Does what you eat increase the risk of skin cancer? Seafood lovers may be concerned about new research finding that eating more fish increases the risk of melanoma.

Co-author Eunyoung Cho, an associate professor of dermatology and epidemiology at Brown University in Providence, Rhode Island, said it was one of the first studies to make the connection.

“Not many people are familiar with the diet associated with skin cancer,” Cho told Today. “You would never expect a diet (to exist) associated with skin cancer.”

Still, she and other experts caution against changing the amount of fish people eat based on the study’s findings, which only show a correlation, not a causation. The main risk factors for melanoma remained the same: UV exposure, having many moles and a family history of the disease.

A “unique” correlation
For the study, published in Cancer Causes and Control, Cho and her colleagues examined the fish eating habits of 491,367 participants in the NIH-AARP Diet and Health Study – a large group of Americans aged 50 to 71 who described their eating habits in a questionnaire in the mid-1990s. mid-1990s.

After following them for more than 15 years, the researchers looked at diagnoses of melanoma – the deadliest form of skin cancer – among the participants. The study found that when they were grouped by how much seafood they ate, it turned out that the group that ate the most fish had a 22 percent higher risk of developing malignant melanoma compared to the group that ate the least fish.

This may be due to contaminants in fish, such as PCBs, dioxins, arsenic and mercury, the authors write.

Arsenic is known to be a skin carcinogen, Cho said. A previous study found that higher blood mercury levels were associated with a higher prevalence of non-melanoma skin cancers.

“But at this point, we really don’t know which pollutant might be causing it. And this study was not designed in such a way that we could assess which specific components of fish would cause this association,” she noted. “There should be more research to address this topic.”

Should you change your diet?
Dr. Adam Friedman, a dermatologist who was not involved in the new study, called the research “interesting, but not a game changer at this point.”

He noted that a “unique” correlation would require more research to show that eating more fish may lead to a higher risk of melanoma.

“Unfortunately, the researchers did not take into account many established risk factors, such as the number of moles, hair color – red hair is an important factor – the number of past burns or sun protection behaviors, which really undermines our ability to interpret these data,” said Friedman, professor and chair of dermatology at the George Washington School of Medicine and Health Sciences.

“Therefore, I would suggest caution in translating these data to diet.”

Cho also advises people to stick with their current seafood menus.

“My advice is: don’t change your fish-eating habits now. People should really wait for more research,” she said.

The U.S. government recommends that adults eat at least 8 ounces of seafood per week.

Eating fish and seafood regularly can reduce the risk of cardiovascular disease, according to the American Heart Association, which recommends two servings of fish and seafood – especially fatty fish rich in omega-3 fatty acids – per week.

But eating large amounts of fish does increase a person’s exposure to mercury, a naturally occurring metal that is toxic to living things. Lisa Young, a registered dietitian nutritionist in New York, previously told Today that people can get into trouble when they hear that fish is healthy and think they should eat as much of it as possible.

Related: What is mercury poisoning?

Fish with the highest mercury levels include mackerel, shark, swordfish and tuna.

Seafood may not be the only dietary factor that affects melanoma risk. In previous studies, increased intake of citrus fruits and alcohol was also associated with increased risk.

Alcohol is the least surprising of all these factors, Cho said, because it has been linked to many different types of cancer.