Until now, fish has always been classified as a healthy food. However, a recent study in the US suggested that eating a lot of fish can cause cancer, confusing many people.
Eating a lot of fish increases the risk of skin cancer
The study was carried out by scientists at Brown University (Providence, Rhode Island, USA). It was published in the journal Cancer Causes and Control, showing that eating a lot of fish is linked to an increased risk of a potentially fatal malignant melanoma cancer.
The team of scientists looked at data from more than 490,000 US adults between the ages of 50 and 71. These people participated in the NIH-AARP Diet and Health Study, run by the National Cancer Institute The United States National Association (NIH) and AARP jointly implement it.
At the beginning of the study, participants were asked to answer detailed questionnaires, including information about how much fish they normally ate. They were then followed for about 15 years for the development of cancer.
The researchers also took into account factors that could have influenced the results. Such as the volunteers’ weight, whether they smoked or drank alcohol, their diet, and family history of cancer. Include average UV radiation levels in their area because sun exposure is also a risk factor for skin cancer.
The results showed that compared with people who ate almost no fish, the group that ate the most fish – an average of 283g, or about 3 servings per week, had a 22% higher risk of developing melanoma.
Specifically, 5,034 people (accounting for 1%) developed melanoma during the study period and 3,284 (accounting for 0.7%) developed stage 0 melanoma. In which, those with a high amount of tuna A daily consumption of 14.2g had a 20% higher risk of developing melanoma than those with a typical intake of 0.3g. People who ate 17.8g of non-fried fish per day had an 18% higher risk of melanoma and a 25% higher risk of stage 0 melanoma compared with eating just 0.3g. However, no significant association was found between eating fried fish and skin cancer.
Why does eating fish increase the risk of cancer?
Assoc. In fact, the fish itself is not the cause of skin cancer, but it is toxic substances from the environment that get into the fish.
Specifically, she says: “Previous studies have found that higher fish intake is associated with higher levels of these pollutants in the body. It has also been identified a link between these pollutants and an increased risk of melanoma skin cancer. The most common fish contaminants are polychlorinated biphenyls, dioxins, arsenic and mercury.”
She also emphasized the fact that marine pollution increases the toxicity of marine fish. A 2019 study in the journal Nature found that due to a warming climate and industrial pollution, marine fish such as cod, Atlantic bluefin tuna and swordfish raised Methyl mercury levels higher than 1 million times more than in the natural environment.
Up to 82% of the methylmercury that Americans are exposed to comes from seafood, of which canned tuna accounts for nearly 40%. Other fish, including mackerel, marlin and shark, are all high in mercury.
However, Assoc. “I wouldn’t advise people to stop eating fish just because of our findings,” she said. In fact, eating fish can help reduce the risk of cardiovascular disease, and some other cancers.”
Because in general, fish is still a healthy source of protein, rich in omega-3 fatty acids, and good for heart and brain health. Nutritionists recommend eating fish twice a week, but be careful about the amount to avoid unwanted effects, including skin cancer.
The US Food and Drug Administration (FDA) also recommends that when eating fish, especially for children or pregnant women, the skin, back, ribs and belly fat and viscera should be removed. Because these are the parts that are susceptible to the accumulation of heavy metals and other harmful pollutants.
Source and photo: Sohu