Anti-aging injection regrows knee cartilage and prevents arthritis | Hacker News Reader

Anti-aging injection regrows knee cartilage and prevents arthritis

scitechdaily.com

400 pointsnis0s178 comments

https://www.science.org/doi/10.1126/science.adx6649

https://www.science.org/action/downloadSupplement?doi=10.112...

Anecdote for any runners reading this: I'm a 75 year old runner. (Some young runners might say I run at a jogger's pace, I just tell them to keep off my lawn.)

A couple decades ago, I stopped running on concrete or asphalt, and took up trail running, i.e. running on (mostly) dirt. It feels way easier than running on asphalt, much less on concrete. If you're skeptical that running on concrete or asphalt feels harder, give it a try. YMMV, but I'd bet you notice a difference.

And yes, I do fall sometimes, tripping over roots or rocks. But I recover quickly.

I'd worry about sprained ankles on a false step or a slippery leaf-rock trap. Is there a technical approach to running in these conditions?

I've heard it's actually beneficial for your ankles long term to get some tilt/pan on them. It reduces your chances of injury by strengthening the twitch muscles in your ankle and legs.

Important to note the point is "trail running" not "alpine running", gravel and dirt vs, steep inclines and big rocks.

Anecdotally, just adjust your pace/length until you're comfortable. I've always done mixed asphalt/dirt-trail and there is a notable difference in my knee fatigue when there is a bigger ratio of one or the other, would always prefer a nice gravel or dirt over the road.

You just get used to trail running over time. If you’re nimble and light on your feet a slip almost never turns into a fall. With practice you dodge the bad steps without much thought or you step knowing it’s iffy, slide and keep running. You don’t commit hard down on your heel.

The form i use basically the “natural” running style. Land with your body over your foot, land on your foot flat or on the ball. This is good for trail running because it’s much easier to not commit to a step when you’re not planting hard with your heel.

I’ve never sprained an ankle trail running, not that it can’t happen. I’ve gone like 90 degrees on my ankle before but I can usually unweight and collapse on that leg and catch myself on the other leg and keep running. I run in sandals and I backpack in trail runners.

Trail running strengthens your ankles what with all the uneven ground that has to be compensated for.

You can exercise your ankles so they are less likely to crumble if forced into an awkward position. Also look at where your feet land compared to each other: if one is almost ahead of the other (think camel stride), your foot is to the left (or right) of its hip and is thus naturally bent outwards. Having your foot land more squarely compared to how the body weight works, reduces the strain on the ankle. If the inside of your ankle/sock is always dirty after a run, this is why. Am currently going through the process of fixing this on myself.

many people try to go too much around puddles, bits of mud, rocks, ... Switching direction is what makes you slip/fall.

Sometimes, you should just focus on going straight, or at least keep your center of mass relatively going in a smooth line.

Yes, sometimes that means going through a puddle or do a small jump, but I find it much safer. Of course, on a potential slippery surface, try to make that 1 step lower impact, basically like an in-between step. This can also imply vary big changes to your cadence, which is not always optimal from aerobic perspective.

For me the biggest insight was that there is no rule I have to be “running” 100% of the time when trail running. If some part of the trail seems sketchy it’s totally fine to just slow down there and do that part carefully. Then speed up to running again on safer parts.

You’re still getting almost all of the cardio benefits, and over time you’ll get more comfortable going faster on different surfaces, just from practice.

OP here. I've fallen many times, but never sprained my ankle. Usually if I have an injury from a fall at all, it's that I've skinned my knee or the palms of my hands (you can wear fingerless leather gloves if you're worried about that).

I have had two injuries that required medical attention. Dislocated my pinky finger once.

The other time I was crossing a wet wooden bridge. On the down-slope of that bridge, my feet went out from under me and I fell on my back. It hurt, so I walked a mile or so back to my car. Hadn't gotten better after a few days, so I checked in at an ER. Turns out I had cracked a rib, and that had caused a small pneumothorax. I was in the hospital for three days while they suctioned it and waited for the lung to heal. (The MD was amazed at my ability to breathe well despite everything.) When I come to that bridge now, I change to a walk.

You're not wrong, but most of us don't live near a good dirt running trail so we have to drive to reach the trail head. When we have to squeeze in a run on workdays it becomes a choice between running on the street versus not running at all. Mud is also a problem for trail running in areas that get much rain.

Treadmills are an option. I highly recommend manual treadmills, feels much more natural imo.

I recommend artificial turf soccer fields. They're padded! They're flat. They're good for watching games, or people watching too. And you can pretend to be a winger or striker, constantly measuring the angle and distance to the far right corner, because who doesn't want to be like the GOAT?

Yes, I noticed this too. I ran a lot in high school / university, and for some reason we mostly ran on the roads. In my late 20s a doctor told me my knees sounded like they were "65".

I read a book my Michael Colgan at the time, and he mentioned training athletes on the trails as much as possible to reduce injury, so I gave it a try ...

That was 25+ years ago. At first people looked at me strange, like I was running from an animal. But its common now, and I'm still running on the trail, and knees seem OK.

Yes of course, you can still trip, step on a snake, etc, but its a different kind of injury. You are adapting gait and balance constantly which is nice too.

Running on the trail is much more interesting, with constant change, ups, downs, variations. Whereas running on grass / asphalt I can go into autopilot mentally and start ruminating, this is harder on the trail and I am more in a state of "here and now".

I switched to trail and found I stopped getting injuries related to lateral stabilization of my hips and legs.

I've come to think it's because the trails challenge those stabilizers sufficiently so they get trained properly rather than... I don't know, repeatedly being irritated by running too straight for long periods of time?

