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Global Iron Deficiency: New Ways of Treating an Old Problem
CHORI Scientist Identifies Novel Mechanism for Iron Absorption

January, 2012 –CHORI Senior Scientist, Elizabeth Theil, PhD, and her international colleagues have discovered that there are at least two independent mechanisms for iron absorption from non-meat sources. In a landmark publication in The Journal of Nutrition, Dr. Theil demonstrates that there is one mechanism for large, protein coated iron minerals (ferritin) found in vegetables and legumes, in addition to the more well-known mechanism for small iron complexes like those found in iron supplements,

“Our study shows that iron absorption from plant ferritin is more efficient,  gives the intestinal cells more control  and can be a key, new contributor to solving global iron deficiency,” says Dr. Theil.

“Iron absorption from plant ferritin is more efficient,  gives the intestinal cells more control  and can be a key, new contributor to solving global iron deficiency.”



Iron deficiency is the oldest and most common nutrient deficiency known to man and affects about two billion people worldwide, from developing and non-developing nations alike.

"Iron deficiency was first diagnosed by medieval physicians about 500 years ago. Given it's just as much a problem today as it ever has been, maybe we haven't had the best approach to fixing it."

Traditional approaches to treating iron deficiency include providing iron supplements and trying to increase meat consumption. Both of these approaches have proven to have significant limitations, however. Iron supplements frequently cause uncomfortable side effects, including gas and bloating, which inhibit consistent consumption, while in some cultures where iron deficiency is endemic, meat is scarce. As a result, meat is frequently reserved for the men, even though growing children and women of child-bearing age are the most susceptible to iron deficiency.

Dr. Theil's discovery of an alternative and highly efficient mechanism for iron absorption from legumes, however, could provide the key to helping solve worldwide iron deficiency by providing an alternative, affordable and readily available source of iron.

“Our study is the first to show that there are at least two independent mechanisms for iron absorption from non-meat sources.”

"Our study is the first to show that there are at least two independent mechanisms for iron absorption from non-meat sources," says Dr. Theil. "One is for the absorption of ferritin, the large, protein-coated iron mineral found in vegetables and legumes, while the other, more well-known mechanism, is for iron absorption of small iron complexes like those found in iron supplements."

The paradigm-shifting study combines the results of two different experiments, one in a rat model, and one in humans. In the rat model experiment, portions of rat intestines were bathed with solutions of traceable iron, either as a typical type of iron supplement, or as ferritin.

Dr. Theil was able to measure how much of each type of iron crossed the intestinal barrier, and at what rates, demonstrating that both the ferritin mineral and the smaller iron atoms were absorbed through the intestines. In the second experiment, traceable iron in ferritin was consumed by volunteers with a 9:1 ratio of unlabelled, non-meat iron dietary supplement, or with hemoglobin, the type of iron in meat, to see if the two types of iron competed with ferritin iron for the same absorption mechanism. In each case, the iron competitor had no effect on the individual's iron levels.

"What these studies show together is that during digestion, ferritin is not converted from its large, mineral complex, which contains a thousand iron atoms, to individual iron atoms like those found in many iron supplements," explains Dr. Theil. "Instead, ferritin iron is absorbed in its mineral form by a different, independent mechanism, which is not only absorbed more slowly, but may as a result provide greater safety to the intestines than iron supplements."

“Our study shows that this different mechanisms of iron absorption from plant ferritin is more efficient, gives the intestinal cells more control, and could be a key, new contributing factor to helping solve global iron deficiency.”

While further studies are needed to elucidate the exact mechanism of ferritin absorption, in the mean time, the results demonstrate that ferritin-rich foods such as legumes can provide a significant source of dietary iron, and provide new hope in the decades-long struggle to reduce global iron deficiency.

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Thursday, May 17, 2012 12:51 PM

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