“One of the things I noticed about the youth in Cambodia was how seemingly fit they were, with bulging muscles and no fat,” Charles says. But it wasn’t long before he observed a disturbing health trend and decided to investigate. 

Even though people looked healthy and strong, Charles saw that many of them behaved as if they were sick—cooped up in their homes and sleeping in the middle of the day. Schools had few students, and those in attendance looked fatigued, with little energy to learn or concentrate.

Charles recognized the culprit: anemia. People with this blood condition have a reduced number of red blood cells in their bodies. Red blood cells contain an iron-rich protein called hemoglobin, which carries oxygen from the lungs to other tissues in the body. If a person doesn’t have enough red blood cells, organs don’t get enough oxygen and therefore don’t work efficiently. The person begins to feel run-down. 

About 2 billion people around the world suffer from anemia, according to the World Health Organization. In the villagers’ case, their anemia is from a lack of iron in their diet, called iron deficiency anemia. A 2005 study found that more than 67 percent of Cambodian children suffered from anemia. 

The villagers’ diet of primarily rice and fish is low in iron. Red meat—the best source of iron—is uncommon in developing countries like Cambodia because raising cattle is expensive. Villagers could take iron supplements, but many people prefer not to because the pills can upset digestion.

The iron our body needs is the same type as the metal found in cast-iron cookware. People can fortify their food with iron by cooking in a cast-iron pot. However, these pots are expensive and heavy, and they rust easily. Still, this gave Charles an idea.

He melted scrap iron into bricks called ingots. He then tried to convince the villagers to cook their food with the bricks. 

But because the ingots looked unappealing, people used them as doorstops and paperweights. So Charles tried a new design: a fish—a favorite Cambodian food and a symbol of happiness or luck. He delivered the Lucky Iron Fish to villagers. It was a success—92 percent of the people used it.

Charles studied about 250 villagers for a year. Those who used the Lucky Iron Fish were about 25 percent less likely to be anemic than those who didn’t use one. Blood tests also showed that levels of both hemoglobin and serum ferritin (a protein that indicates iron levels in the body) rose over time (see graphs). 

Today about 10,000 Cambodian families are using the Lucky Iron Fish, and anyone can purchase one online to boost the iron in their diet.