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Not so long ago, a friend texted me from a coffee shop. He said, "I can't believe it. I'm the only one here without a tattoo!" That might not seem surprising: a quick glance around practically anywhere people gather shows that tattoos are widely popular.

Nearly one-third of adults in the US have a tattoo, according to a Pew Research Center survey, including more than half of women ages 18 to 49. These numbers have increased dramatically over the last 20 years: around 21% of US adults in 2012 and 16% of adults in 2003 reported having at least one tattoo.

If you're among them, some recent headlines may have you worried:

              Study Finds That Tattoos Can Increase Your Risk of Lymphoma (OnlyMyHealth)

              Getting a Tattoo Puts You At Higher Risk of Cancer, Claims Study (NDTV)

              Inky waters: Tattoos increase risk of lymphoma by over 20%, study says (Local12.com)

              Shocking study reveals tattoos may increase risk of lymphoma by 20% (Fox News)

What study are they talking about? And how concerned should you be? Let's go through it together. One thing is clear: there's much more to this story than the headlines.

Why are researchers studying a possible link between tattoos and lymphoma?

Lymphoma is a type of cancer that starts in the lymphatic system, a network of vessels and lymph nodes that twines throughout the body. With about 90,000 newly diagnosed cases a year, lymphoma is one of the most common types of cancer.

Risk factors for it include:

• advancing age
• certain infections (such as Epstein-Barr virus, HIV, and hepatitis C)
• exposure to certain chemicals (such as benzene, or possibly pesticides)
• family history of lymphoma
• exposure to radiation (such as nuclear reactor accidents or after radiation therapy)
• having an impaired immune system
• certain immune diseases (such as rheumatoid arthritis, Sjogren's disease, or celiac disease).

Tattoos are not known to be a cause or risk factor for lymphoma. But there are several reasons to wonder if there might be a connection:

• Ink injected under the skin to create a tattoo contains several chemicals classified as carcinogenic (cancer causing).
• Pigment from tattoo ink can be found in enlarged lymph nodes within weeks of getting a tattoo.
• Immune cells in the skin can react to the chemicals in tattoo ink and travel to nearby lymph nodes, triggering a bodywide immune reaction.
• Other triggers of lymphoma, such as pesticides, have a similar effect on immune cells in lymph nodes.

Is there a connection between tattoos and lymphoma?

Any potential connection between tattoos and lymphoma has not been well studied. I could find only two published studies exploring the possibility, and neither found evidence of a compelling link.

The first study compared 737 people with the most common type of lymphoma (called non-Hodgkin's lymphoma) with otherwise similar people who did not have lymphoma. The researchers found no significant difference in the frequency of tattoos between the two groups.

A study published in May 2024 — the one that triggered the scary headlines above — was larger. It compared 1,398 people ages 20 to 60 who had lymphoma with 4,193 people who did not have lymphoma but who were otherwise similar. The study found that

• lymphoma was 21% more common among those with tattoos
• lymphoma risk varied depending on how much time had passed since getting the tattoo:
  • within two years, lymphoma risk was 81% higher
  • between three and 10 years, no definite increased lymphoma risk was detected
  • 11 or more years after getting a tattoo, lymphoma risk was 19%

There was no correlation between the size or number of tattoos and lymphoma risk.

What else should you know about the study?

Importantly, nearly all of the differences in rates of lymphoma between people with and without tattoos were not statistically significant. That means the reported link between lymphoma and tattoos is questionable — and quite possibly observed by chance. In fact, some of the other findings argue against a connection, such as the lack of a link between size or number of tattoos and lymphoma risk.

In addition, if tattoos significantly increase a person's risk of developing lymphoma, we might expect lymphoma rates in the US to be rising along with the popularity of tattoos. Yet that's not the case.

Finally, a study like this one (called an association study) cannot prove that a potential trigger of disease (in this case, tattoos) actually caused the disease (lymphoma). There may be other factors (called confounders) that are more common among people who have tattoos, and those factors might account for the higher lymphoma risk.

Do tattoos come with other health risks?

While complication rates from reputable and appropriately certified tattooists are low, there are health risks associated with tattoos:

• infection, including bacterial skin infections or viral hepatitis
• allergic reactions to the ink
• scarring
• rarely, skin cancer (melanoma and other types of skin cancer).

The bottom line

Despite headlines suggesting a link between tattoos and the risk of lymphoma, there's no convincing evidence it's true. We'll need significantly more research to say much more than that. In the meantime, there are more important health concerns to worry about and much better ways for all of us to reduce cancer risk.

About the Author

Robert H. Shmerling, MD, Senior Faculty Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Robert H. Shmerling is the former clinical chief of the division of rheumatology at Beth Israel Deaconess Medical Center (BIDMC), and is a current member of the corresponding faculty in medicine at Harvard Medical School. … See Full Bio View all posts by Robert H. Shmerling, MD

Celiac disease is a digestive and immune disorder that can keep the body from absorbing necessary nutrients. “Our conception and awareness of celiac disease has evolved over the past few decades, but there are still aspects that remain poorly understood,” says Dr. Ciaran Kelly, medical director of the Celiac Center at Beth Israel Deaconess Medical Center and professor of medicine at Harvard Medical School.

