Doctors fear iodine deficiency – a dietary problem of the past – could return

NEW YORK (AP) — The 13-year-old boy showed up at the clinic with a rapidly swelling neck. The doctors were perplexed.

Tests dispelled their initial suspicions. But further tests identified what they and the boy were missing: iodine.

A century ago, iodine deficiency affected children across large parts of the country. It virtually disappeared after some food manufacturers began adding it to table salt, bread and some other foods, making it one of the great public health success stories of the 20th century.

But today, people are consuming less iodine because of changes in their diets and how foods are manufactured.

Although most people still get enough, researchers are increasingly reporting low iodine levels in pregnant women and others, raising concerns about its impact on their newborns. And there are also a very small, but growing, number of reports of iodine deficiency in children.

“This needs to be on people’s radar,” said Dr. Monica Serrano-Gonzalez, a Brown University physician who treated the boy in 2021 in Providence, Rhode Island.

What is iodine?

Iodine is a trace element found in seawater and in some soils, mainly in coastal areas. A French chemist discovered it accidentally in 1811 when an experiment with algae ash created a puff of purple vapor. The name iodine comes from a Greek word meaning purple color.

Later in this century, scientists began to understand that people need certain amounts of iodine to regulate their metabolism and stay healthy, and that this intake is crucial in the development of children’s brain functions.

A sign of iodine deficiency is swelling of the neck, called a goiter. The thyroid gland in the neck uses iodine to produce hormones that regulate heart rate and other bodily functions. When there is not enough iodine, the thyroid gland enlarges as it races to compensate for the lack of iodine.

In the early 20th century, goiter was very common among children in some interior regions of the United States, particularly in a “goiter belt” that stretched from the Appalachian Mountains and the Great Lakes to the northwestern United States. -United. Some children were unusually small, deaf, intellectually delayed, and had other symptoms of a syndrome formerly known as “cretinism.”

Add iodine to salt

Public health experts realized they couldn’t solve the problem by feeding everyone seaweed and shellfish, but they learned that iodine can essentially be sprayed onto table salt. Iodized salt first became available in 1924. By the 1950s, more than 70% of American households used iodized table salt. Bread and some other foods were also fortified with iodine, and iodine deficiency became rare.

But diets have changed. Processed foods now make up a large part of the American diet, and although they contain a lot of salt, they are not iodized. Major bread brands no longer add iodine. In the 13-year-old’s case, he has mild autism and was a picky eater, mostly only eating specific brands of bread and peanut butter.

And for those who salt their food, the fashion now is to use kosher salt, Himalayan rock salt or other non-iodized products.

“People have forgotten why there is iodine in salt,” said Dr. Elizabeth Pearce of Boston Medical Center. She is a leader of the Iodine Global Network, a non-governmental agency working to eliminate iodine deficiency disorders.

She noted a reported a 50% drop of iodine levels in the United States among Americans surveyed between the 1970s and 1990s.

How much iodine is enough?

Even though iodine consumption is declining overall, most Americans still get enough in their diet, experts say. But doctors fear this may not be the case for women and children, who are most vulnerable to iodine deficiency.

The American Academy of Pediatrics and other medical societies recommend that all pregnant and breastfeeding women consume 150 micrograms of iodine each day. You can get this from half to three-quarters of a teaspoon of iodized table salt.

Over the past 15 years, American researchers have increasingly reported mild iodine deficiencies in pregnant women. A Michigan State University study of about 460 pregnant women in the city of Lansing, about a quarter of them were not getting enough.

Many prenatal vitamins do not contain iodine, noted Jean Kerver, the lead author of the study. This is why doctors recommend That pregnant or breastfeeding women check labels to make sure they are taking multivitamins or prenatal supplements containing iodine.

Some studies have linked even mild iodine deficiency to lower IQ and language delay in children, although there is debate over exactly where the problems start, Pearce said.

Experts say there hasn’t been enough research to establish what impact this iodine deficiency has actually had on the U.S. population in recent years.

Serrano-Gonzalez said she and her colleagues have seen four other cases in children at their Providence clinic.

“We are concerned that this will increase, especially in patients on a restricted diet,” she said.

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The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Education Media Group. The AP is solely responsible for all content.