story to find out more.
Approximately one of
every 200 to 500 people in the United States has genes than can lead to
increased iron accumulation. For further information, including a free online
fact sheet, visit this
at the U.S. Centers for Disease Control and Prevention. Above: Sample nutrition
label for breakfast cereal.
Casting New Light on Genetic Iron Overload
By Rosalie Marion
Bliss May 12, 2005
Participants in a nutrition study who possessed a single mutated gene
linked with iron overload did not absorb too much iron from foods in the study,
compared to participants who didn't have the mutated gene. The finding is
important because, as a public health policy, some U.S. foods are fortified
with iron to aid consumers who wouldn't otherwise get enough from their diet.
Agricultural Research Service
R. Hunt and molecular biologist
Zeng at the ARS
Forks Human Nutrition Research Center, Grand Forks, N.D., conducted the
study. They wanted to find out whether carriers of a single copy of the genetic
mutation could be at risk of absorbing too much iron. Hunt heads the center's
Micronutrient Absorption and Metabolism Unit.
In people with hereditary hemochromatosis, also known as iron
overload, excess iron is deposited in body organs, leading to diseases such as
cirrhosis of the liver, diabetes, liver cancer and heart and joint diseases.
Those who inherit two copies of the altered gene--one from each parent--have an
increased risk of developing full-blown hereditary hemochromatosis. But
approximately one in 10 people in the United States inherit just one of the
altered genes, which makes them "silent carriers."
For this genotyping study, Hunt and Zeng tested 359 volunteers by
taking DNA samples either from the inside of their cheeks or from their blood.
Those identified as carrying a single copy of the mutation had their iron
absorption measured after consuming regular and iron-fortified meals.
The findings suggest that iron fortification of foods does not pose a
special health risk to the estimated 35 million carriers of one copy of the DNA
mutation. May is "genetic screening awareness month" for the
American Hemochromatosis Society,
based in Orlando, Fla.
about the research in the May 2005 issue of Agricultural Research magazine. ARS
is the U.S. Department of Agriculture's chief
scientific research agency.