Managing Iron Nutrition

Preparing Yourself for a Healthier Tomorrow

Evidence in JAMA has implicated iron excess in many common disorders, notably vascular disease (e.g., heart attack and stroke), malignancy and neurological diseases. A recent report has shown that higher levels of iron in healthy women predict risk of developing diabetes.

The precise value of controlling iron levels is, at present, poorly defined. However, we commonly implement protective measures such as smoking cessation and weight reduction based on strong circumstantial evidence for undesirable effects. This narrative was prepared to provide basic guidance on how individuals presumed, based on the best evidence available, to be at-risk from excess iron can lower iron levels and reduce their risk of iron - related disease. The challenge is to consider the basics of iron nutrition and factors that determine iron levels to avoid both iron deficiency and excess. The complexities of making diagnoses, interpreting test results and implementing recommendations requires consultation with a physician. While guidance for physicians and patients in assessing iron status in the general population is our concern here, related information on management of certain other iron disorders can be obtained from the Iron Disorders Institute and other patient advocacy groups concerned with iron excess. Recommendations are likely to change as new information becomes available but there is ample reason to begin thinking about the problem now.

Why Should Attention be Paid to Amounts of Iron in the Body?

Several studies have shown that levels of iron in the body are related to disease risk, and that controlling iron levels may improve laboratory measures of disease and possibly improve patient outcome (see article published in Vascular Medicine). The role of iron in disease can be compared to that of obesity or smoking. Both are markers of increased risk and both can be managed to reduce disease risk. Elevated iron levels are believed to induce oxidative stress that damages critical molecules to cause disease. Because levels of iron in the body above physiologic requirements serve no known purpose and may be toxic, there is no reason to ignore these levels when means are available to control them.

How Is Body Iron Measured?

A blood test developed over a half century ago called the serum ferritin determination has been shown to reflect the amount of iron in the body. As the amount of iron increases, the cells respond by producing ferritin that binds to the excess iron as if to limit its ability to exert a toxic effect. Ferritin does its job quite effectively but only within limits. According to current concepts, iron can rise to levels above which the ability of ferritin to detoxify it is exhausted. The more iron present and the greater the time it is present, the greater the damage. The fact that iron accumulates imperceptibly and causes damage over relatively long periods of time likely accounts for the general lack of awareness of this association. The gradual rise in body iron, represented by rising ferritin levels, over a period of years has been shown to commence in the late teens for males and following menopause in females; iron accumulation over time is much greater in blacks than in whites. (See analysis of the NHANES database.)

While patients can learn to interpret their own ferritin level, on-going consultation with a physician is required because levels increase not only with increasing body iron but also with various illnesses and with tissue damage as may occur following surgery or trauma. Thus, ferritin levels increase acutely with many diseases including malignancy, infection, in the post-operative period, etc. Ferritin levels below about 12 to 15 ng/ml are characteristic of iron deficiency. However, ferritin levels may be higher than this even though iron deficiency is present because of a co-existing infection or other disease. Likewise, a ferritin level of several hundred ng/ml need not represent extreme body iron levels for the same reasons. Your physician may recommend other tests when uncertainty exists. Nonetheless, patients can learn to interpret their own test results in context, and with coaching and experience just as a diabetic learns to interpret their blood sugar level. In spite of its shortcomings, the serum ferritin level is currently the best test available for measuring levels of body iron.

The "Normal" Level of Iron in the Body

Evidence suggests that the physiologic optimum, or low risk, level for the serum ferritin is between about 15 and 50 ng/ml. Some studies have shown that the thickness of the carotid artery wall begins to increase (reflecting atherosclerosis) with levels above about 50. In the study of diabetes risk cited above the average ferritin in women who later developed diabetes was 109 while the average in women who did not develop diabetes was 71. The population average for the ferritin during childhood and in menstruating women (when health is optimal) is about 25. Highly conditioned athletes characteristically have low ferritin levels. The goal of treatment of individuals with the iron overload disease, hemochromatosis, is to achieve a ferritin level in the range of 25 to 75 ng/ml (see www.irondisorders.org). Consider that the newborn period is naturally iron-spare because milk is almost devoid of iron. Vegetables are a major source of calories for energy and contain iron, typically in small quantities, that is poorly absorbed.

