Selling breast milk is big business.
Each year tens of thousands of women post ads on websites, offering their extra milk for $1 to $3 an ounce: "My rich milk makes giants!" promises one seller. "Organic and Gluten Free Breastmilk," claims another. Then there's this one: "470 oz. of breastmilk must go!!!"
But some women online aren't delivering what they're advertising.
Scientists at Nationwide Children's Hospital in Columbus, Ohio, analyzed 102 samples ordered from popular websites and found about 10 percent of them were "topped off" with cow's milk.
And we're not talking about just a smidge. The tainted samples contained at least 10 percent cow's milk, the team reported Monday in the journal Pediatrics. That's too much to be an accidental contamination. Sellers are diluting the breast milk, the researchers speculate, to make more money.
Dilution with cow's milk is clearly dangerous to babies with milk allergies, says neonatologist Amy Hair, who wasn't involved in the study. "But the diluted milk can – potentially — not provide enough nutrients a growing baby needs to develop properly."
"I'm a proponent of breast milk," says Hair, who directs the neonatal nutrition program at Texas Children's Hospital. "But if the option is buying breast milk online from an unscreened donor, and not from a reputable milk bank, I would recommend formula."
Buying, selling and sharing breast milk online is rapidly growing in popularity, says public health researcher Sarah Keim, who led the current study. "In 2011, we estimated about 13,000 women were participating in it. Now there are 55,000 women."
Back in 2010, the Food and Drug Administration warned that buying breast milk from an unknown seller was dangerous. "We wanted to see how big the risks might be," Keim says.
So she and her team turned to the Web and bought more than 2,000 ounces of breast milk from diverse sellers, for about $8,000. Nearly all the bags of milk arrived at their office above the recommended frozen temperature of -20 degrees Celsius (-4 degrees Fahrenheit). And nearly half were above refrigerator temperature of 4 degrees Celsius (39 degrees Fahrenheit).
Keim and her team found that about 75 percent of the samples had high levels of bacterial contamination or detectable levels of disease-causing pathogens, such as salmonella and E. coli. In other words, "the same kind of bacteria found in human waste," she says. "So these samples were unsuitable for a baby to drink."
In the current study, the team looked for the DNA of cattle in the samples. And Keim was surprised by the high levels of contamination in 10 samples.
"We racked our brains to think of an explanation for how so much cow's milk could get into a baggie of breast milk," she says. They couldn't think of a good reason, and figure the sellers must have done it intentionally.
Now the team is looking to see if samples contain other chemicals that could be even more harmful for babies, such as illegal drugs or some prescription medication. If a donor were a heavy smoker or drinker, she could also have passed nicotine or alcohol on to the baby.
"It really is, 'Buyer beware,' " Keim says. "When you are purchasing milk from a source you're not familiar with, you can't tell by looking at it if it's safe. It's really a risky activity that we don't recommend."
The U.S. has a network of nonprofit milk banks that screen donors, pasteurize the milk and test it for pathogens. But Keim says this milk is very expensive — about $4 per ounce or more. And almost all that milk is fed to preemies in hospitals.
"It's still a new method for feeding preemies," says Dr. Hair, of Texas Children's Hospital. "But there's a lot evidence that it protects them against a devastating intestinal disease, called necrotizing enterocolitis, and helps their immune systems."
"I would urge mothers, if they have an excess supply of breast milk, to consider donating it for premature infants," Hair says. "We're just trying to procure enough human milk for the tiniest babies — who have the most need."
MELISSA BLOCK, HOST:
Selling breast milk is a growing business. Tens of thousands of women buy and sell breast milk over the Internet. But a new study this week finds that some milk bought off the web may be unsafe for babies. NPR's Michaeleen Doucleff is following this story. And, Michaeleen, just how big a business is this?
MICHAELEEN DOUCLEFF, BYLINE: Buying and selling breast milk through the Internet is just exploding in popularity. One researcher that I talked to estimated that about 55,000 women now buy, sell and share their breast milk through the web. And that's about five times more than we saw just a few years ago.
Now, I do want to make a distinction here - I'm talking about individual women who are posting ads online to sell their milk to women that they don't know for a profit - for $1, $2, $3 an ounce. This is really different than a milk bank, which typically are nonprofits that actually screen donors, pasteurize the milk and check it for pathogens and diseases.
BLOCK: And, Michaeleen, that brings us to the study we mentioned that looked at the safety of this milk. What did that study find?
DOUCLEFF: So yeah - so a group of researchers went online and bought about a hundred breast milk samples at different price points - so some cheaper ones and some more expensive ones. And then they wanted to check to see if actually what they bought was pure breast milk. And they did that by looking for cow's DNA in the samples. And they were actually surprised. The researcher I talked to said she was expecting that a few samples might have a little bit of contamination, but actually about 10 percent of the samples had at least 10 percent cow's milk in it.
BLOCK: And what would the concerns be about that - about cow's milk in breast milk?
DOUCLEFF: The cow's milk is definitely dangerous for babies that have cow's milk allergies, but another doctor I talked to was concerned about the nutritional properties of the contaminated breast milk. Pediatricians actually recommend that babies not drink regular cow's milk until they are 1 year old. And that's because the cow's milk doesn't have all the nutrition that a baby needs to grow and develop. For instance, it doesn't have enough iron in it.
BLOCK: So if a woman wants to breast-feed her baby, Michaeleen, can't do that herself, what options does she have?
DOUCLEFF: Yeah, so ideally she would get the breast milk from one of these milk banks. But typically, these milk banks have shortages, and the top priority for the milk is for preemies in the hospitals, so it can be really hard for a woman to get milk from a milk bank. Also, the milk there is very expensive - like, $4 or $5 an ounce. So a bunch of the doctors I talked to actually said, you know, if you have the choice between buying breast milk online from a seller you don't know and formula, then they would definitely recommend formula.
BLOCK: This does seem like a risky proposition, Michaeleen. There was an earlier study that looked at bacterial contamination in breast milk sold online. Now, this one showing that at least some proportion of those samples were contaminated with cow's milk. What other follow-up studies are planned on this?
DOUCLEFF: Yeah, so the same researchers are now looking for other substances that could be in the breast milk, like prescription drugs, illegal drugs. If the donor is a heavy drinker or a heavy smoker then she can pass alcohol and nicotine on to the baby, so they want to see what else is in these samples.
BLOCK: So why isn't this market regulated then?
DOUCLEFF: I think, you know, a few years ago, there wasn't really much of a need for regulation, but now with popularity just skyrocketing, a lot of researchers are calling for regulation.
BLOCK: OK. NPR's Michaeleen Doucleff - we were talking about a new study published this week in the journal Pediatrics that shows breast milk sold online could contain cow's milk. Michaeleen, thanks very much.
DOUCLEFF: Thank you. Transcript provided by NPR, Copyright NPR.