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A chemical so hot it destroys nerve endings – in a good way (wired.com)
185 points by jdnier on Nov 17, 2018 | hide | past | favorite | 59 comments



Naturally I wanted to know if anyone had tried cooking with or eating this super spicy compound. I found this [0]:

> “With a friend, we put one drop of a very dilute solution”—he pointed to the tip of his tongue—“and then immediately rinsed it off. At the point where we put it, I couldn’t feel anything for a week.”

To anyone with the same bad idea as me, the answer is no, we don't want to eat these.

[0] https://www.cooksillustrated.com/science/783-articles/featur...


For anyone else reading this, the link cited above contains a wealth of technical and practical information about peppers and related flavors, and it even delves into the psychological aspects of spiciness. It’s a great read.


Seriously, I went looking for that one thing and almost forgot about it reading through the article! Fantastic read.


This sounds wonderful for chronic pain. Reportedly, only pain neurons are affected. And for joints and other relatively isolated sites, effects can be targeted. So yes, your knee doesn't hurt, and you could injure it worse without the pain feedback. But you'd have ~normal pain sensation elsewhere.

We already use capsaicin patches. So hey.


Definitely not without side effects. Loss of pain sensation in parts of the body (such as the knee) can be really scary and potentially lead to permanent damage if the pain feedback loop doesn’t report that it’s being twisted or stressed.


True. But this is for chronic pain. Especially for pain that's caused by damage that's not expected to heal. So if you have constant knee pain, so bad that you can't stand up, the risk of further knee damage is arguably not such a major issue.

However, I can see how this could be misused. People could put themselves at risk for serious injury, in order to get back to work sooner. It's rather the norm for professional athletes, sadly enough. And for many others who do manual labor.

So in such circumstances, it could be horrible. But for those with chronic pain, perhaps a blessing.


> However, I can see how this could be misused. People could put themselves at risk for serious injury, in order to get back to work sooner. It's rather the norm for professional athletes, sadly enough. And for many others who do manual labor.

Sadly, I see some office workers surrounding me who would happily recieve a shot of permanent painkiller for their backs, necks and wrists to continue their 60+ hour work week race toward promotion, bonuses, reputation and other carrots.


You could of course pair this with a knee brace to prevent doing further damage to the area.


I don't think it'll be used for ligament injuries like MCL/ACL issues where a brace helps, but for chronic issues like osteoarthritis where the cartilage is low or gone. The bone on bone pain is constant and the only long term solution is knee replacement.


There is lots around about people who suffer as a result of not having a pain sensation. Typically post stroke or similar event, but some (rarely) have a congenital absense of pain sensation. The presentation is often bizarre as pain is a very helpful diagnostic tool. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4755825/


What a time to be alive, eh?


My mother in law has been ridden with excrutiating phantom limb pains after being forced to amputate her left arm above her elbow due to injuries she suffered in a car accident a few years ago. Has tried everything from mirror boxes to cannabis as well as a myriad of different medicinal treatments, none having any appreciable effect.

TFA made me think of her, wonder if this also might work against phantom limb pains.


My wife really needs this. Morton's neuroma, botched endometriosis surgery, and fibromyalgia. I don't know about the FM - that's so global I think it would be hard to target a specific nerve ending.


This truly sounds like it could be a fantastic tool for treating neuropathies.

Many patients with diseases such as CRPS (one of the worst pain wise) would be able to kill the pain signal allowing them to rehabilitate the affected area. Hopefully by the time the nerve function returns their body will have been able to battle the affected area into remission and avoid atrophy.


This treatment kills only temperature sensors, so I'm guessing it would only help with a "burning sensation".

Killing nerve tissue can backfire when neurons higher up start compensating for the lack of signal from neurons below (1). The result can be more painful and harder to treat.

The randomized controlled experiment with dogs was for bone cancer and the treatment appears to increase days until euthanasia about 60% (2). That's a real benefit, but not related to runner's knee, which is often related to the ITB band. For possible treatments, see (3)

1. https://en.wikipedia.org/wiki/Phantom_limb

2. https://en.wikipedia.org/wiki/Phantom_limb

3. https://www.runnersworld.com/advanced/a20844564/treating-itb...


The TRPV1 receptor is present on sensory nerves, so although it does primarily detect high temperature[1], regulating it can result in pain relief in general, not just a reduction in "burning sensations." Also, the article simplifies the rather complicated molecular biology, much of which is still being worked out. Importantly the article does not discuss killing nerves, just their nerve endings.