I'm not a kinesiologist so I have no idea what the real difference is, but I do know I get hurt far less on the trails than I did on pavement.

One possibility is that I go slower overall so I can't push the limits of some muscle and tendon groups like I could on pavement. Everything gets more equally pressured, but less on average.

I've thought the same thing. I always feel more balanced when including the challenge of uneven terrain. When I was a kid I used to be able to run full speed through forrest litter.

Interesting, as if a narrow kind of stimulus is detrimental to biomechanics, while diverse terrain, even if more challenging, keeps each angle of motion hit below the limit

Alternatively rubber tracks also are great, if you have one nearby.

Or just treadmills, I find them more gentle on my joints than concrete because it's slightly cushioned.

Why not take up cycling?

>"Why not take up cycling?"

I was a cycling maniac for some time. It fucks one up (knees, back, elbows) anyways. After 10 years of that I cut it down to occasional pleasure rides. Luckily all my pains had stopped after a couple of years.

isn't jogging more impactful to the knees than cycling? I've seen this over and over.

Running absolutely impacts the knees, but the compression of meniscus for example is what circulates nutrients into it so some impact is necessary for healthy knees as well.

I no longer regularly jog / run / cycle, only occasionally for pleasure. I either swim or hike steep hills or if weather is ugly just put treadmill on 15% incline and walk very fast for an hour or so. Wastes energy like crazy and leaves my knees intact.

There is the downhill part of the hikes, unless you have ski lifts or similar way of getting down. I used to do running a bit before major paragliding accident, and I hiked like there is no tomorrow and still do... subjectively the hiking down part felt more stressful on knees than running (maybe not on concrete/tarmac).

I think diversifying the physical activities is a good thing.

Also avoiding using your domotics, motorized vehicles, elevators and escalators, kitchen/cleaning robots/electric devices when there are manual replacement as well as not using domotic, does a super job on its own.

People have become lazy, pretend they don't have time to do stuff, then have to actually dedicate additionnal time so that their body doesn't suffer from their lazyiness. This is bonkers.

One day my brother saw me shirtless and asked me if I was going to the gym. I said no, I just have 2 young kids, carry my groceries including cat litter by foot, use a shovel to clear snow, use a manual coffee grinder and kitchen whisk and only use my car when it would take me more than 1 hours / 30kms by bicycle, etc. And I had an office job. Being active, fit and healthy shouldn't involve having to "exercise".

Yes, but it’s a common misconception that impact is a bad thing.

The body, including bones, muscles, tendons and joints, adapt to stress. Many people do too little, not too much, as they get older.

There’s a limit to that recovery of course, and balancing it with stress is not always simple.

A poorly adjusted cleat is absolute hell on the knee.

It can be difficult to fix too as once your knee is sore it takes ages to come right so it’s not clear if adjusting the cleat is working.

Most people don't need clipless pedals and only do that to mimick pros or because they were told to by other cyclists.

This is stupid (saying that as an ex elite road, track and cyclocross racer).

Maybe not, do what suits but I find it helps, particularly over longer distances or up hills.

I’ve never tried real cleats, I just use mounting biking ones, spd. Doubled sided pedals seem easier in traffic and I use them for a decidedly non-pro 2-300km a week.

I used both and do not see much difference in efficiency. clipless do feel somewhat nicer but that was just a habit. Do not use those any more

> isn't jogging more impactful to the knees than cycling? I've seen this over and over.

my brief reading of studies shows there is no proven negative impact on knees from running. Some studies suggest there is positive impact: https://pmc.ncbi.nlm.nih.gov/articles/PMC11320545/

I can speculate that running is very natural to human, and body evolved for running through the evolution, and cycling is not natural movement.

it is mostly poor fit that fucks one up but sadly very few bike shops offer decent fit/positionning before and after sale service.

>"it is mostly poor fit that fucks one up"

This what they all say to sell "custom fit" services. I now how to fit and have access to pro level fit rig.

Maybe not that well.

I tried swapping running with cycling for a few months but honestly as somebody who spends a good portion of my time on my ass, often with suboptimal posture in front of a screen I hate the idea of exercising still sitting on my ass with bad posture.

The most important thing imo is to find a form of cardio you enjoy. It's not worth stressing over the differences between forms of cardio just find something you like and make it a part of your lifestyle.

Reagarding knee injuries, sure intense running with bad form is more likely to get you an overuse injury but those heal quickly, long term studies don't show increased knee/hip risk for runners.

Strength exercises are also very important for runners. Getting all the muscles arounf your hips, knees and ankles stronger significantly reduces the chance and severity of injuries and has a ton of other benefits.

If you are sitting on your ass (as in the normal definition of buttocks) when cycling, you are doing it wrong or you are riding a recumbent.

Typically you sit on the part in front of your hip, which also has its downsides as it is quite a delicate area where pressions on the wrong area could lead to issues.

MTB is the solution here. You can't really sit down when it gets a bit rough.

I don't like the risk factor. I was a serious cyclist for a decade or so, and went tens of thousands of kilometers over all kinds of terrain at all hours of the day. My take away eventually was that I'd get hit by a car eventually (again), and I don't know how severe it would be. I only cycle with friends leisurely now rather than as a frequent form of exercise.

I live in a city where it's challenging to reach safe riding territory in a reasonable time frame. If I was rural and had access to trail riding (gravel, mountain), I think I'd be all over that.

cycling looks like less whole body and more targeted exercise.

Trail running is fun. But it’s probably not the surface but the technique change, that gets rid of the pain. I’m currently going through the process of shifting my running technique to where I push rather than pull myself forward and it’s a revelation. When your foot lands in front of your center of gravity, it necessarily brakes your forward movement. All that momentum has to go somewhere, eg get absorbed by your joints. Changing this makes you more efficient as well as reducing strain on the soft tissue.

