Do you get dietary iron from cooking in cast iron?
Posted by: Gina Misra | Date: October 15, 2020
Cast iron cookware is great. It's durable, long lasting, it retains it's temperature, and you can even use it over an open fire. Vegetarians are sometimes told that cast iron cookware is also a way to get iron in your diet. So, we decided to look at the science and figure out if there's anything to it.
But first, let's go to dietary iron school. What does iron do? How much do we need? What foods does it come from?
Iron is needed so our red blood cells can carry oxygen to our tissues. It's an incredibly important nutrient. Men need 8.7 mg a day. Women need 14.8 mg a day during child-bearing years and 8.7 mg after menopause.
Iron is a mineral. It comes in two forms - "heme" iron and "non-heme" iron. Heme is a protein that is part of the molecule "hemoglobin," which is what makes blood red and carries oxygen around the body. Heme iron is iron bound to this molecule, while non-heme iron is free floating. Our body absorbs heme iron better than non-heme iron. Cast iron cookware and plant foods provide non-heme iron, while animal foods like meat provide heme iron.
Studies from the 90s suggest cast iron cookware may be a source of dietary iron. But more research was needed.
So, in 2007, scientists conducted an experiment where they prepared rice and tomato sauce in cast iron for 65 vegetarian college students daily for 12 weeks. The experiment showed that the iron content of the tomato sauce increased from 13 mg/kg to 65 mg/kg and the iron content of rice increased from 2 mg/kg to 7 mg/kg when cooked in cast iron over a glass pan. However, the participants only had small increases in blood levels of iron. The scientists concluded that more acidic and liquidy foods are likely to take up more iron from pans.
In 2019, some scientists read everything they could about this subject, to see if this might benefit women and children with anemia. From the data of 11 different studies, they found that about half of the time, women and children showed improvements in their iron status when using cast iron cookware.
So it looks like there is actually some evidence to support the idea that you can get iron from cookware if you don't eat meat. It is chemically the same iron that you would get from iron rich vegetables like leafy greens, microgreens, tomatoes, and mushrooms. Worth a try!