I’m not surprised — tattoo inks are not regulated and the colors are often formed with toxic compounds (e.g. copper). Then the needle avoids the protective barrier provided by the skin.
Ironically, while working on a drug program that involved intradermal injection, we needed to tattoo the injection site so we could find it later. The FDA was very demanding that both the procedure and more importantly to them the dye would not have any effect that might alter the body’s response to the compound under test. We had to do a whole study just to validate this.
So the FDA is concerned about this issue for guinea pigs, but is barred from investigating the effect on humans. All they can do is publish advice on their web site.
Congress only authorizes executive branch agencies to have responsibility for certain things, and tattoos are not within scope, not being a medical treatment of any sort.
BTW FDA was explicitly barred by a corrupt law* from regulating anything "natural" (a poorly defined criterion) so the same happens with all those things you see in Whole Foods: FDA can warn you of certain dangers from their web site but that's it.
* Herbalife got their senator, Orrin Hatch, to get this law passed so they would stop getting in trouble for peddling snake oil in both their products and their MLM business model. His career was basically 100% carrying water for MLM folks and the music industry in exchange for cash.
I don't think this is true. According to the FDA's site they could regulate tattoo inks but have chosen not to.
> FDA considers the inks used in intradermal tattoos, including permanent makeup, to be cosmetics. When we identify a safety problem associated with a cosmetic, including a tattoo ink, we investigate and take action, as appropriate, to prevent consumer illness or injury. The pigments used in the inks are color additives, which are subject to premarket approval under the Federal Food, Drug, and Cosmetic Act. However, because of other competing public health priorities and a previous lack of evidence of safety problems specifically associated with these pigments, FDA traditionally has not exercised regulatory authority for color additives on the pigments used in tattoo inks. The actual practice of tattooing is regulated by local jurisdictions.
We ended up using India ink, which (according to the encyclopedia of ink* ) is mainly soot.
We were able to isolate it in the HPLC and through some histopath experiments show that it didn’t have any negative local effect between (IIRC) seven and 60 days. Why those times? Protocol was to tattoo on day 0, wait a week for the site to recover, then inject our experimental material on day 7, sacrificing subject animals at D14 (one week), 21, 28, 35, 42, 49, and 56 days.
I don’t think lamp black is really a good idea, but was adequate for our purposes. We didn’t have to do any kind of long term study, just demonstrate that it would not interfere with our work in guinea pigs.
* I actually went to a specialist art store and the owner did indeed go to the back of the store and pull out one of the volumes of a multi-volume work on inks and pigments! I don’t know if it was actually named “The Encyclopedia of Ink”, though I do remember that that’s how he referred to it. He just photocopied the relevant page for me, most of which was the entry for India ink.
But, as with anything, it’s about nuance. You can read through the ingredients here[0] and tell me what you’d like in your body.
The earliest tattoos, from my understanding, were done by incision and rubbing carbon into the wound. Regardless if you use old or new inks/techniques, it’s not really cut and dry to say “this is bad/good” because the size of the particulates matter. For a tattoo shop that uses high quality ink, and is diligent in its sterilization, most inks are fine. The large molecules are “trapped” by your immune system to just stay there[1], making them not dangerous.
There is a ton of research on PubMed about tattoos, most being negative. However, I suspect it’s because the authors had a predisposition to be negative from the start based on how the research is conducted and what they focus on. But I could be wrong and you should make up your own mind.
Bottom line: if you get tattoos, pay the premium and go to a good shop. The hygiene and good products are worth it, if that’s your thing.
"We found no evidence of increasing risk with a larger area of total tattooed body surface."
Without a dose response, I'm inclined to believe that the increase in lymphoma seen in people with tattoos has more to do with confounding factors than with the ink or the act of getting a needle poked into your skin. I would think that controlling for all confounders in a study like this would be exceptionally difficult.
That said, I'm pretty sure that at least some inks do contain known carcinogens[1]
This is a Swedish study, so what might be possible is using the population registry to contact siblings of the cancer patients to ask about traits like tattooing and then their health data would already be in Swedish system and linkable. This would control for a lot of the relevant confounders.
