Studying infant brain development using neonatal piglets, University of Illinois researchers have found that piglets experiencing iron deficiency during their first year suffered irreversible developmental problems. The findings, in the Journal of Nutrition, provide much needed insights into iron deficiency and its consequences, which are not well understood.
According to researcher Rodney Johnson, iron deficiency is common in the United States. "Babies born to obese mothers are at risk for iron deficiency," he explained. "Furthermore, the incidence of child obesity is increasing, and being overweight or obese is a risk factor for iron deficiency. Overweight toddlers are nearly three times more likely to suffer from iron deficiency than are those with a healthy weight."
For the study, Johnson took 2-day-old piglets and fed them one of three diets. The diet for the control group contained the recommended levels of iron, the second was mildly deficient, and the third was severely deficient. After 4 weeks, the researchers began testing the piglets in a T-shaped maze.
"Piglets provided the diet severely deficient in iron just didn't learn the task," Johnson said. "It's a T-maze so they have a 50 percent chance of getting it right. Even after 6 days of training, they never performed above chance levels. The piglets given the mildly deficient diet showed intermediate performance... not significantly different from that of piglets given the control diet."
In the second phase of the test, the maze was reversed and the piglets were retested. "We changed the rules so the piglets had to change their strategy," Johnson explained. "It's more demanding, cognitively speaking. The piglets fed an adequate diet learned this task very well. However, piglets fed a diet severely deficient in iron continued to perform poorly while those given a mildly deficient diet showed intermediate performance."
Johnson and his co-researchers then examined iron levels in different parts of the piglets' brains. They found reduced iron levels in the hippocampus, a brain region that is important for spatial learning and memory.
"Iron deficiency is a major problem worldwide," he concluded. "Infants who experience iron deficiency during the first 6 to 12 months of age can have irreversible developmental delays in cognition."
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Source: University of Illinois College of Agricultural, Consumer and Environmental Sciences