Do Chinese people eat too much Iodine?

Modern Express
August 13, 2009

In 1994, China adopted a policy of nation-wide iodization of salt to solve the iodine deficiency problem among its population.

However, recent statistics indicate that there is an increase in the number of newly diagnosed cases of thyroid cancer. This has raised concern over the possible negative effect of the salt iodization policy, and newspaper articles are questioning whether an excessive intake of iodine is the culprit.

According to Cun Gonghao, a professor of Zhejiang University, in China, the average daily salt intake among urban residents is 11 grams, while among the rural residents the number is 17 grams.

Because most of the iodized salt on the market contains 20 to 50 micrograms of iodine per gram, Chinese people’s average daily intake of iodine is between 220 and 850 micrograms, higher than the WHO safe standard of 200 micrograms. Cun said that “with the background of a national campaign for iodine supplements, the health of the half a billion people with sufficient iodine has been neglected.”

In fact, a 1994 law stipulates that salt iodization is not compulsory in eight provinces where the iodine level is relatively high. However, many salt companies, in their pursuit of higher profits only sell iodized salt in these regions.

Today’s Modern Express reports on a 10-year-old boy who was diagnosed with thyroid cancer, a condition which is very rare among this age group. The report quoted a doctor saying that he was told by the mother of the patient, that she usually bought salt that contains highest percentage of iodine and their diet had lots of seaweed, which is rich in iodine too.

But the doctor said there was no real evidence proving a link between the iodine and the boy’s cancer.

The report lists the addresses of nine stores in Nanjing where the residents can buy salt that doesn’t contain iodine.