China will stick to a wide use of iodized salt, and the current level of iodine intake is safe, said a health official, dismissing reports that linked salt iodization to increasing thyroid cancer cases.
"China preliminarily eliminated iodine deficiency diseases by 2000 in most regions, and consumption of iodized salt will be a cost-effective mainstay to avert iodine deficiency," Lei Zhenglong, deputy director of the disease prevention and control bureau under the National Health and Family Planning Commission, said at a news conference on Monday.
Iodine is a micronutrient necessary to produce thyroid hormone, but the human body doesn't make iodine, experts noted.
Iodine deficiency causes enlargement of the thyroid, hypothyroidism, and mental retardation among babies whose mothers are iodine-deficient during pregnancy.
In China, about 30 million people live in high-iodine areas, and 80 to 90 per cent of the iodine intake comes from food, said Yang Xiaoguang, a nutrition researcher for the Chinese Center for Disease Control and Prevention.
In the early 1950s, about 20 million Chinese suffered from thyroid enlargement due to iodine deficiency.
In 1994, China adopted universal salt iodization, which worked well to curb the situation, Yang said.
Currently, average iodine intake among Chinese, as previous studies showed, stands at 240 micrograms a day, an "optimal level", he said.
Lei said a sound surveillance network of public iodine intake and iodine deficiency diseases could help health authorities fine-tune the policy.
The amount of iodine added to table salt has been adjusted three times since 1995 according to surveillance results, he added.
"Varied measures are taken according to real local situations," he said, adding that a number of residents in regions like Xinjiang and Tibet still suffer from iodine deficiency.
But in the naturally iodine-rich southeast coastal regions, locals have access to non-iodized salt, he said.
In recent years, there have been media reports linking too much iodine intake to a rise in thyroid diseases, including cancer, in coastal areas. Some have blamed iodized salt for that.
Yang said the link has not been substantiated, citing a lack of long-term cancer surveillance data and complicated factors related to thyroid cancer.
But he said excessive intake of iodine would affect health, resulting in conditions like hyperthyroidism. He cautioned parents against serving "nori", a kind of seaweed, as snacks for children, citing an ultra-high concentration of iodine.
Food rich in iodine includes seaweed, shellfish, saltwater fish and yogurt.