This sounds interesting. Would you be able to share more information about this style of running? I'm having a hard time imagining how this plays out in real life.

Running barefoot forces you to improve your technique in line with this description. [0] There's also a sizeable market of "barefoot shoes" that's between being barefoot and the regular running shoes, with the manufacturers trying to convince us buying such shoes is the solution. The gait issue become more obvious (and painful) in barefoot shoes, but you can adjust your technique in mass-market running shoes as well.

[0] https://www.youtube.com/watch?v=zSIDRHUWlVo

I first found out about this back when Chris McDougall's "Born to Run" book came out. For anyone that does not know, he follows an Indian tribe in Mexico known for their running prowess, using non-traditional sandles to run in instead of the heavily padded sneakers most of us wear.

I switched briefly around that time to running in vibram five fingers, which trained me how to change my stride and stop heel striking. I no longer wear VFFs but do tend to favor lightweight, minimal heel-drop sneakers, and I still don't heel strike.

I'm not sure you can run with appropriate gait (stop heel striking) in modern mass market running shoes. The heels on many running shoes are 2 inches+ and make it just impossible to avoid heel striking without wasting a lot of motion picking your knees up.

Also, the chances of twisting your ankle when your heels are elevated that much from the road is far higher as well.

Best marathon runners can do it in "conventional" running shoes [0], but I agree it's easier to find the better technique barefoot or in barefoot shoes.

[0] https://marathonhandbook.com/kipchoge-running-form/

I made this change as well. Specifically, I switched from heel strike to forefoot strike, AKA “landing on the ball of my foot.” I changed shoes to zero-drop (Altras) which makes this easier to do.

This sort of automatically limits how far in front of your hips you can land your foot. But then the next step is to change posture and “lean forward” so that it feels like you’re just barely catching yourself with each foot before falling on your face.

The goal is to have your foot land directly under you, then use your quads and glutes to push your foot backward, to create or maintain your forward momentum.

This is why I think trail running is so valuable. You must be aware of your changing environment and how to adjust your body's movement to accommodate. You are exercising your mind to calculate your current momentum, intended placement of your next step, and it's potential impact to the rest of your body. You are running your own mental physics simulation as you work the trail, nothing like running on regular roads.

This sounds a lot like why I find BMX racing less interesting than I thought I would.

It’s also why I make the kids ride elsewhere. Snow provides good physics lessons on traction and centre of gravity.

Trailrunning is less harsh on joints for sure, but certainly not easier based on the times of anyone who's run trail vs road events over any distance.

Mud, obstacles, and terrain that hasn't been bulldozed and rolled to be pan-flat make it much slower.

I'll take that excuse for slow runs! But seriously, I don't run in training for speed, I run for fun and for fitness. And the uphills on the trails certainly help with that.

I have had fairly serious arthritis in my hips for close to a decade now. Cortizone shots directly into the joint have helped the worst of the flare-ups (limping on my way into the shot, having 0 pain walking out of it, lasting a year).

5+ years ago when I was looking for another injection, my PCP said "Well, time for a hip replacement." Now, for reasons I don't understand I think he was being way premature on that (everyone I'd talked to prior to that had said I should wait as long as I can, and it'd been 2+ years since my last shot).

But I'd pretty much accepted that hip pain was just a part of my life, (especially in the morning) picking something off the floor was painful, just walking and in particular walking stairs was just a little painful.

A few weeks ago I tried some stretches I saw on Youtube shorts. Like a minute a day. It's like I've got new hips.

I've never been a very "compliant patient" when it comes to stretching, but that was mostly because I saw no benefits from it. But this one stretch was like a miracle!

Please share which stretches helped you.

These may not be the same as the one suggested above, but when I fell back in early 2025, my lower back, discs, spine got wrecked. I was sent to Physical therapy and was giving exercises similar to these which helped me, may help you. Keep in mind that it is not a cure... https://www.youtube.com/watch?v=0wAw1-1MHa4

These are the ones: https://www.youtube.com/shorts/2gS8RYc9lus

"Frog Mobility" -- Get on hands and knees, spread knees but keep your feet closer together, rock back towards your heels and forward.

"Frog Cat/Cow" -- Same position as above, but tilt your pelvis; curve your back up then down.

"Tactical Frog" -- I haven't done this one yet, but it is frog mobility but with each rocking forward twist one of your feet up into the air; IOW rock back then as you rock forward keep one knee locked so that your calf/foot stays in the same relative position as you move forward.

these look like they have ... other uses.

Every physical motion has other uses. (Obligatory xkcd: https://xkcd.com/940.)

It's helpful to combine fitness with fun.

When you're a hammer, everything starts to look like a nail. Good thing you were able to find a good alternative solution. I suspect a lot of ailments could be resolved with non-medical interventions, but there's little money to be made there and also, a lot of people want the perceived "easier" way out.

Can you please share which stretches helped?

I f'd my knees running track in HS - i suspect some kind of structural problem that alters the way my knees move. Sr year wsa awful, i was just about crawling to class in the morning. MRIs showed nothing and I learned to live with it and eventually it got better when I stopped running.

10ish years later I had started riding my bike a lot during the dotcom explosion induced downtime, I kept it up after I was employed again. Knee pain came back. Went to the ortho again, this time was told "oh you have a torn meniscus, lets go fix it.

So I went under and woke up to be told that my meniscus was fine, and that I had worn grooves through the cartilage and into the bone - doc told me to never run, jump, ski, ride, etc. I was to sit on the couch.

