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Cannabis can alter DNA and cause diseases in both smokers and their offspring Getty Images

Cannabis consumption may alter smokers' DNA structure, potentially causing mutations that may expose them to severe illnesses, scientists have said. Worse still, this could increase the risk of cancers and foetal malformations for their offspring.

In previous epidemiological studies, the link between cannabis and cancer in adults and children, as well as foetal malformations had already been established.

However, the molecular mechanisms behind this phenomenon had not been explained.

The latest study, published in Mutation Research & Fundamental and Molecular Mechanisms of Mutagenesis, focuses on explaining what can happen to chromosomes when THC – the active molecule in cannabis - is present in the body.

Chromosome segregation

The scientists, from the University of West Australia, conducted an extensive review of scientific literature. They discovered that THC - the active chemical compound in cannabis - interferes with the segregation of chromosomes during cell division.

"Through our research we found that cancers and illnesses were likely caused by cell mutations resulting from cannabis properties having a chemical interaction with a person's DNA," Associate Professor Stuart Reece explained in a statement.

This interaction may cause a phenomenon of "chromothripsis" – that is the chromosome shattering into many pieces and then chaotically reassembling into a functioning chromosome. Such an alteration to the DNA structure can cause mutations inducing cancer and other negative health consequences for parents and children.

"When the chemicals in cannabis change a person's DNA structure in such a way, it can lead to slow cell growth and have serious implications for the foetal development of babies that may cause limbs or vital organs not to develop properly or cause cancers", Reece pointed out.

Passed on to children

Although the effects of the mutations are not necessarily observed in cannabis smokers, and they may seem healthy, unseen damage to their DNA can be passed on to their children and cause illnesses for several generations down the line.

"Even if a mother has never used cannabis in her life, the mutations passed on by a father's sperm can cause serious and fatal illnesses in their children," Reece says. "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."