“The early stages of [skeletal fluorosis] may . . . present as subtle changes such as pain in the neck or back with rigidity, joint pains in multiple joints and paraesthesias in the limbs.”
SOURCE: Kumar S, et al. (2011). Skeletal fluorosis mimicking seronegative spondyloarthropathy: a deceptive presentation. Tropical Doctor 41:247-48.

“[Skeletal fluorosis] affects the joints as well as the bones. It is not easily recognizable till advanced stage. In its early stages, its symptoms may resemble those of arthritis.”
SOURCE: Ayoob S, Gupta AK. (2006). Fluoride in Drinking Water: A Review on the Status and Stress Effects. Critical Reviews in Environmental Science and Technology 36:433–487.

“Early signs [of skeletal fluorosis] are vague pains and arthralgia. This generally progresses to backache, pain in the spine, and signs of stiffness and rigidity…”
SOURCE: Littleton J. (1999). Paleopathology of skeletal fluorosis. American Journal of Physical Anthropology 109: 465-483.

“The initial symptoms usually were headache and weakness. These were followed by multiple joint pains, mostly in the feet, knees, and back. Spinal stiffness and kyphosis developed in a few patients.”
SOURCE: Wang Y, et al. (1994). Endemic fluorosis of the skeleton: radiographic features in 127 patients. American Journal of Roentgenology 162: 93-8.

“Symptoms of pain, stiffness and diffuse aches may be dismissed as functional, but may in fact be early signs of fluoride damage to tendinous insertions and ligaments as well as joint capsules.”
SOURCE: Anand JK, Roberts JT. (1990). Chronic fluorine poisoning in man: a review of literature in English (1946-1989) and indications for research. Biomedicine & Pharmacotherapy 44(8): 417-420.

“Vague, diffuse aches and stiffness of joints with decreased range of motion are common initial symptoms.”
SOURCE: Fisher RL, et al. (1989). Endemic fluorosis with spinal cord compression. A case report and review. Archives of Internal Medicine 149: 697-700.

“According to our survey, clinical manifestations of fluoride injury were systemic. A wide variety of vague, subtle symptoms (i.e. backache, restricted joint movement, abdominal pain) occurred either prior to or simultaneously with the development of bone changes similar to those reported previously. Nonskeletal symptoms, therefore, are important for early diagnosis.”
SOURCE: Zhiliang Y, et al. (1987). Industrial fluoride pollution in the metallurgical industry in China. Fluoride 20: 118-125.

“Arthritis of spine and small joints of hands and fingers develops early in the course of the disease with or without demonstrable radiological changes.”
SOURCE: Bhavsar BS, et al. (1985). Neighborhood Fluorosis in Western India Part II: Population Study. Fluoride 18: 86-92.

“In early stages, fluorosis is usually associated only with stiffness, backache, and joint pains which may suggest the diagnosis of rheumatism, rheumatoid arthritis, ankylosing spondylitis and osteomalacia. At this stage the radiological findings of skeletal fluorosis may not be evident and therefore most of these cases are either misdiagnosed for other kinds of arthritis or the patients are treated symptomatically for pains of undetermined diagnosis (PUD). The majority of our patients had received treatment for rheumatoid arthritis and ankylosing spondylitis before they came under our observation.”
SOURCE: Teotia SPS, et al. (1976). Symposium on the Non-Skeletal Phase of Chronic Fluorosis: The Joints. Fluoride 9(1): 19-24.

“In the initial stages, the complaints of the patients are not remarkable. At first they experience vague rheumatic pains, then the pains become localized in the spine, especially in the lumbosacral region. Later, a sensation of stiffness in the lumbar and cervical spine develop. However, we also found patients with slight radiological changes who complained of intense pains in the spine and in the large joints. On the other hand, some patients whose fluorosis was radiologically distinct were almost without complaints.”
SOURCE: Franke J, et al. (1975). Industrial fluorosis. Fluoride 8: 61-83.

