Soybeans May Be A Good Iron Source for Women
By Luis Pons
January 6, 2003
It turns out that some soybean
varieties may be a great help to women who are marginally iron deficient.
Research assisted by the Agricultural
Research Service and reported in this month's American Journal of Clinical Nutrition
showed that ferritin in soybeans is a highly usable source of the iron many
The finding may represent a significant gain against iron deficiency, which
afflicts 30 percent of the world's population. It could refute belief that iron
in the form of ferritin in soybeans has poor bioavailability and thus is not
readily absorbed into the body once ingested.
In the study, 18 female volunteers--most of whom had marginal iron
deficiency--showed iron absorption rates above those expected when they ate
soybeans prepared as broth and muffins. They ate the muffins and had their iron
measured 14 days later, then repeated the process with broth.
The absorption rate of iron in the study averaged 27 percent, exceeding the
5 to 10 percent expected, based on prior studies conducted with humans. It is
believed that use of a soybean variety high in ferritin caused these elevated
This work began in 1994 at North Carolina
State University in Raleigh and at the ARS
Soybean and Nitrogen Fixation
Research Unit on the school's campus. The recent findings were made at
Penn State University's
General Clinical Research Center.
Ross Welch, a plant physiologist with ARS'
Plant, Soil and Nutrition
Laboratory in Ithaca, N.Y., assisted by growing soybeans with a radioactive
isotope of iron that made it possible to "label" the iron in seed
ferritin, making it detectable in red blood cells. Welch cautions that the
results are not unequivocal because not all of the iron in the soybeans used
was in the ferritin form. This is being addressed during the study's current
Read more about this research in the
January issue of
Agricultural Research magazine.
ARS is the chief scientific research agency of the
U.S. Department of Agriculture.