Ask the Doc: Iron: How Much is Enough?
Here's what you need to get just the right dose
BY Neal Barnard, MD
PHOTOGRAPHY Mike Lorrig
Q How can I tell if I'm getting
enough iron?
A That's an important question.
Iron is a key part of hemoglobin,
a protein your red blood cells use
to carry oxygen from your lungs
to the rest of your body. If you're
low in iron, you may feel weak
and run-down because your body
isn't getting enough oxygen.
Many of us grew up with the
idea that red meat is high in
ironand it is. But it's also high
in cholesterol, animal fat, and
other undesirables.
You can easily get all the iron
you need from a healthful plantbased
diet. As a matter of fact,
the American Dietetic Association
and the Dietitians of Canada
reported in 2003 that vegetarians
generally get more iron than
nonvegetarians, and that vegans
do best of all. That's because
beans and green leafy vegetableswhich
vegetarians and vegans tend to eat
plenty ofare loaded with iron. And
many other foods are iron-fortifi ed
(breakfast cereals, for example), as you'll
see on their labels.
A 1-cup serving of green vegetables
provides 13 milligrams of iron, depending
on which vegetable you choose.
A 1/2-cup serving of beans provides 23
milligrams. A bowl of a typical ironfortifi
ed cereal has 18 milligrams.
How much iron do you need? The
recommended dietary allowance for
adult males and for women over 50
is 8 milligrams per day. For women
aged 1950, the RDA is 18 milligrams
per day (it's higher to compensate for
menstrual losses).
So, with all that iron in everyday
foods, how could a vegetarian run low?
Several reasons: First, some people eat
everything veg except those healthful,
iron-rich vegetables and beans. In that
case, it is easy to run low. Also, dairy
products interfere with iron absorption:
if you have a glass of milk with a meal,
it reduces the iron you absorb from
the other foods you eat by about half.
A young woman's menstrual flow leads
to iron losses every month. Distance
runners lose iron too, both in sweat and
through the repeated pounding of their
feet, which breaks up red blood cells.
Q Is there a difference between the
iron in vegetables and the iron in meat?
A Yes. The iron in plants is called
nonheme iron. Its absorption depends on
how much iron is in your body already.
That is, if you are low in iron, your body
absorbs more of it from the foods you
eat. If you already have plenty of iron in
your body, nonheme iron is less absorbable.
That's good. It means you'll get the
iron you need without overdoing it.
The iron in meat is called heme iron.
Its absorption does not change. You may
have plenty of iron stored in your body
already, but like an uninvited guest at a
party, heme iron barges in whether you
need it or not. As a result, many meat
eaters end up with too much iron,
which is dangerous because iron
sparks the production of free radicalsmolecules that can damage your body
tissues. Think of it this way: iron rusts;
that is, it oxidizes. The same chemical
reaction that turns an old nail rusty
red can occur with the iron inside
your body. In the process, iron releases
free radicals that are linked to aging,
cancer, and heart disease.
Q Should I take an iron supplement?
A No, not unless your health care
provider has diagnosed an iron deficiency.
In the past, iron was promoted
as the answer to life's problems. If you
were dragging through the day, iron
pills and various tonics promised extra
iron to perk you up. That was a mistake,
because iron overdose is as dangerous
as iron defi ciency, and is much more
common.
So if you think you might be low in
iron, get tested. It is quick and easy.
And because high levels of iron can be
risky, doctors are quite happy to see
your blood tests come out at the lower
end of the normal range.
But if you really are low in iron, your
health care provider will look for reasons
why. The fi rst concern is bleeding, as can
occur from normal menstrual fl ow, or
from abnormal conditions, such as an
ulcer or colon cancer, that require more
detailed evaluation.
If you do need to boost your iron
intake, the answer is to fill up on "greens
and beans," as well as vitamin Crich
foods, such as fruit and fruit juices,
which increase iron absorption. Avoiding
dairy products also helps (and don't
worry about calciumgreen vegetables
and beans provide a healthful source of
that too). Only in rare cases is an iron
supplement necessary.
Comments
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THANKS! True, as past history shows, women who feel run down should take more iron ... NO, women who feel run down need to look at all phases of their diet! Espec, sugar and the 'monster' salt-intake makes for mood swings and lethargy!
Thanks for the info. I need to know is it the cooked 1cup of greens or uncooked one?
what kind of iron can you find in 1 or 2 glasses of juice?
my dad always gets on me for not eating red meat-- that for some reason i need it. Thanks, i really needed to read this, and i'm glad that i can get enough iron without all of the animal fat, cholesterol, and other such undesirables.