Does cast-iron really add iron to the cooked foods?

[Avumede]

Some say yes it does give you extra iron in the food you cook in it. Some say no it doesn’t, perhaps because the seasoning in the cast iron pan forms a layer that prevents this. What’s the straight dope on this?

[Whack-a-Mole]

It would seem that the answer to this is yes…you do get a metal intake from cookware.

The following quotes come from http://www.urbanlegends.com/medical/cast_iron_poisoning.html

Kuligowski J. Halperin KM.
Stainless steel cookware as a significant source of nickel, chromium, and iron.
Archives of Environmental Contamination & Toxicology. 23(2):211-5, 1992

“Stainless steels are widely used materials in food preparation and in home and commercial cookware. Stainless is readily attacked by organic acids, particularly at cooking temperatures; hence iron, chromium, and nickel should be released from the material into the food. Nickel is implicated in numerous health problems, notably allergic contact dermatitis. Conversely, chromium and iron are essential nutrients for which stainless could be a useful source. Home cookware was examined by atomic absorption spectroscopy: seven different stainless utensils as well as cast iron, mild steel, aluminum and enamelled steel. The materials were exposed to mildly acidic conditions at boiling temperature. Nickel was a major corrosion product from stainless steel utensils; chromium and iron were also detected. It is recommended that nickel-sensitive patients switch to a material other than stainless, and that the stainless steel cookware industry seriously consider switching to a non-nickel formulation.”

Reilly C.
The dietary significance of adventitious iron, zinc, copper and lead in domestically prepared food.
Food Additives & Contaminants. 2(3):209-15, 1985

“The uptake of iron, zinc, copper and lead by food cooked under domestic conditions in utensils made of different metals (cast iron, aluminium, plain and tinned copper) was investigated. It was found that the metal content of the food was generally related to the metal in immediate contact with the food during cooking. Daily dietary intake could vary from 11 to 6 mg of iron, 11 to 9 mg of zinc, 2 to 1 mg of copper and 0.4 to 0.1 mg of lead, depending on the cooking utensils used. . . . The nutritional and toxicological significance of such adventitious sources of metals in the diet are discussed. The need to consider them when investigating the metal intake of individuals is stressed.”

[akrako1]

Mmmm… doesn’t all this info just make you want to run out and buy some non-stick cookware?? I’m sure those long petrochemical name will go down well with my fries.

BTW - this is why I only use cast iron frying pans.

[Avumede]

That’s good info Whack-a-Mole. According to the link, it suggests that it may have trace amounts. Incidently, in Harold McGee’s On Food and Cooking, he relates that a group of Africans had some horrible iron poisoning brought about by brewing beer in cast iron containers. That seems fairly far removed from cooking foods briefly in a seasoned cast iron container, so I don’t think it’s too relevant.