Recent research published in The Journal of Neuroscience concluded that young people—study participants ranged in age from 8 to 26—with lower iron concentrations in their brain tissue also performed more poorly in cognitive tasks, even if they were otherwise healthy. Previous studies have shown similar results with babies and younger children, but this was one of the first studies to show a correlation between brain-iron levels and cognitive skills in teenagers.
Our bodies best absorb iron from animal foods—such as meat, fish, poultry and eggs—but beans and lentils, nuts and seeds, and dark-green leafy vegetables all provide iron as well. Eating them with vitamin C–rich foods can increase absorption.