ROANOKE TIMES
Copyright (c) 1997, Roanoke Times
DATE: Tuesday, March 11, 1997 TAG: 9703110130
SECTION: EXTRA PAGE: 3 EDITION: METRO
COLUMN: PERSONAL HEALTH
SOURCE: JANE BRODY
Generations of Americans have been exhorted to eat spinach or liver for the iron that supposedly made Popeye's muscles bulge or to take iron-rich tonics such as Geritol to revive their ``tired blood.''
But, while some iron in the diet is critical for health and life itself, the overconsumption or overabsorption of this well-known mineral is now under intense scrutiny as a possible cause or contributor to killer ailments such as heart disease and cancer, as well as serious infections.
The story of iron is a classic illustration of ``Just because a little is good does not mean more is better.'' Iron is essential to the formation of the oxygen-carrying pigments: hemoglobin in the blood and myoglobin in the muscles.
But people should not take iron supplements or stuff themselves with iron-rich foods unless medical tests have demonstrated an iron deficiency, those who study iron overload warn.
Some researchers are also concerned about the widespread use of vitamin C supplements, which can enhance the absorption of dietary iron when both are present in the gut at the same time.
Foods and supplements are not the only source of iron. It also can be inhaled, and smokers (tobacco leaves are rich in iron) as well as workers in industries that spew particles containing iron into the air may risk lung cancer in part because their lungs are chronically exposed to excess iron.
The body has only one way to rid itself of iron - bleeding - which is why symptoms of iron overload do not usually show up in menstruating women until after menopause.
For at least 1.5 million Americans who have a genetic disorder called hereditary hemochromatosis, there is no question that even moderate amounts of dietary iron can lead to accumulations of ``rust'' in organs throughout their bodies.
Unless this disorder is identified before it causes serious organ damage and is treated by frequent blood-letting, it can result in such potentially fatal conditions as heart disease, cirrhosis or cancer of the liver as well as thyroid disease, diabetes, arthritis and infertility.
In the early stages of hemochromatosis, symptoms such as chronic fatigue, abdominal pain, impotence and menstrual disruption mimic so many other conditions that doctors often miss the correct diagnosis until vital organs are irreparably damaged.
And because most women menstruate for 30 or 40 years, the problem may not show up in women until after menopause.
Last summer, researchers at Mercator Genetics Inc., a gene discovery company in Menlo Park, Calif., reported identifying the gene that appears to cause hereditary hemochromatosis, a finding that could lead to a simple screening test for this disorder before it results in serious consequences.
There is growing evidence that even people without an inherited disorder can develop problems associated with iron overload. Iron is a catalyst for the formation of free radicals, highly active chemicals that are implicated in heart disease, cancer and the aging of cells.
Dr. Eugene D. Weinberg, a professor emeritus of microbiology at Indiana University in Bloomington who has studied the effects of iron for three decades, is one of several researchers who have warned that an overabundance of iron could be undermining the health and shortening the lives of millions of Americans.
In an interview, he pointed out that both cancer cells and infectious organisms need iron from their host to grow. Cancer cells can live in a semidormant state for a long time, he explained, but they cannot multiply without iron and oxygen from blood.
As for heart disease, a study conducted among 1,900 middle-aged men in Finland indicated that a high iron level was second only to smoking as a cause of heart attacks. Although three American studies failed to confirm or refute this finding, the methods used in these studies were less precise.
The Finnish researchers found that the greatest risk of having high iron occurred in men with high cholesterol levels. In those with low cholesterol, iron had no impact on the risk of heart attack.
A person's iron status can be checked through several blood tests. The most useful is a ferritin test, which can be done as part of a routine blood test.
-New York Times Syndicate
LENGTH: Medium: 80 linesby CNB