Women with low iron stores absorb iron from soybeans
Worldwide, about 30% of the population, mainly women and children, is iron deficient. Iron deficiency is often combated with supplements or fortification of prepared foods. These artificial methods can be expensive, especially in third world countries. Soybeans are a major source of nonheme iron in many Asian diets, but information on iron bioavailability is still conflicting. Compared to other seeds, soybean contains a large fraction of iron in the form of ferritin (intracellular protein that stores iron and releases it in a controlled fashion). Iron in most other seeds, such as wheat grain, is complexed with phytates and therefore relatively less available.
Marray-Kolb and co-workers at Pennsylvania State University re-evaluated the bioavailability of soybean iron in a study group of 18 women, most of which had marginal iron deficiency. They compared the bioavailability of iron in soybean, consumed as soup or muffins, with that of ferrous sulphate. Iron bioavailability from soybeans was 27%, compared to 61% from ferrous sulphate.
The authors concluded that soybeans appear to be a good source of iron in marginally iron-deficient individuals and can be used as a novel way to combat iron deficiencies worldwide.
Source: Women with low iron stores absorb iron from soybeans. Am J Clin Nutr. 2003 Jan;77(1):180-4.