A new study shows tattoo ink drains into the lymphatic system and accumulates in lymph nodes, diminishing the effects of immune cells. This accumulation of ink pigment triggers both local and systemic inflammation that persists for months.

A third of American adults, roughly 32% - or about 80 million people - have tattoos, and they should read this new study published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS).

"Despite safety concerns regarding the toxicity of tattoo ink, no studies have reported the consequences of tattooing on the immune response. In this work, we have characterized the transport and accumulation of different tattoo inks in the lymphatic system using a murine model," researcher Arianna Capucetti wrote in the study.

Capucetti continued:

An initial inflammatory reaction at local and systemic levels follows ink capture. Notably, the inflammatory process is maintained over time, as we observed clear signs of inflammation in the draining LN 2 mo following tattooing. In addition, the capture of ink by macrophages was associated with the induction of apoptosis in both human and murine models. Furthermore, the ink accumulated in the LN altered the immune response against two different types of vaccines.

On the one hand, we observed a reduced antibody response following vaccination with a messenger ribonucleic acid (mRNA)-based severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine, which was associated with a decreased expression of the spike protein in macrophages in the draining LN.

In contrast, we observed an enhanced response when vaccinated with influenza vaccine inactivated by ultraviolet (UV) radiation.

Considering the unstoppable trend of tattooing in the population, our results are crucial in informing the toxicology programs, policymakers, and the general public regarding the potential risk of the tattooing practice associated with an altered immune response.

As we noted earlier this year, "Many tattoo inks contain chemicals that have been classified as carcinogenic — or cancer-causing — by the International Agency for Research on Cancer."

While black tattoo inks use carbon black, colored inks contain pigments designed for industrial applications such as plastics and paints. More troubling, tattoo inks are far less regulated than pharmaceuticals.

We have already covered two important studies:

• A 2024 Swedish study tracking nearly 12,000 people found that individuals with tattoos had a 21% higher risk of malignant lymphoma compared with those without ink.
• A Danish twin study published earlier this year reported similar trends. Tattooed participants showed higher rates of skin cancer.

Dr. Trisha Khanna, dermatologist and medical advisory board member at Codex Labs, recently told The Epoch Times, "Current regulations on tattoo ink ingredients are not sufficient," adding, "This is a growing concern among dermatologists."

And laser removal could make it worse.

Some warning signs people with tattoos should look out for when monitoring their skin health include persistent redness, itching, bumps, new pigmented lesions, color change, ulceration, and bleeding, Khanna said.

Tattoos can also complicate the early detection of skin cancer, Brod said. Since changes in the skin may be obscured by the tattoo pigment, detecting potential issues becomes more challenging.

If people notice a new or changing spot within a tattoo — or anywhere on the skin — it's crucial to seek evaluation from a dermatologist, he said.

Laser Removal

After learning about the risks, some people's first instinct might be to remove their tattoo. However, laser removal could further increase the lymphoma risk. Among tattooed participants who underwent laser treatment, the risk of lymphoma was found to be three times higher.

These findings align with experimental studies showing that laser treatment breaks down azo compounds — chemicals used to color tattoos — into potentially toxic, cancer-causing substances. This breakdown may release more harmful chemicals into the body, further raising the risk.

What to Do if You Have a Tattoo

If you're already tattooed and concerned about the risks, the best approach is to focus on your overall health.

"The best thing we can do for our health, tattoos or not, is to maintain a healthy lifestyle — regular exercise and a nutritious diet," Nielsen said.

Make sure to take an active role in improving your diet to help reduce cancer risk.