Reality TV star Kourtney Kardashian Barker isn’t the first to drink breast milk – but we know surprisingly little about its adult health benefits. Microbiologist Simon Cameron looks at the evidence.
“I just pounded a glᴀss of breast milk because I feel sick. Goodnight!” wrote Kourtney Kardashian Barker on an Instagram story to her 224 million followers in April 2024.
Her comment attracted shock, horror and disgust from many social media users, but it’s not the first time Kardashian Barker has used her milk as medicine. In 2013, she applied her breast milk to her sister Kim Kardashian’s leg in an effort to heal a patch of psoriasis.
The Kardashians are usually trendsetters. But, by drinking her own breast milk, the eldest Kardashian sister helped promote a health trend already steeped in centuries of medical history.
After giving birth to Rocky, her child with Blink 182 drummer Travis Barker, Kourtney clearly wanted to put her extra breast milk to good use again.
But is there any evidence that human milk is an effective remedy for illness?
The production of milk defines mammals. Every mammal produces milk which has been tailored to their offspring over millennia of evolution. As well as providing all the energy and nutrients needed for growth of newborns, human milk packs a punch of extra components that support the development of the immune system.
The World Health Organization recommends exclusive breastfeeding for the first six months of life. Once solid food is introduced, it is recommended that breastfeeding continues to two years of age and beyond.
One thing that is not recommended by any health organisation is adult consumption of human milk.
Bodybuilders think breast is best
Human milk is also used by some bodybuilders to lose fat and bulk up. This has created an online marketplace allowing easy access to breast milk.
The 2020 Netflix series (Un)Well featured an episode focused on the safety and ethics of breast milk for bodybuilding. The practice was found to be both expensive and dangerously unregulated.
As with any private and unregulated market, there are risks, the primary one in this case being microbiological contamination. This can come through the expression process and is typically ᴀssociated with handling and cleanliness of pumps and tubing.
This can be easily minimised by following health authority guidelines (such as from the UK’s NHS). Contamination of expressed milk can also be made worse through improper storage, such as more than a few hours at room temperature or a few days in the refrigerator, before freezing at around -20°C.
Unless they have a well equipped microbiological testing laboratory at home, people who buy human milk have no way of testing the safety of their purchase.
Researchers at Nationwide Children’s Hospital in the US have shown that human milk purchased over informal networks has shown concerningly high levels of microbiological contamination. One in 10 samples were also found to have added formula milk or cow’s milk.