Study Reveals Cannabis Use Can Cause Changes in the Human Body’s Epigenome
A study of over 1,000 adults showed that cannabis use (from the hemp plant) can cause changes in the human body’s epigenome.
The epigenome turns genes on or off to change how our body works.
“We observed an association between cumulative marijuana use and multiple genetic markers over time,” says Lifang Ho, a preventive medicine epidemiologist at Northwestern University’s Feinberg School of Medicine.
Cannabis is a widely used substance in the United States, and 49% of people have tried it at least once in their lives, he and a group of American researchers said in a published article. Some US states and other countries have legalized it, but we still don’t fully understand its impact on our health.
The researchers studied nearly 1,000 adults who had taken part in a previous long-term study that asked them about their 20-year cannabis use. During this period, study participants donated blood samples twice, at ages 15 and 20. Their age ranged from 18 to 30 years.
Using these blood samples five years apart, the team looked at epigenetic changes, specifically DNA methylation levels, in people who had recent or long-term use of cannabis.
The addition or removal of methyl groups from DNA is one of the most studied modifications of epigenetic inheritance. Without changing the genetic sequence, it changes the activity of genes because it is difficult for cells to read the instructions of the genome with these molecular changes in their path.
Environmental and lifestyle factors can cause these methylation changes that can be passed on to future generations, and blood biomarkers can provide information about both recent and past exposures.
“We had previously identified a link between marijuana use and the aging process, captured by DNA methylation,” says Hu. “We wanted to further investigate whether there are specific epigenetic factors associated with marijuana and whether these factors are associated with health outcomes.”
Comprehensive data on cannabis use by participants allowed cumulative use over time as well as recent use to be assessed and compared to DNA methylation markers in their blood for analysis.
They found several markers of DNA methylation in blood samples over 15 years, 22 of which are associated with recent use and 31 with cumulative cannabis use. In samples taken 20 years later, they identified 132 markers associated with recent use and 16 markers associated with cumulative use.
Multiple epigenetic changes associated with cannabis use have previously been associated with things like cell proliferation, hormonal signaling, inflammation, neurological disorders such as schizophrenia and bipolar disorder, and substance use disorders.
It is important to note that this study does not prove that cannabis directly causes these changes or health problems.
“This study provides new insights into the relationship between marijuana use and epigenetic factors,” says epidemiologist Drew Nanini of Northwestern University. “More research is needed to determine whether these associations are consistent across populations. In addition, studies examining the effects of marijuana on age-related health outcomes may provide deeper insights into the long-term health effects of marijuana.”
The study was published in Molecular Psychiatry.
Source: Science Alert