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  • Cannabis is receiving more and more attention from doctors, research groups, and the public

  • as a possible treatment for lots of different medical conditions.

  • But it's also met with lots of hesitation, because marijuana has psychoactive properties

  • and we still have a pretty limited understanding of its effects.

  • Lately, though, some scientists have been studying a compound in cannabis that might

  • have medical benefits without causing a high.

  • It's called cannabidiol.

  • The most famous ingredient in weed is the one that gets you high: THC, or delta-9 tetrahydrocannabinol.

  • THC is a kind of cannabinoid – a molecule that binds to cannabinoid receptors on your cells.

  • Normally, these receptors are activated by chemicals made by your body called endocannabinoids.

  • There are two main kinds of cannabinoid receptors, and they're expressed in different parts

  • of your body.

  • CB1 is mostly in your brain, and CB2 is in your immune system and in your peripheral

  • nervous systembasically, any nerves that aren't in your brain or spinal cord.

  • So cannabinoid signaling affects a lot of different systems in your brain and body,

  • and, for a long time, research involving cannabis has only focused on THC.

  • But marijuana has over 60 different kinds of cannabinoids, and we're realizing some

  • others are really interesting toolike cannabidiol, or CBD.

  • CBD is also a major component of pot.

  • It's kind of like THC's responsible older brother.

  • In fact, it's got the same chemical formula, but the atoms are arranged in a slightly different way.

  • The different structure means that CBD can't bind to cannabinoid receptors the way that

  • THC can, and scientists think that's why CBD doesn't have psychoactive properties.

  • It even seems to be an antagonist, or blocker, of chemicals that bind to cannabinoid receptors.

  • Plus, CBD might bind to other kinds of receptorslike GPR55, which lets calcium into cells,

  • and a bunch of TRP receptors, that sense temperature and pain.

  • Beyond these guesses, we're still not really sure how CBD can affect your brain and body.

  • But there's a lot of appeal in a cannabinoid-based medication that doesn't get you high.

  • So in the last decade or so, research on CBD has exploded.

  • For example, cannabis has been used as a treatment for epilepsy seizures for a really long time.

  • And we're still not sure exactly how it works, because there hasn't been much solid research.

  • But CBD is an appealing treatment option, since the lack of a high means it could be

  • used on a regular basis.

  • A recent study looked at whether CBD might be a safe and effective medication for treatment-resistant

  • epilepsy in people ages 1 to 30.

  • Of the 162 patients in the safety portion of the study, some had to drop out because

  • of adverse events like stomach issues or excessive sleepiness, but not all of these symptoms

  • were necessarily because of the CBD.

  • In total, 137 patients were examined for how effective CBD was at treating seizures.

  • It seemed to help reduce seizures by an average of about 35%, and a few patients didn't

  • have any seizures during the trial.

  • So it does seem to help with severe epilepsy.

  • But, this was a pretty small study.

  • And it's what's known as an open label study, so there was no control group.

  • So we definitely need to better understand the side effects and risks before it becomes

  • a standard treatment.

  • CBD also seems to have some anti-inflammatory properties.

  • Research on mice brains has found that CBD might lower the levels of inflammatory proteins

  • called cytokines.

  • These proteins play roles in all kinds of conditions in humans, like Alzheimer's Disease

  • and migraines.

  • And studies on isolated neurons also suggest that CBD is an antioxidant, so it could help

  • protect cells from degeneration caused by conditions like Alzheimer's.

  • These properties haven't been studied in living humans yet, though, so it's too soon

  • to say if the same is true in actual brains.

  • Marijuana has been prescribed for chronic pain treatment for a while, but it's only

  • recently been studied in any sort of depth.

  • Several different reviews of clinical trials have found that patients prescribed treatments

  • containing THC and CBD reported pain relief compared to a placebo, but it's not a huge effect.

  • It's not totally clear how cannabis relieves pain, but the link between CBD and the TRP

  • channels, which play a major role in pain sensation, means that CBD could play a big part.

  • Lastly, CBD seems to have anti-nausea properties, too.

  • Some scientists have found evidence that giving rats CBD can suppress vomiting, by activating

  • serotonin receptors in areas of the brain associated with nausea.

  • Because of this, it might be able to help cancer patients undergoing chemotherapy.

  • Overall, though, there are a lot of unknowns when it comes to CBD as a safe, effective

  • medical treatment.

  • We don't fully understand a lot of things, like: what's different about how it binds

  • to cannabinoid receptors, why it doesn't cause a high, and what kinds of effects it

  • has on the body and brain during long-term treatment.

  • Another strong medication that can treat serious conditionsespecially things like chronic

  • painthat doesn't have psychoactive properties would be an amazing new tool in medicine.

  • That way, patients can have an option besides things that can be tremendously habit forming,

  • like opioids. Or, just mess you up for a little bit, like THC.

  • But we still have a lot to learn before we know for sure if CBD is a good alternative.

  • Thank you for watching this episode of SciShow, which was brought to you by our patrons on Patreon.

  • If you want to help support this show, so that we can talk about stuff like this without

  • being responsible to advertisers, you can go to patreon.com/scishow.

  • And don't forget to go to youtube.com/scishow and subscribe!

Cannabis is receiving more and more attention from doctors, research groups, and the public

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大麻没有高(CBD: Marijuana Without the High)

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    joey joey 發佈於 2021 年 05 月 15 日
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