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Cow's Milk Found in Online Breast Milk

Apr 06, 2015

The practice of buying and selling human breast milk over the Internet seems to be growing in popularity. Many parents turn to women who are willing to share extra breast milk. They purchase the milk online based on a posted description of the type and quantity of the milk or the health habits of the seller. But when they think they’re getting nutritious, high-quality breast milk, some of them are actually receiving human milk mixed with cow’s milk.

In a study my colleagues and I published in the journal Pediatrics, we found that 10 percent of the breast milk samples we bought on Internet milk-sharing websites contained added cow’s milk. The amount of cow’s milk in the so-called breast milk was probably too high to be accidental.

These findings are compatible with a scenario where  some women selling milk online are purposely adding cow’s milk or infant formula and are still selling it as breast milk.

Why Added Cow’s Milk Matters
Purposely “topping off” bags or bottles of breast milk sold online with cow’s milk is bad for a number of reasons.

  • Cow’s milk could be very dangerous to babies receiving the purchased milk due to medical conditions, cow’s milk allergies or formula sensitivities.
  • Babies need certain amounts of nutrients and fats that are included in formulas and in human breast milk, but not in regular cow’s milk; breast milk with added cow’s milk could be diluting essential nutrients.
  • Added cow’s milk is just the tip of the iceberg. There is no way for parents to know what else is in milk purchased online.

A prior study on milk sharing found that many parents purchase milk over the Internet because their infant has a health problem or formula sensitivity. But the risk of receiving breast milk that has been contaminated with cow’s milk or other potentially dangerous things — like viruses, bacteria and even nicotine or other drugs — could outweigh the benefits of feeding a baby human breast milk.

Our previous research found that more than 75 percent of samples of breast milk we purchased over the Internet had high levels of bacterial growth or disease-causing bacteria. Others had dangerous viral strains or showed that some mothers were smokers even when their ad for milk specifically said they were non-smokers.

What You Need to Know About Milk Sharing
The truth of the matter is that you do not truly know what you are receiving when you buy milk from a stranger over the Internet — no matter how chubby their baby is or how many claims they make about their organic or drug-free or ultra-healthy lifestyle.

Selling breast milk gives people an incentive to add cow’s milk or formula to the milk in order to sell more. When money is involved in an unregulated process like this, you cannot know for sure that the milk is safe to give to your baby.

And while sharing milk with a friend or family member may seem like an attractive alternative, it’s also not an ideal solution for meeting your baby’s nutritional needs. Unsafe levels of bacteria can grow in milk in a matter of hours, and milk can transmit disease and prescription and non-prescription drugs.

Instead of obtaining breast milk over the Internet, work with your child’s pediatrician to identify safe, healthy ways to feed your baby. There are ways to ensure that your baby gets all the nutrients he or she needs to address any health concerns or dietary needs without getting breast milk — or cow’s milk — online.

Find out more about this study:

To learn about safely receiving and donating breast milk, check out the Mother's Milk Bank of Ohio.

Featured Expert

Sarah Keim
Sarah Keim, PhD
Center for Biobehavioral Health

Sarah A. Keim, MA, MS, PhD is a principal investigator in the Center for Biobehavioral Health at The Research Institute at Nationwide Children’s Hospital. She is an assistant professor of pediatrics in The Ohio State University College of Medicine and of Epidemiology in the College of Public Health.

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