New Study Finds Link Between Marijuana Use and Epigenetic Changes
A recent study conducted by Northwestern Medicine has found a connection between both recent and long-term marijuana use and changes in the human epigenome. The research, which focused on observing DNA methylation markers, has significant implications for understanding the potential health effects of marijuana use.
According to data from the Centers for Disease Control and Prevention (CDC), marijuana is the most widely used drug in the United States, with approximately 18% of all Americans having used it at least once in 2019. Despite its prevalent use and legalization in many states, the health consequences of marijuana use remain poorly understood.
Lifang Hou, MD, PhD, chief of Cancer Epidemiology and Prevention in the Department of Preventive Medicine and senior author of the study, explained, “Despite its growing popularity, as well as recent legalization by several states, the effect of marijuana on epigenetic factors has not been well studied…We wanted to further explore whether specific epigenetic factors were associated with marijuana and whether these factors are related to health outcomes.”
The study analyzed whole blood samples taken from participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study, with data from over 900 adults included. Researchers surveyed the participants regarding their recent and cumulative marijuana use and then performed DNA methylation profiling on their blood samples.
By studying changes in DNA methylation, the process by which methyl groups are added to DNA molecules, researchers were able to identify epigenetic changes associated with marijuana use. The study found numerous DNA methylation markers associated with recent and cumulative marijuana use, many of which were linked to cellular proliferation, hormone signaling, infections, and mental health disorders such as schizophrenia, bipolar disorder, and substance use disorders.
While the study does not establish a causal relationship between marijuana use and epigenetic changes, nor between those changes and health outcomes, it provides important insights for future research into the epigenetic effects of marijuana. Drew Nannini, DO, PhD, a postdoctoral fellow in the Hou lab and first author of the study, stated, “This research has provided novel insights into the association between marijuana use and epigenetic factors…Additional studies are needed to determine whether these associations are consistently observed in different populations and to examine the long-term effects of marijuana on health.”
The findings of this study contribute to the growing body of research on marijuana’s effects and highlight the need for further investigation into its potential health implications. The study was supported by the National Heart, Lung, and Blood Institute, the Kaiser Foundation Research Institute, and Northwestern University, with additional funding from the American Heart Association and the National Institute on Aging.