Managing Iron Deficiency

"Anemia" should never be assumed to be due to iron deficiency unless there is an obvious source of blood loss or extreme nutritional deprivation. Anemia commonly accompanies chronic disease and may be mistaken for iron deficiency if only blood counts are measured. In most cases, testing must be done to demonstrate that iron deficiency exists. When iron deficiency has been documented and the cause is not obvious, evaluation by a physician is required to determine whether a hidden source of blood loss or other explanation exists. Iron should never be taken as "shotgun" therapy for anemia, to improve energy or sense of well being, or for any other reason without a prior diagnosis of iron deficiency. The "more is better" concept, in terms of iron consumption, is false and popular icons, such as Popeye swallowing a can of spinach for quick energy, are deceptive.

Managing Iron Excess

Upon consultation with a physician, it may be considered reasonable to control levels of iron that may be excessive and capable of contributing to disease risk. This may be challenging because manufactured foods, such as products produced from cereal grains, are supplemented with iron as government policy. The problem supplementation with iron that is potentially toxic has been addressed unsuccessfully for many years by medical scientists and patient advocacy groups representing individuals with hereditary predisposition to iron accumulation, hemochromatosis. However, their experience with managing iron excess in spite of wide - spread iron supplementation can be helpful for the general population that may also be at risk. Further nformation can be obtained by consulting with an iron overload organization such as the Iron Disorders Institute.

Levels of body iron can be controlled in two ways: by reducing iron intake or increasing iron loss. Although iron is conserved efficiently, small amounts are lost continually as cells slough off the skin and intestinal track. The idea is to match iron intake to iron loss. Iron intake by an unsuspecting public is generally in excess of requirements because of government - mandated iron supplementation of processed foods (such as cereal grains), because of unrestricted access without warning to over-the-counter vitamin and mineral preparations that contain iron and also because of dietary habits.

A study reported in the American Journal of Clinical Nutrition in 2002 provides perspective on factors that contribute to high levels of body iron. This study, conducted in 614 individuals aged 63 to 93, compared patterns of food consumption to levels of the serum ferritin. Ingestion of more whole grain products was associated with lower (more desirable) ferritin levels. High ferritin levels were associated with ingestion of iron supplements (such as iron - containing vitamins), eating four or more servings of red meat per week, and eating over 21 servings of fruit per week. The effect of fruit on elevating ferritin levels is attributable to the fact that the vitamin C in fruit enhances iron absorption into the body.

Managing iron intake. Prescription and over-the-counter medications such as vitamin and mineral preparations containing iron should not be ingested unless iron deficiency has been diagnosed by specific blood tests. The packaging labels on vitamins and nutritional supplements must be read carefully to determine whether the product contains iron and if so how much. Alternatives can be found that do not contain iron. Examples include Centrum Silver and One-A-Day for Men (among others) that are marketed with the recognition that excess iron is unnecessary and potentially harmful. "Sliver" evidently refers to the gray hair of older age. The reference to "men" is misguided; women are also at risk.

Limiting iron intake from processed foods is challenging for several reasons. Avid meat eaters may be disappointed to learn that ingestion of one or two servings of meat per week provides approximately the optimal amount of iron. Iron that is present naturally (usually in small quantities) in vegetables is generally poorly absorbed and relatively safe. Spinach is famous for its relatively high iron content but this iron is mostly not absorbable.

Of concern is supplemented iron. It is impossible to avoid iron - supplemented flour unless prepared by a miller that does not add iron. The iron content of manufactured foods is represented as the percent of the daily requirement on the nutritional information side panel. However, the "daily requirement" used to make the calculation is that of menstruating women who need, on average, about 50% more iron per day than men and post menopausal women. This means that children, men and post-menopausal women are getting far more than the percent of the daily requirement represented on the side panel. Another problem is that it is not possible to determine whether the content of iron represented was added in manufacture or was present in the food (grains, nuts, raisins, etc) from which the cereal was prepared. Cereals with 25% or more of the daily requirement almost certainly have been supplemented with iron. However, it is not difficult to find cereals with 6% or less of the daily requirement. A product that seems to be particularly low in iron is "Rice Crunch-Ems" (Health Valley).

Proper signage in retail outlets should alert customers to select vitamin and mineral products that do not contain iron unless they have been properly diagnosed with iron deficiency. Labeling of manufactured foods should include statement on whether or not iron has been deliberately added to the product and whether the iron content represented in the side panel is that present in the raw food materials from which the product was made. Manufacturers that practice iron supplementation should provide a warning on the label alerting consumers to this fact and to the potential dangers of consuming extra iron in the absence of iron deficiency. As we shall see in the next section, it is also important to label products according to whether they are made with whole grains.

