6 Microwave Myths – Stop the Maddness
The molecular changes caused by cooking a food in a microwave are no different and no more harmful than the heating of a food any other way.
A Dutch study in 1995 that was published in the journal Food Chemistry conducted a toxicity experiment on rats using human food that found the opposite. The researchers intentionally subjected the food to misuse treatment by reheating in a microwave repeatedly to make sure to concentrate any potentially harmful substances. The tests were exhaustive and no harmful effects were found:
“Criteria to assess toxicity included clinical observations, ophthalmoscopy, growth, food and water intake, haematology, clinical chemistry, urinalysis, organ weights, micronucleated erythrocytes in bone marrow, gross examination at autopsy and microscopic examination of a wide range of organs. The results indicate no adverse effects of the diets cooked by microwave compared with those cooked conventionally.”
Myth 4: Microwaves Remove Nutrients out of Food
All forms of cooking can destroy nutrients, but contrary to what most people know, microwave cooking can actually preserve nutrients better than some other cooking methods like boiling. Minerals hold up particularly very well.
At least two studies did raise concern over major flavonoid losses in broccoli and one over vitamin C. One of the studies showed a 97% loss of flavonoids in the broccoli, which has been the basis of the “microwaves zap nutrients” myth ever since. The major nutrient losses were created by cooking the veggies in a lot of water.
Nutrient losses while microwaving depend mostly on cooking power, cooking duration and volume of cooking water. The studies did not conclude that you shouldn’t cook in a microwave oven, they concluded that steaming is the preferred method for retaining the most nutrients in vegetables and that if you cook broccoli or other veggies in a microwave, don’t overcook them and don’t cook them in water.
Vitamin losses from cooking meat in the microwave have also been studied. A 1998 study from Japan showed a 30% loss of vitamin B-12 from cooking meats in a microwave. However, it’s not a massive nutrient loss compared to boiled vegetables and since B-12 is heat sensitive, similar losses occur from conventional cooking as well, so once again it’s not a microwave-exclusive problem.
Many people don’t care for microwaved meat anyway (texture is rubbery), but all things considered, studies say that microwaving your veggies is not a bad way to cook them. In fact, some research says microwaving retains more nutrients due to the fast cooking times. A 1982 study by Cross and Fung published in Critical Reviews in Food Science and Nutrition concluded:
“Overall, the nutritional effects of microwaves on protein, lipid, and minerals appear minimal. A large amount of data is available on the effects of microwaves on vitamins. It is concluded that there are only slight differences between microwave and conventional cooking on vitamin retention in foods. In conclusion, no significant nutritional differences exist between foods prepared by conventional and microwave methods. Any differences reported in the literature are minimal.”
Myth 5: Microwaves Denatures Protein
Here’s an issue that concerns some of us bodybuilders and fitness minded folks: Does microwave cooking damage or denature protein?
In the Journal of Scientific Food Agriculture, Jonker and colleagues wrote:
“In general, the nutritive value of proteins in foods is comparable, whether cooking is done by microwaves or conventional means…”
Cooking at high temperatures has potential to denature protein, but that’s an excess heat issue, not a microwave oven issue. The amount of denaturation depends on how long and at what temperature the food is cooked. Some of the more delicate biological subfractions could be damaged or destroyed in proteins like whey, but that doesn’t mean the protein quality or amino acids themselves are destroyed.
Related Note on Cooking Meat in a Microwave – Bacteria Concerns
Health alarmists often publish claims that deadly and dangerous bacteria can survive in foods cooked in a microwave oven. There have indeed been case studies published in medical journals about listeria, ecoli and salmonella. It can happen with any cooking method if the meat isn’t cooked completely.
Microwave ovens are used most often for reheating food, but some people use microwaves to cook raw meats. Because microwave ovens may heat food non-uniformly, if you try to you cook a whole, stuffed chicken in the microwave, some areas may not get cooked completely, so e.coli or listeria, if present, may not be destroyed.
If you don’t want to take any chances, don’t cook whole raw chickens in the microwave!
Also, lightly cooked eggs could harbor salmonella. Whether you’re using a microwave or a conventional stove top to cook eggs, make sure they’re fully cooked. Salmonella risk from eating raw eggs is very low, but eat them raw at your own risk. Also be careful of microwaved eggs as there is a potential for them to explode inside the microwave or outside, after you’ve removed them.
A Related Note on Non-uniform Cooking – Caution! Watch out for hot spots!
Have you ever noticed how some parts of your microwaved food are cooked thoroughly and others are still lukewarm or even cold? It can definitely be annoying, but experts have expressed a serious concern over the potential for burns in adults, children and infants because one portion of the food can be cool or warm and another scalding hot.
Microwave technology has improved over the years to help mitigate this “hot spot” problem (including rotating carousels), but non-uniform heating is always somewhat of an issue to be aware of when consuming food cooked with microwave ovens.
This problem is easily solved with a little common sense and caution. Just mix or stir your food, and let it stand briefly before eating it. Eat hot food with caution.