Eating Meat Does Not Raise Breast Cancer Risk in Older Women

Eating red or white meat, including meat cooked at high temperatures, does not increase the risk of breast cancer in postmenopausal women, according to a large study conducted by researchers at Albert Einstein College of Medicine of Yeshiva University. The study was published this month in the International Journal of Cancer.

A number of previous studies have found that eating red meat or meat cooked at high temperatures increases the risk of breast cancer. (High temperatures —caused by grilling, barbecuing or pan-frying — produce high amounts of heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) in meat; HCAs and PAHs are mutagens (chemicals capable of causing mutations in DNA) that can cause breast tumors in laboratory animals.)

But a link between meat in the diet and breast cancer in women hasn’t been established. “Previous epidemiologic studies in humans looking at the amount of meat in the diet and estimated intakes of HCAs and PAHs in relation to breast cancer risk have yielded inconsistent results,” says lead author Geoffrey C. Kabat, Ph.D., M.S., senior epidemiologist in the department of epidemiology and population health at Einstein.

To clarify this issue, Dr. Kabat and his colleagues analyzed data on 120,755 postmenopausal women who participated in the NIH-AARP Diet and Health Study, a collaboration between the National Institutes of Health and American Association of Retired Persons. When the women enrolled in the study (between 1995 and 1996), they gave detailed information on what types of food they ate and how often they ate certain foods. In addition, they provided information on meat-preparation methods.

Over the next eight years, approximately three percent, or 3,818, of the women developed breast cancer. The researchers found no evidence that the amount of meat consumed, meat-cooking methods used, or meat-mutagen intake was associated with an increased risk for breast cancer. Reported meat intake included steak, hamburger, chicken, pork, processed meat and meat cooked at high temperatures.

The study also found that consumption of meat or meat cooked at high temperatures, through grilling and oven-broiling, did not increase breast cancer rates in subgroups including obese women, those who did not have children, who were consumers of alcohol, who were smokers, who used menopausal hormone therapy, who had low levels of physical activity, or had a low intake of fruits or vegetables.

Neither the current study nor earlier studies assessed the diets of younger women. “So we haven’t ruled out the possibility that eating meat and exposure to meat mutagens at a younger age — particularly during adolescence when the breasts are developing — may increase one’s risk of breast cancer,” says Dr. Kabat.

The study, “Meat intake and meat preparation in relation to risk of postmenopausal breast cancer in the NIH-AARP diet and health study,” appeared in the May 15, 2009 issue of the International Journal of Cancer. Study co-authors include Amanda J. Cross, Yikyung Park, Arthur Schatzkin, and Rashmi Sinha of the National Cancer Institute; Albert R. Hollenbeck, of AARP; and Thomas E. Rohan, Chairman, Department of Epidemiology & Population Health at Einstein.