鈥淚T WILL cure, eliminate or definitely help any disease,鈥� an assistant in a shop just around the corner from 快猫短视频鈥檚 office in London tells me. Although these extraordinary claims aren鈥檛 made on the product鈥檚 packaging, the substance it contains is quickly gaining a reputation among consumers as a cure-all. Pain, anxiety, depression, cancer, psoriasis, Alzheimer鈥檚, irritable bowel syndrome 鈥� you name it, someone somewhere is saying this substance will help.
This apparently miraculous compound is cannabidiol, better known as CBD, a component of cannabis. Growing health claims coupled with a relaxing of laws around the sale of CBD-containing products has seeded a surge in interest.
Despite the willingness of some to tout CBD鈥檚 curative powers, there is limited evidence to back up these bold health promises. 鈥淭he range of claims is actually quite startling, and I don鈥檛 know whether to be worried or amused,鈥� says Harry Sumnall at Liverpool John Moores University, UK.
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Cannabis has long been suspected of improving health by those who use it. Since November 2018, UK doctors have been allowed to prescribe it in special cases (see 鈥�Medicinal cannabis鈥�, below). The change in legalisation came after high-profile campaigning, including from parents whose children have a severe form of epilepsy that seems to respond to cannabis products. A growing number of US states have legalised the plant for medicinal and recreational use too.
The chemical in cannabis that gets people high is called tetrahydrocannabinol (THC). Products with more than 0.3 per cent THC are illegal in the US and products with any THC at all are illegal in the UK. But CBD is different 鈥� you do not even need a prescription to legally buy products containing it.
We don鈥檛 know all of CBD鈥檚 effects, but some claim that it can give the touted health benefits of cannabis without the high. As a result, CBD is rapidly becoming big business. The US market for CBD products in 2018 was estimated at nearly $1.5 billion.聽 CBD in the UK, where the market is expected to be worth nearly .
The recent explosion of CBD products in the US is partly due to the passing of a piece of legislation known as the Farm Bill in 2018. This legalised the growing of hemp and the selling of cannabis products with very low THC levels.
Companies have heavily marketed the supposed health benefits of these products and they have spread to the UK.
As a result, CBD can now be found in everything from face creams to shampoos and pet foods, sold in dedicated shops and health food stores across the UK, US and elsewhere. It is also a food trend, with bars and restaurants selling CBD-infused drinks, meals and desserts.
How much do we really know about CBD? One salesperson told me the products can work on so many different disorders because CBD will 鈥渞egulate the cells鈥� of my body. The evidence to support claims like this is lacking, to say the least.
Most of the early research into the effects of cannabis and its components focused on negative effects, says Ziva Cooper at the UCLA Cannabis Research Initiative in Los Angeles.
Lack of evidence
More recently, some studies have hinted that CBD and other chemicals derived from cannabis might be and other conditions. For example, CBD seems to improve some symptoms of schizophrenia in people who are already taking other medication, and trials based on giving a single dose of CBD suggest that it might help with anxiety, says Cooper.
But there is very little of the gold standard of evidence: randomised clinical trials comparing CBD to a placebo. Only Epidiolex, a drug with CBD as an active ingredient for children with severe epilepsy, has been approved for medical use in the US.聽.
As the drug has only been around for two years, the long-term effects are unknown, says Barry Gidal at the University of Wisconsin. 鈥淪o far, nothing has cropped up, but it鈥檚 a new drug,鈥� he says. 鈥淲e鈥檙e going to have to watch it for a while and be vigilant.鈥�
From the drug trial, CBD appears to be safe and isn鈥檛 addictive, but the UK鈥檚 National Health Service lists drowsiness, diarrhoea, rashes and an increased risk of infections as .
There is also a lack of evidence on appropriate dosage, although salespeople are often willing to offer advice on how much of each product to use.
鈥�70% of CBD products tested were contaminated with heavy metals鈥�
鈥淚t鈥檚 all made-up stuff,鈥� says Gidal. No one knows how much CBD will affect any one individual, or whether taking it in the form of a pill, spray or tea makes any difference.
On top of that, it isn鈥檛 clear how much CBD is in a product. When the UK , which represents the industry, sent 30 shop-bought CBD products for lab testing, it found that one item 鈥� a 30 millilitre bottle selling for 拢90 鈥� . Almost half the products had measurable levels of THC, making them illegal. And one had enough ethanol to be legally considered an alcoholic beverage.
鈥淲e don鈥檛 actually know what鈥檚 in many of the products that are being sold,鈥� says Sumnall, as there is no specific body checking CBD products. 鈥淏ecause the CBD market is not regulated properly, we don鈥檛 really have any control over quality or content,鈥� he says.
Several factors can influence how much CBD is in a product extracted from a cannabis plant. Levels can vary between batches from the same grower. There are only a couple of firms worldwide that supply standardised products certified for medical use.
Worse, CBD products could also contain potentially harmful heavy metals and pesticides. Cannabis plants are especially good at sucking these up from soil. Tests of 240 CBD products in the US suggested that 70 per cent were contaminated with heavy metals, as well as pesticides and toxic mould, according to a report from media outlet CBS Austin in May. Other media investigations have made similar findings, although the retailers dispute the results.
Another worry is that those who are unwell might be getting medical advice and treatment from people who aren鈥檛 qualified to give it. 鈥淭he vernacular term in the US is the 鈥榖udtender鈥�,鈥� says Gidal. 鈥淲ho knows what educational background they have and they are making important medical decisions for you about the dose and what preparation you ought to be taking.鈥�
I was tempted to try CBD to see what all the fuss is about. But with 10 CBD gummies costing 拢20, the price alone was enough to put me off. Given that I can鈥檛 be sure what is in the products 鈥� let alone their effects on my body and brain 鈥� I have decided I would rather not put my health in the hands of the budtender.
Medicinal cannabis
As of 1 November last year, doctors in the UK have been able to prescribe medical cannabis. But now they also face advice not to.
released last week by the National Institute for Health and Care Excellence states that cannabis products shouldn鈥檛 be offered to people with chronic pain or muscle spasticity, unless as part of a trial. It also says there isn鈥檛 enough evidence that these products work in severe epilepsy.
The guidelines, which are open to comments, will come as a disappointment to individuals who are already struggling to get a prescription for medical cannabis products. The UK produces more legal cannabis than any other country, but medical cannabis is still hard to come by. Some National Health Service trusts won鈥檛 pay for cannabis prescriptions, so some people may obtain them from private clinics.
The US landscape is even messier. At the federal level, cannabis that contains less than 0.3 per cent of the psychoactive component tetrahydrocannabinol (THC) is legal. Plants with higher levels are not.
Still, whether or not you can legally buy cannabis varies from state to state. Some have legalised medical cannabis; others have approved the drug for recreational use. Again, the list of conditions that can be used as a legitimate reason to buy medical cannabis varies by state.
鈥淲hen states passed laws, those laws weren鈥檛 based on evidence 鈥� they were passed for political reasons,鈥� says Ziva Cooper at the UCLA Cannabis Research Initiative in Los Angeles.
