Smoking weed can alter your DNA.

As increasing numbers of countries and states review and relax their marijuana laws, it seems as though each new day brings yet another study either lauding or demonizing the drug. However, anti-weed researchers will have to really go some way to trump the latest study by a group of scientists from the University of Western Australia, who claim that marijuana use can mutate a person’s DNA, potentially making their children more susceptible to cancer.

The basis for this claim, which is outlined in the journal Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, revolves around a previous study into how certain genetic mutations occur. According to this paper, a process known aschromothripsis – or “chromosomal shattering” – can alter our DNA in such a way that we become more genetically predisposed to develop cancer and other serious illnesses.

This occurs when something goes wrong during cell division, otherwise known as mitosis. During this process, a cell’s chromosomes are arranged on microtubules known as mitotic spindles, ensuring the right genes are aligned in the right way when pairs of chromosomes break apart and re-join each other. However, ingesting certain toxic substances can cause these spindles to become deformed, meaning our DNA gets all jumbled up when our cells divide, often weakening the genes that protect us from cancer.

In light of this new information, the researchers point to a number of other studies that highlight an association between cannabis use and a range of life-threatening illnesses, including several types of cancer. They then cite another study that showed how THC – the active ingredient in marijuana – disrupts the formation of chains of proteins called tubulin, which just happens to be what mitotic spindles are made out of.

During mitosis, chromosomes become aligned along spindles. Giovanni Cancemi/Shutterstock

Extrapolating from this, they suggest that cannabis use may induce chromosomal shattering, causing smokers to become carriers of certain genes that increase their likelihood of suffering cancer, adding that these genes can then be passed on to future generations.

Summarizing this conclusion in simplified terms, study co-author Stuart Reece explainedthat he and his team “found that cancers and illnesses were likely caused by cell mutations resulting from cannabis properties having a chemical interaction with a person’s DNA.”

“The parents may not realise that they are carrying these mutations, which can lie dormant and may only affect generations down the track, which is the most alarming aspect,” he adds.

Though the research does provide some alarming insights into the potential consequences of smoking pot, it is important to note that these conclusions have not been experimentally verified, and much more work will be needed before the authors’ claims can be substantiated.