Fathers' THC exposure before conception caused lasting attention problems in rat offspring
Even modest, short-term THC exposure in male rats before mating produced long-lasting attention deficits in their adult offspring, suggesting epigenetic transmission through sperm.
Quick Facts
What This Study Found
Paternal THC exposure (2 mg/kg/day for 12 days) did not affect litter size, sex ratio, birth weight, or survival, but caused significant, long-lasting impairment in attentional performance and increased habituation of locomotor activity in adult offspring.
Key Numbers
2 mg/kg/day oral THC for 12 days (described as modest dose and brief period). Significant attention impairment detected in offspring during adulthood. No effects on clinical health markers at birth.
How They Did This
Male rats received oral THC (2 mg/kg/day for 12 days) or vehicle before mating. Offspring were tested in adulthood for attention (operant task) and locomotor behavior. Previous work from the same group confirmed THC-associated changes in sperm DNA methylation.
Why This Research Matters
Most research on cannabis and reproduction focuses on maternal exposure. This study demonstrates that paternal cannabis use before conception can also affect offspring through epigenetic changes in sperm, expanding the scope of reproductive risk.
The Bigger Picture
The companion human study from the same research group found similar epigenetic changes in sperm of men who smoke cannabis, raising the possibility that these animal findings translate to human fathers.
What This Study Doesn't Tell Us
Rat model with single dose level and duration. Mechanism (epigenetic transmission) is inferred from companion methylation study but not directly proven in this behavioral study. Only male offspring behavioral data presented.
Questions This Raises
- ?At what point before conception must a father stop using cannabis to avoid these effects?
- ?Do these epigenetic changes persist across multiple generations?
Trust & Context
- Key Stat:
- Attention deficits in adult offspring
- Evidence Grade:
- Preliminary: single animal study, though supported by companion epigenetic data in rats and humans.
- Study Age:
- Published in 2019.
- Original Title:
- Paternal THC exposure in rats causes long-lasting neurobehavioral effects in the offspring.
- Published In:
- Neurotoxicology and teratology, 74, 106806 (2019)
- Authors:
- Levin, Edward D(8), Hawkey, Andrew B(4), Hall, Brandon J(2), Cauley, Marty, Slade, Susan, Yazdani, Elisa, Kenou, Bruny, White, Hannah, Wells, Corinne, Rezvani, Amir H, Murphy, Susan K
- Database ID:
- RTHC-02134
Evidence Hierarchy
Tests effects in animals (usually mice or rats), not humans.
What do these levels mean? →Frequently Asked Questions
Can a father's cannabis use affect his children?
This rat study found that even short-term THC use before mating caused lasting attention problems in offspring, likely through changes in sperm DNA. Similar sperm changes have been found in human cannabis users.
Were the offspring physically affected?
No. Litter size, birth weight, sex ratio, and survival were all normal. The effects were behavioral, specifically impaired attention in adulthood.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-02134APA
Levin, Edward D; Hawkey, Andrew B; Hall, Brandon J; Cauley, Marty; Slade, Susan; Yazdani, Elisa; Kenou, Bruny; White, Hannah; Wells, Corinne; Rezvani, Amir H; Murphy, Susan K. (2019). Paternal THC exposure in rats causes long-lasting neurobehavioral effects in the offspring.. Neurotoxicology and teratology, 74, 106806. https://doi.org/10.1016/j.ntt.2019.04.003
MLA
Levin, Edward D, et al. "Paternal THC exposure in rats causes long-lasting neurobehavioral effects in the offspring.." Neurotoxicology and teratology, 2019. https://doi.org/10.1016/j.ntt.2019.04.003
RethinkTHC
RethinkTHC Research Database. "Paternal THC exposure in rats causes long-lasting neurobehav..." RTHC-02134. Retrieved from https://rethinkthc.com/research/levin-2019-paternal-thc-exposure-in
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.