Eating a lot of fish, including tuna and raw fish, appears to be associated with a higher risk of developing malignant melanoma, according to a large-scale US adult study published in the authoritative journal Cancer Causes & Control.
A number of studies suggest that regular, moderate fish consumption reduces the risk of cardiovascular disease and improves cognitive function. However new study challenges stereotype of fish being healthy.
Researchers at Brown University in the US found that those whose average daily intake was 42.8 grams of fish had a 28% higher risk of developing abnormal cells in just the outer layer of the skin, known as stage 0 or melanoma in situ melanoma, than those whose average daily intake was 3.2 grams of fish (one serving is about 140 grams of cooked fish).
“Melanoma is the 5th most common cancer in the United States and the lifetime risk of developing melanoma is 1/38 in whites, 1/1000 in people of color and 1/167 in Hispanics. Although fish consumption has increased in the US and Europe over the past decade, previous studies examining a possible link between fish consumption and melanoma risk have not been consistent. “Our results represent a data link that warrants further investigation,” study author Yoonyoung Cho said.
To investigate the relationship between fish consumption and melanoma risk, the authors of the scientific study analyzed data collected from 491,367 adults between 1995 and 1996. Participants, who were 62 years old on average, reported how often they had eaten fried fish, uncooked fish and tuna during the previous year, as well as portion sizes. news4health.gr.
The researchers calculated the incidence of new melanoma, which developed over an average of 15 years, using data obtained from cancer registries. Also taken into account were: sociodemographic factors, BMI of participants, levels of physical activity, smoking history, consumption of alcohol, caffeine, and “empty” calories (junk food), family history of cancer, and average UV exposure in their area. 5034 participants (1.0%) developed malignant melanoma during the study period, and 3284 (0.7%) developed stage 0 melanoma.
The researchers found that higher consumption of uncooked fish and tuna was associated with an increased risk of developing malignant melanoma and stage 0 melanoma. Those whose average daily intake of tuna was 14.2 grams had a 20% higher risk of malignant melanoma, compared with those , whose average daily intake of tuna was 0.3 grams.
An average intake of 17.8 g of non-fried fish per day was associated with an 18% increased risk of malignant melanoma and a 25% increase in stage 0 melanoma compared with an average intake of 0.3 g of non-fried fish per day. The researchers found no significant association between fried fish consumption and the risk of developing malignant melanoma or stage 0 melanoma.
Recall that modern industrial activity leads to the pollution of rivers and lakes, and as a result – the world’s oceans, the inhabitants of which are literally saturated with toxic substances through and through, and then end up on our table.
Yoonyoung Cho summarizes: “We hypothesize that our findings may be related to the presence of contaminants such as PCBs, dioxins, arsenic and mercury in fish. Previous research has shown that heavy fish consumption is associated with higher levels of these hazardous substances entering the human body and subsequently causing skin cancer. However, we note that our study did not study the concentrations of these substances in the body of the participants. Therefore, further studies are needed to confirm this relationship.”