Lifesavers · No. 23
Iodized salt
Adding a trace of iodine to table salt has prevented an estimated 720 million cases of iodine deficiency disorders worldwide since 1993, protecting brain development in millions of infants.
A 2020 modeled estimate in the journal Thyroid, comparing 2019 iodine status against 1993 levels across 139 countries. The same model finds about 20.5 million newborn cases of iodine deficiency prevented each year, against 4.8 million still affected in 2019.
How it saves lives
Iodine is a trace mineral the thyroid needs to make hormones that guide brain development, especially in the womb and the first two years of life. Without enough of it, a fetus or infant's brain does not develop fully, a harm that cannot be reversed later. Mixing a tiny, cheap amount of iodate into table salt puts iodine into nearly every meal, without asking anyone to change their diet.
The story
It is one of public health's plainest trades: a few cents of iodate stirred into salt, in exchange for protecting a child's brain before it has even finished forming. The idea reached Switzerland and Michigan within two years of each other in the 1920s, well before anyone could measure the results at a population scale. It took until 2020 for economists and physicians to size them: a modeled 720 million cases of iodine deficiency disorders averted worldwide since 1993, alongside millions of newborns each year no longer losing points of intelligence they would never get back.
From the record
720 million cases of clinical IDDs have been prevented by USI (a reduction of 75.9%).
From the record
Nearly 19 million babies born globally every year - 14 per cent - are at risk of permanent yet preventable brain damage and reduced cognitive function due to a lack of iodine in the earliest years of life
Asked often
How many lives has iodized salt saved?
A 2020 study in the journal Thyroid modeled the impact of universal salt iodization and estimated it prevented 720 million cases of iodine deficiency disorders worldwide between 1993 and 2019, including about 20.5 million newborn cases a year.
Who invented iodized salt?
There was no single inventor. Physician David Marine linked iodine deficiency to goiter, pediatrician David Cowie championed salt iodization in Michigan, and Switzerland iodized its salt supply first, in 1922, two years before Michigan followed.
The next one is being invented now.
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