Health and microwave heated food
While there are a number of “urban legends” floating around the internet implying that cooking with microwaves is either not safe or not healthy, each of these tales has been thoroughly debunked, and have no basis in fact. There are two legitimate safety/health issues. The first is microwave leakage. National safety agencies have set standards for microwave leakage, and manufactured ovens must meet these standards. Consumer common sense, however, is urged. If the oven door has been damaged, the oven should not be used until checked by a competent technician.
The second concern is uneven heating, resulting in cold spots where the heating is insufficient to kill pathogenic microbes. In terms of prepared “microwaveable” foods, most are of the ‘ready to eat’ (RTE) category in which the components are cooked sufficiently before being sold to kill all pathogens, and all the consumer is doing with the microwave is heating the product to serving temperature. However, a small fraction of prepared “microwaveable” foods is in the ‘not ready to eat’ (NRTE) category; there have been a few infection incidents with NRTE foods such as those containing poultry. While food companies make great efforts to develop products and preparation instructions that insure safety, consumers should both follow these directions, and further exercise the same care they would follow in preparing food with any technique.
Cooking food from raw ingredients using a microwave oven requires the same level of care that a cook must exercise when cooking these ingredients using every other technique. For example, roasting poultry in an oven requires that the cook insure that the interior portions are sufficiently heated. Some suggestions will be offered that are specific for microwave cooking.
On the other hand, the fast heating offered by microwave cooking can have a significant health advantage. Many nutrients, such as vitamins, are “denatured” (i.e. decomposed) by prolonged exposure to high temperature. The longer the food remains at high temperature, the more nutrients that are lost. Furthermore, conventional fast cooking technique use some form of fluid, e.g. an oil for frying, or water for boiling or steaming. Much of the nutrients, that survive exposure to high temperature are dissolved in these fluids, and are not served with the dish. In contrast, microwaves can be applied directly to food, without an intervening fluid. The cooking time to reach the same effect on the cooked food is less than with conventional techniques, and thus fewer nutrients and are destroyed, and fewer are lost by dissolution into an intervening fluid, resulting in a healthier cooked dish.
Furthermore, in conventional cooking not only nutrients are lost to oil and water, but also flavor elements. We conventionally compensate for this lost by applying seasonings, especially salt, or preparing rich sauces and gravies. Directly “microwaved” food retains more of these flavor elements in the food, and we tend to use less salt and sauces, helping us maintain a more healthy diet.