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.
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.
Human subjects are crazy to work with for a few reasons
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.
If only there was a place where humans who have a tendency to get tattoos are in cages for an exrended period of time with a relatively consistent, trackable food intake, and constantly tracked behaviour. Humans who might even be motivated by privileges to volunteer for such studies.