MIAMI – Eating large amounts of red and processed meats may be linked to an increased risk of prostate cancer, researchers report in the American Journal of Epidemiology.

The authors followed 175,343 men in the United States who were 50-71 years old from 1995 until 2003. They recorded the participants’ meat consumption, including the type of meat they ate and how they cooked it, and monitored their iron levels, nitrite/nitrate intake and the number of prostate cancer diagnoses.

By the end of the study, 10,313 developed prostate cancer, of which 419 died.

After adjusting for various factors known to increase the risk of prostate cancer, the authors found that men who ate the most red meat were 12 percent more likely to develop prostate cancer and 33 percent more likely to develop advanced prostate cancer than those who ate the least amount.

Processed meat was also linked to a higher risk of prostate cancer. However, the authors noted that red processed meats (like hot dogs and bacon) were linked to a greater cancer risk than white processed meats (like turkey sandwich meat).

Grilling was the only cooking method that was linked to an increased risk of prostate cancer. It has been suggested that cancer risk may be increased by compounds called heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs), which are formed when meat (especially red meat) is cooked at high temperatures. When heated, the amino acids, sugars and creatinine are converted into HCAs and PAHs, which have been linked to various cancers, including stomach, colorectal, pancreatic and breast cancers, in humans.

Nitrate intake was also correlated with an increased risk of the disease. Nitrates are preservatives that are added to processed and cured meats such as cold cuts and bacon. The preservatives have been associated with cancer-causing chemicals called nitrosamines.

This study supports growing evidence that too much meat may be unhealthy. Earlier studies suggest that red or processed meat may increase the risk of colon cancer and death (particularly from cancer and heart disease) and may be linked to age-related macular degeneration. Red meat also contains high amounts of saturated fats, which have been shown to increase the risk of heart disease.

Some other dietary changes may help reduce the risk of prostate cancer. For instance, eating fewer dairy products that are high in fat (like ice cream, cheese and sour cream) may be beneficial. Also, cruciferous vegetables (such as broccoli, cabbage and cauliflower) have been reported to contain cancer-fighting phytochemicals that may decrease the chances of developing prostate cancer.

The American Urological Association (AUA) encourages men who are in good health to have annual PSA testing starting at age 50, or at age 40 if they are in high-risk groups, such as African American men or those with histories of the disease.