A new analysis from a Brown University team shows a connection between eating fish and developing skin cancer, and the researchers say bio-contaminants like mercury are a likely cause.
Eating higher amounts of fish, including tuna and non-fried fish, appears to be associated with a greater risk of malignant melanoma, according to a large study of U.S. adults published in the journal Cancer Causes and Control.
“This study is important because it’s very large and it’s prospective by design, meaning that fish intake was assessed before the development of cancer,” said author Eunyoung Cho, an associate professor of dermatology and epidemiology at Brown University. “Although fish intake has increased in the U.S. and Europe in recent decades, the results of previous studies investigating associations between fish intake and melanoma risk have been inconsistent — our findings have identified an association that requires further investigation.”
The researchers found that compared to those whose median daily fish intake was 3.2 grams (.11 ounces), those whose median daily intake was 42.8 grams (1.5 ounces) had a 22% higher risk of malignant melanoma and a 28% increased risk of developing abnormal cells in the outer layer of the skin only — known as stage 0 cancer or melanoma in situ. A serving size of cooked fish is approximately 140-170 grams (5-6 ounces); a can of tuna is 142 grams (5 ounces).