Using these two criteria, we'll explore why stainless steel and cast iron are your best choices. But first, let's review why aluminum, copper, and non-stick cookware are types we choose not to use.
Cookware to avoid
Aluminum cookware
Cookware made from materials that carry with them substantial risk of toxicity, even if research shows relatively little leaching of their toxic substances, should automatically not be considered to be among your best options. We would put aluminum cookware into this category. In the past five years, we've seen over 100 studies about aluminum and disease. This metal has consistently been placed in the top 200 health-jeopardizing toxins by the ATSDR (Agency for Toxic Substances and Disease Registry) at the U.S. Department of Health and Human Services.
We realize that many improvements have been made in aluminum pots and pans with the advent of anodized aluminum (in which a thicker aluminum oxide layer is created on the surface of the pan). Yet, we still recommend avoidance of aluminum cookware due to the potential toxicity of aluminum itself. (This focus on the health aspects of aluminum cookware does not even take into account environmental problems related to the mining and dressing of aluminum.)
Non-stick cookware
Pots and pans with non-stick coatings are another type of cookware we would put into this category of toxic materials risk. The non-stick coating industry started out with Teflon in 1946 but has since grown to include many other coatings including Silverstone, Tefal, Anolon, Circulon, Caphalon and others. Products like Calphalon actually combine aluminum with non-stick materials by subjecting anodized aluminum to a polymer infusion process. We do not like to use cookware with non-stick surfaces.
Copper cookware
Pots and pans made from 100% copper fall into a slightly different category. Even though it is also a metal on the ATSDR priority toxin list just like aluminum, copper is an essential mineral that is currently deficient in many U.S. diets. Its essential nutrient status makes it different from aluminum, and some people include it as a desirable cookware material for this reason.
We take a somewhat conservative approach here since we don't like the idea of cooking directly on a copper surface due to potential (however slight) risk of copper toxicity. Adults need approximately 900 micrograms of copper per day, according to the Dietary Reference Intakes (DRIs) established by the National Academy of Sciences. The Tolerable Upper Limit (UL) for copper is about 10 times that amount, at 10,000 micrograms (the same as 10 milligrams). While you're very unlikely to get that amount of copper migration from your cookware into your food (even under highly acidic conditions that increase leaching), we prefer to avoid all possible risk.
Recommended cookware
Stainless steel
With stainless steel, you get a cooking surface that can include some less risky materials than aluminum or non-stick coatings (such as the essential minerals iron, chromium, and manganese). It is is also more stable and less prone to leaching. While some research has expressed concern about leaching of chromium from stainless steel, this mineral is both essential and currently deficient in the diets of many U.S. adults. Based on the research, we believe the health risk here is less than the risk posed by leaching of another essential mineral, copper, from the surface in a 100% copper pan.
Stainless steel pans often have an inner core of aluminum or copper (and some have a copper-clad bottom). The reason this is done is because these two metals are very efficient heat conductors. Since the aluminum or copper is sandwiched between layers of steel and neither come in contact with the food, we think that these types of stainless steel cookware are fine to use.
What some cite as a concern for stainless steel is the leaching of nickel, a potentially toxic metal fairly high up on the ATSDR list of priority toxins. Yet, because the alloy (combination of metals used) in stainless steel cookware is more stable than other cookware materials you are less likely to have any leaching, of any metal, including nickel. An exception would be stainless steel pots and pans that have been damaged by harsh scouring with an abrasive material like steel wool. Provided that you take good care of your stainless steel cookware and keep the cooking surfaces intact, we believe you are making an excellent choice in cookware with this material.
Cast iron
Cast iron is also a cookware material we really like. When properly seasoned, the surface itself is great for cooking, and when material does leach from cast iron, it's an essential mineral (iron) that many of us can easily incorporate into a healthy day of mineral intake. For some individuals, cast iron cookware can actually make a very important contribution to health. An exception would be individuals who may be at risk of iron overload. If you already have plenty of iron in your diet, in your bloodstream, and attached to storage proteins in your cells, you do not want to be adding leached iron from cast iron cookware. You may want to visit an iron disorders website like www.irondisorders.org or www.ironoverload.org to learn more about potential risk factors in this area.
The bottom line
Our favorite all-around cookware pieces are those made from stainless steel or cast iron. More than likely, the stainless steel cookware will have a core made from aluminum or copper since these metals are efficient conductors of heat. While we don't recommend cookware that features aluminum or copper as the cooking surface, stainless steel cookware with cores (or even bottoms) made from these materials are acceptable. That's because if you take care of your pots and pans and don't excessively scrub them, the copper or aluminum will not come in contact with your food.
Cast iron is another type of cookware we recommend. Even if some of the iron leaches from the cookware into your food, in most cases this is acceptable since many people can easily incorporate iron into a healthy day of mineral intake.
We like to avoid pans with non-stick coatings as well as those made from anodized aluminum.