Somehow I ended up taking karate, and the knees hurt for a bit, but the stretching we did helped loosen up my hams and quads. It didnt make the knee pain go away, but it made it tolerable in that it no longer affected my day to day.

I'm constantly telling people to look up physical therapy movements/stretches for whatever they've got going on. Slept wrong? Tweaked your neck? You absolutely do NOT have to suffer with that until it goes away on its own, they can show you how to fix it.

If your insurance covers it, go see one! Them being able to actually see and feel what's going on specifically with you makes them markedly better at their jobs.

Can’t find the link now but a very comprehensive analysis of surgery vs physiotherapy for lower back issues found that physiotherapy was as effective as invasive, often dangerous spinal surgery. The only difference was time - surgery with recovery + recovery physio fixed the pain in about 4-6 months, while physiotherapy took 18-24 months

But on the plus side, physiotherapy is “free”, has no real risk, and most people who opted for the physiotherapy path found that they were happier and also fixed a lot of other pains simply because of regular stretching and exercise

Would be great if you could find that link.

I had a similar thing happen. What multiple doctor visits could not even diagnose was fixed with resistance band side walks.

When doing stretches, don't forget the opposite side of the equation which is strength.

Not the "I'm going to bench 200lbs" type strength, but the musculature that supports movement.

It's quite easy to always focus on stretching, but not build the muscles that support good movement. You can turn yourself into a floppy noodle, which brings on more injury.

The two kinds of strength are correlated and ability to push heavy weights is super useful. In my experience, it helps.

The body is very weird and finds ways to compensate

I had a football injury when I was 13 that badly damaged my knee meniscus (though I didn’t know it at that time). At 16, I had a complete menisectomy - total removal of the lateral meniscus in my right knee

I was told that I would need to get a transplant and/or new knees in 10-15 years. I was also told that I shouldn’t put too much strain on the knee

I’m now 38 and my knee is mostly…fine. I can run, squat a reasonable amount of weight, walk for miles. Only thing I can’t do is fast directional changes (like in football) or bending down on the lateral side of my right knee

My plan is to extend this as long as possible and hopefully in 10 years, they’ll have tech to fix this for good

Some anecdotal knowledge I can share on why they used to say wait as long as you can for a hip replacement:

We were told this was because it used to be that they could only do the hip replacement surgery once, and the replacement joint would only last around 20 years max.

So basically it had to be for the expected life span of the patient!

But now this is no longer true. Well, in Australia at least with access to modern replacement parts, surgical techniques and specialists!

I could be muddling it up a bit, so happy to be corrected :-)

I recently got told something similar in Europe, and anecdotally anyone who’d had a hip replacement and waited on it regretted not doing it as soon as the doc told them.

This has been my experience with every sports of weightlifting injury I've had and I'm in my 40s. The body wants to heal or at least compensate in some way. Light activity is often better than rest. I've got a knee that is acting up a little bit but I think I've figured out how to keep it healthy while running.

Hey, could I ask which stretch it was?

Look for the reply with "Frog Mobility" in the body, I posted in reply to another comment.

thanks for sharing, that’s wild! i’ll definitely take stretching more seriously now

Cartilage is really the final frontier of health. If it wasn’t for joints going bad, people could stay very active and fit pretty much all their life, with consistent exercise and healthy weight.

I'd say spinal and optic nerve regeneration is more "final" than cartilage.

Well yea but not in terms of the amount of lives that will be improved.

Alzheimer's and similar, matter a lot too. Brain controls body.

> Osteoarthritis occurs when a joint is stressed by aging, injury or obesity. The chondrocytes begin to release pro-inflammatory molecules and to break down collagen, which is the primary structural protein of cartilage. When collagen is lost, the cartilage thins and softens; the accompanying inflammation causes the joint swelling and pain that are hallmarks of the disease.

Collagen synthesis in the human body can be aided by hydrolyzed collagen, Vitamin C, zinc and copper.

Evidence seems to be lacking though. Do you have any specific source in mind?

There's very good evidence coming out of UC Davis.

they have MRIs, decent experimental evidence, and biochemical explanations.

They have published quite a few papers over the years.

You can start here, https://pmc.ncbi.nlm.nih.gov/articles/PMC9267994/

https://pmc.ncbi.nlm.nih.gov/articles/PMC5183725/

Look up Keith Baar.

Keith Baar's videos on YT have helped me a lot; both for treating my knee pain and for increasing overall muscle strength. The videos tell you how to heal or strengthen your tendons, ligaments, and muscles.

I found that second link interesting although it raised the question of why gelatin versus amino acids in general.

However neither link seems to have anything to do with UC Davis or biochemical mechanisms related to collagen supplementation. I realize that it probably wasn't your intent but the mismatch leaves me feeling vaguely as though you tried to deceive me there.

They have published a lot of stuff.

I don't remember the exact link for the biochem stuff. Something about collagen being glycine limited and vitamin C being a catalyst for synthesis for tendon tissue regrowth.

Here are the two papers I remember reviewing.

https://escholarship.org/uc/item/2wn8s39q

https://escholarship.org/content/qt2j57t1j1/qt2j57t1j1.pdf

Among endurance athletes collagen supplements have become increasingly popular the past couple years -- from what I understand the evidence is kind of mixed though

e.g. https://thefeed.com/products/pillar-performance-collagen-1?v...

I don't get what's the supposed mechanism of action here. Collagen is a hard to digest protein and it has to get digested to be processed and then it's no longer collagen. Why not just eat any other protein source instead?

Different protein sources have different amino acid compositions and they have different effects on the body.

Still, if you eat enough complete protein sources you'll have all the amino acids you need.

