Cast iron pans have been used for hundreds of years to sear, saute, roast, stew and bake an array of food items. While the versatile pan is a favorite among chefs, you may have concerns about the side effects of iron utensils if you're worried about iron overload.
Too much iron is a concern for people with hemochromatosis, a medical condition which increases iron absorption from food and can lead to life-threatening problems. There's also evidence that too much iron in the blood increases risk of cancer. However, while you may consider these health concerns to be disadvantages of cast iron cookware, the use of iron utensils may not have much of an effect in either case.
When it comes to health, there are very few dangers with the use of cast iron pans. In fact, the pan may promote health by increasing the iron content in your food, a benefit for children and premenopausal women.
Cooking in Cast Iron Pans
Cast iron cookware may take a long time to heat to the proper cooking temperature, but provides an even source of heat after it is hot, according to Utah State University Extension. The metal pots are also able to withstand very high temperatures, which makes them ideal for searing meat to lock in flavor.
However, the iron in cast iron pans causes a chemical reaction with high-acid foods, such as tomatoes and wine, which may oxidize the pan. But if you season your cast iron pan well prior to cooking anything acidic, you can prevent this reaction. Properly seasoning your cast iron pan also prevents the cookware from rusting.
To season your cast iron pan, coat the entire pain (inside and out) with oil or shortening and bake in the oven at 400 degrees Fahrenheit for an hour, suggests the West Virginia Department of Agriculture. You will need to re-season it periodically to maintain the quality of your cast iron pan. The frequency of your seasoning may depend on how often you use your cast iron cookware.
Side Effects of Iron Utensils
One of the side effects of iron utensils, which can be good and bad depending on your needs, is that it may add iron to your food. Iron is an essential mineral your body needs to make red blood cells. An adequate intake of iron also supports physical growth and neurological development in children and teens.
Not getting enough iron in your diet may lead to iron-deficiency anemia. Children, pregnant women and premenopausal women are at greatest risk of not getting enough iron to meet their needs, according to the Office of Dietary Supplements. Your daily iron needs vary based on your age and gender:
- Infants birth to 6 months (both genders): 0.27 milligram
- Infants 6 to 12 months (both genders): 11 milligrams
- Children 1 to 3 years (both genders): 7 milligrams
- Children 4 to 8 years (both genders): 10 milligrams
- Children 9 to 13 years (both genders): 8 milligrams
- Male teens 14 to 18 years: 11 milligrams
- Female teens 14 to 18 years: 15 milligrams
- Males 19+ years: 8 milligrams
- Females 19 to 50 years: 18 milligrams
- Females 51+ years: 8 milligrams
- Pregnant women: 27 milligrams
- Lactating women: 8 to 9 milligrams
Women of childbearing years have higher iron needs than men due to blood loss from menstruation.
The amount of iron added to the food from cast iron utensils depends on the moisture, acidity and length of cooking time. According to the advice site Go Ask Alice at Columbia University, cooking 100 grams of tomato sauce in a cast iron pan increases iron content from 0.6 milligrams to 5.7 milligrams. The significant increase in iron may be due to the long cooking time needed to make tomato sauce, as well as its high acidity content.
By comparison, the iron content in hamburgers, cornbread or liver and onions doesn't increase as much, according to Go Ask Alice. This may be due to a shorter cooking time or the frequent turning needed to cook some of these foods.
A November 2018 study published in the Journal of Public Health and Nutrition examined the differences in iron content in chickpeas and beets cooked in a non-iron pan versus a cast iron pan. The researchers found that cooking in a cast iron pan increased iron content in both the chickpeas and beets.
In the cast iron pan, 5 grams of chickpeas contained 0.06 milligram of iron versus 0.053 milligram when cooked in the non-iron pain. The same serving of beets contained 0.0081 milligram after cast iron cooking versus 0.007 milligram after cooking in the non-iron pan.
Additionally, the authors of the study from the Journal of Public Health and Nutrition noted that the method used for cooking didn't alter the taste or appearance. The authors suggested that, in addition to being a less expensive cooking tool, the side effects of iron utensils would benefit those at risk of not getting enough iron in their diet.
Hemochromatosis Cast Iron Cooking
Many groups benefit from getting more iron in their diet, including women and children. But too much iron in the diet isn't good for everyone, such as those with hemochromatosis, which may be viewed as one of the disadvantages of cast iron cookware.
Hemochromatosis causes your body to absorb an excessive amount of iron from food, according to the Mayo Clinic. Your body then stores the excess iron in your liver, pancreas and heart, which increases risk of liver disease, diabetes and heart disease.
The primary treatment for hemochromatosis includes regular blood draws, not an iron-restricted diet. According to the National Institute of Diabetes and Digestive and Kidney Disorders, if you have hemochromatosis the only recommended diet change is to consume moderate amounts of red meat and organ meats. In addition to being high in iron, these meats also contain heme iron, which is better absorbed than the non-heme iron found in plant foods.
Limiting your intake of alcohol is also recommended if you have hemochromatosis in order to reduce the risk of liver damage.
If you have hemochromatosis, you also need to avoid the use of iron and vitamin C supplements. While the Iron Disorders Institute suggests that you cook with glass or ceramic cookware when your iron levels are high, there are no restrictions on the type of cookware you use when your iron levels are within normal range.
Too Much Iron and Cancer
Due to its oxidative activity that can lead to DNA damage, it's been suggested that too much iron in your blood may increase your risk of certain types of cancer.
According to a January 2014 meta-analysis and epidemiological study published in Cancer Epidemiology Biomarkers & Prevention, which included a total of 56 studies, researchers found an association between high intakes of heme iron (iron from animal sources), high serum iron levels and cancer. However, the researchers recommended more studies to further evaluate cause and effect.
Soon thereafter, another study also found an association between iron and cancer. This November 2014 epidemiological study published in Cancer Research included 309,443 participants, and it found that high serum iron was a risk factor for certain types of cancer, including liver and breast cancer.
As cast iron pots are a potential source of iron in your diet, this may be viewed as one of the disadvantages of cast iron cookware. However, as previously noted, the amount of iron added to food from the iron utensil may depend on the food being prepared. Additionally, your medical history and the sources of iron (heme versus non-heme) that you consume may play a role in your serum iron levels.
- Office of Dietary Supplements: "Iron"
- Columbia University: Go Ask Alice: "Does Cooking With Cast Iron Pots and Pans Add Iron to Our Food"
- Journal of Public Health Nutrition: "Effect of Cooking Utensil on Iron Content of Food"
- Mayo Clinic: "Hemochromatosis"
- National Institute of Diabetes and Digestive and Kidney Diseases: "Hemochromatosis"
- Iron Disorders Institute: "Frequently Asked Questions (FAQs)"
- Cancer Epidemiology Biomarkers & Prevention: "Iron and Cancer Risk—A Systematic Review and Meta-Analysis of the Epidemiological Evidence"
- Cancer Research: "High Serum Iron Is Associated With Increased Cancer Risk"
- West Virginia Department of Agriculture: "Cast Iron Cookbook 2: Today and Yesterday"
- Utah State University Extension: "Cooktops and Cookware"
- Utah State University: Summit County Extension: "Dutch Oven Cooking"