Gabe Mirkin, M.D.
Many people remember the old "tired blood" ads for iron pills and still believe that iron supplements can treat fatigue. However, no one should take iron pills unless blood tests show a deficiency.
Several studies have shown that high blood levels of iron are
associated with an increased risk of suffering heart attacks and
cancers, particularly, those of the esophagus and bladder.
A
study from Harvard showed that it may be the meat source of
iron, rather than just the iron itself, that causes the heart attacks
and cancers. People who eat a lot of meat, fish and chicken
have higher blood levels of iron than vegetarians. The iron in
meat, fish and chicken is called heme iron, which is absorbed at
a very high level, around 10-20 percent. On the other hand, the
iron that you get from plants is absorbed very poorly; only one to
three percent of the iron from leafy green vegetables and other
plant sources of iron is absorbed.
Other studies show that iron deficiency can be
healthful. Before the bad LDL cholesterol can form plaques in
arteries, it must be converted to oxidized LDL and iron causes
this reaction. Lack of iron reduces your chances of forming
plaques in your arteries and suffering heart attacks and strokes.
Less than 50 percent of the iron in your body is in your
red blood cells. Most iron is in your iron reserves in your liver,
spleen and other tissues. Your body needs iron to make red
blood cells and if your body does not contain enough iron, you
will become anemic, but you will not become anemic until you
have depleted all your iron reserves. You can be iron deficient
but not anemic when you have an adequate supply of red blood
cells, but no iron reserves. Iron deficiency does not make you
tired unless you are also anemic, but it can tire athletes
exercising at their maximum.
You can find out if your iron level is too high by asking
you doctor to draw blood for a test called transferrin iron binding
saturation. People with a transferrin iron binding saturation of
more than 60 percent are at increased risk for developing heart
attacks and cancers. If your level is greater than 60 percent, you
can reduce your intake of iron by restricting meat, fish, chicken
and iron-supplemented foods, and you can get rid of extra iron
by donating blood six or more times a year.
If your
blood iron levels are low and you are not anemic, you need a
special test called ferritin to measure iron reserves. If your
ferritin is low, your doctor will look for a source of bleeding such
as heavy menstruation or bleeding in your intestinal tract. If no
serious source is found, you need no treatment unless you are a
highly competitive athlete. More on chronic fatigue
Checked 7/9/09