People who tuck into fortified breakfast cereals may actually be causing themselves more harm than good, according to a study by government researchers published in the June edition of the Journal of the American College of Nutrition 2001 (pp. 247-254).

Many of the enriched products actually contain more of the nutrients than it states on the labels and studies have shown that getting too much of nutrients such as iron and folate can be harmful. The problem is exacerbated by the fact that most consumers eat more than the recommended portion size.

Together with colleagues from the FDA's Center for Food Safety and Applied Nutrition in Washington, Dr Paul Whittaker compared nutrition information from the labels of 26 ready-to-eat cereals and three hot cereals with a chemical analysis of the actual amounts of iron and folate the cereals contained.

Of the cereals, 14 of the 27 that listed folate as an ingredient on their labels were actually found to contain over 150% the amount listed. While folic acid is a useful part of a pregnant woman's diet, researchers point out that too much folate can hide anaemia.

Twenty-one of the cereals were found to contain 120% or more of the amount of iron specified on the label, and according to a spokesperson from the FDA, "higher iron status in males may be associated with an increased risk for cancer and heart disease".

The Food and Nutrition Board of the National Academy of Sciences recommends that the daily intake of iron is 18mg. For folic acid, it recommends a daily value (DV) of 400 micrograms.

The scientists are concerned that actual intakes of iron and folate can be increased dramatically, after their studies confirmed that people tend to serve themselves more than two times the portion size recommended on the cereal box.