Cannabis Use During Breastfeeding Changed Protein and Fat Levels in Breast Milk
Breast milk samples with detectable cannabis metabolites had higher protein levels and 11% lower fat content compared to samples without cannabis exposure, though calorie and carbohydrate levels were unchanged.
Quick Facts
What This Study Found
The presence of cannabis metabolites in breast milk was associated with an increase of 0.244 mg/dL in protein and an 11% reduction in fat content. Energy and carbohydrate levels were not significantly different between exposed and unexposed samples.
Key Numbers
637 breast milk samples; 165 with detectable cannabis metabolites; protein increase of 0.244 mg/dL (95% CI 0.112-0.376, p<0.05); 11% reduction in fat (p=0.020); no significant differences in energy or carbohydrates.
How They Did This
Cross-sectional study analyzing 637 breast milk samples, of which 165 had detectable cannabis metabolites (study group) and 472 did not (control group). Multivariable linear regression was used to assess associations between cannabis metabolite presence and protein, carbohydrate, fat, and calorie content.
Why This Research Matters
As cannabis use rises among lactating women, understanding its effects on breast milk composition is important for infant nutrition. Changes in protein and fat levels could theoretically affect infant development, though the clinical significance of these specific changes is unknown.
The Bigger Picture
This is one of the first studies to examine how cannabis affects the macronutrient composition of breast milk beyond simply detecting THC transfer. The finding adds a new dimension to discussions about cannabis and breastfeeding that have mostly focused on THC exposure to infants.
What This Study Doesn't Tell Us
Cross-sectional design cannot establish causation. Self-reported cannabis use may underestimate exposure. Cannot determine dose-response relationships. The clinical significance of the observed macronutrient changes for infant health is unknown. Does not account for all potential confounders (diet, other substances).
Questions This Raises
- ?What are the downstream effects of altered breast milk macronutrients on infant growth?
- ?Does the frequency or amount of cannabis use affect the degree of macronutrient change?
- ?What mechanisms explain how cannabis alters breast milk composition?
Trust & Context
- Key Stat:
- Cannabis-exposed breast milk had 11% less fat and more protein than unexposed samples
- Evidence Grade:
- Moderate: Meaningful sample size with objective metabolite detection and multivariable adjustment, though cross-sectional design and unknown clinical significance of findings are limitations.
- Study Age:
- Published in 2025.
- Original Title:
- The Effect of Cannabis Consumption During Lactation on the Macronutrient Concentrations in Breast Milk.
- Published In:
- Breastfeeding medicine : the official journal of the Academy of Breastfeeding Medicine, 20(1), 33-41 (2025)
- Authors:
- Narayanan, Priyadharshini, Bertrand, Kerri, Waalen, Jill, Chambers, Christina, Ferran, Karen, Bandoli, Gretchen
- Database ID:
- RTHC-07234
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Is it safe to use cannabis while breastfeeding?
This study found that cannabis use changes the macronutrient composition of breast milk but did not assess whether those changes affect infant health. The question of safety requires further research, particularly regarding how altered protein and fat levels influence infant development.
How were cannabis metabolites detected in breast milk?
The study used laboratory testing to detect measurable levels of cannabis metabolites directly in breast milk samples. Some mothers who self-reported cannabis use did not have detectable metabolites, and these were placed in the control group.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-07234APA
Narayanan, Priyadharshini; Bertrand, Kerri; Waalen, Jill; Chambers, Christina; Ferran, Karen; Bandoli, Gretchen. (2025). The Effect of Cannabis Consumption During Lactation on the Macronutrient Concentrations in Breast Milk.. Breastfeeding medicine : the official journal of the Academy of Breastfeeding Medicine, 20(1), 33-41. https://doi.org/10.1089/bfm.2024.0083
MLA
Narayanan, Priyadharshini, et al. "The Effect of Cannabis Consumption During Lactation on the Macronutrient Concentrations in Breast Milk.." Breastfeeding medicine : the official journal of the Academy of Breastfeeding Medicine, 2025. https://doi.org/10.1089/bfm.2024.0083
RethinkTHC
RethinkTHC Research Database. "The Effect of Cannabis Consumption During Lactation on the M..." RTHC-07234. Retrieved from https://rethinkthc.com/research/narayanan-2025-the-effect-of-cannabis
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.