Back in 2013, we observed (“Buyer Beware” — The PediaBlog 10/22/13) the popularity of Internet sites offering breast milk for sale and concluded that, “unscreened, unpasteurized breast milk from anonymous sources, offered for sale on the unregulated Internet, is potentially dangerous,” after a study found bacterial contamination in a majority of samples tested. A new study by the same authors, published this week in Pediatrics, found that about 10% of Internet breast milk samples contained significant quantities of cow’s milk. Some samples contained an equal, 50-50 quantity of breast milk and cow’s milk!

Pediatricians recommend waiting until 12 months old before introducing cow milk to drink because its proteins can be difficult for infants to digest, leading to abdominal pain, diarrhea, constipation, microscopic gastrointestinal bleeding, and anemia.

The researchers also found a 5-fold increase in advertisements to buy or sell milk over the Internet from 2011 (11,000 postings) to 2014 (55,000). Melinda Beck spoke with an expert:

The American Academy of Pediatrics strongly favors breast-feeding, but Joan Y. Meek, who heads its section on breast-feeding, said: “Just because the milk ordered via the Internet looks like milk does not mean that it is human milk or only human milk.”

“Spoiled milk, adulterated milk, contaminated milk, or even a substance that looks like human milk but is not milk are too risky to feed to a young infant with an underdeveloped immune system and a high risk for adverse reaction,” she said.