Maybe, maybe not. It would depend on a variety of factors including the activities you do, your age, etc. Maybe athletes need more collagen compared to people who don’t exercise, etc, etc.

Also complete protein sources are definitely not easy to get. Good luck if you have dietary constraints.

Notably, whey is a complete protein source and very easy to get, while collagen is a crappy source.

I just wish whey was as easy to get unflavored. Let me handle the flavoring, you provide the protein.

Yes, I'm aware you can buy unflavored whey protein, but it's more expensive and you have to order it online. I can get a huge tub of "Delicious quadruple chocolate delight" BS from Costco for comparative pennies.

> Also complete protein sources are definitely not easy to get.

... all of the essential amino acids? What is difficult about that?

Quinoa is a complete protein, containing all amino acids that the body cannot produce on its own, and is gluten free.

You need to eat a ton of quinoa. Only the most dedicated vegan bodybuilder will eat that much quinoa. No thanks.

Also, only animal sources contain hydroxyproline amino acid in significant amounts, which you pretty much only get from collagen sources.

So while quinoa and other like even whey might advertise themselves as complete protein sources, no, they do not contain all the amino acids humans can use in significant amounts.

Vegan bodybuilders would just use pea/rice protein extracts, which are about as commercially available as whey (very).

Hydroxyproline isn't essential though, humans can produce their need from collagen, which they also produce as well as most other animals.

> You need to eat a ton of quinoa

Most don't: at 4.4% protein, a 65kg man like me needs 1.5kg of cooked quinoa per day and it's not a big deal:

- You'll digest it like a king: quinoa is full of soluble and insoluble fibers and you won't feel puffy for eating too much. Easy in, easy out.

- Like milk or wheat, there's many transformations possible like flour, flakes, marinades, beverages, soups... alway a joy to cook and eat, no boredom with that grain.

Can't speak for the bodybuilders though but I'm sure most manage they nutrition. I think soy/pea is more popular.

By the way, very few eats only quinoa or any other single aliment. They also get amino acids from grains, pulses and seeds... even fruits like tomatoes but it's obviously negligible.

Quinoa is also fulled with minerals, vitamins and it's proteins have the same biological value (BV) as beef - or more depending on the source.

> its high-quality protein, complete set of amino-acids, and high content of minerals and vitamins. [0]

> exceptional balance between oil, protein and fat [1]

> Quinoa has a high biological value (73%), similar to that of beef (74%) [2]

0 https://www.tandfonline.com/doi/full/10.1080/15528014.2022.2...

1 https://scijournals.onlinelibrary.wiley.com/doi/10.1002/jsfa...

2 https://www.researchgate.net/publication/303845280_Quinoa_Ch...

There are plenty of studies showing that collagen supplementation helps athletes. Which means there are cases where the body doesn’t produce enough collagen for itself. And as you age, your body produces less collagen. Reasons enough to supplement with collagen.

Likely yes, but I've had enough chicken breast for life during my fit 20s. I just don't feel like stuffing myself with tasteless sources of protein anymore and testy ones (burgers, steaks, grilled salmon, etc.) will cause unwanted side effects and risks when consumed in high amounts.

Even bodybuilders and powerlifters admit that 2g protein per kg of body weight is about all you need. You can get that with a normal diet and a couple of protein shakes, which taste fine if you use milk and half a banana. You don't need to eat a whole chicken breast for every meal.

I made spaghetti bolognese last night and it had 60 grams of protein per 800 kcal serve. Admittedly I used lean kangaroo mince, because I'm Australian and it was on sale. Still: three meals like that and you wouldn't even need a protein shake.

> lean kangaroo mince

I first read "mice" which was startling, then realized it was "mince" and then realized it was kangaroo! How would you describe the flavor?

Gamy, a bit like deer.

I have yet to see anything against regular eating of fish and fatty fish other than the "scare" of heavy metals, which only applies for wild fish.

I was going to say that too, thanks for beating me to it!

Yes, that seems to sort of be the criticism and mixed results. Although not everyone has a complete protein diet so theoretically although it breaks down the idea is you then have all the things you need, should your body choose to use it to build collagen.

But I agree, I'd rather start solving deficiencies at the diet level than the supplement level and haven't integrated collagen personally so far.

TBH I suspect marketing plays a big role. "Collagen = good, therefore just buy it and eat it" makes logical sense if you don't actually do any research first.

A recent meta analysis suggests the positive results for collagen are mostly funding bias. See discussion here:

https://massresearchreview.com/2025/09/29/connecting-the-dot...

I have been taking collagen, but will likely stop.

As I've gotten older, my knees have been the main signal letting me know. I tore my meniscus years ago. This is exciting news for people like me.

The joint at the base of my thumb started telling me it's 60 years old. I stopped being able to open jars easily last year and would like to get my grip strength back.

> The joint at the base of my thumb started telling me it's 60 years old

This is my biggest apprehension. I've become quite a good guitarist, and I know that can't last forever. Getting my accomplishments in while I can.

You better. I have an uncle who was a very accomplished pianist and who can't play anymore due to arthritis. Play the paint off it while you can.

Ironically, last year i decided to relearn piano after some 40 years. Learned one piece (a pretty good one, fortunately) and a once a day play triggered it. So. It's more like once every 2-3 weeks now, not long enough to forget, but long enough to keep the thumb feeling all right.

Your accomplishments? For me playing music is for joy, not for status

1: They didn't say anything about status.

2: Developing a capacity or facility is an accomplishment regardless what purpose it's put to.

Trying to tell someone they don't have the right attitude based on something they didn't even say was an interesting way to profess joy.

