Too Much Dietary Iron a Cancer Risk for Some

The combination of high iron stores in the body and a high iron intake from food could raise a person's risk of cancer, a new study suggests.

Researchers estimate that up to 10 percent of Americans have iron stores high enough that, when coupled with excessive iron intake, could increase their likelihood of developing cancer.

The study, involving a nationally representative sample of U.S. adults, looked at a measure called transferrin saturation. Transferrin is a protein that transports iron through the body, and transferrin saturation levels in the blood are an indicator of the body's iron stores.

Research has linked excessively high transferrin saturation to an elevated risk of death from any cause, and possibly to an increased cancer risk. In general, the evidence has suggested that transferrin saturation levels of 60 percent or higher -- found in about 1 percent of the U.S. population -- may present a cancer risk.

However, the new findings implicate lower levels of transferrin saturation -- 41 percent or higher -- that are seen in about 10 percent of Americans.

The findings are published in the current issue of the Annals of Family Medicine.