Even a correlation with the amount of ink could be a lifestyle confound. I'm pretty sure that the population that has a small tattoo differs from the one with large parts covered. Indeed, it is hard to find a cause.
Yes. Also, the survey response rate was the biggest difference between groups (54% vs 47%), which could easily explain the observed differences. The confidence intervals cross 1.0 for nearly all reported IRR values.
For those who don't know how to interpret medical evidence, this study is very weak.
Those response rates are fairly awful with two groups that are markedly different. Seems very likely that they’d self-select on the face of it especially if they knew what the research question was.
Indeed. It's not the ink content that led to Am J Clin Pathol. 2014;142(1):99-103. saying:
"The mean age of death for tattooed persons was 39 years, compared with 53 years for non-tattooed persons (P = .0001). There was a significant contribution of negative messages in tattoos associated with non-natural death (P = .0088) but not with natural death."
I'm not sure "people with negative msgs in tattoos died 14 years earlier" sheds light for me on the TFA.
TFA has a more direct, physical, concern - it starts from a well-known, that tattoo ink ends up in lymph nodes, and it does a statistical analysis showing there's a significant statistical result in lymphoma occurence.
I think people with negative tattoos dying younger reduces the # of people with tattoos who get lymphoma, as they have less ink-in-lymph-nodes years.
Yeah totally agree. That the size of the tattoo or the number of them not increasing risk makes no sense. Somewhat like claiming whether you smoke a cigarette or 20 a day, the risk is the same. If the latter was true it would more likely indicate that there is some other commonality in that group increasing the risk.
Also the slicing and dicing, “11 more than the index year” and so on, is multiple hypothesis testing on the face of it; I wonder if they adjust for that.
> A hypothesis that Christel Nielsen's research group had before the study was that the size of the tattoo would affect the lymphoma risk. They thought that a full body tattoo might be associated with a greater risk of cancer compared to a small butterfly on the shoulder, for example. Unexpectedly, the area of tattooed body surface turned out not to matter.
As someone pointed out on the other thread about this[1], the lack of dose response makes it very difficult to see this as a direct correlation and not reflective of other confounding factors.
Why so? Zero-order effects are not unheard of in biology. Example: the elimination rate of ethyl alcohol is dose-independent because any practically noticeable concentration of ethyl alcohol will saturate available alcohol dehydrogenases.
I doubt if they’ve completely eliminated social factors. Apparently people with tattoos “have higher levels of need for uniqueness, sensation seeking, and thrill and adventure seeking, but they have lower levels of self-esteem, attend religious services less, and are generally much less educated than individuals who did not have tattoos.”
> generally much less educated than individuals who did not have tattoos
To me, this seems obviously about social/economic class. If you work a good paying job, then you are much less likely to have tattoos, primarily because your co-workers do not have them. Before every HN commenters jumps on me, think about all the office worker normies out there, working normie office jobs, the pressure to conform is much higher than bro-grammers who are allowed to go work in jeans and hoodie. From my experience, the (middle/senior) manager types (including lawyers) are the least likely to have tattoos.
That's 0.5 percentage points. Would be nice to get that metric, too, alongside percentages sometimes. Here the initial likelihood is relatively high, when the likelihood is low, percentage increases can be very misleading. Particularly if the uncertainty around the increase is high.
Non-Hodgkin lymphoma (NHL) is a cancer that starts in lymphocytes, a type of white blood cell that helps fight infection. Lymphocytes are found in the bloodstream but also in the lymph system and throughout the body.
I would be surprised if injecting foreign material that stays almost permanently and is released slowly to the rest of the system does not influence the system in some way. Is it cancer, I don't know close enough to say, but I would be surprise if it does nothing.
The problem with these studies is that it is exceedingly difficult to correctly account for all the additional differences between people who do get tattoos and those who don't.
Plus, if you don't find an effect, there is no paper to publish.
So, the proper correction factor is not just to account for the data in this study; scientists would also need to implicitly correct for all the other (unpublished) attempts by other scientists that found no effect.
