4th May 2018, Volume 131 Number 1474

Michael Godfrey

A 79-year-old lady presented with a history of diffuse sero-negative arthritis dating from early adulthood. Numerous investigations and therapies had failed to provide any significant benefit and both knees and a hip had been replaced when initially seen a year ago. On questioning at that time, she admitted to daily drinking at least six cups of black tea since childhood. She lives in a retirement village where there has not been water fluoridation since 1994. However, her fasting fluoride results (Medlab) were elevated:

  • Serum fluoride 2.5µmol/L (Ref. range 0.3–2.2)
  • Urine fluoride 58µmol (Ref. range 0–31)
  • Fluoride: creatinine ratio 13.5µmol (Ref. range 0–3.1)

She used a standard fluoridated toothpaste but was otherwise not on any fluoridated medications. However, given the fact that her preferred tea exceeded 3mg fluoride/L1 it is possible that she has been unwittingly overdosing for many years. Skeletal fluorosis from tea has been identified.2 Furthermore, excessive use of fluoridated toothpaste caused severe arthritis initially diagnosed as ankylosing spondylitis with full recovery after stopping exposure.3 A year after stopping black tea drinking and changing to a herbal non-fluoridated toothpaste, this elderly woman’s joint pain levels had markedly decreased with considerably improved mobility enabling her to have a long-awaited trip overseas.

Discussion

Fluoride exposures are pervasive. Traditionally, this country has been a major tea consumer and the consequences of fluoride in tea have recently been extensively covered with one cup of the most widely consumed tea brands supplying over 1mg of fluoride per teabag even without any added water fluoridation.1 Absorption of fluoride from toothpaste at 1,000ppm are considerable and equivalent to, or more than from a cup of tea.1,4 Fluoride is present in beverages, and in over 200 pharmaceuticals with some being given on a long-term daily basis, eg, atorvastatin, fluvastatin, fluticasone, celecoxib and fluoxetine.

Long-term accumulative exposures to fluoride even at low levels carries a risk of sub-clinical or stage-1 musculo-skeletal fluorosis presenting as joint pain or arthritis.5 Notably, arthritis is a leading cause of disability with 647,000 now affected in this country and annual costs exceeding $3 billion.6 Chronic pain was also reported in a New Zealand community study with the most common pain locations being lower back (59%), pelvis/abdomen (49%), joints (39%), neck (34%), muscle (31%) and headache (31%).7 It would thus be logical to include possible fluorosis in the differential diagnosis of these patients with at least urine fluoride assessments. Notably, this woman’s serum fluoride level was considerably higher than that of women in her age group living in a low fluoride area, with a mean serum level of 0.56µmol/l and 0.948µmol/l being the highest recorded with impaired renal function.8

Prescriptions for arthritis are among the highest on Pharmac lists with similar health problems being recorded in the Republic of Ireland, the heaviest tea-drinking nation and with long-term nationwide fluoridation. Excessive tea consumption can cause skeletal fluorosis2 as can toothpaste.3 The accumulating evidence could suggest that the population is potentially being overdosed with fluoride and certainly exposed to far more than the initial well-intentioned dental hypothesis of 1mg/day for caries prevention proposed in the US 70 years ago.

The findings in this case would indicate that further primary health investigations are warranted and for those interested, Dr Susheela, a leading fluoride researcher, gives a useful diagnostic protocol.9 Notably, the evidence presented here is but a fraction of the available peer-reviewed literature, demonstrating the potential for harm from this element as reviewed by Peckham and Awofeso.10

Author Information

Michael Godfrey, Retired GP, Tauranga.

Correspondence

Michael Godfrey, Retired GP, Tauranga.

Correspondence Email

mike@godfreymedical.nz

Competing Interests

Nil.

References

  1. Waugh DT, Godfrey M, Limeback H, Potter W. Black Tea Source, Production, and Consumption: Assessment of Health Risks of Fluoride Intake in New Zealand. J Environ Public Health (2017) 5120504. doi: 10.1155/2017/5120504. http://www.ncbi.nlm.nih.gov/pubmed/28713433
  2. Kakumanu N, Sudhaker D, Rao SD. Skeletal Fluorosis Due to Excessive Tea Drinking. N Engl J Med 2013; 368:1140 DOI: 10.1056/NEJMicm1200995.
  3. Kurland ES, Schulman RC, Zerwekhm JE, Reinus WR, et al. Recovery from skeletal fluorosis (an enigmatic, American case). J Bone Miner Res. 2007 Jan; 22(1):163–70.
  4. Ekstrand J, Koch G, Petersson LG. Plasma fluoride concentrations in pre-school children after ingestion of fluoride tablets and toothpaste. Caries Research. 1983; 17(4):379–384. doi: 10.1159/000260691. [PubMed] [Cross Ref
  5. Fluoride in Drinking Water: A Scientific Review of EPA’s Standards Chapter 5 Musculoskeletal Effects. ISBN 978-0-309-10128-8 | DOI 10.17226/11571
  6. www.arthritis.org.nz (accessed January 2018).
  7. Swain N, Johnson M. Chronic pain in New Zealand: a community sample. The New Zealand Medical Journal. 2014; 127(1388):21–30. [PubMed]
  8. Itai K, Onoda T, Nohara M, Ohsawa M, et al. Serum ionic fluoride concentrations are related to renal function and menopause status but not to age in a Japanese general population. Clinica Chimica Acta 411 2010; 263–266.
  9. Susheela AK. Fluorosis and Associated Health Issues Indian Journal of Practical Pediatrics 2015; 17(2):138. 
  10. Peckham S, Awafeso N. Water fluoridation: A critical review of the physiological effects of ingested fluoride as a public health intervention. The Scientific World Journal (2014) Volume 2014, Article ID 293019, 10 pp. http://dx.doi.org/10.1155/2014/293019