this post was submitted on 28 Nov 2025
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Science

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Study

The researchers discovered that once a tattoo is made, the ink rapidly travels through the lymphatic system and, within hours, accumulates in large quantities in the lymph nodes — key organs of the body’s defense system. Inside these nodes, immune cells called macrophages actively capture all types of pigment. This ink uptake triggers an inflammatory response with two phases: an acute phase lasting about two days after tattooing, followed by a chronic phase that can persist for years. The chronic phase is particularly concerning because it weakens the immune system, potentially increasing the susceptibility to infections and cancer. The study also showed that macrophages cannot break down the ink like they would other pathogens, wich causes them to die, especially with red and black inks, suggesting these colors may be more toxic. As a result, ink remains trapped in the lymph nodes in a continuous cycle of capture and cell death, gradually affecting the immune system’s defensive capacity.

The study found that tattooed mice produced significantly lower levels of antibodies after vaccination. This effect is likely due to the impaired function of immune cells that remain associated with tattoo ink for long periods. Similarly, human immune cells previously exposed to ink also showed a weakened response to vaccination.

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[–] vatlark@lemmy.world 59 points 8 hours ago (1 children)

In the study the longest they waited after tattooing the mouse before giving the vaccine was 2 months.

They made some connections with people that had tattoos for a much longer time. But I can't tell how meaningful those connections are.

This is well outside of my field.

[–] SendMePhotos@lemmy.world 2 points 5 hours ago (1 children)

... This is the internet. You can always be like the rest and pretend you know everything and are multi discaplined, instead of taking the proper, less fun, honest route.

[–] gusgalarnyk@lemmy.world 17 points 3 hours ago

Why make this comment encouraging bad behavior? This feels like injected negativity for negativity sake. Idk man, be the change you want to see in your community.

[–] p03locke@lemmy.dbzer0.com 35 points 4 hours ago* (last edited 4 hours ago) (5 children)

There are far too many humans with tattoos that could have been researched extensively, but they chose mice. Mice do not have the same kind of skin density as humans, and I doubt a tattoo artist or researcher would have the talent to tattoo a mouse's skin.

There's just so many things wrong with using mice in this study. So many bad ratios with the size of the animal. I mean, for fuck's sake, tattoo artists already practice on pig skin. Pigs would have been a better analogue, but honestly, they should have picked the millions of humans who were already tattooing themselves.

Of course, if they did that, they wouldn't get the same result and be able to push this sensationalist science news title, now would they? Except, in this case, we've gone from research paper to straight to sensationalist news title in one step! Just let the institute PR department push the narrative for you, without having to wait for that pesky news cycle to crawl through the telephone game.

[–] Horsey@lemmy.world 16 points 3 hours ago* (last edited 3 hours ago) (1 children)

Human subjects are crazy to work with for a few reasons

  1. People don’t follow instructions perfectly
  2. Research subjects often don’t take the research project very seriously.
  3. It’s not uncommon to have dropouts, thus you either have to find more subjects or have less data.
  4. It’s impossible to know what the subjects are doing to cause data variability (diet, vices, etc)
  5. You can’t lock subjects in a room and force them to eat and drink the same food every day.
  6. There’s a financial (time) penalty to many research studies that can get in the way of enthusiastic participation.

Laboratory mice literally live 5 to a cage with almost no diet variability, in a controlled environment. Yes shit does happen with research mice, but it’s something that is easy to control overall.

[–] p03locke@lemmy.dbzer0.com 7 points 1 hour ago

And yet, we manage to have hundreds of thousands of studies written about humans with human subjects. This sounds like a boatload of excuses that could be summed up as "science is hard". Sure, it's hard, but it's better than putting out a flawed study that can't scale properly.

[–] bonenode@piefed.social 10 points 2 hours ago (1 children)

You are generally not wrong but where can you find people who are tattooed, not yet vaccinated, but happy to get vaccinated for this study? It is wrong to say this definitely works the same in humans, but it is not easy to setup such a study.

[–] p03locke@lemmy.dbzer0.com 5 points 1 hour ago

Within a single city, hundreds of people get tattoos each day. A large cross-section of those probably haven't refreshed their COVID vaccine, but only because they haven't gotten around to it.

[–] EtherWhack@lemmy.world 7 points 4 hours ago* (last edited 4 hours ago)

I think it's more the news article that's upselling it and with it being "groundbreaking", it is likely only at the initial stages.

Mice are usually the first phase are they do have a similar immune response (systemically), have a fast metabolism and quick to mature. They're also clones, which helps eliminate external factors that could contribute to what they're studying. More or less, mice are just a quicker litmus test to just show that something is possible and if it warrants a study on a closer analogue.

