A recent study has found that cannabis use may lead to significant epigenetic modifications in the human body, impacting how genes are expressed rather than altering the DNA sequence itself. Conducted by researchers at Northwestern University, this investigation included data from over 1,000 adults and revealed associations between cannabis consumption and epigenetic markers over time.
Lifang Hou, an epidemiologist involved in the study, explained, “We observed associations between cumulative marijuana use and multiple epigenetic markers across time.” The findings were published in Molecular Psychiatry in 2023, contributing to the ongoing discussion about the health implications of cannabis, a substance that nearly half of Americans have tried at least once.
The researchers analyzed data from a long-term health study that tracked participants from the ages of 18 to 30 over two decades. Participants provided information about their cannabis use and blood samples at intervals of 15 and 20 years. The study focused on examining epigenetic changes, specifically looking at DNA methylation levels, which can influence gene expression without modifying the underlying genetic code.
Methylation involves the addition or removal of methyl groups to DNA, affecting how cells interpret genetic instructions. Environmental and lifestyle factors can trigger these methylation alterations, which may even be inherited by future generations. The researchers identified multiple DNA methylation markers associated with cannabis use, noting that they found 22 markers related to recent use and 31 linked to cumulative use in the 15-year blood samples. By the 20-year mark, they identified 132 markers associated with recent use and 16 linked to cumulative usage.
Interestingly, the study consistently identified one methylation marker previously associated with tobacco use, suggesting a potential overlap in the epigenetic mechanisms of both substances. The implications of these epigenetic changes are significant, as they have been linked to various health issues, including cellular proliferation, hormone signaling, and neurological disorders such as schizophrenia and bipolar disorder.
Although the study provides valuable insights, it is crucial to note that it does not establish a direct causal relationship between cannabis use and health problems. As Drew Nannini, another epidemiologist with the research team, stated, “This research has provided novel insights into the association between marijuana use and epigenetic factors.”
Nannini emphasized that further studies are necessary to determine whether these associations hold true across different populations. Investigating the impact of marijuana on age-related health outcomes may yield additional information regarding its long-term effects on health.
The study adds to the growing body of research on cannabis, especially as legalization spreads in various regions. With the aim of understanding how cannabis affects health, ongoing research will be pivotal in providing clarity on this complex topic.
