A recent study involving over 1,000 adults has revealed that cannabis use may have lasting effects on the body by altering the epigenome, a complex system that influences how genes are expressed. Researchers from Northwestern University found that cannabis may lead to changes in epigenetic markers, which function like switches that turn genes on or off, impacting various bodily functions.
Lifang Hou, an epidemiologist at Northwestern University, emphasized the significance of these findings, stating, “We observed associations between cumulative marijuana use and multiple epigenetic markers across time.” The study, published in Molecular Psychiatry in July 2023, highlights the ongoing evolution of cannabis research, especially in light of its increasing legality across the United States and other countries.
The researchers accessed data from a long-term health study that tracked participants from the ages of 18 to 30 for two decades. Participants reported their cannabis usage and provided blood samples at the 15-year and 20-year marks. This comprehensive approach allowed the team to analyze the epigenetic changes over time, particularly focusing on DNA methylation levels—a key form of epigenetic modification.
DNA methylation involves the addition or removal of methyl groups from DNA, which influences how cells interpret and utilize genetic instructions. These modifications can be influenced by environmental and lifestyle factors and may even be passed down to future generations. “We previously identified associations between marijuana use and the aging process as captured through DNA methylation,” Hou added.
The analysis revealed multiple DNA methylation markers linked to cannabis use. In samples taken at the 15-year point, researchers identified 22 markers associated with recent usage and 31 linked to cumulative use. By the 20-year mark, the number of markers related to recent usage increased to 132, while 16 remained tied to cumulative use.
Interestingly, the study identified a consistent epigenetic marker previously associated with tobacco use. “This suggests a potential shared epigenetic regulation between tobacco and marijuana use,” Hou explained. The implications of these findings are significant, as previous research has linked various epigenetic changes to issues such as cellular proliferation, hormone signaling, and neurological disorders including schizophrenia and bipolar disorder.
Despite these findings, the authors caution that the study does not establish a direct causative link between cannabis use and health problems. Drew Nannini, another epidemiologist at Northwestern, noted, “This research has provided novel insights into the association between marijuana use and epigenetic factors.” He emphasized the need for further studies to confirm whether these associations hold true across different populations and to explore the long-term health impacts of cannabis use.
As cannabis use becomes more prevalent, understanding its effects on health and well-being is increasingly important. This study adds to the growing body of research that explores the complex relationship between lifestyle choices and genetic expression. Future studies will be crucial in providing clearer insights into how cannabis affects the human body over time.
