How alcohol and cannabis together change gene activity at different life stages | Research

The takeaway

Combined alcohol and cannabis exposure may cause lasting changes to gene expression through epigenetic mechanisms, with effects varying by life stage from prenatal development through adulthood.

People interested in how substances affect genetics, the science of addiction, or risks of combining alcohol and cannabis.

97.5 million Americans have used cannabis; epigenetic effects may compound with alcohol

What the researchers found

Both alcohol and cannabis independently modulate the epigenome through chromatin modification and remodeling, affecting gene activation and silencing. Co-exposure may have compounding effects that differ across developmental stages, contributing to addiction, behavioral abnormalities, and neurodegeneration.

Why it matters

Most substance research studies alcohol and cannabis separately, but many people use both. Understanding how they interact at the molecular level through epigenetic changes could reveal why co-use carries different risks than either substance alone.

The numbers in context

97.5 million Americans over 12 have used cannabis for non-medical use. 1 in 10 cannabis users develop dependence. 16% of US substance abuse admissions are cannabis-related (second to alcohol). 16 million adults have alcohol use disorders.

How the study worked

Narrative review covering epigenetic mechanisms (DNA methylation, histone modification, chromatin remodeling) affected by cannabis and alcohol exposure, examining evidence across prenatal, adolescent, and adult stages.

What this study cannot tell us

This is a narrative review with inherent selection bias. Much of the evidence comes from animal studies. The epigenetic overlap between alcohol and cannabis is largely theoretical at this stage. Individual genetic variation in epigenetic susceptibility was not addressed.

How to read the evidence

Preliminary: narrative review synthesizing mostly animal data with theoretical framework for co-exposure effects.

When this study was published

Published in 2019.

The bigger picture

Epigenetic changes can be passed to future generations, meaning substance use effects may extend beyond the individual user. Understanding these mechanisms is essential as both substances become more accessible through legalization.

Questions still open

Are epigenetic changes from co-exposure reversible with cessation? Do certain genetic backgrounds make people more susceptible to epigenetic damage from these substances? Can epigenetic markers be used to identify at-risk individuals?

Common questions

What are epigenetic changes?

Epigenetic changes alter how genes are read and expressed without changing the DNA sequence itself. Substances like alcohol and cannabis can turn genes on or off through mechanisms like DNA methylation and histone modification.

Is using alcohol and cannabis together worse for your genes?

This review suggests both substances independently cause epigenetic changes, and co-use may have compounding effects. However, much of this evidence comes from animal studies, and the human implications are still being researched.

Read the original research

The epigenetic modulation of alcohol/ethanol and cannabis exposure/co-exposure during different stages.

Open biology, 9(1), 180115

View on PubMed ↗Publisher’s paper ↗

Citation

Dobs, Yasminah Elsaadany; Ali, Mohamed Medhat. (2019). The epigenetic modulation of alcohol/ethanol and cannabis exposure/co-exposure during different stages.. Open biology, 9(1), 180115. https://doi.org/10.1098/rsob.180115