A study by Northwestern Medicine links recent and long-term marijuana use to changes in the human epigenome. In this study, important epigenetic changes were identified through observation of DNA methylation markers. While this study does not prove causality, it does set the stage for further research into the epigenetic effects of marijuana and its potential health effects.
Recent and long-term marijuana use are linked to changes in the human epigenome, new Northwestern Medicine study published in the journal molecular psychiatry I found
Marijuana ranks as the most widely used drug in the United States. According to data from the Centers for Disease Control and Prevention (CDC), approximately 48.2 million people, or about 18% of all Americans, used marijuana at least once in 2019. This is the most recent year for which data are available.
Despite the widespread and legalization of marijuana use in several states, the health effects of marijuana use are poorly understood, according to Liefang Hou, M.D., director of cancer epidemiology and prevention in the Department of Preventive Medicine and the study’s lead author.
Drew Nannini, Ph.D., a postdoctoral fellow in the Hou lab, is the lead author of the study published in 2006. molecular psychiatry. Credit: Northwestern Medicine
“Despite the growing popularity of marijuana, and its recent legalization in several states, the effects of marijuana on epigenetic factors are understudied,” said Dr. Hou, who is also director of the Center for Global Oncology at the Robert J. Havey, M.D., Global Health Institute. “We previously identified a link between marijuana use and the aging process. DNA methylation. We wanted to further investigate whether specific epigenetic factors are associated with marijuana and whether these factors are associated with health outcomes. ”
In this study, researchers analyzed whole blood samples collected 5 years apart from people who had previously participated in the Young Adult Coronary Artery Risk Development (CARDIA) study. The current study included data from more than 900 adults.
The scientists surveyed each participant about recent marijuana use and estimated cumulative use, and then performed DNA methylation profiling on blood samples to reveal epigenetic changes associated with marijuana use.
By studying changes in DNA methylation—the biological process by which methyl groups are added to DNA molecules, thereby altering gene expression—scientists were able to link marijuana use to changes in the human epigenome.
Overall, the researchers observed 22 and 31 DNA methylation markers associated with recent and cumulative marijuana use, respectively, from the first sample and 132 and 16 methylation markers from the second batch of samples, according to the study.
Many of the epigenetic changes were found in pathways previously associated with mental health disorders such as cell proliferation, hormone signaling, infectious diseases, schizophrenia, bipolar disorder and substance use disorders, Ho said.
Dr. Lifang Hou, Chief of Cancer Epidemiology and Prevention, Department of Preventive Medicine, said: molecular psychiatry. Credit: Northwestern Medicine
“In our study, we observed associations between cumulative marijuana use and multiple epigenetic markers over time,” Hou said. “Interestingly, we consistently identified markers previously associated with tobacco use, suggesting that there may be common epigenetic regulation between tobacco and marijuana use. The observed marijuana markers were also associated with cell proliferation, infections and psychiatric disorders, but additional studies are needed to replicate and validate these findings.”
Although the study does not establish causal links between marijuana use and epigenetic changes, or between those epigenetic changes and observed health outcomes, the findings may aid future research into the epigenetic effects of marijuana use, said Drew Nannini, DO, PhD, a postdoctoral fellow in the Hou lab and the first author of the study.
“This study provides new insight into the link between marijuana use and epigenetic factors,” Nanini said. “Additional research is needed to determine whether these associations are consistently observed in different populations. In addition, studies investigating age-related health effects of marijuana may provide further insight into the long-term effects of marijuana on health.”
Reference: Genome-wide DNA methylation association study of recent and cumulative marijuana use in middle-aged adults. Drew R. Nannini, Yeahan Zheng, Brian T. Joyce, Kyeezu Kim, Tao Gao, Jun Wang, David R. Jacobs, Pamela J. Schreiner, Kristine Yaffe, Philip Greenland, Donald M. Lloyd-Jones, Lifang Hou, May 31, 2023. , molecular psychiatry.
DOI: 10.1038/s41380-023-02106-y
This research was supported in collaboration with the National Heart, Lung, and Blood Institute and the Kaiser Foundation Research Institute. Northwestern University. Additional funding was provided by American Heart Association grants 14SFRN20790000 and 17SFRN33700278, and National Institute on Aging grants R21AG063370, R21AG068955, R01AG081244, and R01AG069120.
