New research has found that THC in blood and saliva are poor measures of cannabis impairment, potentially having major implications for global drug-driving laws.
Researchers at the University of Sydney’s Lambert Initiative analysed all available studies on the relationship between driving performance and concentrations in blood and saliva of tetrahydrocannabinol (THC), the intoxicating component of cannabis.
The results indicate that blood and oral fluid THC concentrations are relatively poor or inconsistent indicators of cannabis-induced impairment.
This contrasts with the much stronger relationship between blood alcohol concentrations and driving impairment.
Lead author Dr Danielle McCartney, from the Lambert Initiative for Cannabinoid Therapeutics, said: “Higher blood THC concentrations were only weakly associated with increased impairment in occasional cannabis users while no significant relationship was detected in regular cannabis users.
“This suggest that blood and oral fluid THC concentrations are relatively poor indicators of cannabis-THC-induced impairment.”
For the study, researchers analysed data from 28 publications involving consumption of either ingested or inhaled forms of cannabis. They then characterised the relationships between blood and oral fluid THC concentrations and driving performance (or driving-related skills such as reaction time or divided attention).
For infrequent, or occasional cannabis users, some significant correlations between blood and oral fluid THC concentrations and impairment were observed. However, the researchers note that most of these relationships were “weak” in strength.
No significant relationship between blood THC concentration and driving performance was observed for ‘regular’ (weekly or more often) cannabis users.
The research raises questions about the validity of the methods used to assess cannabis-related impairment.
This includes the widespread random mobile drug testing for THC in saliva in Australia and the testing for specific concentrations of blood THC that is used to detect impaired drivers in some US states and in Europe.
Dr McCartney said: “Our results indicate that unimpaired individuals could mistakenly be identified as cannabis-intoxicated when THC limits are imposed by the law. Likewise, drivers who are impaired immediately following cannabis use may not register as such.”
The researchers also found that subjective intoxication – how “stoned” individuals reported that they felt – was also only weakly associated with actual impairment.
This means that drivers should not necessarily rely on perception of their own impairment in deciding whether they are fit to drive.
Co-author Dr Thomas Arkell from the Lambert Initiative said: “Individuals are better to wait a minimum length of time, between three and 10 hours, depending on the dose and route of administration, following cannabis use before performing safety-sensitive tasks. Smartphone apps that may help people assess their impairment before driving are currently under development and may also prove useful.”
Academic director of the Lambert Initiative, Professor Iain McGregor, said: “THC concentrations in the body clearly have a very complex relationship with intoxication. The strong and direct relationship between blood-alcohol concentrations and impaired driving encourages people to think that such relationships apply to all drugs, but this is certainly not the case with cannabis.
“A cannabis-inexperienced person can ingest a large oral dose of THC and be completely unfit to drive yet register extremely low blood and oral fluid THC concentrations. On the other hand, an experienced cannabis user might smoke a joint, show very high THC concentrations, but show little if any impairment.
“We clearly need more reliable ways of identifying cannabis-impairment on the roads and the workplace. This is a particularly pressing problem for the rapidly increasing number of patients in Australia who are using legal medicinal cannabis yet are prohibited from driving.
“The increase in legal recreational use of cannabis across multiple jurisdictions worldwide is also making the need for reform of cannabis-driving laws more urgent.”
The UK campaign for law reform
Earlier this year the Seed Our Future campaign in the UK, called for urgent reforms to legislation around cannabis and driving, as its latest report revealed the extent of patients risking criminalisation
Although patients who hold a legal prescription have a right to a medical defence, this is not always taken into account and those who are unable to afford one risk being criminalised and having their licences removed without any evidence of driving impairment.
The group, which lobbies for the decriminalisation of cannabis, is calling for the removal of THC from Section 5 and reverted to Section 4 of the Road Traffic Act 1988 (RTA), where evidence of impairment would be required to convict.
The Australian study was published in Neuroscience & Biobehavioral Reviews.
New studies examine effects of THC and CBD on stroke
New data suggests both positive and negative effects of cannabis in stroke patients
A new study has shown that pre-treatment CBD may have a neuroprotective effect in stroke patients.
The study aimed to investigate the effect of CBD on oxidative stress and cell death which occurs in ischemic stroke patients.
It revealed that the cannabinoid may reduce the destructive effects of cell damage associated with stroke.
