Could smoking cannabis prevent or treat cancer?
The internet is full of claims about miracle cures for diseases like cancer - with some people suggesting cannabis could be of them.
There has been speculation for a long time that cannabis could not only help cure cancer, but also both prevent it and help relieve its symptoms.
On the flip side, one recent study suggested cannabis could actually increase the risk of developing cancer.
Here is what Cancer Research UK has to say about what is true and false to help clear up some of the myths:
Could cannabis help cure cancer?
The short answer is no - or not that we know about yet.
Cancer Research UK says on its website: “
At the moment, there simply isn’t enough evidence to prove that cannabinoids – whether natural or synthetic – works to treat cancer in patients, although research is ongoing. And there’s certainly no evidence that ‘street’ cannabis can treat cancer.”
And the experts at the charity are not impressed by online videos suggesting cannabis can be some kind of miracle cure: “Extraordinary claims require extraordinary evidence – YouTube videos are emphatically not scientific evidence, and we are not convinced by them.”
They say they have been dubbed “part of a global conspiracy to suppress cancer cures” - but say this is absurd, and that they do fund cannabis research when it meets their funding rules.
Could the drug help prevent cancer?
There have been experiments with mice with more positive signs on this front - but the evidence is reportedly far from solid.
“In experiments with mice, animals given very high doses of purified THC seemed to have a lower risk of developing cancer, and there has been some research suggesting that endocannabinoids, cannabinoids produced by the body, can suppress tumour growth,” according to Cancer Research UK.
“But there’s no solid scientific evidence at the moment to show that cannabinoids or cannabis can cut the risk of cancer in people.”
Could cannabis reduce the pain and symptoms of cancer?
Many individuals swear by cannabis as a form of pain relief for serious conditions.
The evidence is better here for the benefits of cannabis, but there are still hurdles to overcome.
Several parts of the world have legalised medical use of marijuana for palliative care to relieve pain from illnesses including cancer.
Some research has also suggested cannabis can help prevent vomiting caused by chemotherapy.
But Cancer Research UK warns: “One of the problems of using herbal cannabis is about dosage – smoking it or taking it in the form of tea often provides a variable dose, which may make it difficult for patients to monitor their intake.
“So researchers are turning to alternative dosing methods, such as mouth sprays, which deliver a reliable and regulated dose.”
The NHS website has also warned that the “toxic components” of weed also mean its use as medicine has not been sanctioned - with more work needed to make it safe and effective.
Is there any risk of cannabis causing cancer?
The British Lung Foundation made the headlines in 2012 after highlighting cannabis as a potential cause of lung cancer.
Dame Helena Shovelton, chief executive of the charity, said at the time: “Young people in particular are smoking cannabis unaware that, for instance, each cannabis cigarette they smoke increases their chances of developing lung cancer by as much as an entire packet of 20 tobacco cigarettes.”
But several experts are highly sceptical about the controversial claim, and NHS chiefs have called for more studies because there are so few on cannabis’ effects on lung health.