There
seems to be quite a stir about certain nutrients being deficient in the diet of
Americans. While other nutrients may have more significance in the prevention of
disease, it is generally those nutrients which have some commercial significance
which receive the greatest public and media interest. The relationship of
calcium to milk, vitamin C to citrus fruits, and B-12 to eggs and milk are good
examples of this.
Iron
is another of these special interest nutrients and many Americans are taking
some kind of commercial preparation of iron for a supposed iron deficiency. Yet,
the level of hemoglobin (blood iron) which most Americans carry appears to be
too great for the most optimum health. Most textbooks give values for hemoglobin
as 12 to 16 grams per 100 cc of blood for women, and 14 to 18 grams for men. Any
value below that is considered low. These hemoglobin values would correspond to
hematocrit levels of 36 to 54. These levels are too high and are not compatible
with the best health as measured by freedom from complication of
labor and delivery, and recuperative ability in surgery. It is probable that
at sea level the ideal hemoglobin for optimum performance of the body is between
10.5 and 12.5 in women, and 12 to 15 grams in men.
If
a woman complains of fatigue, her physician may suggest dietary supplements,
even though her hemoglobin is above 12 grams. In one study it was found that
women having babies have a better outcome of the pregnancy if the hernatocrit
(packed red blood cells) before delivery varied from 29 to 33 for black women
and from 31 to 35 for white women, Another study showed that men undergoing
surgery have fewer complications if their hematocrits are under 40, as
compared to those whose hematocrits are over 40. The improved condition of the
patient is due to the easier access thinner blood has to small blood
capillaries. We need to redefine what is a normal level of hernatocrit and
hemoglobin.
The
emphasis on giving dairy milk to children is undoubtedly one cause of juvenile
iron deficiency. There are two reasons for this condition: milk is low in iron
and dairy milk injures the lining of the digestive tract; and especially in
infancy promotes the loss of blood through the bowel. Dairy milk should not be
fed before 140 days of age as it has been shown that a significant number of
babies have blood in their stool if they are fed milk before that age.1
The
basic mechanisms for the regulation of iron absorption are not fully understood;
however, it is understood that the need for more iron can increase the
absorption of iron from the intestinal tract. It is also known that there is
competition with other metals for iron binding sites at the lining of the
intestines.
Unbelievable
as it may seem with all the blood we make, there is less than one teaspoon of
iron in the body of a normal healthy adult; that's about the amount in a medium
nail. But its importance to our well-being is strikingly out of proportion to
the quantity we find. Sixty to seventy percent of the iron in the body is found
in the blood hemoglobin. There are iron stores in the liver, spleen, bone
marrow, and muscles; blood serum and certain enzymes also contain iron. When
hemoglobin is broken down the iron is captured by the bone marrow, liver, or
spleen, and again becomes a part of the iron stores. Hemoglobin combines with
oxygen in the lungs to form oxyhemoglobin which travels to the tissues where oxygen
is released to take part in the cell processes. At that point, carbon dioxide,
formed by the metabolic processes, is carried back to the lungs by the same
hemoglobin.
The
making of hemoglobin by the body depends on the presence of copper, proteins,
and iron. Vitamins C, E, and B- 12 also influence the rate of destruction of
RBCs. Myoglobin, found only in muscle tissue, is related to blood hemoglobin
both in structure and in function. It is an oxygen carrier capable of
supplying oxygen to the muscles and of removing carbon dioxide.
Apart
from meat and eggs, there are many other good sources of iron such as green
leafy vegetables, potatoes, dried fruits, and bread. Whole grain breads and
cereals are excellent sources. All dairy products are almost devoid of iron.
Molasses and raisins are rich on a percentage basis, but the small quantities of
these foods which are usually infrequently served make them not as important a
source of food iron as whole grain breads and cereals.
Iron salts in nature are all highly colored compounds and usually give
color to a food rich in this
element. Therefore, spinach could be expected to have more iron than celery, and
this is the case.
Generally
speaking, iron is better absorbed if the meal does not contain large varieties
of food. A menu consisting of two vegetables and whole grain bread will be
better for iron absorption than a menu containing four vegetables, two fruits,
and whole grain breads. Large amounts of fiber or substances that form
insoluble complexes with iron, such as phytates and sulfur-containing compounds,
reduce absorption. Prunes, dried apricots, all types of greens, peas fresh or
frozen, raspberries, sweet potatoes, and carrots and cauliflower are all high
in iron. Pastas (macaroni, spaghetti and noodles) from whole grains are high in
iron.2
The
body has built-in mechanisms for the prevention of iron overload. There are many
evidences that absorption of too much iron by the body interferes with its
function and injures its cells. Studies suggest an iron-rich environment
predisposes to infections by bacteria, viruses, and fungi.3
Iron
overload can occur on an acute or chronic basis. Acute effects of iron
intoxication such as in children who take their mother's supplement tablets
occur in the form of nausea within the hour, vomiting soon followed by
diarrhea and gastrointestinal bleeding. Circulatory collapse and death may
follow. Up to 20% of patients taking oral preparations of iron complain of
pain in the upper abdomen, colic, and constipation.
Despite
a low intake of meat and eggs, the foods usually thought of by dieticians as the
best sources of readily absorbed iron, Seventh-day Adventist vegetarian women
appeared in one large study to be quite adequate in their iron and zinc status
even though long-term vegetarians.4
Since
there are limited ways of getting rid of iron in the body, an excess in the
diet should be avoided. Hemorrhage is one way to get rid of excess iron. Adult
men rarely lose sufficient blood through accidental hemorrhage to cause them to
be deficient in iron. Women with heavy menstruation commonly lose significant
quantities of iron. There is some iron excreted in the bowel movements, some
from the skin through the loss of the outer layer of cells, particularly in
people living in hot, moist climates. In women 50 years old the largest amount
of variation in hemoglobin lost at menstruation was found. The usual menstrual
loss is 60 to 80 milliliters of blood (1/4 to 1/3 cup) per menstrual period;
yet, women who are unaware that their menstrual periods are abnormal may lose
more than 100 milliliters (1 cup) and sometimes more than 200 milliliters per
menstrual period. A relatively small chronic loss of blood may significantly
increase the iron requirements to maintain body stores of iron.
REFERENCES
1.
The Journal of Pediatrics 98 (4):540, April, 1981
2.
Mitchell, et al. Nutrition in Health and Disease, Philadelphia, J.B. Lippincott
Co. 1976
3,
American Journal of Disease - Diseases of Children 135(l):18-20 January, 1981
4.
American Journal of Clinical Nutrition of June, 1981
Disclaimer: The above counseling sheet
is provided courtesy of the Uchee Pines
Health Institute. The Uchee Pines Institute was started almost 30 years ago
by Calvin Thrash, M.D., specialist in Internal Medicine, and his wife, Agatha
Thrash, M.D., board specialist in pathology. It is a non-profit, health
educational and treatment facility located in the country near Seale, Alabama,
15 miles from Columbus, Georgia. (Address: Uchee Pines Institute, 30
Uchee Pines Road
Seale, Alabama 36875-5702. Phone: (334) 855-4764. Fax: (334)
855-4780. Email: ucheepines@msn.com.
Location Map: Click Here).
The information contained in the counseling sheets is presented as a general
educational and information guide. The counseling sheets are not intended to be
used for instruction in medical treatment. The author cannot assume the medical
or legal responsibility of having this information misinterpreted and considered
as a prescription for any condition or any person.