It’s a common urban legend: Stand too close to a microwave, and the body could absorb second-hand radiation and even (ack!) increase the risk of cancer. But is there actually any truth to this one? We decided to find out if the FDA can back up its claim that microwaves are perfectly safe.

Photo by Nicole Fara Silver

Catchin’ Some Waves — Why It Matters

Microwaves are a type of electromagnetic wave (shocker, right?), just like UV rays and radio waves. Instead of cooking food with heat like a conventional oven, microwave ovens “excite” atoms (or get ’em all moving around), cooking food evenly throughout rather than from the outside in (like an oven does). The health concerns surrounding this modern cooking method are two-fold: There’s the food that comes out of the microwave, and there’s also concern over the waves microwaves emit.

Some researchers suggest getting the cells that make up food all hot and bothered from microwaving them causes chemical changes in the food. When the cells are altered, they claim, the body digests them differently, and the abnormal digestion process might increase the risk of developing cancerous cells. However, evidence of this claim in reputable, peer-reviewed journals is hard (read: impossible) to come by, and the USDA maintains that food exposed to this type of radiation does not transfer it to our bodies. Moreover, any amount of radiation created by microwaves is way below the threshold of what could cause damage to humans. In fact, some studies suggest exposing food to electromagnetic rays can actually kill bacteria, making it safer to eatFood irradiation: a safe and useful technology. Parnes, R.B., Lichtenstein, A.H. USDA/Jean Mayer Human Nutrition Research Center at Tufts University, 711 Washington Street, Boston, MA. Nutrition in Clinical Care, 2004 Oct-Dec;7(4):149-55.Irradiation in the production, processing and handling of food. Final rule. Food and Drug Administration, HHS. Federal Register, 2008 Aug 22;73(164):49593-603..

Time to Hang Ten? — The Answer/Debate

But the potential damage to food isn’t the only concern over microwaves. Many also worry about standing too close to these radiation-emitting beasts. So let’s get one thing straight— microwaves do emit radiation, technically speaking, but it’s not the DNA-damaging radiation we’re used to hearing about. Microwaves, along with radio waves from (you guessed it) radio and cell phone towers, are types of non-ionizing radiation. Despite significant research, scientists have struggled to prove a definitive link between non-ionizing radiation and cancer— but there have been several studies that show a correlationExtremely low-frequency electromagnetic fields exposure and female breast cancer risk: a meta-analysis based on 24,338 cases and 60,628 controls. Chen, C., Ma, X., Zhong, M., et al. Faculty of Preventive Medicine, Department of Occupational Health, Key Laboratory of Electromagnetic Radiation Protection, Third Military Medical University, Chongqing, 400038, China. Breast Cancer Research and Treatment, 2010 Sep;123(2):569-76.Residential and occupational exposures to 50-Hz magnetic fields and breast cancer in women: a population-based study. Kliukiene, J., Tynes, T., Andersen, A. The Cancer Registry of Norway, Institute of Population-based Cancer Research, Oslo, Norway. American Journal of Epidemiology, 2004 May 1;159(9):852-61.Residential and occupational exposure to 50-Hz magnetic fields and brain tumours in Norway: a population-based study. Klaeboe, L., Blaasaas, K.G., Haldorsen, T., et al. The Cancer Registry of Norway, Institute of Population-Based Cancer Research, Oslo, Norway. International Journal of Cancer, 2005 May 20;115(1):137-41.. Questionable, we know.

But let’s assume for a second that microwaves could cause cancer. Just because they’re “nuking” the food doesn’t mean microwaves are releasing those same rays into the environment (or into us, the impatient bystanders awaiting steamy ramen noodles). The FDA actually keeps a pretty tight lid on how many waves microwaves can actually emit, and that number is far lower than any amount that could cause actual harm. The FDA does note that upkeep is important, though— damage to hinges or latches could allow more radiation to be released. As long as it’s in good working order, the more likely danger posed by a microwave is in the form of burns from over-heated food or even exploding superheated water (yeah, really).

The Takeaway

There’s no evidence that proves microwaves can release enough radiation to actually do any damage.