My first bluegrass record:

https://justinholmes.bandcamp.com/album/vowel-sounds

Second record in progress:

https://justinholmes.bandcamp.com/album/4masks

Broke this one in a motorcycle accident and I'm really, really not looking forward to the late life implications of it.

I've torn mine as well and am yet to get it repaired. Did you get surgery? Anything working for you?

I got surgery about 8 years ago, after 10 years of on/off knee pain that I ignored. I had locking in the knee so I needed to so something so I could walk. Surgery was fine, they opened me up and my meniscus was all stringy as if you cracked an egg in boiling water, so no fixing it and they cut off 50% of my meniscus. I recovered quite easily, stupidly did not do any formal physio but proceeded to do mostly moderately heavy lifting with some light running and cycling (very light cardio for the runners around, but still something compared to couch potatoes). Since about 2 years I have pain and a pressure in the knee, not very intense pain but more unsettling. Pain also seems to show up after some sort of activity threshold and the effort accumulates. I eventually took an MRI about a month ago, I have first to second degree condroathy. A couple of physio sessions seemed to help but I need to take the time to do a full physio cycle. I can't wait for cartilage Regen tech. It's very nice being physically active. Worst case, I use it until I can't anymore, do a knee replacement and after that fails hop on one leg as a pirate.

My hope to pull another 15 years of functional use out of it, enough to do fun activities with my son.

Every son dreams that his Dad has a little bit of pirate! Congrats!

Something similar was done in a sheep model:

"A bioactive supramolecular and covalent polymer scaffold for cartilage repair in a sheep model" - https://www.pnas.org/doi/10.1073/pnas.2405454121

"Abstract: Regeneration of hyaline cartilage in human-sized joints remains a clinical challenge, and it is a critical unmet need that would contribute to longer healthspans. Injectable scaffolds for cartilage repair that integrate both bioactivity and sufficiently robust physical properties to withstand joint stresses offer a promising strategy. We report here on a hybrid biomaterial that combines a bioactive peptide amphiphile supramolecular polymer that specifically binds the chondrogenic cytokine transforming growth factor β-1 (TGFβ-1) and crosslinked hyaluronic acid microgels that drive formation of filament bundles, a hierarchical motif common in natural musculoskeletal tissues. The scaffold is an injectable slurry that generates a porous rubbery material when exposed to calcium ions once placed in cartilage defects. The hybrid material was found to support in vitro chondrogenic differentiation of encapsulated stem cells in response to sustained delivery of TGFβ-1. Using a sheep model, we implanted the scaffold in shallow osteochondral defects and found it can remain localized in mechanically active joints. Evaluation of resected joints showed significantly improved repair of hyaline cartilage in osteochondral defects injected with the scaffold relative to defects injected with the growth factor alone, including implantation in the load-bearing femoral condyle. These results demonstrate the potential of the hybrid biomimetic scaffold as a niche to favor cartilage repair in mechanically active joints using a clinically relevant large-animal model."

Paper: https://www.science.org/doi/10.1126/science.adx6649

The supplementary material is freely available here:

https://www.science.org/action/downloadSupplement?doi=10.112...

It identifies the compound used as SW033291. Searching for it on clinicaltrials.gov gives no hits.

It does , however, provide the ApexBio catalog number A8709, which is this 15-PGDH inhibitor:

https://www.apexbt.com/sw033291.html

oh, what a time to be a mouse!

Top comment my whiskered friend.

Lots of folks are pointing this out, but it's not like there isn't evidence to suggest this will also apply to humans.

> Human knee tissue collected during joint replacement surgeries also responded positively to the treatment. These samples, which include both the joint’s supporting extracellular scaffolding, or matrix, and cartilage-producing chondrocyte cells, began forming new cartilage that functioned normally.

Too bad that as a mouse you die after two years tops.

Turns out the pain in my knee was a latent infection with staph aureus, forming small nubs under the skin. Debrided the skin, removing the nubs, applied 3% doyiciclin creme and pain is gone. This for a knee with 2 operations before and teo doctors saying I need a replacement. Doctors are mostly unhelpful idiots imho.

Yea, same here, following the studies had helped me fix a 18 year old shoulder tendon issue.

I owe that research group a lot.

What happened to you? Might anything you have learned help me? Recommended reading?

I too have a shoulder tendon issue: 14 months ago a loud one-time "pop" occurred while doing a simple external rotation shoulder exercise with very light weight. I immediately lost most strength lhs and the shoulder felt very loose. More than a year later + 1 steroid shot my shoulder is much better but still loose.

It's complicated, rotator cuff tear combined with a bunch of rib, shoulder and neck injuries. I never properly healed them, just rest, career in tennis ended after trying to rest and heal 3 times over 8 years.

YouTube and Physical Therapy combined with the UC David protocol has brought back more strength and mobility than I've ever had.

My main issue I had before was I kept pushing my injury too hard without proper remodeling.

The UC Davis protocol requires a specific isometric, loaded stretch while dosing Vitamin C and Type 2 Collagen an hour before isometrics.

It took about 6 months before I felt it getting significantly better, and I'm not fully healed yet, but I can actually throw balls to my kids without feeling my injury now.

Thank you! I searched for "UC Davis protocol for shoulder" and found Dr. Keith Baars at UC Davis and his research on tendons:

[Tim Ferriss podcast re Baars' work at

https://tim.blog/2025/02/27/dr-keith-baar-transcript/

and "dastratman" has produced an excellent summary of Baars' and Ferriss' discussions:

https://hackmd.io/@dastratman/rygQhSmhke ]

I searched your old HN posts and found that you've explained this before to HN denizens! Thank you, thank you so much!

