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Related to this question but from nutritional point of view.

Does microwave heating (not excessive) reduce human breast milk nutritional qualities?
Especially compared to conventional stove heating.

Never microwave breast milk -- overheating destroys valuable nutrients

Don't use the microwave for defrosting or warming, because it kills the nutrients in breast milk

My problem is that with microwave I get a more predictable heating result while with the hot water stove top heating I always overheat the bottle and need to wait till it cools down.

Andrew Grimm
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bestander
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    I seriously doubt a microwave oven would cause more chemical changes to the milk than other means of heating it to the same temperature. Maybe you should focus on that, whether microwave ovens lead to the milk heating to a higher temperature than other means employed. – jwenting May 21 '15 at 11:17
  • @jwenting "The adverse effects [of microwaving] on anti-infective factors are difficult to explain based upon hyperthermia alone since the temperatures used were not excessive" Quan et al. Pediatrics Vol. 89 pp. 667-669 http://www.eatsonfeets.org/docs/MicrowaveandBreastmilk.pdf – DavePhD May 22 '15 at 11:30

2 Answers2

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A few related studies I found:

The effect of microwave heating on vitamins B1 and E, and linoleic and linolenic acids, and immunoglobulins in human milk. - says there are no effects on B1/E/acids if resulted average heat is not higher than 60 C

Effects of Microwave Radiation on Anti-infective Factors in Human Milk -

Microwaving at low temperatures (20°C to 53°C) had no significant effect on total IgA, specific IgA to E coli serotypes 01 and 04, but did significantly decrease lysozyme and specific IgA to E coli serotype 06. Even at 20°C to 25°C, E coli growth was five times that of control human milk. Microwaving appears to be contraindicated at high temperatures, and questions regarding its safety exist even at low temperatures

I don't have a better way to search medical databases, so any links and interpretation is welcome

DavePhD
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bestander
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  • Microwaving reduces the immunological properties of milk by damaging lysozyme and a specific IgA, but it does not destroy nutrients if it is done at low temperature. The milk is still nutritious after microwaving. – DavePhD May 21 '15 at 14:21
  • @DavePhD how does that compare to heating on a stove? – nico May 21 '15 at 14:39
  • @nico The best way to warm milk is to put it in a warm water bath. If you directly heat on a stove, there will be significant temperature gradients. The portion near the inner surface of the pot would be hot and proteins there would be denatured, causing loss of immunological properties. – DavePhD May 22 '15 at 11:17
  • Full text no-paywall link to "Effects of Microwave Radiation on Anti-infective Factors in Human Milk" http://www.eatsonfeets.org/docs/MicrowaveandBreastmilk.pdf – DavePhD May 22 '15 at 11:32
  • @DavePhD what I mean is that paper only shows an effect of temperature on protein denaturation which is hardly surprising. However, how is that microwave specific is not investigated at all... I bet that stovetop heating (which is what the OP is asking as a comparison) has a very similar effect... which possibly heating in a water bath has not. – nico May 22 '15 at 11:58
  • @nico actually, the paper says ""The adverse effects [of microwaving] on anti-infective factors are difficult to explain based upon hyperthermia alone since the temperatures used were not excessive" – DavePhD May 22 '15 at 12:17
  • @DavePhD I guess what they cannot explain by hypertermia alone is the 20-25°C result, but they don't have any data involving microwaves either. However http://www.ncbi.nlm.nih.gov/pubmed/8889628 shows no significant loss of Ig with microwaving provided that temperatures are <60°C and this shows continued antibacterial properties after microwaving even if a fraction of IgA is lost: http://www.ncbi.nlm.nih.gov/pubmed/8870401 – nico May 22 '15 at 12:34
  • @nico what do you mean by "they don't have any data involving microwaves either" All the data is from using microwaves. Also, the point is one particular IgA, specific to "E coli serotype 06" is affected, not IgA generally. – DavePhD May 22 '15 at 12:52
  • @DavePhD they do not have data of the effect of microwaves alone vs the effects of temperature. If you do not compare with another method of heating you cannot distinguish between the two as exposure to microwaves will increase temperature. The other papers, as well as some of their references (see #14 for instance) use more appropriate controls. – nico May 22 '15 at 12:55
  • @nico But they are only heating to room temperature (20-25 degrees C), lower than the ~37 degrees the milk was coming from the breast orginally. A reasonable control would be just waiting until the milk equilibrates with ambient temperature. Sigman et al. do the controls you are hoping for in http://www.ncbi.nlm.nih.gov/pubmed/2723294 , but I don't have full text. – DavePhD May 22 '15 at 13:29
  • I agree with @nico - I did not find the second paper convincing at all. There appear to be multiple discrepancies in methodology and they have not compared microwave heating to non-microwave heating, despite claiming to have shown that microwave heating is problematic. They even cite other research which suggests it is likely due to heating in general. It is odd. – Sam Brightman Dec 09 '18 at 12:36
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From the question that you quoted, one of the studies quoted there covers some aspects of nutrition.

Microwave heating of infant formula: a dilemma resolved Pediatrics (1992) vol. 90 pages 412-415. (Bold emphasis is mine)

Microwave heating of infant formula is a common practice despite concerns of infant scalding. Beyond the issue of physical safety, little is known about the effects on nutrient content of microwave heating of infant formula. Casein-predominant infant formula in 120- and 240-mL glass and plastic nursing bottles of varying colors were heated for 40 seconds and 60 seconds, respectively. Temperature profiling was monitored during the heating cycle. Analysis of riboflavin and vitamin C was made prior to and after heating .... There was no significant loss of either riboflavin or vitamin C ....

Sean Duggan
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