Bustin’ nutrition myths: Cooking in microwave ovens, in aluminum pots, and what about teflon?

Some urban legends refuse to die. According to Dictionary.com, an “urban legend” is a modern story of obscure origin and with little or no supporting evidence that spreads spontaneously in varying forms and often has elements of humor, moralizing, or horror.

Although myths typically contain specks of truth, let’s put some scientific facts alongside these myths and put them to bed.

Myth #1: Microwaving food makes it toxic

The movie American Hustle features a hilarious scene — Rosalyn (Jennifer Lawrence) microwaves some leftovers covered with aluminum foil. Ka-BOOM! She rants to her husband, “You shouldn’t have brought it into the house in the first place! Don’t you know it leaches out the nutrition?!”

Just like zombies, the microwave myth refuses to die. One of the many myths circulating on the Internet is that microwaving food or water causes the formation of “radiolytic compounds,” new chemicals created by the “tearing apart of molecules.” Depending on the version of the microwave myth, these chemicals are said to be “cancerous,” “radioactive,” “unnatural,” or…. well… you fill in the blank.

The exploding microwave in American Hustler.

Of course, food cooked in a microwave oven does not become “radioactive” and neither does water. Just like when you turn off the light bulb no light remains, so it is that when your food is cooked, no microwave energy remains in the oven…or in your food. All microwaving does is cause the molecules in food to move, and very quickly. The molecular motion is what causes the heat.

As far as changing the chemical composition of food, consider this: what happens to food when you bake, broil, sauté, or otherwise apply heat to it?  All cooking methods change the nutrient value of foods, and in fact, often cooking makes nutrients more bio-available.

I stand by my recommendation to enjoy the convenience of a microwave oven. And in some instances, microwave cooking can actually be healthier! Far from “leaching out nutrients,” microwaving food generally preserves more nutrients, mostly because cooking time is shorter and the food can be cooked in less water.

The grain of truth: Some containers are absolutely NOT recommended for microwave cooking. Just like you wouldn’t put a plastic or Styrofoam take-out container into the regular oven to reheat your food, never use these in a microwave oven either. Use glass or ceramic containers. Even if plastic cookware is labeled “manufactured for microwave oven use,” don’t do it.

Don’t ever use metal in a microwave. Microwaves pass through plastic, glass and ceramic, but metals reflect them. Thin pieces of metal like aluminum foil or the tines of a fork can act like an antenna, and the waves can cause sparks. Learn more about microwave ovens here.

Myth #2: Drinking out of aluminum cans or cooking with aluminum pots and pans leads to Alzheimer’s disease.

The Alzheimer’s Association experts report that during the 1960s and ‘70s, aluminum emerged as a possible suspect in Alzheimer’s disease, a theory debunked with studies showing no link between everyday exposure to aluminum pots and pans, beverage cans, antacids, and antiperspirants. The minute amounts of aluminum that may be transferred from the pan to the food have not been shown to be dangerous under normal conditions.

Milk is often carried to market in aluminum containers.

The grain of truth: Cooking highly acidic foods like tomatoes, citrus, and vinegar can react with aluminum. The amount of aluminum that might leach into the food is minimal, however, it can make your food taste metallic.

But if you’re concerned, and don’t want to buy multiple pots and pans, anodized aluminum cookware is a good bet. Anodized aluminum is electrochemically processed to seal the aluminum in the cookware and it’s fairly nonstick (except for eggs, I’ve found).

Other good cooking options include stainless steel, cast iron, and ceramic cookware. Glass is best for storing acidic foods.

Do not store acidic and salty foods in aluminum containers since they can lead to pitting of the surface. If you’re worried about buying fresh milk from Cuenca vendors, milk is barely acidic, with a pH of 6.5-6.7 (neutral is 7.0). The Institute of Food Technologists reports that aluminum milk cans are used throughout the world to safely store and transport milk. Aluminum containers keep milk cold longer than ceramic ones.

Myth #3: Teflon cookware causes cancer.

As reported by the Australian Cancer Council and the American Cancer Society, Teflon™ is a brand name for a man-made chemical known as polytetrafluorethylene (PTFE), in commercial use since the 1940s, and used in a wide variety of products, including fabric protectors and cookware. It’s versatile because it’s extremely stable (it doesn’t react with other chemicals) and as the ACS reports, it “can provide an almost friction-less surface.)

Perfluorooctanoic acid (PFOA) is used in the manufacture of Teflon, but because it’s burned off in the process, it is not present in large quantities. Teflon itself is not suspected of causing cancer, although in animal lab studies tumors have been found in large exposure to PFOA (not to Teflon).

The Cookware Manufacturers Association writes, Nonstick cookware has been used in millions of households around the world for over 40 years, and authoritative agencies around the world have confirmed its safety when used as intended.

