Niki Bezzant: Myth of microwave debunked

We can relax and use our microwaves without fear. There's no evidence microwave ovens are harmful. Photo / iStock

Did you hear the one about the microwave oven?

Apparently, when some school students did a science project in which they compared a plant watered with regular water and one with microwaved water, the microwaved water killed the second plant. The conclusion (according to the story) is that microwaves are dangerous and "kill" our food.

Stories like this have been doing the rounds since the internet was born. In the days before social media, they circulated like chain letters, via email. I can't remember how many times over the past 10 years I've been sent the one about margarine being "one molecule away" from plastic.

Now, in the social media age, it's even easier for stories like this to spread, gain momentum and achieve the status of "truthiness", as comedian Steven Colbert would say. Truthiness - apart from being an excellent "stunt word" - describes things we believe or wish to be true, rather than actual facts. They're things we feel "in our gut" to be true, whether or not there's any evidence they are.

These days, most of us live in social media echo chambers. We hang out online mostly with people whose opinions and world views reflect our own, and we're exposed less and less to other perspectives. We may be perfectly happy with that. But it does mean we're vulnerable to truthiness being presented as fact. In food and health, this is rife. Food myths are everywhere.

There are myths about sugar - that using "healthy" sugars like coconut sugar or rice malt syrup mean a recipe is sugar-free. There are myths about food allergies and gluten - the idea that getting your hair tested will reveal whether you have allergies. There are myths about milk - that homogenisation is harmful. There are myths that fruit should only be eaten on an empty stomach otherwise it rots in your gut (ew).

There are many myths about food ingredients - just ask McDonald's, which is still asked if there is pig fat or chicken feathers in its milkshakes.

And speaking of chicken, the New Zealand poultry industry still battles the myth that there are hormones in our chicken, which has never been true.

Myths about food sometimes have elements of truth, which makes them sound so science-ish - a little bit of fact lends credibility.

For years all sorts of nefarious claims have been made about canola oil, that it's an industrial oil not fit for human consumption and that it's toxic, etc. There's truthiness here: canola oil used to be high in erucic acid, a substance associated with negative health effects.

It was used as an industrial lubricant during World War II. However, 40 years ago selective breeding produced low-erucic acid canola oil, which is what is available now as a safe and useful cooking oil. This oil also has a pretty healthy nutrition profile, according to oil experts.

And on microwaves, for the record: the plant experiment has been widely debunked. We can relax and use our microwaves without fear. There's no evidence microwave ovens are harmful. The claims they change the structure or energy of food have no basis in science.

The only thing to watch is that we use containers that are microwave safe, and don't let plastic wrap touch food, in case it melts. That wouldn't kill the food, but it might destroy dinner.

Niki Bezzant is the editor-in-chief of Healthy Food Guide.