“Arthritis of the spinal column develops early in the disease with or without demonstrable radiological changes.”
SOURCE: Waldbott GL. (1974). The pre-skeletal phase of chronic fluorine intoxication. Fluoride 7:118-122.

“In spite of this distinctive clinical picture of advanced fluorosis, the earlier stages of the disease are more difficult to recognize. The initial symptoms are quite non-specific and not obviously linked to fluoride. The onset of fluorosis leads to tingling sensations in the hands and feet, pain similar to arthritic pain in the joints and the lower back, stiffness, and motor weakness. The first reliable diagnostic sign is increased bone density in X-ray examination, but in some early cases early bone changes are not radiologically detectable.”
SOURCE: Groth, E. (1973). Two Issues of Science and Public Policy: Air Pollution Control in the San Francisco Bay Area, and Fluoridation of Community Water Supplies. Ph.D. Dissertation, Department of Biological Sciences, Stanford University, May 1973.

In the early stages of skeletal fluorosis, the “only complaints are vague pains noted most frequently in the small joints of hands and feet, the knee joints and those of the spine. . . . Such symptoms may be present prior to the development of definite radiological signs.”
SOURCE: Singh A, et al. (1963). Endemic fluorosis. Epidemiological, clinical and biochemical study of chronic fluoride intoxication in Punjab. Medicine 42: 229-246.

“The onset was insidious, and stiffness of the back and legs was a universal complaint. Almost all the patients complained of vague fleeting pains all over the body, particularly in the spine and in the knee-joints.”
SOURCE: Singh A, et al. (1961). Skeletal fluorosis and its neurological complications. Lancet 1: 197-200.

The Misdiagnosis problem:

“Even if skeletal fluorosis has been widely studied for more than 40 years, because some of the early clinical symptoms resemble those of osteoarthritis, the first clinical phases of skeletal fluorosis could be easily misdiagnosed.”
SOURCE: Petrone P, et al. (2011). Enduring Fluoride Health Hazard for the Vesuvius Area Population: The Case of AD 79 Herculaneum. PLoS ONE 6(6): e21085.

“The patient in our report presented with symptoms like those of enteropathic arthritis and the diagnosis of fluorosis could have been missed if attention had not been given to the increased density in the pelvic bones and ligamentous calcification.”
SOURCE: Gupta R, et al. (2007). Skeletal fluorosis mimicking seronegative arthritis. Scandanavian Journal of Rheumatology 36(2):154-5.

“The most frequent symptoms in those exposed >6 yr were low back pain, painful knee, elbow, and hip… Analysis of workers’ complaints showed no specific pain or other symptom that we could refer only to fluorosis…The only characteristic feature would be multiple-joint involvement in the case of fluorosis. This would differentitate fluorosis from monoarticular osteoarthritis (OA), but unfortunately not from multiple-joint osteoarthritis or rheumatoid arthritis (RA).”
SOURCE: Czerwinski E, et al. (1988). Bone and joint pathology in fluoride-exposed workers. Archives of Environmental Health 43: 340-343.

“Because some of the clinical symptoms mimic arthritis, the first two clinical phases of skeletal fluorosis could be easily misdiagnosed… Even if a doctor is aware of the disease, the early stages are difficult to diagnose. ”
SOURCE: Hileman B. (1988). Fluoridation of water. Questions about health risks and benefits remain after more than 40 years. Chemical and Engineering News August 1, 1988, 26-42.

“Early bone fluorosis is not clinically obvious; often the only complaints of young adults are vague pains in the small joints of the hands, feet, and lower back. Such cases may be misdiagnosed as rheumatoid arthritis or ankylosing spondylitis.”
SOURCE: Smith GE. (1985). Repetitive Strain Injury, or Incipient Skeletal Fluorosis? (Letter.) New Zealand Medical Journal 98:328.