It's a tricky business for sure and not one with a reasonable solution.
Hence I would not read too much into this study ...
> The problem with these studies is that it is exceedingly difficult to correctly account for all the additional differences between people who do get tattoos and those who don't.
I don't disagree to the gist of your post. However, in biomedical and public health research, papers are published even "if you don't find an effect", for good reasons. There could be simply very many unknown factors at the initial phase of some research topics. Researchers find or notice some things, publish them with rigorous discussions, proposed hypothesis with explicitly mentioned assumptions, etc. Other researchers build upon the existing results, add more discoveries, which can be proving or disproving, partially or wholly, etc. It often takes years of multiple teams to get a good enough understanding of a topic. This implicit collaboration is a positive feedback loop to advance the research.
The issue is that the vast majority don't read the detailed discussion in the papers and thus could get a partial thesis, which in many cases lead to incorrect conclusions. Media reports don't help, because they are essentially a simplified version. Otherwise, they can simply refers to the original papers and ask the audience to read them. Also, not many reporters have solid scientific training in the fields they report and don't understand the papers well enough. I don't blame them, since it is hardly their job. Good readers must be aware that the reports can be misleading, or biased, or simply wrong.
Readit News
Ironically, while working on a drug program that involved intradermal injection, we needed to tattoo the injection site so we could find it later. The FDA was very demanding that both the procedure and more importantly to them the dye would not have any effect that might alter the body’s response to the compound under test. We had to do a whole study just to validate this.
So the FDA is concerned about this issue for guinea pigs, but is barred from investigating the effect on humans. All they can do is publish advice on their web site.
Had one that was used to give someone eyebrows that got all toasty in an MR scanner.
rohs solder. Leaded paints, enamel paints, water based paints. cars with smog pumps and catalytic converters.
Wait they're legally prevented from investigating tattoo inks? Why?
BTW FDA was explicitly barred by a corrupt law* from regulating anything "natural" (a poorly defined criterion) so the same happens with all those things you see in Whole Foods: FDA can warn you of certain dangers from their web site but that's it.
They have a summary page that talks about the history of law that apply to them: https://www.fda.gov/about-fda/fda-history/milestones-us-food...
* Herbalife got their senator, Orrin Hatch, to get this law passed so they would stop getting in trouble for peddling snake oil in both their products and their MLM business model. His career was basically 100% carrying water for MLM folks and the music industry in exchange for cash.
> FDA considers the inks used in intradermal tattoos, including permanent makeup, to be cosmetics. When we identify a safety problem associated with a cosmetic, including a tattoo ink, we investigate and take action, as appropriate, to prevent consumer illness or injury. The pigments used in the inks are color additives, which are subject to premarket approval under the Federal Food, Drug, and Cosmetic Act. However, because of other competing public health priorities and a previous lack of evidence of safety problems specifically associated with these pigments, FDA traditionally has not exercised regulatory authority for color additives on the pigments used in tattoo inks. The actual practice of tattooing is regulated by local jurisdictions.
- https://www.fda.gov/cosmetics/cosmetic-products/tattoos-perm...
I believe you meant "Folie a Deux"?
We were able to isolate it in the HPLC and through some histopath experiments show that it didn’t have any negative local effect between (IIRC) seven and 60 days. Why those times? Protocol was to tattoo on day 0, wait a week for the site to recover, then inject our experimental material on day 7, sacrificing subject animals at D14 (one week), 21, 28, 35, 42, 49, and 56 days.
I don’t think lamp black is really a good idea, but was adequate for our purposes. We didn’t have to do any kind of long term study, just demonstrate that it would not interfere with our work in guinea pigs.
* I actually went to a specialist art store and the owner did indeed go to the back of the store and pull out one of the volumes of a multi-volume work on inks and pigments! I don’t know if it was actually named “The Encyclopedia of Ink”, though I do remember that that’s how he referred to it. He just photocopied the relevant page for me, most of which was the entry for India ink.
But, as with anything, it’s about nuance. You can read through the ingredients here[0] and tell me what you’d like in your body.
