Though none of us are guaranteed a clean bill of health as we age, we can do plenty of things to reduce our risk of serious chronic illnesses. In particular, lowering your cancer risk is among the most important measures you can take to ensure a long and healthy life. Maintaining a healthy diet is a key component of cancer prevention—along with quitting smoking and exercising. Now, experts are calling out particular foods that could be putting you at high risk of cancer, including fish prepared a certain way. Read on to learn which style of fish is considered a "Group 1 carcinogen" by the World Health Organization, and why it raises your cancer risk.
Several types of meat are considered carcinogenic.
Several types of meat are believed to cause cancer, and as such have been labeled as "Group 1 carcinogens" by the World Health Organization (WHO). This means that the organization has found "convincing evidence" that these foods and other substances cause cancer. Grouped alongside tobacco and asbestos, processed meats such as hot dogs, deli meat, beef jerky, and charcuterie fall into this category. These types of meat are associated with higher rates of colorectal and stomach cancer.
Only slightly less concerning, red meat is classified as a Group 2A carcinogen, meaning it is "probably" cancer-causing in humans. "The strongest link between eating red meat and cancer is colorectal cancer, however, there is also evidence of links to both pancreatic and prostate cancer," explain medical experts on behalf of the health insurance company Aetna.
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Fish is often recommended as an alternative to cancer-causing meats.
A lean source of protein rich in Omega-3 fatty acids, fish is generally considered part of a healthy diet. The American Institute for Cancer Research (AICR) says it may also help protect against cancer. "Again and again, research shows that people eating diets with a moderate amount of seafood have lower risk of cancer and other chronic diseases and longer lives," the AICR writes. "This could be due to other parts of the diet. For example, if you're eating more fish for dinner, you may be eating less red and processed meats, which increase colorectal cancer risk," their experts note.
Additionally, eating a diet that includes fish has been linked with lower rates of obesity. "Overweight and obesity is now linked to increased risk of 10 cancers, including postmenopausal breast, liver and colorectal," the AICR says.
However, eating fish prepared this way can cause cancer.
Though fish is generally associated with lower cancer rates, fish prepared in one particular way is believed to cause cancer in humans, according to the WHO: salt-preserved fish.
"Salting is a traditional method of preserving food—especially fish—frequently used in southeast Asia and China," explain Aetna health experts. "This method of preserving unfortunately results in the production of carcinogenic byproducts, meaning it can cause cancer in humans. Chinese-style salted fish is a Group 1 carcinogen, like processed meat."
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Here's why experts say it happens.
Studies have shown a link between salted fish and cancer of the nasopharynx (located in the upper throat) and stomach. When it triggers cancer in the nasopharynx, it is usually due to a reaction between nitrogen compounds in the fish and nitrates and nitrites in the crude salt used to preserve it.
Meanwhile, most stomach cancer cases begin with damaged cells on the inner lining of the stomach. "Scientists believe the increased stomach cancer risk from salt-preserved foods is because they contain a large amount of salt, which infuses the foods during the preservation process. Experimental research has shown that salt damages the stomach lining and causes lesions, which, if left to develop, can become stomach cancer," explains Stephanie Fay, MD, on the World Cancer Research Fund International (WCRFI) website.
To lower your risk, reduce the amount of preserved fish in your diet and limit your salt intake to fewer than five grams of salt daily, says the WHO. Speak with your doctor if you are concerned about your cancer risk, or have questions about how this risk factor may affect you or your diet.