Tattoo ink is among the most ignored and underrated health risks. A large population in the US (over 30 percent) and Europe (~12 percent) has tattoos, but most never think about the chemicals that go inside their bodies along with the tattoo ink. A new study suggests that tattoos may even lead to lymphatic cancer (lymphoma).

The study authors initially wanted to know whether large, full-body tattoos increase the risk of cancer in humans. They didn’t find any association between tattoo size and cancer risk, but interestingly, they did discover that people with tattoos have a higher chance of developing lymphoma, a type of blood cancer.

“We found that tattooed individuals had a 21% higher risk of overall malignant lymphoma compared with non-tattooed individuals and that the association was strongest for diffuse large B-cell lymphoma and follicular lymphoma,” the study authors note.

Studies in the past highlighted the presence of carcinogenic chemicals in tattoo ink, including polycyclic aromatic hydrocarbons (PAHs) typically found in black ink. However, this is the first study to link tattoo exposure to lymphoma. Here is how the researchers came across this shocking finding.

The strange connection between tattoos and lymphoma

The researchers used the Swedish National Register to identify thousands of people diagnosed with lymphoma and compared them with healthy individuals of the same age and gender. 

For their study, they selected a total of 11,905 individuals: 2,938 lymphoma patients, and the rest of the healthy participants acted as the control group. The tattoo prevalence was 21 percent and 18 percent, respectively. 

They asked each participant to answer a questionnaire about their tattoos and lifestyle-related factors such as diet, smoking behavior, and so on. About 54 percent of the lymphoma patients (1,398 individuals) and 47 percent of healthy people (4,193) provided answers. 

When the study authors analyzed the data they found that “the risk of lymphoma was highest in individuals with less than two years between their first tattoo and the index year. The risk decreased with intermediate exposure duration (three to ten years) but increased again in individuals who received their first tattoo ≥11 years before the index year.”

Index year refers to the year when an individual is diagnosed with a disease, which in this case is lymphoma. The study also concluded that compared to non-tattooed individuals, the risk of developing lymphatic cancer was 21 percent higher in tattooed people. 

It’s important to note that this is an observational study. The researchers did not establish a causal relationship between tattoos and cancer. So far, there has been no case of cancer confidently attributed to tattoos.

However, the observed effect is significant and concerning. Tattoo inks may contain polycyclic aromatic hydrocarbons (PAHs) and primary aromatic amines (PAAs), both known carcinogenic chemicals. Further research is required to confirm if tattoo ink is truly a cancer-causing agent.

Removing an existing tattoo is not a good idea

If you have a tattoo and you’re concerned by these findings, the thought of removing your tattoo might pop into your mind. However, the researchers found that this may make things worse.

“An intriguing finding was that laser treatment for tattoo removal modified the effect of exposure and resulted in a substantially higher risk estimate,” the study authors said.

This is only the first study that highlights tattoos as a risk factor for lymphatic cancer. One study is never enough to establish causality and not everybody with a tattoo among the study participants developed lymphoma. Now is not the time to panic.

However, it is quite clear that “not only the long-term health effects of tattoo exposure per se but also the implications of laser treatment for tattoo removal warrants further investigation in light of the potential public health implications,” the study authors added.

The new findings also serve as a reminder that much of the tattoo ink industry is unregulated. Recent research from Binghamton University has unveiled startling discrepancies between what is listed on tattoo ink labels and the actual ingredients within these bottles. Of the 54 inks they subjected to chemical analysis, 45 of them — a staggering 90% — contained pigments and additives that were not listed on the ink bottle’s official ingredient list.

The study is published in the journal eClinicalMedicine.