Iodine deficiency substantially heightens the risk of thyroid cancer
in children exposed to radioactive iodine and iodine supplementation can markedly
reduce that risk, according to a study of individuals living in areas affected
by the 1986 Chernobyl nuclear power plant accident (J Natl
Cancer Inst. 2005;97:703-704).
The study, led by researchers at the International Agency for Research
on Cancer in Lyon, France, and other institutions, involved 276 individuals
with thyroid cancer and 1300 controls, all of whom were age 15 years or younger
at the time of the Chernobyl disaster. The researchers found a strong dose-response
relationship between radiation dose to the thyroid and thyroid cancer risk
and determined that the risk was 3 times higher in iodine-deficient areas
than in other regions. However, the risk was reduced by one third in children
who received potassium iodine supplements after the accident.
Stephenson J. Iodine and Thyroid Cancer. JAMA. 2005;293(23):2850. doi:10.1001/jama.293.23.2850-d