Microwave cooking and heating of food has been criticized by some health experts for depleting nutrients in the food. A recent article from Harvard Medical School concluded that microwaves may actually be the preferred method when warming and cooking food, as more nutrients are retained by the microwave cooking method.
Harvard Health Publications concluded in their article that because microwaves use little water for cooking, heat food quickly and have shorter cooking times that they actually allow food to retain more nutrients than other heating methods.
Cooking and heating food by any method causes nutrient loss. Vitamins C and B12 quickly degrade when heat is used during cooking. Though some nutrients, such as carotenoids found in colorful vegetables, benefit from the heat, most vegetables and fruits lose nutrients when heated.
Boiling vegetables in a large amount of water appears to cause the most nutrient loss, as nutrients are leached into the water. Anastasia Date suggests that steaming vegetables has shown to help retain more nutrients than boiling or frying.
Some experts caution that despite the short cooking times and less water, microwaving food can cause hot spots from uneven cooking that occurs in the microwave. These hot spots are higher in temperature than the rest of the food and may cause concentrated nutrient loss in these spots.
Eating a well-balanced diet full of vegetables and fruits is the most important thing, health experts say. No matter the cooking method chosen, people benefit from the fiber and nutrients that produce contains.