SIR, A high intake of fluoride (F-) is known to cause severe skeletal fluorosis, but the actual fluoride intake required to produce fluorosis is unknown. I have shown that tea-drinking in Britain causes a high intake in both children and adults, maximum intakes in children surveyed reaching nearly 6 mg daily in unfluoridated areas and nearly 7 mg daily in fluoridated areas. (1) It is possible that fluoride intake from tea may be sufficient to cause fluorosis, and I report here a case which gives

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SIR, A high intake of fluoride (F-) is known to cause severe skeletal fluorosis, but the actual fluoride intake required to produce fluorosis is unknown. I have shown that tea-drinking in Britain causes a high intake in both children and adults, maximum intakes in children surveyed reaching nearly 6 mg daily in unfluoridated areas and nearly 7 mg daily in fluoridated areas. (1) It is possible that fluoride intake from tea may be sufficient to cause fluorosis, and I report here a case which gives some evidence for this.

A woman of 55 had been crippled by arthritis for about 25 years. 12 years ago she moved to a higher water-fluoride area because she understood it was healthy for teeth and bones. The water contained 0.67 p.p.m. fluoride. She was a heavy tea-drinker, and sought my help after reading an article by me in a lay magazine. Blood calcium, magnesium, and inorganic phosphorus, obtained by her local doctor, were normal. X-rays from the local hospital showed spinal disc degeneration but no obvious signs of fluorosis; some discs showed possible signs of osteoarthritis, and there were some exostoses. I carried out fluoride-balance studies on her fluid intake and urinary excretion, the diet remaining unchanged throughout the investigation. She was drinking 3-4 pints of tea daily, and fluoride intake, measured with a specific fluoride electrode, reached over 9 mg. daily. The following results were obtained:

Date
24-hr. F intake
from tea and water (mg)
24-hr. urinary F
excretion (mg)
F retention
(mg)
Feb. 9, 1970
6.90
Feb. 16, ”
9.34
2.76
6.58
June 4, ”
6.32
1.56
4.76
July 3, ”
7.62
3.07
4.55

On July 10, 1970, her tea intake was stopped, and subsequent figures were as follows:

Date
24-hr. F intake
from tea and water (mg)
24-hr. urinary F
excretion (mg)
F retention
(mg)
Aug. 24, 1970
0.76
0.75
0.01
Sept. 24, ”
0.66
1.50
-0.84
Oct. 19, ”
0.68
0.66
0.02
Nov .25, ”
0.53
0.58
-0.05
April 1, 1971
0.48
0.72
-0.24

On Nov. 11, 1970, she was examined and re-X-rayed by Dr. J.T. Scott, of the Kennedy Institute of Rheumatology. He confirmed the longstanding disc degeneration, and stated that, in his opinion, her case did not appear suggestive of fluorosis.

If this patient was indeed suffering from the effects of high fluoride intake, it could not be diagnosed radiologically. It is noteworthy that the urinary excretion of fluoride, before tea-drinking stopped, was in the range of 1.5 to 2.0 ppm, which according to Machle and Largent (2) is indicative of fluoride retention.

Little more than 3 months after stopping tea-drinking she reported that pain had diminished to the point where she was almost able to do without analgesics, and that mobility had increased so that she had been able to take on a job as representative, involving a considerable amount of walking. The improvement continued, and after 6 months she reported that she was virtually free of pain, and considered she could do without drugs. In July, one year after stopping tea-drinking, she reported that further improvement had apparently ceased, but there had been no deterioration and she was able to do without pain-killing drugs except in emergency.

Possibly some cases of pain diagnosed as rheumatism or arthritis may be due to subclinical fluorosis which is not radiologically demonstrable.

H.A. Cook
Scientific Committee for the
Study of Fluoridation Hazards
14 St. Albans St.
London S.W.1.


References:

1. Cook, H.A. Health for All, Jan. 1970, p. 622.
2. Machle, W., Largent, E.J. J. ind Hyg. Toxicol. 1943, 25, 112.