A NOVEL STUDY has found that consuming increased levels of fish appears to be associated with a greater risk of developing malignant melanoma. Though fish consumption in the USA has increased over the previous decade, previous research on the association with melanoma risk has been inconsistent. Melanoma is the fifth most common cancer in the USA, and the risk of an individual developing it over their lifetime is one in 38 for White people, one in 1,000 for Black people, and one in 167 for Hispanic people.
Researchers from Brown University, Providence, Rhode Island, USA, examined the relationship between fish intake and melanoma risk by collected data from 491,367 adults recruited as part of the NIH-AARP Diet and Health study between 1995 and 1996. Participants reported how frequently they ate fish throughout the previous year, including fried fish, non-fried fish, and tuna.
The incidence of new melanomas that developed over a median period of 15 years was obtained using data from cancer registries. This data accounted for sociodemographic factors, BMI, physical activity, smoking history, daily alcohol intake, family history of cancer, and average UV radiation in the local area.
Researchers investigated individuals whose median daily fish intake was 3.2 grams compared to those with median fish intake of 42.8 grams, finding that risk of melanoma was 22% higher in the higher consumption group. This group was further found to have a 28% increased risk of developing abnormal cells in the outer layer of the skin.
“We speculate that our findings could possibly be attributed to contaminants in fish, such as polychlorinated biphenyls, dioxins, arsenic, and mercury. 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,” stated Eunyong Cho, study author.
The authors cautioned of the observational nature of the study, noting that the correlation did not allow for conclusions of a causal relationship. The authors suggested that future research was needed to investigate the components of fish that could contribute to the observed association and begin to articulate any biological mechanisms underlying this.