Toronto, Canada (CTV Network) — A new study has found that eating more fish may be associated with an increased risk of certain skin cancers.
The findings, published by Brown University researchers in the journal Cancer Causes & Control, show that higher levels of fish consumption, namely tuna and unfried fish, appear to be associated with an increased risk of melanoma. clever.
However, the researchers do not recommend people change the amount of fish they eat and say more studies are needed.
They warn that their study, since it was observational, does not conclude that there is a causal relationship between fish consumption and the risk of melanoma. And they say they calculated average daily fish consumption at the start of the study, which means it may not represent a participant’s lifetime diet.
Their study also did not take into account certain risk factors for melanoma such as the number of moles, hair color, history of severe sunburn and sun-related behaviors.
“We speculate that our findings could possibly be attributed to contaminants in fish, such as polychlorinated biphenyls, dioxins, arsenic and mercury. Previous research has shown that higher fish consumption is associated with higher levels of these contaminants in the body and identified associations between these contaminants and a higher risk of skin cancer,” Eunyoung Cho, the study’s corresponding author, said in a statement.
“However, we note that our study did not investigate the concentrations of these contaminants in participants’ bodies and therefore further research is needed to confirm this relationship.”
Canada released its latest version of the National Food Guide in 2019, which dissolved the four traditional food groups and recommended serving sizes, emphasized healthier eating habits and encouraged plants and water in the diet. diet of a person with less meat and dairy products.
HOW HIGHER IS THE RISK OF MELANOMA?
Researchers looked at data from 491,367 adults across the United States who participated in the NIH-AARP Diet and Health Study between 1995 and 1996.
The average age of the participants was 62 years old. As part of the study, everyone reported how often and how much they had eaten fried and unfried fish, as well as tuna, in the previous year.
The researchers then calculated the incidence of new melanomas over a median period of 15.5 years, using data from cancer registries.
They say they took into account socio-demographic factors, participants’ BMI or body mass index, physical activity, smoking history, daily alcohol consumption, caffeine, calories, cancer history and the average levels of UV radiation in their area.
They found that 5,034 participants, or about 1%, developed malignant melanoma and 3,284, or about 0.7%, developed stage 0 melanoma, also called melanoma in situ, where abnormal cells grow only in the outer layer of the skin.
Those with a median daily fish consumption of 42.8 grams had a 22% higher risk of malignant melanoma than those with a median daily fish consumption of 3.2 grams.
The group with the highest daily intake also had a 28% increased risk of developing stage 0 melanoma.
Scientists say that one serving of fish equals approximately 140 grams of cooked fish.
Participants whose median daily tuna consumption was 14.2 grams had a 20% higher risk of malignant melanoma and a 17% higher risk of stage 0 melanoma compared to those whose median consumption was 0.3 gram.
Compared to the same lower consumption group, those whose median consumption of unfried fish per day was 17.8 grams had an 18% higher risk of malignant melanoma and a 25% higher risk of stage 0 melanoma.
The researchers found no significant association between fried fish consumption and the risk of malignant melanoma or stage 0.