Red meat intake in early adulthood may be linked to breast cancer risk

Substituting one serving per day of legumes for one serving per day of red meat may help lower a woman’s risk of breast cancer, according to results of a multicenter study based on data from the Nurses’ Health Study II. The findings, published in BMJ, represent 20 years of follow up on a questionnaire on diet.

During the 2-decade study period, the researchers documented 2830 cases of breast cancer in a prospective cohort of 88,803 premenopausal women. A higher risk of breast cancer overall (relative risk 1.22, 95% confidence interval 1.06 to 1.40; Ptrend=0.01 for highest fifth v lowest fifth of intake) was associated with higher intake of total red meat. No relationship was seen, however, between breast cancer overall and intake of poultry, fish, eggs, legumes, and nuts. Taking into consideration menopausal status, higher intake of poultry was associated with a lower risk of breast cancer in postmenopausal women (0.73, 0.58 to 0.91; Ptrend=0.02 for highest fifth v lowest fifth of intake) but not in premenopausal women (0.93, 078 to 1.11; Ptrend=0.60 for highest fifth v lowest fifth of intake).

Looking at the impact of substituting protein sources, the researchers estimated a 15% lower risk of breast cancer among all women (0.85, 0.73 to 0.98) and a 19% lower risk among premenopausal women (0.81, 0.66 to 0.99) if one serving per day of legumes was substituted for one serving per day of red meat. Substituting one serving per day of poultry of one serving per day of red meat was associated with a 17% lower risk of breast cancer overall (0.83, 0.27 to9 0.96) and a 24% lower risk of the disease in postmenopausal women (0.76, 0.59 to 0.99). a 14% lower risk of breast cancer oval (0.86, 0.78 to 0.94) and premenopausal breast cancer (0.86, 0.76 to 0.98) was associated with substituting one serving per day of combined legumes, nuts, poultry, and fish for one serving per day of red meat.

“Consistent with the American Cancer Society guidelines,” the authors concluded, “replacement of unprocessed and processed red meat with legumes and poultry during early adulthood may help to decrease the risk of breast cancer. Further study of the relation between diet in early adulthood and risk of breast cancer is needed.”

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