A mutation in a gene that regulates the body's handling of iron increases the risk of dying from heart disease. The finding supports the results of previous studies, which suggested that high levels of iron increased the risk of heart disease. Humans have two copies of HFE, the gene that controls the body's storage of iron. Abnormalities in both copies result in a condition called hemochromatosis, in which abnormally high levels of iron accumulate in the body, resulting in dysfunction of several organs.

Those with an abnormal iron gene faced a 52% increased risk of heart attack with each 100 microgram increase in ferritin, while the risk in those with normal iron genes varied little with ferritin concentration. Male carriers of the common hemochromatosis gene mutation are at 2-fold risk for first (heart attack) compared with noncarriers. Carriers are a large part of the population. Something like 10% to 30% of the population carry at least one gene for hemochromatosis. Full-blown hemochromatosis affects about 1 in 200 individuals. Carriers almost universally don't know that they are at increased risk... They have almost no increase in iron stores, but that small increase is significant and that small increase is probably what caused the increased incidence of heart disease deaths.

Circulation: Journal of the American Heart Association September 21, 1999;100.

COMMENT: One should never take iron supplements unless a professional has diagnosed them with iron deficiency. This is usually done by a serum ferritin level lower than 20. If one already has elevated ferritin levels (above 80) then lowering iron stores by regular blood donation could reduce the risk of heart disease, especially among individuals with the abnormal iron gene.