People who eat seafood advised to avoid iodine

Taking in too much iodine from sources such as iodized salt and experiencing too much stress are directly related to thyroid diseases, especially hyperthyroidism, local researchers say.

Healthy people in Shanghai are advised to avoid iodized salt, since they frequently eat seafood, which is a source of iodine, experts said yesterday.

China, where iodine-deficiency once was widespread, started adding iodine to salt in 1995, which greatly dropped the prevalence of iodine deficiency disorders. However, the rise of iodine-related illness in recent years has made locals wonder about whether using iodized salt is necessary.

Researchers covered 20 hospitals and interviewed 4,970 patients and doctors to study thyroid diseases. Women were three times more likely to have thyroid diseases than men. The most common thyroid diseases are hyperthyroidism (overactive thyroid), thyroid nodules and hypothyroidism (underactive thyroid).

"Having a lack of iodine or having too much iodine is closely related with thyroid diseases, especially hyperthyroidism," said Dr Wang Weiqing, director of Ruijin Hospital's endocrinology department.

Non-iodized salt is available in special sales center in each district and in hospitals. "The Ministry of Health has realized there is an issue and dropped the iodine levels in iodized salt in recent years to control thyroid diseases," Wang said.