Consideration should be given to ingesting whole grain bread that is prepared without yeast (so called "flat", un-raised or unleavened bread). The germ present in whole grain flours contains a substance called phytic acid (inositol hexaphosphate), which binds iron and individuals who eat more whole grain products tend to have lower (less risky) ferritin levels (see above). Individuals who ingest flat bread for ethnic or cultural reasons tend to have even lower iron levels. Fermentation, which causes bread to rise upon addition of yeast, destroys phytic acid freeing more iron for absorption. Lack of phytic acid plus the addition of supplemental iron may be a particularly disadvantageous combination. The fact that phytic acid and other substances present naturally in foods can limit iron absorption into the body provides hope that simple, inexpensive and safe methods may be devised for population - based limitation of iron accumulation.

Reducing iron levels through intervention. Drugs have been developed that bind iron and increase its removal from the body. Such drugs are used to treat certain cases of extreme iron overload. However, they are expensive and may be toxic, and are not yet appropriate for general use. Medical scientists (particularly in Europe and Asia) continue to develop safer and more effective iron binding drugs that may some day be suitable for general use.

Blood removal is a safe method for rapid and precise iron reduction. Iron loss is natural for menstruating women and iron accumulation following menopause had been proposed to contribute to disease risk following menopause. There is no "natural" source of blood loss in men. Studies comparing frequent with infrequent blood donors have shown significant improvement in several measures of health status with donation of two to three units of blood per year. Interestingly, the amount of iron lost from donating this amount of blood is very close to the amount of iron absorbed in excess of requirements per year in the average individual.

The amount of iron lost by blood donation can be calculated easily. One unit (pint) equals 500 cc of blood. Moving the decimal point one place to the left indicates the amount of iron lost. Thus, removal of 500 cc of blood will lower the ferritin level by about 50 ng/ml. The American Red Cross and other blood collection agencies remove blood in one-unit (500 cc) volumes. However, fractions of a unit may be removed to fine-tune the amount of iron removed from the body. Routine blood donation is a highly desirable and altruistic activity. Whether or not an individual should donate blood can be determined objectively by measuring the serum ferritin. However, the Red Cross has strict rules governing who may donate blood for infusion into another individual and individuals must present themselves for determination of donor eligibility. Drawing blood in calibrated amounts (to be discarded or used for research purposes) specifically to reduce body iron or to prevent its accumulation may become more common in the future as more information becomes available on the usefulness of controlling levels of iron.

It is intriguing to ponder the peculiarities of iron nutrition. Iron does not add to the color or taste of food and does not contribute to the pleasure of eating. Unlike certain other potentially harmful substances, it is not distasteful. Salt and water ingested in excess are eliminated immediately to restore balance but the body does not automatically eliminate excessive quantities of iron that may be harmful. It may one day be shown that our bodies are capable of good health over longer periods of time than most of us now experience simply through avoidance of iron accumulation. One might reasonably conclude that an iron spare state is optimal and that ingestion of excess iron represents an intercept that interferes with an efficiently designed and durable system. Like other public health measures such as maintenance of water purity and sanitary disposal of waste, the problem of iron excess must be first deciphered and the solution implemented through information transfer. This seems worth pursuing because of the potential impact on quality and quantity of life, and the cost of medical care.

Summary

1. Consult with your physician about your health and about testing to determine the amount of iron in your body.
2. Learn to interpret serum ferritin levels. Testing at intervals will show trends in iron accumulation or reduction over time and whether ferritin levels reflect amounts of iron or some other illness apart from amounts of iron.
3. Do not ingest iron or iron - containing products unless you are iron deficient.
4. Learn to read the labels on vitamin preparations. Avoid excess vitamin C that enhances iron uptake.
5. Choose prepared foods (such as breakfast cereals) with the lowest per-cent of the daily requirement of iron. Products with 6% or less of the daily requirement are not difficult to find.
6. Eat a well-balanced diet rich in whole grain products in which red meat is alternated with poultry, fish and vegetarian meals. Avoid one-theme diets such as those with high consumption of fruits.
7. Determine whether you are qualified to be a blood donor and aim to donate about 2 or 3 times each year unless your ferritin falls to near iron deficient levels. This can usually be accomplished by determining the ferritin level about once or twice per year.
8. Learn more about nutrition in general and iron nutrition in particular. Keep track of developments in this field. Return to this page from time to time. Its content will surely change as more information becomes available.

Disclaimer

Various products are mentioned in this text for informational purposes only. The author has no conflict of interest to declare with respect to any product or any other aspect of this text.

Leo R. Zacharski, M.D.
January 1, 2005

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