Perhaps not surprisingly, misconceptions are widespread among the general public. One example? Many people assume that everyone who has celiac disease is plagued by abdominal pain, bloating, or diarrhea. But actually, many adults newly diagnosed with this inherited gluten intolerance don’t have these symptoms.

What’s more, gluten — the sticky protein found in grains such as wheat, barley, and rye — can cause gastrointestinal distress and other symptoms in people who don’t have celiac disease. Read on for a deeper dive into four myths and facts about celiac disease and related digestive conditions.

Myth # 1: Celiac disease is usually diagnosed at a young age

Not typically. While celiac disease can develop any time after a baby’s first exposure to gluten, it’s usually diagnosed much later in life. According to the National Celiac Association, the average age of diagnosis is between 46 and 56. Around 25% of people are diagnosed after age 60.

Celiac disease is slightly more common in women and among people with other autoimmune conditions, including type 1 diabetes, Hashimoto’s thyroiditis (a common cause of low thyroid levels), and dermatitis herpetiformis (a rare condition marked by an itchy, blistering rash).

“We don’t know why some people go from being susceptible to actually having celiac disease,” says Dr. Kelly. The prevailing theory is that some sort of physical or emotional stress — such as a viral infection, surgery, or anxiety from a stressful life event — may “flip the switch” and cause the disease to appear, he says. “Increasing numbers of people are being diagnosed at midlife and older, often after they’re found to have conditions such as anemia or osteoporosis caused by nutrient deficiencies,” says Dr. Kelly.

Myth #2: Celiac disease only affects the gut

When people have celiac disease, eating gluten triggers an immune system attack that can ravage the lining of the small intestine. A healthy small intestine is lined with fingerlike projections, called villi, that absorb nutrients. In celiac disease, the immune system attacks the villi, causing them to flatten and become inflamed — and thus unable to adequately absorb nutrients.

While gastrointestinal problems can occur, they aren’t always present. In fact, celiac disease can present with many different symptoms that affect the nervous, endocrine, and skeletal systems. A few examples are brain fog, changes in menstrual periods, or muscle and joint pain.

Myth # 3: Celiac disease versus gluten intolerance

If you feel sick after eating gluten, you probably have celiac disease, right? Actually, that may not be true. Some people have non-celiac gluten sensitivity (also called gluten intolerance), which can cause uncomfortable digestive symptoms after eating gluten. But gluten intolerance differs from celiac disease.

• Celiac disease is diagnosed with blood tests that look for specific antibodies. If antibodies are present, a definitive diagnosis requires an intestinal biopsy to look for signs of damage that characterize the condition.
• Non-celiac gluten sensitivity does not trigger antibodies or cause intestinal damage. Yet some people with this problem say they also experience brain fog, trouble concentrating, muscle aches and pain, and fatigue after eating gluten-containing foods.

“Non-celiac gluten sensitivity appears to be a real phenomenon, but it’s not well defined,” says Dr. Kelly. It’s unclear whether people experiencing it are intolerant to gluten or to something else in gluten-containing foods.

• One possibility is sugarlike molecules known as FODMAPs, which are found in many foods — including wheat. Short for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, gas and bloating can occur when gut bacteria feed on FODMAPs.
• Another possibility is an allergy to wheat, which can cause symptoms such as swelling, itching, or irritation of the mouth and throat after eating wheat. Other symptoms include a skin rash, stuffy nose, and headache, as well as cramps, nausea, and vomiting. Some people may develop a life-threating allergic reaction known as anaphylaxis.

Myth #4: A gluten-free diet always relieves the symptoms and signs of celiac disease

The sole treatment for celiac disease — adopting a diet that avoids all gluten-containing foods — doesn’t always help. This problem is known as nonresponsive celiac disease.

“About 20% of people with celiac disease have ongoing symptoms, despite their best efforts to stick to a gluten-free diet,” says Dr. Kelly. Others have intermittent signs and symptoms, particularly when they are accidentally exposed to gluten. Accidental exposures often happen when people eat prepared or restaurant foods that claim to be gluten-free but are not. Cross contamination with gluten-containing foods is another potential route.

Potential solutions to nonresponsive celiac disease are being studied. Three promising approaches are:

• Enzymes that break down gluten, which people could take alongside gluten-containing foods. “It’s a similar concept to the lactase pills taken by people who are lactose intolerant to help them digest dairy products,” says Dr. Kelly.
• Dampening the immune response to gluten by inhibiting an enzyme called tissue transglutaminase that makes gluten more potent as an antigen.
• Reprogramming the immune response to prevent the body from reacting to gluten.

About the Author

Julie Corliss, Executive Editor, Harvard Heart Letter

Julie Corliss is the executive editor of the Harvard Heart Letter. Before working at Harvard, she was a medical writer and editor at HealthNews, a consumer newsletter affiliated with The New England Journal of Medicine. She … See Full Bio View all posts by Julie Corliss

About the Reviewer

Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Howard LeWine is a practicing internist at Brigham and Women’s Hospital in Boston, Chief Medical Editor at Harvard Health Publishing, and editor in chief of Harvard Men’s Health Watch. See Full Bio View all posts by Howard E. LeWine, MD