Ischemic strokes are the most common type of stroke. They occur when a blood clot blocks a flow of oxygen or blood to the brain. This takes place in arteries that have been narrowed or blocked over time by fatty deposits (plaques). The most common symptoms of a stroke include facial drooping on one side, not being able to lift your arms and slurred speech.
If this occurs, it is vital that a person be taken to the emergency room immediately.
The National Institute of Health Care and Excellence (NICE) estimate that there are around 100,000 strokes every year in the UK. It is also thought that 1.3 million people live with the effects of a stroke.
Stroke recovery and CBD results
The Study showed that CBD reduced the amount of infarction in those samples which had been given the cannabinoid. Infarction refers to the death of tissue as a result of a lack of blood supply and is commonly due to a blood vessel being obstructed or narrowed.
There were also differences in malondialdehyde level (MDA) – a common marker of oxidative stress – between the brains of the CBD group and the vehicle group.
It also revealed that CBD may help to protect tissue by preventing further damage.
THC and stroke risk
According to findings, cannabis consumers who experience a stroke known as an aneurysmal subarachnoid haemorrhage (aSAH), are twice as likely to develop further complications.
An aSAH occurs when a weakened blood vessel bursts on the surface of the brain leading to bleeding between the brain and tissue that covers it. It can result in neurological disabilities, long-term slurred speech or even death. It is estimated that aSAH affects around eight people per 100,000 of the population each year, accounting for six per cent of first strokes.
The study by the American Stroke Association suggested there is twice the risk of developing delayed cerebral ischemia for cannabis consumers. The researchers analysed data from 1,000 patients who had received treatment for bleeding over a 12 year period. In the group of participants, 36 per cent developed cerebral ischemia and 50 per cent had moderate to severe disabilities.
When comparing the results of patients who tested positive for THC with those who did not, they found cannabis consumers were 2.7 times more likely to develop cerebral ischemia. They were also 2.8 times more likely to develop long-term moderate to severe physical disabilities.
However, compared to those who tested negative for THC, the cannabis group did not have larger aneurysms, higher blood pressures or worse stroke symptoms when admitted to the hospital. They did not have any higher cardiovascular risk factors than the negative group.
Researchers are now conducting further studies in which they hope to better understand if THC can impact aneurysm formation and rupture.
New study shows CBD may prevent Covid-19 infection
Researchers are calling for more trials to determine if CBD could be a preventative or early treatment for the virus.
Researchers are recommending clinical trials to examine if CBD could help to prevent Covid infection after more positive findings have been published.
Researchers from the University of Chicago have reported that CBD may stop the infection of Covid-19 by blocking its ability to replicate in the lungs.
A number of cannabinoids including CBD and THC were tested along with 7-Hydroxycannabidiol (7-OH-CBD) which is thought to be produced when cannabidiol is processed by the body.
The study found that CBD showed a significant negative association with SARS-CoV-2 positive tests in a national sample of patients who were taking high doses of CBD, prescribed for epilepsy.
As a result of their findings, researchers are calling for more clinical trials to determine whether CBD could eventually be used as a preventative or early treatment for the virus.
Covid and CBD study
Researchers treated human lung cells with a non-toxic dose of CBD for two hours before exposing the cells to SARS-CoV-2 and monitoring them for the virus and the viral spike protein.
They found that, above a certain threshold concentration, CBD inhibited the virus’ ability to replicate.
Further investigation found that CBD had the same effect in two other types of cells and for three variants of SARS-CoV-2 in addition to the original strain.
CBD did not affect the ability of SARS-CoV-2 to enter the cell. Instead, CBD was effective at blocking replication early in the infection cycle and six hours after the virus had already infected the cell.
Like all viruses, SARS-CoV-2 affects the host cell by hijacking its gene expression machinery to produce more copies of itself and its viral proteins. This effect can be observed by tracking virus-induced changes in cellular RNAs. High concentrations of CBD almost completely eradicated the expression of viral RNAs.
When it came to the other cannabinoids, CBD was found to be the only potentially potent agent. There was no or limited antiviral activity noted by the similar cannabinoids including THC, CBDA, CBDV, CBC or even CBG.
Marsha Rosner, PhD, professor and senior author of the study said it was a completely unexpected result, she commented: “CBD has anti-inflammatory effects, so we thought that maybe it would stop the second phase of COVID infection involving the immune system, the so-called ‘cytokine storm.’ Surprisingly, it directly inhibited viral replication in lung cells.
