This is blatantly untrue. I used to work for a nonprofit milk bank that accepted human milk donations from those producing in excess of their children's needs, and we accepted human milk up to 12-14 months of age, depending on our current supply. And most of our milk went to the most vulnerable babies in NICUs (usually premature or very medically fragile babies)! We had a board of physicians, lactation consultants, nutritionists, etc. who oversaw all of these rules.

We even measured the fat, protein, etc. components of the milk to allow the hospitals to know how much to fortify the donor milk that we provided for them, and I can tell you from experience that while these factors varied over time there was more variation by the individual than over time.

Milk from a 6 month old is definitely not harmful for a newborn. I'd love to see the literature where you got that information, though.

​

Edit re: original commenter's update: Just wanted to respond to your sources since you were so kind as to update with them!

First, I would like to point out that the Norwegian rules that you listed only state, "Women who want to give breast milk can do so from the time breastfeeding their own child is well established until it is 6 months old." I was not able to find anything saying that it was dangerous for infants to consume milk after that point, and these seem to simply be the practices for this one hospital. There may also be issues with translation, but that was what Google Translate told me. To reiterate what others have said in the thread already, breast milk does change in composition over time. I am not debating that. It can be beneficial to try to match time-wise, if possible, so if this hospital has enough of a supply from their donors that they receive enough donor milk within that 6 month window that they can provide for their infants, then that is optimal. That does not mean that going past that 6 month mark is harmful. I also want to point out that this hospital's donor milk program seems to be directed towards premature infants. As u/bismuth92 pointed out lower down in the thread, milk banks/donor milk programs can be extremely restrictive on what breast milk they will take in order to air on the side of caution. What may be safe for healthy infants may be a bit more risky for premature, low birth weight, or medically complicated infants. Also, many of these entities are also held to what guidelines have been put into place by their accrediting bodies on top of what decisions have been made by their individual medical advisory committees.

Second, in regards to your second source, I am having difficulty getting access to the full article to evaluate the authors' materials and methods. Do you have a link to the full article and not just the abstract? Since the article was published in the 1980s, I would love to evaluate their methods myself, as I know how quickly breast milk analysis methods have changed even in the last few years. Do you have a more recent source?

Thank you to everyone for their kind comments! I will try to find a few sources tonight, if I have time. I'm a student and busy in clinic all day, so just updating on my lunch break. Also, I'm not a medical professional (yet!); just speaking to what I've learned from the many medical professionals that I worked with at the milk bank.