[–] voodooattack@lemmy.world 2 points 1 hour ago

Unless we dissect the original paper in its entirety, I don’t think we should dismiss their methods out of hand.

I’ll reserve judgement until peer-reviews can confirm or rebuke the results.

[–] leftzero@lemmy.dbzer0.com 1 points 30 minutes ago* (last edited 24 minutes ago)

Just use pigs.

Basically the same thing as a human (except for the opposable thumbs, which explains us eating them), but cleaner and smarter on average.

[–] answersplease77@lemmy.world 26 points 8 hours ago (2 children)

followed by a chronic phase that can persist for years.

how many years? am I doomed for life because what I did to my body when I was 18 :(

[–] DarkCloud@lemmy.world 36 points 7 hours ago (2 children)

I think if these effects were universal and as serious as the paper makes out,, we'd have noticed them waaay sooner.

[–] scytale@piefed.zip 20 points 6 hours ago

To be fair, it’s possible it has been a significant factor to weakend immune systems all along; it was just now that the connection/link with tattoo ink was identified. Not a scientist obviously, just spitballing.

[–] jacksilver@lemmy.world 12 points 4 hours ago (1 children)

And yet things like asbestos, lead, and smoking all took way longer than you'd expect (given they were a lot more universal).

And yet humans have been tattooing themselves since the dawn of recorded history - significantly longer than any of those other things were around before their harm became evident.

[–] tuff_wizard@aussie.zone 26 points 6 hours ago

Yes but that applies to almost everything you did when you were 18.

[–] DozensOfDonner@mander.xyz 17 points 9 hours ago (1 children)

Ah pretty interesting. Good to clarify that its in mice, not humans.

[–] thejoker954@lemmy.world 27 points 8 hours ago (2 children)

The study found that tattooed mice produced significantly lower levels of antibodies after vaccination. This effect is likely due to the impaired function of immune cells that remain associated with tattoo ink for long periods. Similarly, human immune cells previously exposed to ink also showed a weakened response to vaccination

[–] Onomatopoeia@lemmy.cafe 17 points 8 hours ago* (last edited 8 hours ago) (1 children)

"Human immune cells", not cells in humans.

That's not to say this doesn't happen in humans, it very well may. It's intriguing research, but it's still only demonstrated in mice. Important to always keep that in mind until we get better information (which this research is at least leading us to).

Lots of stuff happens in mice (or pigs, or a petri dish) and we find doesn't replicate to homo sapiens.

[–] FlexibleToast@lemmy.world 14 points 8 hours ago* (last edited 8 hours ago) (1 children)

It's also important to keep on mind that the burden of proof is on something to prove it is safe, not that something is unsafe. It happening to human cells in mice would have me assume it happens to human cells in humans until proven otherwise (that's the null hypothesis in this situation). But also I don't have a tattoo or any interest in getting one so I'm not too bothered by this.

[–] ada@piefed.blahaj.zone 12 points 7 hours ago (1 children)

Humans have been tattooing each other for over 5000 years. I would argue that it's not really a case of "they need to be proven to be safe". That ship has sailed. If they are unsafe, we should know, but I think the burden of proof has definitely shifted on tattoos given their extensive history without obvious negative repercussion

[–] pulsewidth@lemmy.world 1 points 2 hours ago

What you're missing is that the ingredients of tattoo ink have changed dramatically in the last 100 or so years.

Prior to then tattoo inks were made mostly with soot or black ash mixed with plant oils.

Nowadays the inks are almost entirely synthetic, sourced from the same companies that make industrial paint, and have been tested and some found to contain carbon black nanoparticles, Texanol, BHT, 2-phenoxyethanol, and various other things that are confirmed (or reasonably suspected) to be toxic and which definitely wouldn't be in historical inks.

The proof should be entirely on the suppliers and administrators (tattooists) to confirm their ink and tattoos are safe, not the users. Yet their regulations are very lax in most countries, requiring no pharmaceutical testing even though they are injected into people's skin.

Some refs: https://pubmed.ncbi.nlm.nih.gov/25833640/
https://pubmed.ncbi.nlm.nih.gov/38387033/
https://theconversation.com/whats-in-tattoo-ink-my-teams-chemical-analysis-found-ingredients-that-arent-on-the-label-and-could-cause-allergies-22481

[–] grue@lemmy.world 1 points 5 hours ago

I suspect the effect might be less significant in humans (not human cells, whole humans) because of the square-cube law.

[–] Wubwub@lemmy.zip 16 points 8 hours ago (2 children)

The anti tatto crowd licking their lips over this one.