[1]TRPV1 also detects high acidity and the endocannabinoid anandamide.

https://en.wikipedia.org/wiki/TRPV1

PS: Your links [1] and [2] are identical... mistake?


Thanks! Both for the clarification and noting the mistake. Here's the original article: (2) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4431903/


Interesting... so it looks like RTX can cause cell death. Perhaps this shouldn't be surprising. Glad you updated that link.


Time to retire the Scoville index. Anything with that range is next to useless as a real measure.


You gotta understand how it works though - basically, it works by diluting a pepper seed concentrate as many times as necessary until every member of a panel of 5 testers can no longer taste a hint of spiciness.

https://en.wikipedia.org/wiki/Scoville_scale

the problem is that we don't have a physiological basis for "spiciness" in order to create a more objective scale. Instead, we rely on subjective taste tests to get those numbers, and mitigate the subjectivity by having multiple taste testers.

I'm actually thinking about applying a similar process to a few image analysis problems at work that are (currently) necessarily subjective, in order to produce better data for the eventual ML algorithms.


What's the error bar on that I wonder.


In secondary link in the top comments they say that it can now be measured mechanically (they mention only capsaicin though, so I'm not sure if it works for the other types).


I wouldn't say range is a good heuristic for retiring units of measure. Do you retire the meter because both galaxies and bacteria exist?


it's not so bad if you treat it as a log scale.


pScoville


Nerve damage or loss leads to muscle atrophy. Also, nerve regeneration is still unresolved.


That's about motor nerves. This is about pain nerves.


Capsaicin works topically, so I would presume this does too. Have any individuals actually tried this?


Is this permanent?

Somehow, I do not see this ending well. As attractive as eliminating pain may be, the fact is we need a sense of pain.

A knee that cannot communicate pain lacks the feedback needed to prevent further damage.


Pain feedback equating to null would be a win for me. I prefer life requiring heightened awareness than constant pain. Some people don't realize that consistent psychological or physical pain is like living with a cold for your whole life. Every day you think of how ungrateful you were when you could breathe freely. Also if this dramatically decreased life expectancy by the increased danger from lack of feedback.. it still seems like a win with how shit life is when in pain till you die.


Totally fair.

What I wonder about is choice. You've expressed yours, and it's solid. Others may well make other choices.

Will they be able to, or are we headed toward a new paradigm, where it's "just fixed, you can go" as opposed to management, options?

Then again, perhaps most people don't care.

I had skimmed this, found it thought provoking. Missed where there is nerve recovery. I do know, from some personal experiences, nerve regrowth, if it happens and it doesn't always happen, is sloooow.

Looks like there is recovery, meaning it's not permanent. I feel a whole lot better about that.


It seems like we both agree that people should be free to make their own choice.

Where I struggle to understand your perspective is here:

> Will they be able to, or are we headed toward a new paradigm, where it's "just fixed, you can go" as opposed to management, options?

As a society right now we are way tipped on the scale toward not giving choice by denying access as opposed to forcing access, so the concern that we'd be forced into relief seems the opposite of my concern (that we will be denied relief).

Doctors are getting really stingy with many medications (because of DEA threats (and in some cases actions) to throw them in prison if their patient does something wrong with them, or even if they are just statistically writing more than other doctors). Try going to get some Xanax, or Adderall, or Percocet. Good luck! If you've had it before it's easier, but new patients you can basically forget about it without a hard diagnosis (which they will happily take tens or hundreds of thousands of dollars, and still not provide, because again doctors are terrified of mis-diagnosis and getting sued or treated as a criminal, so they will only do it if there is hard indisputable evidence, which is infrequently the case).


Yeah, exactly. Your last paragraph is my concern. "Let's just burn the pain out of them" = no issues.

When there are always potential issues.

The US perspective on this stuff is terrible. Frankly, the state of health care, markets, all the BS?

Wish I were not living here. No joke. I've already had take serious financial hits --twice, for people I love.


As someone with chronic neuropathic pain, there are some times where pain does need to be eliminated in order for you to live a fulfilling life. Not all pain is necessarily related to direct communication, sometimes it's just there for what seems like no apparent reason.

I'm curious as to whether or not there could be applications for people with spinal cord injuries


> we need a sense of pain

The article addresses this:

“Now, the thing with pain is, it evolved for a reason. It’s an indispensable tool for you to feel if you’re doing something to your body that you shouldn’t be, like holding a scalding cup of coffee. Of course we want to alleviate pain, but might that be problematic if it’s too effective?

