Too Much Red Meat May Raise Breast Cancer Risk

Breast cancer risk lower in women who replaced red meat with fish and other healthier foods

(RxWiki News) Red meat seems to be a staple of the American diet. However, eating too much red meat has been linked to a variety of health problems that could affect unexpected parts of the body.

A recent study found that eating high amounts of red meat during early adulthood increased the risk of breast cancer for women.

The researchers discovered that replacing a serving of red meat per day with any combination of legumes, poultry, nuts and fish lowered the risk of breast cancer.

"Limit red meat in your diet."

The lead author of this study was Maryam S. Farvid, PhD, from the Department of Nutrition at Harvard School of Public Health in Boston, Massachusetts and the Department of Community Nutrition at Shahid Beheshti University of Medical Sciences in Tehran, Iran.

The study included 88,803 premenopausal women who completed a diet questionnaire for the Nurses’ Health Study II in 1991.

None of the women had any prior diagnosis of stroke, coronary heart disease, diabetes or cancer (except skin cancer). The women’s ages ranged from 26 to 45 years old in 1991, with the average age being 36 years old.

Every woman in this study completed a questionnaire in 1995, 1999, 2003 and 2007 about their dietary habits, including how much red meat, poultry, fish, legumes and nuts they ate on a daily basis.

Average daily intake of each food category was split into fifths, with the highest fifth consuming 1.50 servings per day and the lowest fifth consuming 0.14 servings per day.

The women also reported menopause status and breast cancer status via questionnaire. Diagnoses were verified with medical records.

The researchers conducted follow-up for 20 years.

The findings showed that 2,830 women developed breast cancer over the course of the study.

A total of 1,511 women developed breast cancer before menopause, 918 developed breast cancer after menopause, and 401 were not clear about their menopausal status when they developed breast cancer.

Those who developed breast cancer before menopause were, on average, 45 years old when diagnosed. On average, those with postmenopausal breast cancer were 55 years old at diagnosis.

The researchers determined that the women who ate the most red meat were 22 percent more likely to develop breast cancer than the women who ate the least red meat.

The overall risk of breast cancer was not affected by eating higher amounts of poultry, fish, eggs, legumes and nuts. However, when Dr. Farvid and team looked at the premenopausal women and the postmenopausal women separately, intake of these foods affected their risk of breast cancer.

The postmenopausal women who ate the most poultry had a 27 percent decreased risk of breast cancer compared to the postmenopausal women who ate the least amount of poultry.

The findings revealed that eating one serving of legumes per day instead of one serving of red meat per day lowered the risk of breast cancer by 15 percent in all the women, and by 19 percent among the premenopausal women.

One serving per day of poultry substituted for one serving of red meat per day lowered the risk of breast cancer by 17 percent among all the women.

For the postmenopausal women, a single-serving poultry substitution for red meat lowered the risk of breast cancer by 24 percent.

The researchers also discovered that eating one serving per day of combined nuts, legumes, poultry and fish instead of one serving of red meat was associated with a 14 percent decreased risk of breast cancer overall and among the premenopausal women.

Dr. Farvid and team concluded that eating a lot of red meat in early adulthood increased the risk of breast cancer in women.

One limitation of this study was that the women were mostly white, educated and American, so the findings may not be generalizable to people of other races, ethnicities or economic statuses, and dietary intake was based on self-report.

This study was published on June 10 in BMJ.

The National Institutes of Health provided funding.

Review Date: 
June 11, 2014