Consumer Magazine:

The all-time classic is cast-iron cookware. It's been with us for nearly 3,000 years, since it was first used in China to cook rice, and remains a staple among the glamorous additions in cookware stores. Cast iron is strong, inexpensive, and it?s an even conductor of heat for browning, frying and baking foods.

Cooking with cast iron also provides a source of an important nutrient. Some nutritionists suggest that foods cooked in unglazed cast iron contain twice or more the amount of iron they would contain otherwise.

Cast-iron utensils should be handled differently from other utensils. To prevent rust damage, the inside of cast iron cookware should be coated frequently with unsalted cooking oil. It should not be washed with strong detergents or scoured and should be wiped dry immediately after rinsing.

Source:

Article: FDA Consumer Magazine - Is That Newfangled Cookware Safe?
Author: Dale Blumenthal
http://findarticles.com/p/articles/mi_m1370/is_n8_v24/ai_9073336/ (11.07.2011)

To help the blood …., you can add extra iron to your diet by cooking food in a cast iron frying pan. Iron helps oxygen attach to the hemoglobin in your blood for delivery to the cells which require fresh oxygen. By adding iron to your diet naturally from colloidal minerals and cooking in a cast iron frying pan, you will be assisting the blood. When you cook in a cast iron frying pan, the iron leeches out of the pan into the food you are cooking. I am not saying to fry everything in a cast iron pan but if you need to make spaghetti sauce, make it in the cast iron pan. If you are warming pizza up, warm it slowly in a covered cast iron pan.

Source:

Source: http://www.cancer-info.com/ 14.07.2003