Study: Pan-fried fish may raise cancer risk

In the United States, more than 240,000 men are diagnosed annually with prostate cancer and about 33,720 die from the disease, according to the National Cancer Institute. Only lung cancer kills more American men. According to the Prostate Cancer Foundation, there are no proven strategies for preventing the disease, but changes in diet and lifestyle appear to have reduced the risk of disease progression.

The researchers by  University of South California analyzed data from nearly 3,000 men who participated in the California Collaborative Prostate Cancer Study in the Los Angeles and San Francisco Bay areas. Study participants completed a comprehensive survey that included questions about the amount and types of fish they consumed on a weekly basis and how the fish was cooked. More than 60 percent of the men were diagnosed with advanced prostate cancer.

Diets high in dark fish like salmon, mackerel, and sardines reduced the risk of prostate cancer if the fish were cooked at low temperatures, like baking or boiling. This suggested protective effect disappeared when the fish was cooked at high temperatures, such as broiling, grilling, or pan-frying.

Surprisingly, men who ate two or more servings per week of white fish cooked using high-temperature methods were twice as likely to develop advanced prostate cancer than men who never ate any fish. The study found no association between cancer and diets high in white fish cooked using low-temperature methods.

The study also noted that high intake of deep-fried fish, such as fish sticks and fish sandwiches, was linked to an increased risk of prostate cancer among Hispanic men, but not among non-Hispanic whites or African-Americans, who reported the highest intake of fried fish than any other ethnic group studied.