A recent study conducted by an Ohio State researcher suggests excess iron intake could cause healthy people to be susceptible to intestinal infection.
Researchers found cells containing high amounts of iron were more easily invaded by bacteria than cells with normal amounts of iron. The study questions the necessity of enriching foods with iron, a process to combat iron deficiency.
Iron deficiency is not a problem in the United States, said Dr. Mark Failla, chair of the Department of Human Nutrition and senior author of the study. Two percent of the population is iron-deficient, while 10 percent is at risk of iron overload, Failla said.
The government has established Recommended Dietary Allowances. One bowl of iron-enriched cereal provides the RDA for iron. The problem is many Americans eat iron-enriched foods and then take an iron supplement, Failla said.
The RDA for iron is 10 milligrams per day for men and 15 milligrams per day for women. Iron supplements generally contain 50 milligrams of iron, said Dr. Gail Kaye, OSU professor of nutrition and registered nutritionist.
“This has the potential to do more damage than good. Instead of fortifying everyone’s diet with excess iron, we should diagnose iron deficiency and then provide supplements only to those who need it,” Failla said.
Despite this, a response is not expected from food companies which enrich their products with iron, because this was a preliminary study conducted in a laboratory, Failla said.
In the study, cells virtually identical to the cells lining the small intestine were exposed to a form and amount of iron comparable to what is found in iron supplements. Cells were then exposed to a bacteria, commonly known as salmonella. Researchers found the cells exposed to iron were more easily invaded by the salmonella.
“It is a complicated matter. To solve one problem of deficiency, we are possibly creating another,” Failla said.
Follow-up studies are planned to determine why high iron intestinal cells are more susceptible to infection.