Protect nutrients in breast milk
Nutritional elements in breast milk are damaged if heated up to more than 45˚ C or warmed / kept warm for longer time. The longer the time period, the bigger the damage. Consequently, quick and correct heating in microwave, if you make sure not to overheat for example by correct use of milkymeter, is a safe way to preserve nutrients in the milk.
Bottle heater, water bath or microwave?
You may have heard that it is always better to heat a baby bottle in a water bath or bottle heater. However, this is not correct.
Most often you want to heat quickly, and to do this you will need very hot water in the water bath or the bottle heater. Research show a larger amount of milk to be heated to higher temperature for a longer time period when heating in waterbath or bottle warmer, than with controlled microwave heating (that is when using milkymeter and stopping the microwave when the light flashes green).
High temperatures and being exposed to heat for a long time damages nutrients - regardless of heating method.
Warm safely in the microwave oven with milkymeter
milkymeter measures temperature while the baby bottle is being heated in the microwave. It flashes a green light when milk reaches body temperature making it possible for you to stop the microwave in time thereby obtaining the right temperature.
Research document that microwaves do not harm breast milk (Lassen, Anne and Ovesen, Lars. "Nutritional effects of microwave cooking." Nutrition & Food Science 95.4 (1995): 8-10). The nutritional elements in breast milk are damaged if overheated, regardless of heating method.
Nutrition and heating of breastmilk. Scientific studies
Sharron Bransburg-Zabary, 1 ,* Alexander Virozub, 2 and Francis B. Mimouni 3, Umberto Simeoni, Academic Editor: "Human Milk Warming Temperatures Using a Simulation of Currently Available Storage and Warming Methods." PLoS One. 2015; 10(6): e0128806.
Wardell J, Wright A, Bardsley W, D’Souza S. “Bile Salt-Stimulated Lipase and Esterase Activity in Human Milk after Collection, Storage, and Heating: Nutritional Implications” Pediatr Res 18: 382–386.PMID: 6718097. 1984
Lassen, Anne and Ovesen, Lars. "Nutritional effects of microwave cooking." Nutrition & Food Science 95.4 (1995)