The tattoos can be harmful to the immune systemundermining the body’s defense against certain infections or types of cancerwarns a study by the University of Italian Switzerland published in the American magazine Proceedings of the National Academy of Sciences.

A group of researchers led by Santiago F.González, from the Biomedical Research Institute linked to the university, has concluded that after tattooing the ink doesn’t just stay on the skinbut it spreads quickly to the lymphatic system.

Within a few hours, it accumulates in large quantities in the gangliavital organs of the immune system.

“Inside the ganglia, immune cells known as macrophages actively capture all the pigments, triggering an inflammatory response in two phases,” explains the Swiss university in a statement.

The first acute phase lasts only about two days, but after it “a chronic phase occurs that can last for years,” and is particularly worrying because in it the immune system is weakened“potentially increasing susceptibility to infections and cancer.”

The study indicates that macrophages cannot break down ink in the same way as they would other pathogens, which results in their death.

It indicates that this impossibility occurs especially in red and black inks, which suggests that they could be more toxic (it was investigated with these two colors and green, as they are the three most used in tattoos).

“Consequently, the ink remains in the lymph nodes, in a continuous cycle of cell capture and death, progressively affecting the defense capacity of the immune system,” he concludes.

The study lasted seven years, involved 12 international research groups and was funded by several Swiss organisations.

One of the experiments involved vaccination of laboratory mice, some of them tattooed and others without tattoos, and it was revealed that the former developed fewer antibodies than the latter.

These results “raise concern regarding the tattoo safety“, emphasizes the Swiss university, recalling that in the world it is estimated that almost one in five people has at least one on their skin.