“Pinet and Pinet described in detail X-ray changes encountered in skeletal fluorosis in North Africa that are in every respect identical with those present in the arthritic spine of the elderly elsewhere.”
SOURCE: Waldbott GL, et al. (1978). Fluoridation: The Great Dilemma. Coronado Press, Inc., Lawrence, Kansas.

“Understandably, it is not uncommon to find reference to arthritic changes, if for no other reason than the difficulty of distinguishing them from certain fluoride effects on bone.”
SOURCE: Hodge HC, Smith FA. (1977). Occupational fluoride exposure. Journal of Occupational Medicine 19(1): 12-39.

“This case supports the premise that some forms of arthritis are related to sub-clinical fluorosis, i.e. fluorosis which is not sufficiently advanced to show the characteristic skeletal changes radiologically.”
SOURCE: Cook HA. (1972). Crippling fluorosis related to fluoride intake (case report). Fluoride 5(4): 209-213.

“Possibly some cases of pain diagnosed as rheumatism or arthritis may be due to subclinical fluorosis which is not radiologically demonstrable.”
SOURCE: Cook HA. (1971). Fluoride studies in a patient with arthritis. The Lancet 1: 817.

“Whereas dental fluorosis is easily recognized, the skeletal involvement is not clinically obvious until the advanced stage of crippling fluorosis… [Early cases of fluorosis] may be misdiagnosed as rheumatoid or osteo arthritis.”
SOURCE: Singh A, Jolly SS. (1970). Chronic toxic effects on the skeletal system. In: Fluorides and Human Health. World Health Organization. pp. 238-249.

“The onset of chronic fluorosis is insidious and may be confused with chronic debilitating diseases such as osteoarthritis . . . .”
SOURCE: Shupe JL. (1970). Fluorine toxicosis and industry. American Industrial Hygiene Association Journal 31: 240-247.

additional research:

“The authors describe a 50-year-old man with previously treated cancer who was using tray-applied topical fluoride gel. He complained of gastric symptoms, difficulty in swallowing, leg muscle soreness and knee joint soreness… The patient’s fluoride regimen was altered, and within a short period his urinary fluoride levels returned to normal and his symptoms resolved.”
SOURCE: Eichmiller FC, Eidelman N, Carey CM. (2005). Controlling the fluoride dosage in a patient with compromised salivary function. Journal of the American Dental Association 136:67-70.

“[A]rthopathy and arthritis affected a significant number of the (fluorosis) patients, resulting in functional disability… The physical signs of brick tea-type skeletal fluorosis were elbow, shoulder and knee articular dysfunction, which was the most common pathology. X-ray examination revealed that the interosseous membrane ossification, tendon attachment calcification and articular degeneration were the causes of these functional disorders.”
SOURCE: Cao J, et al. (2003). Brick tea fluoride as a main source of adult fluorosis. Food and Chemical Toxicology 41:535-42.

“The radiological severity of knee osteoarthritis was greater in the endemic fluorosis group than in controls… [E]ndemic fluorosis may increase the severity of osteoarthritis in the knees.”
SOURCE: Savas S, et al. (2001). Endemic fluorosis in Turkish patients: relationship with knee osteoarthritis. Rheumatology International 21: 30-5.

“Our findings demonstrate a highly significant relationship between the frequency of back and neck surgery, fractures, symptoms of musculoskeletal disease and a past history of diseases of the bones and joints. In the absence of so-called classic fluorosis, a disease complex was established which involves much more than merely the radiologic appearance of dense bone.”
SOURCE: Carnow BW, Conibear SA. (1981). Industrial fluorosis. Fluoride 14: 172-181.

“Although a few subjects had no symptoms, the fluoride exposed workers had a higher frequency of joint pain and stiffness than the control group. This joint pain resulted in disability in some cases.”
SOURCE: Boillat MA, et al. (1980). Radiological criteria of industrial fluorosis. Skeletal Radiology 5: 161-165.

