CHICAGO, Feb. 21 (Xinhua) -- Iron deficiency in the first four weeks of a piglet's life, equivalent to roughly four months in a human infant, impairs the development of key brain structures, and the abnormalities remain even after weeks of iron supplementation begun later in life, researchers at the University of Illinois (UI) have found.
The finding has been newly published in the journal Nutrients.
Pigs have anatomically similar brains to humans.
The researchers used magnetic resonance imaging and other noninvasive techniques to determine the relative iron content, volume and structural integrity of specific brain regions.
By comparing piglets with and without iron-deficient diets in the first four weeks of life, and then again at eight weeks after all received sufficient iron for four weeks, the researchers were able to determine whether the brain anomalies seen at four weeks persisted after the iron-deficient piglets' diets were corrected.
The analysis revealed that the brains of iron-deficient piglets did not fully recover. They had reduced iron content in several brain regions, including the left hippocampus, a region essential to learning and memory. Giving the piglets an iron-replete diet for another four weeks did not appear to increase the iron content of these brain regions.
The iron-deficient piglets also had structural deficiencies in their gray matter and white matter in several brain regions at four and eight weeks. Only the olfactory bulb, a brain structure that supports the sense of smell, was bigger in the iron-deficient piglets than in those that had never been deficient. The olfactory bulbs of the deficient piglets also had greater iron content than those of piglets that had never been deficient.
The finding suggests there could be a compensatory mechanism in the brain that concentrates available iron in the olfactory bulb to encourage an animal that normally roots around in the dirt with its snout to do so more aggressively to obtain sufficient iron from soil, the researchers said.
While this is only a hypothesis and has not been proved, an interesting thing is that humans with iron deficiencies sometimes experience a condition known as pica, which makes them want to eat unusual substances, including dirt, the researchers said.
Research in humans has shown that iron deficiency early in life results in delayed motor development by 10 months of age, delayed cognitive processing by 10 years of age, altered recognition memory and executive functions at 19 years of age, and poorer emotional health in the mid-twenties.
The finding adds to the evidence that iron deficiency early in life can have long-lasting consequences for the brain.
