Sean Cate

Sean Cate

October 18, 2024

Cannabis Use Linked to Epigenetic Changes, Study Shows

New research is shedding light on how cannabis use may lead to changes in the human epigenome—potentially affecting gene expression and possibly influencing health outcomes. Let’s explore what scientists have discovered about the links between cannabis use, DNA methylation, and the potential long-term implications for health.

Understanding Epigenetic Changes

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Epigenetics involves changes in gene activity that do not alter the DNA sequence itself but can significantly impact how cells read these instructions. One of the most common forms of epigenetic modification is DNA methylation, where methyl groups are added to DNA molecules, influencing gene expression.1 These changes can be triggered by environmental factors, lifestyle choices, or even drug use, like cannabis.

Researchers have found that these epigenetic modifications can sometimes be passed down to future generations, potentially affecting not only the individual using cannabis but also their descendants.2 This raises important questions about the broader impacts of marijuana use beyond the immediate effects.

Cannabis Use and DNA Methylation

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A study conducted by Northwestern Medicine and published in Molecular Psychiatry found significant links between cannabis use and DNA methylation changes in human blood samples. Researchers observed 22 DNA methylation markers associated with recent cannabis use and 31 markers linked to cumulative use.3 These findings suggest that even occasional cannabis consumption could have a measurable impact on gene activity.

Lifang Hou, the senior author of the study, noted that despite the rising popularity and legalization of marijuana, its effects on epigenetic factors have been largely understudied. “We wanted to further explore whether specific epigenetic factors were associated with marijuana and whether these factors are related to health outcomes,” Hou explained.

Long-Term Implications for Health

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One of the key findings from the research involved the potential health implications of these epigenetic changes. Many of the DNA methylation markers identified in cannabis users were previously linked to pathways involving cellular proliferation, hormone signaling, and mental health disorders such as schizophrenia and bipolar disorder. This discovery indicates that cannabis use might influence genetic factors tied to these conditions.

Drew Nannini, the study’s first author, highlighted the importance of these findings: “We consistently identified one marker that has previously been associated with tobacco use, suggesting a potential shared epigenetic regulation between tobacco and marijuana use“. This overlap could mean that similar mechanisms influence how the body responds to both substances, impacting health risks over time.

Read More: 7 Surprising Side Effects of Cannabis After 50

Cannabis Use and Reproductive Health

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The impact of cannabis use extends to reproductive health as well. Delta-9-tetrahydrocannabinol (Δ9-THC), the primary psychoactive compound in cannabis, has been shown to affect the sperm epigenome, particularly at the DNA methylation level. This could have consequences for the health of offspring, with potential effects on developmental genes like DLGAP2.

Studies in both humans and animal models have revealed that marijuana exposure can lead to conserved epigenetic targets in sperm cells, although some level of recovery may occur after drug abstinence. These findings are particularly concerning for young men, who are the most frequent cannabis users in Western countries.

The full leaf of a marijuana plant
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Despite the growing acceptance and legalization of cannabis, misconceptions about its safety persist. Many people view marijuana as a harmless recreational substance, but its influence on the epigenome suggests otherwise. The study’s findings emphasize the need for more research to understand the long-term effects of cannabis use, especially given its increasing prevalence in society.

Cannabis is the most widely used illicit drug in Western countries, with an estimated 48.2 million Americans having used it at least once in 2019. As legalization efforts continue, it’s crucial for both the public and policymakers to consider these potential health risks when discussing cannabis regulation and use.

Future Research Directions

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While the Northwestern Medicine study provided valuable insights into the link between cannabis use and epigenetic changes, the researchers stress the need for further studies to confirm these findings. “Additional studies are needed to determine whether these associations are consistently observed in different populations,” said Nannini. More research is also necessary to explore how these epigenetic changes might contribute to age-related health outcomes or other long-term effects.

As our understanding of the genome continues to evolve, so too will our comprehension of how substances like cannabis influence our genetic makeup and overall health. This study marks an important step toward uncovering these intricate connections.

Read More: Cannabis: If You’re Trying to Relieve Stress Less is More. Here’s How Much You Need.

Sources

  1. Cannabis Use Linked to Epigenetic Changes, Study Shows.” Science Alert. Rebecca Dyer. September 2024
  2. Cannabis and Paternal Epigenetic Inheritance.” NCBI. Filomena Mazzeo and Rosaria Meccariello. May 2023.
  3. Marijuana Use Linked to Epigenetic Changes.Northwestern Medicine. Olivia Dimmer. July 18, 2023.