| |
 |
|
|
Science Forum Index » Medicine - Nursing Forum » Iron / bacteria
Page 1 of 1
|
| Author |
Message |
| Guest |
 Posted: Tue Dec 19, 2006 11:41 pm |
|
|
|
|
http://oncampus.osu.edu/v31n7/discoveries.html
Mark Failla and his colleagues suggest that enriching foods with iron
could cause health problems.
Excess iron intake increases risk of intestinal infection
By Yudhijit Bhattacharjee, Research Communications
Researchers at Ohio State believe that an overdose of iron in the
nation's diet could be rendering thousands of otherwise healthy people
prone to intestinal infection.
In a laboratory study, the researchers found that human intestinal
cells with excess iron were more susceptible to attack by bacteria that
cause infection of the small intestine.
The study suggests that enriching breakfast cereals and other foods
with high doses of iron -- a nutritional strategy that has been widely
adopted to eliminate iron deficiency in the population -- could be
causing other health problems.
"Instead of fortifying everyone's diet with excess iron, we should
diagnose iron deficiency and then provide supplemental iron only to
those who need it,"said Mark Failla, professor of nutrition and the
senior author of the study. Failla and his colleagues reported the
study in a recent issue of the Journal of Nutrition.
Failla's group arrived at these conclusions after laboratory
experiments with human cells that are virtually identical to cells
lining the small intestine. These epithelial cells of the small
intestine transfer iron from digested foods to the bloodstream for
transport to the body's various organs. Iron is vital for a variety of
metabolic processes, including the binding and release of oxygen by red
blood cells.
In their experiments, Failla and his colleagues exposed cells to a
common form of iron that is present in iron supplements. Iron-laden
cells were then exposed to Salmonella enteritidis, a bacterium that
causes intestinal infections in humans. Infection from Salmonella
enteritidis often results from eating undercooked eggs, and is
accompanied by fever, abdominal cramps and diarrhea.
The scientists found that cells containing high levels of iron were
more easily invaded by the bacteria. Moreover, greater numbers of
bacteria survived inside cells with high iron than cells with normal
amounts of iron.
Cells with elevated levels of iron also synthesized higher amounts of
cytokines and chemokines -- classes of defense proteins -- in response
to bacterial infection. The secretion of many of these proteins is
associated with the development of inflammation.
"The finding suggests that excess iron in the absorptive cells in the
gut may increase both the risk of infection and damage other tissues in
the intestine in response to the greater degree of inflammation,"Failla
said.
To prevent iron overload, the researchers suggest a revision of the
standard policy of iron fortification of the general population. They
recommend periodic evaluation of the iron status of individuals,
particularly women in the reproductive period of their life cycle. If
an individual exhibits iron deficiency, therapeutic iron can be
administered by injection or by judicious use of dietary supplements as
prescribed by a physician or registered dietitian.
"Iron is a double-edged sword,"Failla said."Although it is an
absolutely essential nutrient, excess tissue iron can cause pathology."
Failla and his colleagues are planning further experiments to explain
why intestinal cells with high iron levels are more readily infected.
The studies would also help understand the mechanism behind the
heightened expression of defense proteins in these cells in response to
bacterial invasion.
The research was funded by the U.S. Department of Agriculture and the
North Carolina Institute of Nutrition.
Who loves ya.
Tom
Jesus Was A Vegetarian!
http://jesuswasavegetarian.7h.com
Man Is A Herbivore!
http://tinyurl.com/a3cc3
DEAD PEOPLE WALKING
http://tinyurl.com/zk9fk |
|
|
| Back to top |
|
| |
|
Page 1 of 1
All times are GMT - 5 Hours
The time now is Fri Dec 05, 2008 12:30 pm
|
|