FWIW I've never been able to throw w/o shoulder pain and, now that you mention it, I may make it my goal to build up to that!

Yep you found it, sorry I got a bit mixed up with the threads here.

Glad to hear you’re feeling better! How did you find out the root cause and treatment?

In some contexts (e.g., pancreas), 15-PGDH inhibition can promote tumor growth by increasing specific signaling.

Yeah, a lot of healing mechanisms are also behind many tumor/cancer factors. There's a lot of reasons behind aging phenomenons, and a lot are self protective. It's not given all of the aging is intended and can't be reversed, but a lot of it is there for biological reasons.

They don't say what is injected, calling it only a "gerozyme inhibitor". Original article appears to be:

https://www.science.org/doi/10.1126/science.adx6649

Inhibition of 15-hydroxy prostaglandin dehydrogenase promotes cartilage regeneration Mamta Singla https://orcid.org/0000-0002-6408-1167, Yu Xin Wang https://orcid.org/0000-0001-8440-9388, Elena Monti https://orcid.org/0000-0002-3767-0855, Yudhishtar Bedi https://orcid.org/0000-0002-1213-4116, [...] , and Nidhi Bhutani https://orcid.org/0000-0002-7494-5870

FTFA: "Both systemic and local inhibition of 15-PGDH with a small molecule inhibitor (PGDHi) led to regeneration of articular cartilage and reduction in OA-associated pain."

"PGDHi" is a name for both the process "15-hydroxyprostaglandin dehydrogenase inhibition" and any inhibitor.

This link(a PDF file) shows PGDHi's are powerful stuff:

https://www.biorxiv.org/content/biorxiv/early/2025/04/17/202...

"PGDHi" could be prostaglandin-E2 (dinoprostone):

https://en.wikipedia.org/wiki/Prostaglandin_E2

which was used in:

https://med.stanford.edu/news/all-news/2025/06/muscle-aging....

I wonder if this would apply to backs/back injuries. This is super exciting, if it pans out. I can't wait for the follow up research. A pill that 'just works' is an amazing thing. Loosing mobility later in life leads to a lot of problems so directly attacking the cause of (a lot) of mobility loss is really great to see.

Hold your humans: in mice!

At this rate we're going to have mice outliving humans by 2100

“A pill-based version of the same therapy is already being tested in clinical trials aimed at treating muscle weakness associated with aging.”

Just think of mice as the staging environment for production humans.

ATG exercises have helped me with my knee pain. Their exercises help to strengthen the cartilage and ligaments around the knee.

JAK-STAT inhibitors also downregulate 15PGDH, and in humans

they are just insanely expensive in the USA because of drug patents

I am 41 years old and have had hip osteoarthritis since I was 36. I am not supposed to do a hip replacement at such a young age, they prefer older people with weaker muscles to do less damage to an artificial joint.

A cure like this would be a godsend for me.

I run regularly. Some years back I switched from a heel strike stride to a ball-of-foot strike. It greatly reduced the shock load on my knees and hips. It's the same gait you'd naturally do if you took off your shoe and ran barefoot.

I would love this for some of my finger joints beat up from decades of typing.

Have you tried mechanical keyboards? They were a life saver for me. I can type more than 100k keystrokes/day without any pain whatsoever.

Yep. On a keyboard with 8 thumb cluster keys per side, and custom 35g switches to lower the force needed to actuate, that helped a lot, but still not enough to be pain-free. Unfortunately once the damage is done on certain joints you can only do so much short of not using those fingers at all. 30 years of hammering keys pretty hard eventually catch up to you.

You should try 20g springs, they are really good for typing. I also removed the keycaps and replaced them with small pieces of band-aid on top of the switch stems which also helped. Also dictating plain text like comments and typing only for correcting errors in dictation and for short actions is better. It's easier to press a button rather than say a lengthy command, because vocal cords can also be damaged by speaking too much.

Where have you been able to find ultralight springs available to consumers? I was looking into this last week and the 10-20g ones were only available straight from the factory in South Korea with shipping costing $200... I was happy to get them and swap them out, but that shipping pricetag was too much of a highway robbery.

Would appreciate any advice here :)

And, intrigued about the idea of not using key switches at all. Are there any aftermarket alternatives available online for "keycaps" that are better at softening the impact on the finger, something softer and bouncier perhaps? Seems like something people would have experimented with.

Here is an interesting discussion about low-weight springs old.reddit.com/r/MechanicalKeyboards/comments/ojk0em/experiences\_with\_very\_low\_weight\_8\_to\_25g\_spring/. It has a link to rndkbd.com /products /sprit-springs?variant=43822770782442, where I purchased my springs. They have a full range starting from 12g, but they are currently out of stock. You can ask about the next restock on their Discord server.

One thing I discovered about lightweight springs is that lubing the switch doesn't work at all, it just stops resetting. I also think that with traditional MX-style switches going with weight less than 20g might not work out well because even with 20g springs some of my keys are not resetting properly, they remain stuck when I lift my finger, and I get "aaaaaaaaaaaaaaaa"s instead of just "a" for example.

As for removing keycaps, my keyboard looks like this: m.youtube.com/watch?v=647FeK3\_Bek, except I left the spacebar keycap on, and I have a small piece of adhesive plaster tape on top of the plastic parts that resembles a plus sign "+" on every switch to increase friction. But I don't think removing keycaps works for switches box type switches with stems that look like [+]. I also had to open the space bar switch and add a little aluminum foil ring inside where the spring is located because it consistently wouldn’t reset.

Lightweight springs also slightly reduce the key travel distance, and the actuation point becomes very high, practically no actuation point. It produces a keystroke the moment you touch it. This is now possible with harder springs too with the advent of Hall effect keyboards, but the lightest spring available for that type of keyboard is 28g, which is a bit too heavy.