She added: “We just wanted to know if CBD would affect the immune system. No one in their right mind would have ever thought that it blocked viral replication, but that’s what it did.”
The researchers do caution that this is not possible with commercially available CBD. The CBD tested was high-purity and also medical grade.
However, Rosner cautioned: “Going to your corner bakery and buying some CBD muffins or gummy bears probably won’t do anything. The commercially available CBD powder we looked at, which was off the shelf and something you could order online, was sometimes surprisingly of high purity but also of inconsistent quality. It is also hard to get into an oral solution that can be absorbed without the special, FDA-approved formulation.”
CBD and Covid studies
This is the second study to be released showing the potential for cannabinoids in Covid management and prevention.
A study by Oregon State University has revealed that the compounds cannabigerolic acid (CBGA) and cannabidiolic acid (CBDA), may have the ability to prevent the virus that causes Covid-19 from entering human cells.
Researchers and scientists, led by Richard van Breedan, found that a pair of cannabinoid acids bind to the SARS-CoV-2 spike protein, blocking a step in the process the virus takes for infection.
Targeting compounds that block the virus-receptor interaction has been helpful for patients with other viral infections such as HIV-1 and hepatitis.
The researchers and scientists identified the two cannabinoid acids through a screening technique, developed previously in van Breeman’s laboratory. The team also screened different botanicals such as red clover, hops, wild yam and three types of liquorice.
Could this natural compound – produced by the human body – be a substitute for CBD?
Studies show PEA may act in a similar way to CBD by interacting with our endocannabinoid system
A new review suggests that Palmitoylethanolamide (PEA) may be a safer, therapeutic alternative to CBD. But what is it and how could it help?
The review titled, ‘A Potential Alternative to Cannabidiol‘ examined if PEA could be a safer alternative to certain cannabinoids, in particular for those who may be concerned about THC in cannabis.
PEA is a chemical made from fat, which is found naturally in foods such as egg yolks and peanuts, as well as in the human body.
The report was commissioned by Gencor Pacific, a company which uses PEA in its products for sleep and sports recovery.
Researchers stated that the ambiguity surrounding the regulatory status and the insufficient studies on CBD’s efficacy, may present an opportunity for PEA. They cited a demand for alternative compounds that produce similar results but have a more defined regulatory status.
The authors wrote: “CBD… is reported to have beneficial medicinal properties including analgesic, neuroprotective, anxiolytic, anticonvulsant, and antipsychotic activities, while apparently lacking the toxicity of THC.
“With proven efficacy in several therapeutic areas, its safety and tolerability profile and the development of formulations that maximise its bioavailability, PEA is a promising alternative to CBD.”
They added: “The therapeutic actions of CBD and PEA overlap in their biochemical roles in humans. There is a need for further investigation of their pharmacokinetics, specifically regarding definitive bioavailability and volume of distribution, and safety and efficacy when used long-term in diseased and healthy populations. At this time PEA’s safety, tolerability, consistency and regulatory profile confer certain advantages.”
What is PEA?
Palmitoylethanolamide (PEA) is a lipid mediator which may have anti-inflammatory, analgesic and neuroprotective benefits. It also appears to work with the endocannabinoid system in a similar way to CBD while providing the same benefits.
It is structured in a similar way to the bliss molecule, anandamide, and may enhance its effects in the body. Anandamide is an endogenous cannabinoid known to act upon the CB1 receptors in our endocannabinoid system. CBD also affects the CB1 receptors although it is not fully understood how this happens.
PEA may also stop the production of inflammation in the body which makes it perfect for sports relief topicals. It acts as an anti-inflammatory and analgesic by binding to the TRPV-1 channel, CB1 and CB2 receptors.
Another difference between CBD and PEA is that we do not naturally produce cannabidiol in our bodies. However, PEA is found naturally in our cells, tissues, brain and fluids. It can also be found in foods such as egg yolk or soybean lecithin. PEA has been associated with relief for the common cold, eczema, influenza and neurodegenerative disorders
Why do I need an alternative to CBD?
While the study presents PEA as an alternative to CBD, it doesn’t have to be.
It can be something that is boosted naturally by eating more foods that contain it. CBD and PEA work in similar ways but may have slight differences in how they interact with receptors.
Where it may work as a substitution is for people who struggle with allergies to different terpenes in cannabis or dislike taking something related to the plant. If someone is worried about tetrahydrocannabinol (THC) appearing in drug tests if they take CBD then potentially, this may present an alternative.
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