Recent research conducted by Northwestern Medicine has shed light on the impact of marijuana use on the human epigenome, revealing associations between cannabis consumption and changes in DNA methylation. The study, published in the journal Molecular Psychiatry, delved into the long-term effects of marijuana use on the epigenetic factors that regulate gene expression and control how our bodies function.
Marijuana remains the most widely used drug in the United States, with approximately 48.2 million people, or roughly 18% of all Americans, reporting marijuana use at least once in 2019, according to data from the Centers for Disease Control and Prevention (CDC).
The research, led by Dr. Lifang Hou, Chief of Cancer Epidemiology and Prevention in the Department of Preventive Medicine, aimed to explore the effects of marijuana use on epigenetic factors and their potential health implications. The team studied a group of over 1,000 adults who had participated in a long-term study, which spanned two decades, and provided blood samples at two time points: 15 and 20 years after baseline. These participants were aged between 18 and 30 at the start of the study.
Epigenetic changes were assessed by examining DNA methylation levels in the blood samples. DNA methylation involves the addition or removal of methyl groups from DNA, which can influence gene activity without altering the genetic sequence. Such changes can be triggered by environmental and lifestyle factors and may be inherited by future generations.
The study found significant associations between cumulative marijuana use and multiple epigenetic markers over time. Specifically, 22 DNA methylation markers were associated with recent marijuana use, and 31 markers were linked to cumulative cannabis use in the blood samples taken at the 15-year point. At the 20-year mark, 132 markers were identified in association with recent use and 16 markers with cumulative use.
Notably, one of the identified markers was also previously associated with tobacco use, indicating a potential shared epigenetic regulation between marijuana and tobacco consumption.
Dr. Hou emphasized that while the research has provided new insights into the connections between marijuana use and epigenetic factors, it does not establish a direct causal relationship between cannabis consumption and the observed changes. The study also does not definitively determine the health consequences of these epigenetic alterations.
Experts are urging further investigation to determine if these associations are consistently observed in different populations. Additionally, research examining the long-term effects of marijuana on age-related health outcomes could provide more comprehensive insights into the potential impacts of cannabis use on overall health.
The findings from this study underscore the need for a deeper understanding of the effects of marijuana on the human body, given its widespread use and increasing legalisation in various states. Future research could contribute to informed decision-making surrounding cannabis use and its potential implications for public health.