Thanks for sharing all that, appreciated. I had looked at that particular store last month and they were sold out of the lighter springs, but I'll check with them again to see if that's changing. And great point around switches being stuck with the lighter springs, definitely something I'll have to watch out for if I ever get that far.

I've also enjoyed Topre switches in the past, I remember those feeling pretty light as well, although I can't quite recall how my injured joints worked with them, that was in the healthy days.

The next best thing then is to try weight lifting exercises for the hands. This also helps a lot because it strengthens the muscle.

I would say mechanical keyboard (used ErgoDox for years, now I use a Lily58). Now I would say learn how to make AI type for you.

Big fan of my Dygma Defy and I've been using WisprFlow super heavily this last year, but the immediacy of typing is still hard to beat. But yeah, I hope the voice tools keep getting better, they've been a real life-saver so far and fortunately I'm a very fast talker.

Curious, does anyone know if this might also apply to tendons? I've had patella tendonitis for years (jumpers knee) and have tried everything (isometrics, shockwave, PRP injections, etc...).

And you've been to a physio?

As far as I recall, the treatment I was prescribed for the same thing was mostly eccentric single leg squats, ideally on a 30 degree angled board.

And rest...

Yep. Do those on a slant board. And knee extensions. And a few others. Plus drink collagen before it. I’m still working my way through it so it might work, but I’d love for something like this to work.

What is the relation between 15-PGDH and NAD+ [1]?

[1] https://en.wikipedia.org/wiki/HPGD

Does anyone have any idea if you have arthritis what you can do to manage the symptoms? I figure there are some people here that researched it relatively well.

I think it really depends on your age and underlying cause.

Everyone with it I've ever talked to said staying moving is important: "motion is lotion."

My elderly family use lots of anti-inflammatory drugs (NSAIDS) and one of them is on Prednisone.

Two of my friends with rheumatoid arthritis (only in their 30's) are on an injectable immunotherapies (DMARDs) that have been life changing for them.

Disclaimer: not a doctor, just have lots of sore friends/family and an interest in this stuff since I have a torn ACL and fear the future.

I've had arthrosis in both knees for several years (due to a combination of youthful sports injuries and overweight). A few years ago I saw a knee specialist who predicted I was due for knee replacement sometime soon.

On the advice of a massage therapist I instead started a habit of using a home cycling machine for half an hour each morning. So far, it has worked wonders for me, and I hope I can hold on for a decade more, by which time the injection mentioned in the article might be ready for humans.

Diclofenac (voltaren) is a topical NSAID that can be useful for managing symptoms. Over the counter in the US.

Arthritis is a general term; need narrow down for useful advice on managing symptoms.

Two most common types are osteoarthritis (wear-and-tear associated with aging and/or injuries) and rheumatoid arthritis (autoimmune).

I only know about age-related knee osteoarthritis to try to help my mom manage her symptoms, so I'll share my understanding of treating that.

High ROI, low cost: - weight management. Extra lbs are extra stress on the knees, plus I suspect chronic inflammation associated with being overweight can exacerbate arthritis independent of mechanical stress. - exercise, specifically low impact cardio and any pain-free strength/hypertrophy work targeting the musculature around the knees (mainly quads).

Variable ROI, low cost: - NSAIDs, specifically topical to focus on treatment area and reduce impact on GI system/kidneys. - curcumin, mixed evidence but some people report benefits.

Variable ROI, high cost: - PRP injections. Apparently the quality on these varies dramatically by provider. Would recommend doing research and comparing multiple providers if possible. - Knee replacement. Far from a panacea; you'll lose range of motion forever, plus plenty of other trade-offs. Most people recommend putting this off for as long as possible.

Also interesting is low dose radiation treatment for knee OA. More affordable than other procedures and has some promising research.

Not much else on the novel treatment front that I've found. Curious if anyone thinks I've missed anything worthwhile.

I have had hip osteoarthritis for five years and have followed my plan here - https://joelx.com/joels-hip-osteoarthritis-diet-nutrition-pl.... I feel vastly better and can even ski now.

I've been having good results with recovering my knee's cartilage with Flexofytol, which is based on Boswellia Serrata and curcuma.

Knee replacement surgeons should be worried. Both my father and FIL had their knees replaced.

afaik surgeons are able to perform quite a few types of surgeries, obviously the ones working on brains more advanced than ones working on knees it's probably only a few years to transition to a different type of category.

I'd like to think orthopedists would rather be overjoyed at this. My wife had her knee and hip done by a cracking orthopedist, and his primary concern was her quality of life. He even went to the state physicians' board to argue that her hip surgery should be considered necessary rather than elective for purposes of COVID restrictions, so that we could get it done months before it was originally scheduled.

Hey, if they can commercialize this into a real therapy, that would be amazing.

Could the same be applied to arthritic ankles?

Almost certainly. Ankles also rely upon hyaline cartilage (as opposed to fibrocartilage). I found this out when I had microfracture surgery for a bad ankle injury.

Looking forward to this therapy. My fibrocartilage is wearing out!

Here for the same question! Broke my left ankle three times as a football (soccer) playing youth who cared not for rehab! Now stuck with limited range of monitor and arthritis in my foot / ankle.

My body is a mess! Where do I sign up :)

Better than mesenchymal stem cells?

in mice

Always a good call out, but also:

Also interesting that trials for the blocker have been successful in humans to restore muscle growth.

Good, but what does it mean for tissue samples to function normally? Function as what?

let me be excited for things!

Just think of mice as the staging environment for production humans.

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