[–] fu@libranet.de 11 points 7 hours ago (2 children)

@Wubwub anti tattoo crowd? Like fundamentalist Baptists?

[–] thymos@discuss.tchncs.de 3 points 7 hours ago (2 children)

I suppose I would be in that crowd. I'm an atheist, but I think the whole tattooing thing is kinda stupid. To each their own of course, I don't care if anyone gets a tattoo, but the culture around it annoys me and I think it's a waste of one's body. I do like some of the art styles, but why not just print it on a shirt and wear it?

That being said, I think it's petty bad if it turns out the ink causes a higher risk of disease. Like with cigarettes in the past people weren't informed about the consequences before making their choices. That sucks and I don't wish it on anyone.

[–] otter@lemmy.dbzer0.com 10 points 7 hours ago

It's good that you've expressed misconception as the source of this opinion, and admitted to your lack of understanding. The rest of the work could fall in nicely, if you put the effort forth. I'll give ya one for free: "the culture around it" isn't some singular entity, but a varied and colorful amalgam of countless inspirations, backgrounds, beliefs, reasons, etc., and the only thing that oversimplifying does here is stunt your personal growth.

You got this. 🤘🏼

[–] leftzero@lemmy.dbzer0.com 1 points 13 minutes ago

Like with cigarettes in the past people weren't informed about the consequences before making their choices.

Yeah, but the tobacco cartels had performed studies which clearly demonstrated how absolutely horrible their shit was and not only not made them public, but used them to maximise addiction (and cancer, as a side effect they didn't give a single shit about).

I very much doubt the tattoo industry has ever studied anything.

[–] rabber@lemmy.ca -2 points 6 hours ago* (last edited 6 hours ago)

I'm a pantheist and think that tattoos are just another form of self harm

My gf has tattoos and I don't mind them but I wish she wouldn't get any more. Impossible to find a girl without tattoos who would date me anyway lol I tend to attract the alternative crowd and basically everyone I'd be into has them so it is what it is

[–] UnderpantsWeevil@lemmy.world 8 points 5 hours ago (1 children)

It's just tiresome to hear these hyperventilating articles without any real measure of the degree of risk or long term consequences.

[–] Wubwub@lemmy.zip 2 points 5 hours ago

Exactly, I understand the concept of the harm they are talking about but they don't really give much exact examples of the degree of harm its a total nothing burger of an article

[–] salacious_coaster@infosec.pub 13 points 8 hours ago (2 children)

Well, then. That could explain a lot about why I always feel like I'm dying.

[–] bjoern_tantau@swg-empire.de 18 points 7 hours ago (1 children)

I have the opposite problem, my immune system is in overdrive. I should get a tattoo to reign it in.

[–] Tollana1234567@lemmy.today 2 points 1 hour ago

i feel like that would cause an immediate inflammation, if your immune system is dysregulated, it would have a likely opposite effect of what it suppose to do. ive seen alot of people in tattoo sub said they had a reaction to the tattoo after its done.

[–] proper@lemmy.world 2 points 7 hours ago

are you the puzzle man?

[–] supersquirrel@sopuli.xyz 9 points 8 hours ago (1 children)

What is your opinion on how much this applies to humans?

[–] Kyle_The_G@lemmy.world 25 points 8 hours ago

I spent a career in translational medicine (research). Its not a perfect 1:1 but most of the time these models are very good.

[–] astutemural@midwest.social 7 points 3 hours ago
[–] arctanthrope@lemmy.world 5 points 5 hours ago (1 children)

would it be possible to solve this problem by making different inks? or would any ink that doesn't have this problem just inherently be non-permanent

[–] pulsewidth@lemmy.world 3 points 2 hours ago

Not a biologist but I believe the latter. If the ink could be broken down by the macrophages in your lymph nodes it would likely be broken down in its intended location in your skin too, as their are lyphatic capillaries and vessels throughout our skin.

[–] Fandangalo@lemmy.world 4 points 6 hours ago

I don’t want to use AI to generate the sick, tattooed mice in this story, but I bet they’re pretty rad. (Animal testing, less so, jokes aside)

[–] mika_mika@lemmy.world 4 points 4 hours ago

I should schedule a new tattoo appointment.

[–] Tollana1234567@lemmy.today 3 points 1 hour ago* (last edited 1 hour ago)

thats why some people get a rash at the tattoo sites, or it triggers shingles. make sense since macrophages clean up melanin pigment produced by post-inflammatory hyperpigmentation, a brown spot after a severe pimple or something.

[–] Pavidus@lemmy.world 3 points 4 hours ago

Ephemeral Remi should be dead by now.