Tattoos are a common sight these days, but have you ever stopped to think about what happens to the ink once it’s on your skin? You may be surprised to hear that not all ink stays put, as scientists believe a small portion can migrate to your lymph nodes.
A study spearheaded by the University of Southern Denmark (SDU) explored the long-term health effects of this. Their findings from a comprehensive analysis involving thousands of twins suggest there may be cause for concern.
Specifically, individuals with tattoos seem more prone to certain cancers. “For skin cancer and lymphoma, increased hazards were found for tattoos larger than the palm of a hand,” the authors wrote. “[Our] study suggests an increased hazard of lymphoma and skin cancers among tattooed individuals, demonstrated through two designs: a twin cohort and a case-cotwin study.
“We are concerned that tattoo ink interacting with surrounding cells may have severe consequences. Studies that pinpoint the etiological pathway of tattoo ink-induced carcinogenesis are recommended to benefit public health.”
Lymph nodes, integral to the immune system, are instrumental in warding off infections and potentially damaging substances. There’s growing speculation among experts that tattoo ink can infiltrate the skin and provoke ‘chronic inflammation’ within the lymph nodes.
This factor is what could give rise to abnormal cell growth, increasing the risk of cancer over time. “We can see that ink particles accumulate in the lymph nodes, and we suspect that the body perceives them as foreign substances,” said Professor Henrik Frederiksen of SDU.
The university’s explanation continues: “This may mean that the immune system is constantly trying to respond to the ink, and we do not yet know whether this persistent strain could weaken the function of the lymph nodes or have other health consequences.
“Studying this link is challenging because cancer can take years to develop. This means that exposure in youth may not lead to illness until decades later, making it difficult to measure a direct effect.”
As the university implies, there is still much uncertainty surrounding the processes at play and other contributing factors. Investigators are now exploring the effect of tattoo ink at a ‘molecular level’ and how specific cancers correlate closely with tattoos.
Professor Signe Bedsted Clemmensen added: “In our study, we do not see a clear link between cancer occurrence and specific ink colours, but this does not mean that colour is irrelevant. We know from other studies that ink can contain potentially harmful substances, and for example, red ink more often causes allergic reactions. This is an area we would like to explore further.
“We want to gain a better understanding of the biological mechanisms—what happens in the lymph nodes when they are exposed to ink particles over decades? This can help us assess whether there is a real health risk and what we might do to reduce it.”