“Most often the patients complained of back pain. Pains in the shoulders, elbows, forearms and lower legs were common. These pains differed in intensity and occurred constantly or periodically with no clear relationship to effort.”
SOURCE: Czerwinski E, Lankosz W. (1977). Fluoride-induced changes in 60 retired aluminum workers. Fluoride 10: 125-136.

“The investigation of a high incidence of arthritis in 21 dairy herds disclosed elevated fluorine levels in bone samples… There was a statistical correlation between a high incidence of damage to peri-articular structures, resulting in debility and loss of production, and elevated bone fluorine.”
SOURCE: Griffith-Jones W. (1977). Fluorosis in dairy cattle. The Veterinary Record 100: 84-89.

“All the patients had typical diagnostic features: skeletal pains, backache, stiffness, rigidity and restricted movements of the spine and other joints.”
SOURCE: Faccini JM, Teotia SPS. (1974). Histopathological assessment of endemic skeletal fluorosis. Calcified Tissue Research 16: 45-57.

“Schlegel presented data on 61 cases of skeletal fluorosis among workers of a Swiss aluminum factory… Their major symptoms were arthritic changes in the joints, especially in the spine… In contrast to non-industrial fluorosis, the author noted excessive involvement of the elbow joint which is presumably due to habitual use of the arms… The author also emphasizes the difficulty in differentiating spontaneous arthrosis from fluorotic arthritis.”
SOURCE: Schlegel HH. (1974). Industrial skeletal fluorosis: preliminary report on 61 cases from aluminum smeleter. Sozial und Praventivmed. 19:269-74. (Abstracted in: Fluoride 1975; 8:177)

“All but one of the 17 patients complained of vague pains and stiffness in the lower and upper extremities, shoulders, neck and lower back. In none of the cases could another disease of the bone or of the joints be found, except arthrotic lesions… If signs of fluorosis are present, they may lead to symptoms of the osteoarticular system.”
SOURCE: Vischer TL, et al. (1970). Industrial fluorosis. In: TL Vischer, ed. (1970). Fluoride in Medicine. Hans Huber, Bern. pp. 96-105.

“Joint changes or fluoric arthrosis may be very severe especially in the hip, knee and elbow joints. . . . Around joints, thick marginal osteophytes develop. In some instances, they grow to such an extent as to block joint movement (‘blocking arthrosis’). The joint block can also be induced by calcification of the periarticular ligament. The most common sites of articular involvement are the hips, the sacroiliac, elbow and knee joints. In older persons, the vetebral column is commonly affected. Advanced stages of the disease show atrophy and ulceration of joint cartilage.”
SOURCE: Soriano, M. (1968). Periostitis deformans due to wine fluorosis. Fluoride 1(2): 56-64.

“Another frequent finding was the calcification of ligaments and muscle attachments … Approximately three quarters of those later found to have radiological evidence of skeletal involvement did complain of pains mainly in the back, chest, and legs.”
SOURCE: Latham MC, Grech P. (1967). The effects of excessive fluoride intake. American Journal of Public Health 57: 651-660.

“The ligamentous calcification [of skeletal fluorosis] is often periarticular and shows as osteoarthritis of the spine and hip joints as well as of the sacro-iliac joints.”
SOURCE: Kumar SP, Harper RA. (1963). Fluorosis in Aden. British Journal of Radiology 36: 497-502.

“It is quite possible that endemic centres [of skeletal fluorosis] exist but that the cause of the disabling spondylitis or other joint affections has not been determined, and a diagnosis of chronic arthritis has resulted. Few cases in Canada or the United States will be found to be as dramatic as that recorded here from Southwest China, but by calling attention to the advanced stage of this condition help may be afforded to the diagnosis of early cases.”
SOURCE: Kilborn LG, et al. (1950). Fluorosis with report of an advanced case. Canadian Medical Association Journal 62: 135-141.