THC study boosts cannabis pain relief claim
More research needed on long-term outcomes and side-effects of psychoactive chemical, say researchers
CANNABIS products containing the psychoactive chemical which gets people “high” may help to alleviate pain, a study suggests.
Scientists have been debating the pros and cons of the drug as a pain relief treatment for years but there is as yet no consensus on its use.
A study run by Oregon Health and Science University (OHSU) in the United States looked at 25 studies and collated all the available data to see if taking marijuana had any benefits.
The research, funded by the US department of health and human services, was published in the Annals of Internal Medicine. It found that cannabis products with high levels of THC “may be associated with short-term improvements in chronic pain”.
However, the researchers warned that these same products also increase the risk of side-effects, including dizziness and sedation.
“Studies are needed on long-term outcomes and further evaluation of product formulation effects,” they said.
Cannabis was legalised for medicinal use in the UK in November 2018 but remains largely unprescribed with doctors unconvinced by the current body of evidence.
Some experts have called for placebo-controlled clinical trials, the gold standard of medicinal research, to provide a robust analysis of cannabis as a treatment. This review provides no new data, but does bring together various studies and scrutinises the available information to offer yet more evidence that cannabis, and THC, may be an effective medicine for short-term ailments lasting less than six months.
Prof Marian Mcdonagh, lead author at OHSU, said: “In general, the limited amount of evidence surprised all of us.
“With so much buzz around cannabis-related products, and the easy availability of recreational and medical marijuana in many [US] states, consumers and patients might assume there would be more evidence about the benefits and side effects. Unfortunately, there is very little scientifically valid research into most of these products.
“We only saw a small group of observational cohort studies on cannabis products that would be easily available in [US] states that allow it and these were not designed to answer the important questions on treating chronic pain.”
The authors add: “For some cannabis products, such as whole-plant products, the data are sparse with imprecise estimates of effects and studies had methodological limitations.” Cannabis products are based on their ability to mimic the body’s own endocannabinoid system.
This is composed of receptors and enzymes in the nervous system that regulate bodily functions and can affect the sensation of pain.
In the evidence review, researchers sorted the available cannabis-related products into high, comparable and low ratios of THC with CBD, another medicinal chemical ingredient present in the plant but one with no psychoactive properties.