Does cooking with cast iron pots and pans add iron to our food?

Dear Martha,  

Get pumped—it's time to talk about iron! 

When you hear the term pumping iron, you might think of bodybuilders or gym rats lifting big weights. However, iron is also an important mineral that the heart needs to pump oxygen throughout the body to keep you strong. Using cast-iron pots and pans can help add iron to food, but there are also lots of iron-rich food sources that you can add to your diet that may help to increase your iron intake.  

What is iron and what is the recommended daily intake?  

Iron is a mineral that the body uses to grow and develop. Your body uses iron to make hemoglobin and myoglobin, the proteins in red blood cells that carry oxygen to muscles throughout the body.  

The recommended maximum iron intake is 45 milligrams (mg) for most healthy adults and 40 mg for healthy children. Many people get sufficient iron by incorporating iron-rich food into their diet. That said, some groups of people may be more at risk of having an iron deficiency and therefore might need to consume more iron daily to ensure proper bodily function. These groups of people may include: 

• People who menstruate. This group may need to get more iron daily than those who either don’t menstruate or have stopped menstruating because of the blood they lose during their period.
• Vegetarians. Vegetarians may need almost twice the amount of iron as people who eat meat because the human body isn’t as effective at absorbing iron from plants as it’s from animal products.  
• Pregnant people. Growing a human can put a significant amount of strain on the body's ability to take in nutrients. As such, pregnant people might need more than the standard recommended amount of iron because their body needs to produce more blood to support the placenta and growing fetus.  

What are ways to increase iron consumption through food?  

Some everyday foods are real heavyweights in disguise when it comes to iron content. You may be able to meet your recommended daily iron intake by eating foods such as:  

• Lean meat, seafood, and poultry
• Iron-fortified breakfast cereals and breads
• White beans, lentils, spinach, kidney beans, and peas.
• Nuts and some dried fruits, such as raisins  

List adapted from National Institutes of Health  

The human body is better at absorbing iron from plant-based sources when they’re eaten alongside animal-based sources. If you’re vegetarian, you can maximize your body’s iron absorption by eating plant-based sources alongside vitamin C-rich food like citrus fruits, sweet peppers, tomatoes, broccoli, and strawberries. Pairing foods that help with absorption can help your body Fe-el the benefits (Fe is the shorthand for iron on the periodic table). 

Can cooking in an iron pan increase the iron content of food?  

Yes, cooking with iron cookware can be an additional way to increase your iron intake. This strategy works when the acids in food interact with the iron in the cookware, leading to a small release of iron into the food. The body can absorb the released iron when eating food cooked on iron cookware.  

The amount of iron absorbed depends on the food being cooked and how it’s prepared. You’ll get the greatest amount of iron absorption when cooking something acidic at a high temperature for an extended period of time. For example, a tomato-based stew that’s left to cook for a while would likely absorb more iron than an egg that’s quickly fried in an iron pan. Depending on the cooking circumstances, there’s some evidence that cooking in an iron pan may add enough iron for healthy, non-menstruating people to meet their minimum daily recommended intake. 

Is it possible to have too much iron?  

Yes, it’s definitely possible to have too much of a good thing. If you’re consistently consuming too much iron, you might develop an inflamed stomach lining and be at a greater risk for stomach ulcers. Overconsumption of iron can also make it harder for your body to absorb zinc, another mineral that’s important for growth, development, and the immune system.  

Increased iron consumption may be especially dangerous for people who have hereditary iron overload disorders, the most common of which is called hereditary hemochromatosis. This condition makes it difficult for the body to figure out how much iron is already in the blood. This means the body may continue to absorb iron even after you’ve consumed enough. Too much iron built up in the body may eventually lead to organ damage. 

What happens if you don’t consume enough iron? 

If your body’s not getting enough iron, you might develop iron-deficiency anemia. When you’re anemic, your red blood cells shrink, and as a result, contain less hemoglobin. This leads to the blood carrying less oxygen throughout the body. The symptoms of anemia include tiredness and lack of energy, shortness of breath, problems with concentration and memory, and gastrointestinal (GI) system upset. When your iron’s low, even getting off the couch can feel like lifting weights—without the gym gains.  

If you do find that you’re iron deficient, a health care provider might recommend increased iron intake or prescribe an iron supplement for a short period to raise those levels. 

What can you do if you're concerned about your iron intake?  

If you’re concerned about your iron intake, you might consider reaching out to a health care provider to understand what the daily intake recommendations are for your body, sex-assigned at birth, and lifestyle. They can also provide more information on iron-deficiency anemia if you notice symptoms, or if they run tests and find that you’re anemic.  

Cooking with cast iron cookware can be an additional way to increase your iron intake. However, the amount of iron absorbed through cooking is unpredictable. So, if you need to increase your iron intake, consider incorporating more iron-rich foods into your eating plan to ensure that you’re getting the recommended amounts of iron.  

Hope this ironed out some of your confusion!