Women who consume or use cannabis while breastfeeding are passing delta-9-tetrahydrocannabinol (THC), the psychoactive component in the drug, on to their nursing child, according to a new study.
THC Remains Present in Breastmilk
Unlike alcohol, which has a peak accumulation time in breast milk, THC remains consistently concentrated in breast milk, according to the results published in Breastfeeding Medicine.The concentration of THC in breastmilk was relatively low according to the researchers—infants who consumed breastmilk containing THC were still ingesting around 0.07 milligrams of the compound daily. To put that amount into perspective, a typical low-dose cannabis edible product contains a much higher dose of approximately 2 mg of THC.
The research team analyzed milk donated by 20 breastfeeding mothers who frequently used cannabis. The participants all had infants younger than six months. The milk was obtained 12 hours after the breastfeeding mother’s last cannabis use and then at regular eight to 12-hour intervals afterward.
The breastmilk always had detectable amounts of THC, even when the mothers had abstained for 12 hours.
“Human milk has compounds called lipids, and cannabinoids are lipophilic, meaning they dissolve in those lipids,” Ms. Meehan said. “This may mean that cannabinoids like THC tend to accumulate in milk — and potentially in infants who drink it,” she added.
The research team also observed differences in peak concentrations based on how much cannabis a person used. Although the study’s small sample size and observational design limited definitive conclusions, participants whose breastmilk showed the quickest peak in THC levels (30-35 minutes after cannabis use) were currently more frequent users who had maintained that higher usage rate for a longer period compared to those with later THC peaks.
“There was such a range,” Elizabeth Holdsworth, the lead author of the study, said in a statement. “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 milk.”
Data on Cannabis and Breastfeeding Limited
Little research exists about the impacts of cannabis on breastfeeding babies, since breastfeeding women are often excluded from clinical trials on medicines, Shelley McGuire, a professor of nutrition at the University of Idaho and co-author of the study, said.“This is an area that needs substantial, rigorous research for moms to know what’s best,” Ms. McGuire said.
