Microwaving is one of the BEST cooking methods for preserving nutrients. Shorter cook time + less water = fewer lost vitamins.
The Science
Nutrient loss in cooking depends on: TIME (longer = more loss), TEMPERATURE (higher = more loss), and WATER (water-soluble vitamins leach into cooking water). Microwaving: short time, moderate temp, minimal water = preserves more nutrients than boiling, and often more than steaming or baking. Vitamin C retention: microwave 90%, boil 50%, steam 70%. The microwave myth persists because "radiation" sounds scary. Microwave radiation is non-ionizing (cannot damage DNA — same frequency as WiFi, just more power). It heats by vibrating water molecules — that's it. No "radiation residue." Food is perfectly safe.
Microwaving in plastic containers can leach chemicals — use glass or ceramic. Microwaving destroys some beneficial bacteria in fermented foods (reheat gently). Microwaving meat can create hot spots — rotate/stir for even cooking.