Eating too much red meat or not enough fish may increase your risk of developing colon cancer.

Researchers say the results confirm previous studies that have shown that eating large amounts of red or processed meat raises the risk of colon cancer while eating lots of fish has the opposite effect.

The study, which followed more than 500,000 men and women from 10 European countries, showed that people who ate the most red and processed meats had a higher risk of colon cancer than those who ate the least. Meanwhile, people who ate the most fish had a lower risk of colon cancer.

The results appear in the June 15 issue of the Journal of the National Cancer Institute.

Read WebMD's "The Red Meat-Colon Cancer Connection"

Red Meat Raises Cancer Risk

In the study, researchers looked at the association between how much red or processed meats, poultry, or fish people ate and their risk of developing colon cancer over nearly five years of follow-up.

During that time, more than 1,300 cases of colon cancer were diagnosed among the participants.

But the study showed that colon cancer was more common among heavy red and processed meat eaters (an average of more than 5.6 ounces per day).

For example, researchers estimate that 1.71 percent of heavy meat eaters would develop colon cancer during 10-year period meat compared with 1.28 percent among those who ate the least (an average of less than an ounce per day).

The researchers found that the chance of developing colon cancer was higher with processed meats compared with just red meats.

They also found that the risk of colon cancer was lower among people who ate the most fish (an average of nearly 3 ounces per day) compared with those who ate the least (an average of about a third of an ounce per day).

For fish, the researchers estimate that 1.28 percent of heavy fish eaters would develop colon cancer during a 10-year period compared with 1.86 percent of those who ate the least amount of fish.

There was no link between poultry consumption and colon cancer risk.

Researchers say an estimated 70 percent of colon cancer cases could be avoided through changes in lifestyle in Western countries.

Read WebMD's "Cancer Prevention: What Really Works?"

By Jennifer Warner, reviewed by Michael W. Smith, MD

SOURCES: Norat, T. Journal of the National Cancer Institute, June 15, 2005; vol 97: pp 906-916. News release, National Cancer Institute.