Several studies have shown that high blood levels of iron are associated with an increased risk of suffering heart attacks and cancers, particularly those of the esophagus and bladder. A study from Harvard showed that it may be the meat source of iron, rather than just the iron itself, that causes the heart attacks and cancers.

People who eat a lot of meat, fish and chicken have higher blood levels of iron than vegetarians. The iron in meat, fish and chicken is called heme iron, which is absorbed at a very high level, around 10-20 percent. On the other hand, the iron that you get from plants is absorbed very poorly; only one to three percent of the iron from leafy green vegetables and other plant sources of iron is absorbed.

Even though there is an association between high iron levels and cancer and heart attacks, we do not know if the iron causes these diseases. You can find out if your iron level is too high by asking you doctor to draw blood for a test called transferrin iron binding saturation. People with a transferrin iron binding saturation of more than 60 percent are at increased risk for developing heart attacks and cancers. If your level is greater than 60 percent, you can reduce your intake of iron by restricting meat, fish, chicken and iron-supplemented foods, and you can get rid of extra iron by donating blood six or more times a year.

Hemochromatosis is an inherited condition in which a person stores too much iron. It is easily treated by donating blood periodically, and when that is done the person will lead a perfectly normal life. Problems only occur when the condition is not diagnosed.

Gabe Mirkin, M.D.

Dr. Gabe Mirkin has been a radio talk show host for 25 years and practicing physician for more than 40 years; he is board certified in Sports Medicine and three other specialties.

Dr. Mirkin's daily features on fitness have been heard on CBS Radio News stations since the 1970's. He has written 16 books including The Sportsmedicine Book, the best-selling book on the subject that has been translated into many languages. His latest book is The Healthy Heart Miracle, published by HarperCollins.

Dr. Mirkin is a graduate of Harvard University and Baylor University College of Medicine. A Boston native, Dr. Mirkin did his residency at the Massachusetts General Hospital. He has served as a Teaching Fellow at Johns Hopkins Medical School, Assistant Professor at the University of Maryland, and Associate Clinical Professor in Pediatrics at the Georgetown University School of Medicine. He has run more than forty marathons and is now a serious tandem bicycle rider with his wife, nutritionist Diana Mirkin.