Online Breast Milk Buyers May Get Cowed

An analysis of human breast milk bought online reveals that some 10 percent of the samples contained cow’s milk. Dina Fine Maron reports

Illustration of a Bohr atom model spinning around the words Science Quickly with various science and medicine related icons around the text

Join Our Community of Science Lovers!


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


A small but growing market exists on the internet for human breast milk. Now a study finds that buyers should really beware—some purveyors of breast milk appear to be adulterating their product with cow’s milk.

Such bovine contamination is more than just a scam: it can be a health risk for infants who are allergic to or intolerant of cow’s milk. The study, the first to document this milk fraud, is in the journal Pediatrics. (Sarah A. Keim et al, Cow’s Milk Contamination of Human Milk Purchased via the Internet)

Researchers purchased 102 samples of supposed human breast milk online. Tests found that ten of these samples had enough bovine DNA to indicate that at least 10% of the milk in the sample actually came from cows. 

Human milk is an ideal source of nutrients for infants—when it’s safe. Prior studies on breast milk purchased online have revealed dangerous amounts of bacterial growth that make it unsuitable for infant consumption. Since no one typically screens these internet-sold milk products for pathogens or other contamination it’s up to consumers to protect themselves. Some human milk banks do voluntarily screen their products. So it’s best to check with local departments of health to find safe products.

—Dina Fine Maron 

[The above text is a transcript of this podcast.]

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American

Subscribe