New research suggests that cannabis use may lead to significant epigenetic changes in the human body. A study involving over 1,000 adults, published in 2023, indicates that cannabis may affect how genes are expressed, rather than altering the DNA sequence itself. The findings, validated by a systematic literature review conducted in Portugal in 2024, highlight the need for further investigation into the health implications of cannabis consumption.
Epidemiologist Lifang Hou from Northwestern University led the research team that analyzed data from a long-term health study. This study tracked participants, who were aged 18 to 30 at its inception, over two decades. Participants reported their cannabis use throughout the study and provided blood samples at 15 and 20 years. The research aimed to explore how cannabis use correlates with changes in the epigenome, particularly through DNA methylation levels.
The addition or removal of methyl groups from DNA is a key epigenetic modification that can influence gene expression without altering the genetic code. This process can affect how cells interpret genetic instructions, similar to obscuring critical lines in a set of instructions. The researchers focused on the blood samples collected five years apart to identify specific epigenetic markers associated with cannabis use.
At the 15-year mark, the team identified numerous markers linked to recent cannabis use, including 22 markers for those who used cannabis recently and 31 related to cumulative use. By the 20-year mark, this number rose significantly; the researchers found 132 markers associated with recent use and 16 associated with cumulative use. Notably, one of the markers was previously linked to tobacco use, indicating a possible shared epigenetic mechanism between tobacco and cannabis.
The study also found multiple epigenetic changes associated with cannabis use that have been linked to various health issues. These include effects on cellular proliferation, hormone signaling, and neurological disorders such as schizophrenia and bipolar disorder. Although the study reveals associations between cannabis use and these epigenetic changes, it does not establish a direct causative relationship with health problems.
“This research has provided novel insights into the association between marijuana use and epigenetic factors,” said Drew Nannini, another epidemiologist from Northwestern University. He emphasized the need for additional studies to confirm whether these associations are consistent across different populations.
As cannabis use continues to be legalized in many regions, understanding its long-term health effects remains a critical area of research. The study has been published in the journal Molecular Psychiatry and underscores the importance of examining the implications of cannabis on health as societal attitudes continue to evolve.
The findings from this study contribute to a growing body of literature that seeks to unravel the complexities of cannabis use and its potential effects on human health, highlighting the necessity for ongoing research in this area.
