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THC from cannabis use lingers in breast milk of new mothers

As cannabis gains popularity and acceptance, a growing concern arises for breastfeeding mothers who use the drug. A recent study has shed light on the presence of THC, the psychoactive component of cannabis, in the breast milk produced by these mothers.

The findings raise important questions about the potential effects on infants and the need for further research.

Milk, moms, and marijuana: A delicate balance

Courtney Meehan, a biological anthropologist at Washington State University, led a groundbreaking study published in the journal Breastfeeding Medicine.

The research team analyzed breast milk donated by 20 breastfeeding mothers who used cannabis, aiming to uncover how long cannabinoids, like THC, persisted in breast milk.

“Breastfeeding parents need to be aware that if they use cannabis, their infants are likely consuming cannabinoids via the milk they produce, and we do not know whether this has any effect on the developing infant,” said Meehan, the study’s corresponding author.

THC levels found in breast milk

The researchers discovered that the amount of THC detected in the breast milk was low, with an estimated average of 0.07 mg of THC per day consumed by infants.

To put this into perspective, a common low-dose edible contains 2 mg of THC. However, the research team stressed that it is unknown whether this amount has any impact on the infant.

“Human milk has compounds called lipids, and cannabinoids are lipophilic, meaning they dissolve in those lipids. This may mean that cannabinoids like THC tend to accumulate in breast milk — and potentially in infants who drink it,” explained Meehan.

Knowns and unknowns of cannabis and breast milk

The study revealed that, unlike alcohol, when THC was detected in breast milk, there was no consistent time when its concentration peaked and started to decline. This makes it difficult for breastfeeding mothers to avoid feeding their infants when THC levels are at their highest.

“There was such a range. If you’re trying to avoid breastfeeding when the concentration of THC peaks, you’re not going to know when THC is at its peak in the breast milk,” said lead author Elizabeth Holdsworth, who worked on this study while a WSU post-doctoral researcher and is now on the faculty of The Ohio State University.

Furthermore, scientists know almost nothing about how many commonly used drugs may impact breastfeeding babies, partly because women, especially those who are breastfeeding, have historically been left out of clinical trials on medicines.

Thoughtful decisions and therapeutic use

A related qualitative study by the research team revealed that many breastfeeding moms are using cannabis for therapeutic purposes — to manage anxiety, other mental health issues, or chronic pain. The mothers often chose cannabis over using other medications because they felt it was safer.

“Our results suggest that mothers who use cannabis are being thoughtful in their decisions,” said co-author Shelley McGuire, a University of Idaho professor who studies maternal-infant nutrition. “These women were mindful about their choices. This is far from a random lifestyle choice.”

Substantial, rigorous research needed on THC and breast milk

While some research has been done regarding alcohol, with guidelines for new mothers to wait at least two hours after consuming alcohol before breastfeeding, nothing similar has been developed for cannabis.

“This is an area that needs substantial, rigorous research for moms to know what’s best,” McGuire said.

The collaborative research team is currently working to address some of that knowledge gap with further research on cannabis use in breastfeeding moms, holistic composition of the milk they produce, and its effects on infant development.

Navigating cannabis use as a breastfeeding mother

In summary, as the landscape of cannabis use continues to evolve, breastfeeding mothers face a unique set of challenges and uncertainties.

The Washington State University-led study has taken the first steps in unraveling the complex relationship between cannabis use and breastmilk, but it has also highlighted the urgent need for further research.

Only through rigorous scientific inquiry can we provide breastfeeding mothers with the knowledge and support they need to make informed decisions about their health and the well-being of their infants.

By prioritizing this area of study, we can work towards creating a safer, more informed environment for mothers and their babies, ensuring that the choices they make are grounded in evidence and understanding.

The full study was published in the journal Breastfeeding Medicine.


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