Red Meat, Processed Meats May Raise Prostate Cancer Risk

By David Liu and editing by Rachel Stockton

A new study published in the Nov 1, 2009 issue of American Journal of Epidemiology suggests that eating too much red and processed meats may increase risk of prostate cancer.

The study showed that a high intake of meat is associated with an elevated risk of prostate cancer, which is diagnosed in more than 170,000 men in the United States and kills about 40,000 each year.

Sinha R and colleagues at the National Cancer Institute  analyzed data from 174,343 US men aged 50 to 71 who were followed up for nine years to record prostate cancer cases.  Study subjects were surveyed for their intake of meat.

During the follow-up between 1995 and 2003, 10,313 prostate cancer cases with 1,102 advanced and 419 fetal cases were registered.

Compared to men who consumed the lowest quintile of red meat intake, those who consumed the highest quintile of red meat intake were at 12 percent increased risk of total prostate cancer. For processed meat, the risk was increased by 7 percent.

Highest intake of red meat and processed meat was associated with 31 percent and 32 percent increased risk of advanced prostate cancer, respectively.

Highest intakes of heme iron, barbecued/grilled meat, and benzo[a]pyrene were all positively associated with a 9, 11, and 9 percent increased risk of total prostate cancer, respectively.

The risk for advanced prostate cancer in men who had the highest intakes of heme iron, barbecued/grilled meat, and benzo[a]pyrene was increased by 28, 36 and 28 percent higher respectively, compared with those whose intakes were lowest.

Highest intakes of nitrite and nitrate, both used as preservatives in processed meats such as hotdogs, bacon, sausages and hams, were associated with 24 percent and 31 percent increased risk of prostate cancer.

The researchers concluded "Red and processed meat may be positively associated with prostate cancer via mechanisms involving heme iron, nitrite/nitrate, grilling/barbecuing, and benzo[a]pyrene."

The study is merely an association and the results do not mean that eating meat would definitely increase risk of prostate cancer.  Further studies are needed to clarify whether or not there is a causal relationship between meat consumption and risk of prostate cancer.

One recent review published in the June 2009 issue of Journal of Human Nutrition and Dietetics suggests that a diet low in fat and red meat and high in fruits and vegetables helps prevent and treat prostate cancer.

Researchers found a diet that incorporates lots of vegetables and fruit, and low intake of meat and dairy products and calcium may help prevent prostate cancer. It may also help treat patients diagnosed with prostate cancer. The study was conducted by Robert W.-L. Ma and K. Chapman of The University of New South Wales.

Foods that seem to reduce the risk of prostate cancer include tomatoes, cauliflower, broccoli, green tea, and vitamins such as vitamin E and selenium. A diet that includes highly processed or charcoaled meats, dairy products and fats were correlated with high risk of the malignancy, said researchers.

Source:

Am J Epidemiol. 2009 Nov 1;170(9):1165-77.
Meat and meat-related compounds and risk of prostate cancer in a large prospective cohort study in the United States.
Sinha R, Park Y, Graubard BI, Leitzmann MF, Hollenbeck A, Schatzkin A, Cross AJ.
Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland 20892, USA.