Long term use of triclosan toothpaste and thyroid function

Cullinan, Mary P., Palmer, Janet E., Carle, Anne D., West, Malcolm J. and Seymour, Gregory J. (2012) Long term use of triclosan toothpaste and thyroid function. Science of the Total Environment, 416 75-79. doi:10.1016/j.scitotenv.2011.11.063

Author Cullinan, Mary P.
Palmer, Janet E.
Carle, Anne D.
West, Malcolm J.
Seymour, Gregory J.
Title Long term use of triclosan toothpaste and thyroid function
Journal name Science of the Total Environment   Check publisher's open access policy
ISSN 0048-9697
Publication date 2012-02-01
Year available 2011
Sub-type Article (original research)
DOI 10.1016/j.scitotenv.2011.11.063
Volume 416
Start page 75
End page 79
Total pages 5
Place of publication Amsterdam, Netherlands
Publisher Elsevier
Collection year 2012
Language eng
Formatted abstract
The long term effects of usage of triclosan-containing toothpaste on thyroid function are currently unknown. Triclosan is structurally similar to thyroid hormones and reductions in serum thyroid hormone levels have been observed in animal studies following oral administration of triclosan. Therefore, an assessment of thyroid function over 4 years was undertaken in a subset of individuals in a randomised, placebo controlled clinical trial comparing the effects of 0.3% triclosan toothpaste with placebo toothpaste in subjects with coronary heart disease. Thyroid stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), antithyroglobulin antibody (anti-TGab) and antithyroid peroxidase antibody (TPOab) were measured.

Paired serum samples at year 1 and year 5 from 132 subjects (64 triclosan group, 68 placebo group) were analysed. At year 1 there were no significant differences in thyroid function between the groups: mean (SD) TSH 1.4 (0.8) and 1.6 (0.9) mU/L, triclosan and placebo groups respectively, fT4 15.8 (2.2) and 15.2 (2.1) pmol/L; fT3 4.8 (0.5) and 4.8 (0.5) pmol/L. Similarly, for antithyroid antibodies there were no group differences at year 1. Median (25th, 75th percentile) for anti-TGab, 38 (34, 42) and 37 (30, 42) U/mL triclosan and placebo groups respectively; anti-TPOab, 15 (10, 22) and 18 (10, 24) U/mL. At year 5, fT4 was the only measure to show a significant difference between groups (mean and 95% Confidence Interval) 15.6 (15.1, 16.1) and 14.7 (14.2, 15.1) pmol/L triclosan and placebo respectively (p = 0.01). This reflects reduced levels in the placebo group but no change in the triclosan group.

In conclusion, over 4 years triclosan toothpaste had no detectable effect on thyroid function. The data support the view that 0.3% triclosan in toothpaste is safe and free of significant thyroid adverse effects.
Keyword Triclosan
Thyroid function
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Available online 22 December 2011

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2012 Collection
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