For people with knee pain, not really—the injection is targeting a specific area, so the rest of your body can still feel pain. And for end-of-life care, a central injection can bring long-awaited relief.“

https://www.wired.com/story/resiniferatoxin/


I feel people are speculating, but you're correct. I had old school, cut your knee cap in half ACL surgery. Exactly half, the right half, of me knee is completely numb. Not only have I hurt my skin a few times without noticing, I've had bad knocks/bruises that probably would have kept me from walking comfortable otherwise.


This appears to target pain, leaving touch. Not quite as bad as numb. I have a small numb zone too. It's part of a toe, and I've shredded it before. Not a care in the world!

(disturbing, because I could lose the damn thing and not know, or not know how bad it is)


Pain returned to the dogs up to 18 months...

> “The animals went from basically limping to running around.” One dog even went 18 months before its owners noticed the pain had returned.

So the nerves must repair themselves over time which is great.


It could also be that the nerves don't actually repair themselves, but your body adjusts to the lack of sensitivity and amplifies signals from a few surviving neurons. So every injection would kill more of the neurons, and at some point it is permanent.


In the tongue it seems that whatever is damaged when it's burned (literally or via hot spice) is regenerated.


I wondered if this was the case too. I’m also curious the mechanism this uses, what’s mentioned in the article (flood of calcium into the nerve ending) doesn’t make sense to me, but I have no expertise in this field.


The article discusses experiments in dogs and notes that the effects lasted from 3.5 to 18 months, so temporary in those tests.

Elsewhere, it said that this specifically activates temperature sensitive sensory neurons leaving others (touch, for example) unaffected.


This is to be used on patients who would otherwise be continuously on painkillers anyway.


The source article mentions that for dogs the average was an effective range of 5 months, with one dog making it 18 months before needing reapplication.


according to the article, dogs treated with this need a re-injection after 5 months.


That’s an interesting apporoach. Maybe next time I have lower-back pain, I’d wrap habanero peppers around my back.


My mother has been eating large amounts of of hot fresh chillies with every meal for the last decade and has noted a huge improvement in her arthritis pain, to the point where if she travels and forgets to take chillies with her, the pain seems to return swiftly.

It may be psychosomatic, but the benefits to her seem to have been huge, for an incredibly low cost and risk.


It's unfortunate that pain is so damn complex. It seems possible that repeatedly oral exposure to capsaicin results in long-term neurological consequences (for better or worse) in addition to the local effects which are regularly discussed. But hey I'm no scientist.


What is a large amount?

Is it the quantity of chilli peppers that are eaten that is important on the heat of the pepper? So 4 weak chillis is the same as eating one very spicy pepper?


I say large amounts, I really mean 'the amount of fresh chilli that would easily heat a curry or chilli con carne for 2 or 3 adults'.

Some meals she'll sprinkle them on, some she'll just eat before or after her meal. She's not a massive fan of spicy foods but the benefits mean that she's carried on with this. I think she read it in an article a year or so before she started - and then ended up with some chillies in the fridge and decided to eat them before they went bad and found a positive impact pretty quickly.

As I say, might all be psychosomatic, but she's happy ;)


Bit anecdotal, but if I eat a tablespoon of Pepper X with other food, I do feel a general numbing of pain for a while after.


Very spicy foods cause you to release endorphins.


You can buy patches that contain capsicum. Or more old-school, ointments.


For how often front-end development is shat on you’d think something as trivial as adding the ability for a user to close a registration dialog would be child’s work.


works on my machine™


  Inject RTX, as it’s known, into an aching joint, and 
  it’ll actually destroy the nerve endings that signal 
  pain. Which means medicine could soon get a new tool 
  to help free us from the grasp of opioids.
You know, I appreciate that someone out there is trying to address an addiction crisis more deadly than HIV, particularly because HIV can also compound the crisis through injection use, but...

Using a toxic capsaicin analog to destroy nerve endings sounds like an option (when taking to the inevitable extremes we are all dreading here), which could actually be worse than simply locking someone in a room so that they don't harm themselves or others with a different substance.

Reading this sounds like something out of a Shadowrun supplement, describing an intentionally horrifying prerequisite to some kind of cybernetic augmentation that renders your character a partially comatose brain in a vat.


I guess you haven't lived with chronic joint pain if you think that locking people into rooms is better than destroying the pain receptors in the joint.


The article isn't about reducing opioid addiction. It's about a more-specific treatment for chronic pain.


RTFA. The nerves eventually recover. They've tried it with dogs with joint problems and after about 5 months they need to be re-injected.




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