The earliest tattoos, from my understanding, were done by incision and rubbing carbon into the wound. Regardless if you use old or new inks/techniques, it’s not really cut and dry to say “this is bad/good” because the size of the particulates matter. For a tattoo shop that uses high quality ink, and is diligent in its sterilization, most inks are fine. The large molecules are “trapped” by your immune system to just stay there[1], making them not dangerous.
There is a ton of research on PubMed about tattoos, most being negative. However, I suspect it’s because the authors had a predisposition to be negative from the start based on how the research is conducted and what they focus on. But I could be wrong and you should make up your own mind.
Bottom line: if you get tattoos, pay the premium and go to a good shop. The hygiene and good products are worth it, if that’s your thing.
[0]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9846827/#:~:tex....
[1]: https://pubmed.ncbi.nlm.nih.gov/29511065/
Without a dose response, I'm inclined to believe that the increase in lymphoma seen in people with tattoos has more to do with confounding factors than with the ink or the act of getting a needle poked into your skin. I would think that controlling for all confounders in a study like this would be exceptionally difficult.
That said, I'm pretty sure that at least some inks do contain known carcinogens[1]
[1]https://tattoo.iarc.who.int/background/
For those who don't know how to interpret medical evidence, this study is very weak.
"The mean age of death for tattooed persons was 39 years, compared with 53 years for non-tattooed persons (P = .0001). There was a significant contribution of negative messages in tattoos associated with non-natural death (P = .0088) but not with natural death."
TFA has a more direct, physical, concern - it starts from a well-known, that tattoo ink ends up in lymph nodes, and it does a statistical analysis showing there's a significant statistical result in lymphoma occurence.
I think people with negative tattoos dying younger reduces the # of people with tattoos who get lymphoma, as they have less ink-in-lymph-nodes years.
Also the slicing and dicing, “11 more than the index year” and so on, is multiple hypothesis testing on the face of it; I wonder if they adjust for that.
As someone pointed out on the other thread about this[1], the lack of dose response makes it very difficult to see this as a direct correlation and not reflective of other confounding factors.
[1] https://news.ycombinator.com/item?id=40492364
https://www.jyi.org/2016-april/2017/3/12/got-ink-an-analysis...
From the article: "we found that the risk of developing lymphoma was 21 percent higher among those who were tattooed"
Let's put this number into context, because "percent of increased risk" is always something I struggle to picture"
"Overall, the chance that a man will develop NHL in his lifetime is about 1 in 42; for a woman, the risk is about 1 in 52." [1]
So the overall risk is ~2 %. That means getting a tattoo will bring your overall risk of developing NHL from 2 % to 2.5 % instead.
[1] https://www.cancer.org/cancer/types/non-hodgkin-lymphoma/abo...
https://chpgroup.com/evidence-in-ih/tattoo-ink-can-mimic-lym...
Plus, if you don't find an effect, there is no paper to publish.
So, the proper correction factor is not just to account for the data in this study; scientists would also need to implicitly correct for all the other (unpublished) attempts by other scientists that found no effect.
It's a tricky business for sure and not one with a reasonable solution.
Hence I would not read too much into this study ...
I don't disagree to the gist of your post. However, in biomedical and public health research, papers are published even "if you don't find an effect", for good reasons. There could be simply very many unknown factors at the initial phase of some research topics. Researchers find or notice some things, publish them with rigorous discussions, proposed hypothesis with explicitly mentioned assumptions, etc. Other researchers build upon the existing results, add more discoveries, which can be proving or disproving, partially or wholly, etc. It often takes years of multiple teams to get a good enough understanding of a topic. This implicit collaboration is a positive feedback loop to advance the research.
The issue is that the vast majority don't read the detailed discussion in the papers and thus could get a partial thesis, which in many cases lead to incorrect conclusions. Media reports don't help, because they are essentially a simplified version. Otherwise, they can simply refers to the original papers and ask the audience to read them. Also, not many reporters have solid scientific training in the fields they report and don't understand the papers well enough. I don't blame them, since it is hardly their job. Good readers must be aware that the reports can be misleading, or biased, or simply wrong.
edit: grammar