Endocannabinoids in human breast milk are important for human development, but not present in cannabis
Human breast milk contains endocannabinoids, which are neurotransmitters naturally produced by the human body and are important for infant development. However, endocannabinoids are not the same as the cannabinoids found in cannabis/marijuana. The suggestion that cannabis exposure is beneficial to infant development is not supported by scientific evidence.
Inaccurate: Human breast milk does not contain the same cannabinoids as the Cannabis plant.
Fails to grasp significance of observation: A study by Dreher et al. cited in support of this claim did find improved behavioral scores in babies breastfed by mothers who used cannabis, but this was actually attributed to the higher socioeconomic status of these mothers, not to cannabis exposure itself, as the article claims.
This article by CBDLife was published in January 2017, but recently went viral on Facebook and has received more than 51,000 shares. It claims that “human breast milk naturally contains the same cannabinoids found in the Cannabis plant, which are vital for proper human development”. The article reports that “the findings of several major scientific studies” support its claim, but it only names one study by Dreher et al, published in 1994.
Scientists who reviewed the claim explained that human breast milk does indeed contain cannabinoids, but these are endocannabinoids which are important for human development[2,3] and are different from the type of cannabinoids found in cannabis (also known as marijuana). Therefore, the article’s claim is inaccurate.
It is true that Dreher et al. reported that “neonates of heavy-marijuana-using mothers had better scores on autonomic stability, quality of alertness, irritability, and self-regulation”. However, the authors concluded that “the better scores of exposed neonates at 1 month are traceable to the cultural positioning and social and economic characteristics of mothers using marijuana that select for the use of marijuana but also promote neonatal development.” In short, the higher behavioral scores in cannabis-exposed babies were attributed to the relatively higher socioeconomic status of mothers who used cannabis during pregnancy and lactation (compared to mothers who did not use cannabis), not to cannabis exposure itself.
This claim in the article “According to the findings of several major scientific studies, human breast milk naturally contains […] the same cannabinoids found in the Cannabis plant, which are vital for proper human development” is patently false. It is true that endocannabinoids such as anandamide (AEA) and 2-Arachidonoylglycerol (2-AG) are found in breast milk[4,5] and do play an important role in development[2,3]. But endocannabinoids are not the “same cannabinoids found in the Cannabis plant.” That would be the functional equivalent of saying that because norepinephrine exhibits many of the same receptor binding profiles as psychomotor stimulants like cocaine and amphetamines, that we all have cocaine in our blood all the time.
Also note that the article they referenced found that the slight differences between cannabis-exposed and non-exposed children were due to sociodemographic positioning, rather than the cannabis itself. As the study’s authors reported in their conclusions: “The absence of any differences between the exposed [and] nonexposed groups in the early neonatal period suggest that the better scores of exposed neonates at 1 month are traceable to the cultural positioning and social and economic characteristics of mothers using marijuana that select for the use of marijuana but also promote neonatal development.”
Our recent review from Trends in Neurosciences briefly discusses the negative consequences of cannabis consumption by lactating mothers.
Trainee Clinical Psychologist, South London and Maudsley NHS Foundation Trust
The article’s main pitfall is in saying that “human breast milk naturally contains […] the same cannabinoids found in the Cannabis plant”. This is not correct. Some studies state that human breast milk does indeed contain cannabinoids, but they are endocannabinoids – ‘endo’ means within, meaning made by the body. Cannabinoids in cannabis are what we call phytocannabinoids – ‘phyto’ meaning plant. Endocannabinoids and phytocannabinoids have a similar chemical structure, but they are not the same. Phytocannabinoids are not “vital for proper human development”. However, the endocannabinoid system in the human body is indeed involved in regulating brain development, motor control, cognition and emotional responses.
Furthermore, the study that the article refers to actually attributes the better performance on certain measures to the “cultural positioning and social and economic characteristics of mothers” who use cannabis, rather than the cannabis exposure itself.
The statement “Cannabinoids are not, however, present in baby formula, which makes it far more inferior to breast milk” could be problematic as it seems to pressure women into successful breastfeeding. Some women find it really difficult and do not get the correct support and while the World Health Organization recommends breastfeeding until a child is 2 years old, a fed baby (via breastfeeding or bottle feeding) is best.
Postdoctoral Research Fellow, Western Sydney University School of Medicine
The 1994 study by Dreher et al. does not measure cannabinoid levels in breast milk. From this study, one cannot make any claims about the presence or quantities of cannabinoids in breast milk.
However, there is more recent evidence suggesting metabolites of the endogenous cannabinoid system are present in breast milk. It appears these endogenous cannabinoids facilitate the suckling response and enhance feeding behaviour in infants.
Undark published an article in August 2019 discussing the study by Dreher et al. and how the effects of prenatal cannabis exposure are still unclear.
- 1 – Dreher et al. (1994) Prenatal marijuana exposure and neonatal outcomes in Jamaica: an ethnographic study. Pediatrics.
- 2 – Fride E. (2008) Multiple roles for the endocannabinoid system during the earliest stages of life: pre- and postnatal development. Journal of Neuroendocrinology.
- 3 – Heng et al. (2011) Differential developmental trajectories for CB1 cannabinoid receptor expression in limbic/associative and sensorimotor cortical areas. Synapse.
- 4 – Wu et al. (2016) Oxylipins, endocannabinoids, and related compounds in human milk: Levels and effects of storage conditions. Prostaglandins and Other Lipid Mediators.
- 5 – Gaitán et al. (2018) Endocannabinoid Metabolome Characterization of Transitional and Mature Human Milk. Nutrients.
- 6 – Scheyer et al. (2019) Consequences of perinatal cannabis exposure. Trends in Neurosciences.
- 7 – Zanettini et al. (2011) Effects of Endocannabinoid System Modulation on Cognitive and Emotional Behavior. Frontiers in Behavioural Neuroscience.