Q. What is iron?
A. Iron is the major element on earth, making up 35 per cent of the earth's interior. Iron and its alloys, such as steel, are familiar substances to everyone, In the body, iron is involved in energy production and other important functions.
Q. What role does iron play in the body?
A. Four atoms of iron are present in every molecule of the hemoglobin which carries oxygen throughout the body. Since oxygen is required in every cell to produce energy, iron is the backbone of energy production. Iron is also part of oxygen-carrying proteins (my globins) in the muscles. Iron occurs in various enzymes and is-involved in the production of thyroid hormones (which regulate many metabolic processes), in the production of connective tissues, in the maintenance of the immune system and in the production and regulation of several brain neurotransmitters
Q. I thought you said earlier that oxygen was harmful to the body, but now you're telling me that it is an important part of energy production. How do you explain that?
A. Oxidative reactions are vital for life, but can be harmful if they go beyond what is necessary for energy production. Oxygen can generate harmful free radicals, which, you'll recall, can damage cells.
Q. Can you have too much iron in your body?
A. Yes. Several conditions are characterized by an excess of iron. One condition, called haemochromatosis, is a genetic disorder in which there are excessive deposits of iron in the liver, heart, pancreas, skin and other organs, all of which are subject to serious damage from free radicals generated by the iron. Haemochromatosis is considered to be fairly rare, but some researchers think it is simply under-diagnosed. A simple blood test to check for this condition measures serum feiritin, the stored form of iron.
Q. Can you get too much iron from supplements or from eating iron-rich foods?
A. If you have haemochromatosis, getting too much iron from supplements, iron-enriched foods can become a problem. However, normal people don't usually develop high levels of iron because their intestines absorb less and less of it as iron levels reaches optimum amounts in the blood.
Q. Has too much iron been associated with any other health problems?
A. One study from Finland suggests that even as small as a I per cent increase in iron levels can cause a 4 per cent increase in the risk of heart attack. Most scientists, however, believe it is too soon to draw any definitive conclusions about iron's effects on the risk of heart disease.
Q. How would high iron levels contribute to heart disease?
Researchers think high levels of iron cause increased oxidative damage to the heart and blood vessels and, perhaps, increased oxidation of LDL cholesterol, which then begins to clog arteries.
Q. What about cancer? Are high iron levels associated with an increase in cancer?
A. Animal studies suggest that, depending on the conditions, iron can either enhance or inhibit tumor development. Iron is necessary for the division of cells and, in some animals; iron deficiency has been shown to slow tumor growth. On the other hand, in population studies, iron deficiency has been associated with an increased risk of cancers of the throat and stomach. This doesn't necessarily mean that it causes them. Iron-deficient people are likely to have other problems. Research is going on to see if higher-than-normal body stores of iron increase a woman's risk of developing breast cancer.
Q. Don't some athletes take extra iron to boost their performance?
A Unless you are running low on iron, extra amounts of this mineral do nothing to improve athletic performance. Iron deficiency is associated with muscle weakness and reduced stamina, however, and this weakness and loss of stamina apparently can occur even though iron levels have not dropped low enough to cause anemia. Studies in women suggest that moderate exercise does not deplete iron stores.
Q. Do most people get enough iron?
A. No. Dietary surveys show that many people don't get enough iron to meet their needs, with 32 per cent of people getting less than 70 per cent of the RNI. Menstrual blood loss is an important way of losing iron from the body. Iron deficiency is the most common nutritional deficiency in some Western countries.
IRON
QUICK-REFERENCE GUIDE
RNI
Men; women aged 50 or older; 10 mg Women aged I I -50: 15 mg
Sources
Liver, meats, beans, nuts, dried fruits, poultry, fish, whole grains or enriched cereals, and most dark green, leafy vegetables.
Signs of Deficiency
Anemia, fatigue, rapid heartbeat, breathlessness, inability to concentrate, sluggishness, disturbed sleep, impaired immune response; menstrual symptoms, including behavioral changes and autonomic effects (such as sweating and dizziness), decreased efficiency, poor performance at work or school and increased daytime sleepiness.
Iron-deficiency anemia has been implicated in emotional, social and learning difficulties in children and adults.
Iron deficiency has also been associated with the Plummer-Vinson syndrome. In this condition, a thin web-like membrane grows across the top of the oesophagus, making it difficult to swallow. This syndrome used to be fairly common in Sweden but has been almost completely eliminated by the use of iron supplements.
Risks for Deficiency
Infants, children and teenagers, especially girls; women of childbearing age, as menstruation, pregnancy and lactation all draw on the body's iron stores.
Possible Toxicity Problems
Constipation is the most common side-effect associated with iron supplements^ Children who eat tablets containing iron supplements may end up in a hospital emergency room, as large doses are poisonous. Sugar-coated iron tablets intended for anemia treatment are even more dangerous. However, advances in treatment have virtually eliminated childhood deaths by iron poisoning.
High body levels of iron may be associated with an increased risk of heart disease and, possibly, cancer. The risk of getting too much iron from foods is quite low. However, the risks of long-term use of moderate-to-high doses of iron (25 to 75 mg a day) are unknown, don’t take chances.
