SMOKING/THYROID
 Heavy smokers have been shown to have substantial decreases in two thyroid hormones, T-3 (triiodothyronine) and T-4 (serum thyroxine). Several constituents of cigarette smoke are known to have antithyroid activity. Thyroid hormone level changes may have a profound effect on overall metabolism, as well as androgenic and estrogenic steroid activity. Light and moderate smokers demonstrated a milder decrease in thyroid hormone levels. (Archives of Internal Medicine 144:501-503, March, 1984) Copyright Phylis Austin

RADIATION THERAPY/THYROID CANCER
 Women who have undergone radiation therapy to the head or neck are 16.5 times more likely to develop thyroid cancer than are those not exposed to radiation. Women exposed to radiation at 19 years-of- age or younger had a higher risk than those exposed after 20 years- of-age. (Journal of the National Cancer Institute 73:575-581, 1984) Copyright Phylis Austin

BLADDER CANCER/COFFEE/PHENACETIN/THYROID STUDIES
 A study of women aged 20 to 49 years who had developed bladder cancer revealed that these women consumed more coffee, used more phenacetin-containing medications, and were more likely to have undergone radioactive iodine thyroid uptake studies than had a similar group of women who did not have bladder cancer. (American Journal of Epidemiology 123(6)1033-1042, 1986) Copyright Phylis Austin

BREAST FEEDING/THYROID DISEASE
 Adolescents who were breast-fed as infants are apparently at decreased risk of developing autoimmune thyroid disease. (Pediatric Research 23(4 Pt. 2)276A, April 1988) Copyright Phylis Austin

"NATURAL" THYROID PREPARATIONS
 So-called "natural" thyroid preparations which are sold in health food stores may cause serious problems, according to a report from the Tufts University School of Medicine. Researchers there point out that these preparations are not standardized and the hormone content may vary widely. Because the amount of hormone cannot be precisely controlled individuals using them in the treatment of thyroid disease may have hormone levels that are either too high or too low. Levels that are too high may produce seizures, ischemia, heart failure, or even death. (Archives of Internal Medicine 149:2117-2118, September 1989) Copyright Phylis Austin

IODINE ABSORPTION/THYROID
 An elderly man whose bed sores were treated with povidone-iodine (Betadine) applications developed high levels of thyroid hormones in the blood stream. It was determined that he absorbed large amounts of iodine from the topical medication. (Archives of Internal Medicine 150:2400-2401, November 1990) Copyright Phylis Austin