Higher total fish intake is associated with increased risk for malignant melanoma and melanoma in situ, according to a study published online June 8 in Cancer Causes & Control.

Yufei Li, from Brown School of Public Health in Providence, Rhode Island, and colleagues examined the associations between intake of total fish and specific fish types and risk of melanoma among 491,367 participants of the U.S. National Institutes of Health-AARP Diet and Health Study.

The researchers identified 5,034 cases of malignant melanoma and 3,284 cases of melanoma in situ during 6,611,941 person-years of follow-up. Positive associations were identified between higher total fish intake and risk of malignant melanoma and melanoma in situ (hazard ratios, 1.22 and 1.28, respectively, for top versus bottom quintiles). Across several demographic and lifestyle factors, the positive associations were consistent. Positive associations were also seen between intake of tuna and nonfried fish and risks of malignant melanoma and melanoma in situ. An inverse association was seen for fried fish intake with malignant melanoma but not melanoma in situ.

"We speculate that our findings could possibly be attributed to contaminants in fish, such as polychlorinated biphenyls, dioxins, arsenic, and mercury," a coauthor said in a statement. "Previous research has found that higher fish intake is associated with higher levels of these contaminants within the body and has identified associations between these contaminants and a higher risk of skin cancer."

Abstract/Full Text (subscription or payment may be required)