Washington State University researchers investigated the duration of the cannabinoid tetrahydrocannabinol (THC) in breast milk. Previous studies have shown that alcohol detected in breast milk demonstrated a time when its concentration peaked and began to decline. However, it is more difficult to detect these levels when THC is present in milk. The findings published in the journal Breastfeeding Medicine suggest that a baby can ingest an average of 0.07 mg of THC per day. More research is needed to determine if there is any impact on the infant.
The researchers analyzed milk donated by 20 breastfeeding mothers who used cannabis. The participants described their cannabis consumption as part of the study and collected milk after abstaining from cannabis for at least 12 hours. They also collected milk at regular intervals after use.
The researchers found that the milk produced by these women always had detectable low levels of THC, even when the mothers refrained from cannabis use for 12 hours. Study author Dr. Courtney Meehan explained the reason for the presence of THC in all samples: “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 milk—and potentially in infants who drink it.” Additional research will examine the peak and decline of THC concentration and the impact of these levels on infants.
The study indicated that the participants had different peak THC concentrations in their milk. THC peaked approximately 30 minutes to 2.5 hours after use and then started to decline for participants who used cannabis only one time during the study. A majority of participants who consumed cannabis multiple times during the study showed a continual increase in concentrations across the day.
The research team is planning to conduct further research on cannabis use in breastfeeding mothers, the composition of breast milk they produce, and potential impacts on infant development.
Sources: Breastfeeding Medicine, Eureka News Alert, Washington State University Insider