The grain of truth: The words, “when used as intended” are critical. Teflon pans should never be overheated, and never heated without food. At high heat, the Teflon coating may begin to break down and release compounds that could produce “flu-like symptoms” in humans. It’s suggested to never keep your little pet parakeet in the kitchen because if an overheated pan releases fumes it could mean curtains for the delicate respiratory system of the little chickadee.

The ACC writes, Fumes are only released from Teflon-coated cookware when it is heated to extremely high temperatures (340°C-650°C or 644°F-1202°F); temperatures so high they would incinerate your food. There is no evidence that fumes are released from cookware at or below normal cooking temperatures. It is however advisable not to overheat an empty non-stick pan or to leave it unattended on the stove, particularly at a high setting.

Here are some tips to assure your Teflon nonstick pans stay in good shape:

Use wood or heatproof silicone utensils to cook with if your pans are a few years old or older. Newer pans may be “metal-utensil safe” because modern coatings may be more durable, but there’s always a higher risk of scratching the nonstick surface with metal utensils.

Start cold. Unlike cooking with cast iron, never heat your pan without the food and a little fat, if you’re using oil or butter. Don’t use cooking spray – although it’s not unsafe, (and cooking spray can be the subject of an entire column), cooking sprays will eventually cause a layer of film to build up on the surface of the coating, and your nonstick pan will eventually become sticky.

Wash softly. Never use a scouring pad or steel wool on a nonstick pan.  Use a soft sponge or brush and dish soap.

And an update to this column: a reader wrote to alert me to the very real concern that scientists have about PF.  As noted in EnvironmentalProtection.com,  “PFAS chemicals do not occur in nature, and some of them take a very long time to break down in the environment… and have the potential to build up in the organs and tissues of humans and animals. Animals further up the food chain—such as humans—may accumulate even more of the chemicals in their bodies when they eat plants or animals that have been exposed to PFAS.

There are concerns that PFAS chemicals may have toxic effects on humans and animals. Some animals exposed to high levels of PFAS show changes in hormone levels and in liver, thyroid, and pancreatic function. Some studies in humans have suggested that PFAS may affect the development of fetuses and young children, leading to possible growth, learning, or behavioral problems. Other studies have pointed to possible links to cancer, immune system disorders, and fertility problems.”

The recommendations of The Madrid Statement on Poly- and Perfluoroalkyl Substances (PFASs) include this missive to manufacturers:

Product manufacturers:

1. Stop using PFASs where they are not essential or when safer alternatives exist.
2. Develop inexpensive and sensitive PFAS quantification methods for compliance testing.
3. Label products containing PFASs, including chemical identity and safe disposal guidelines.
4. Invest in the development and use of nonfluorinated alternatives.

There are options if you’d like to cook in a nonstick pan, but want to avoid Teflon. Here’s a link to The Cookware Advisor’s guide to non-stick cookware, including some brands that are PTFE and PFOA-free. http://www.thecookwareadvisor.com/what-do-you-mean-its-not-teflon/

Sources

American Cancer Society. Teflon and Perfluorooctanoic Acid (PFOA).https://www.cancer.org/cancer/cancer-causes/teflon-and-perfluorooctanoic-acid-pfoa.html

Cancer Council Australia. Teflon cookware does not cause cancer. https://www.cancercouncil.com.au/86095/cancer-information/general-information-cancer-information/cancer-questions-myths/environmental-and-occupational-carcinogens/teflon-cookware-does-not-cause-cancer/

eHealthMD. Microwave Myths
http://ehealthmd.com/content/microwaved-food-dangerous-myths-and-facts#ixzz3WHaVqta7

Environmental Health Perspectives. The Madrid Statement on Poly- and Perfluoroalkyl Substances (PFASs) https://ehp.niehs.nih.gov/1509934/

Environmental Protection.com. What are PFAS and why should you care?  https://eponline.com/articles/2017/06/15/what-is-pfas.aspx

GMM Nonstick Coatings.  Nonstick Coating Myths. http://www.gmmdl.com/research-testing/nonstick-coating-myths#.WoNYppM-dyp

GoodHouseKeeping.com. 11 Surprising Facts & Myths About Microwave Ovens.
http://www.goodhousekeeping.com/food-recipes/news/a18064/microwave-radiation-ovens-460709/

Institute of Food Technologists (IFT.org).  Food Packaging — Roles, Materials, and Environmental Issues. http://www.ift.org/knowledge-center/read-ift-publications/science-reports/scientific-status-summaries/food-packaging.aspx

The Cookware Advisor. What do you mean it’s not Teflon??http://www.thecookwareadvisor.com/what-do-you-mean-its-not-teflon/

ThoughtCo.com. Learn What Type of Cookware Is Safest for Cooking.https://www.thoughtco.com/type-of-cookware-safest-for-cooking-1204032