Dietary consumption of phytochemicals and breast cancer risk in Mexican women.

Objective: To perform an evaluation of selected phytochemicals intake and breast cancer (BC) risk in Mexican women.

Design: We conducted hospital-based case-control study.

Setting: Mexico City between 1994 and 1996.

Subjects: A total of 141 histologically confirmed BC cases were age-matched (+/-3 years) to an equal number of hospital controls. The reproductive history of each woman was obtained by direct interview. The dietary consumption of flavonols, flavones, flavan-3-ols, cinnamic acid, lariciresinol, pinoresinol, secoisolariciresinol, matairesinol and coumestrol was obtained by means of a validated FFQ.

Results: Among postmenopausal women, high dietary intake of flavonols and flavones was associated with a significant reduction of BC risk (high v. low tertile: OR = 0.21, 95 % CI 0.07, 0.60, P for trend = 0.004 and OR = 0.29, 95 % CI 0.10, 0.82, P for trend = 0.025, respectively); consumption of lignans (lariciresinol and pinoresinol) showed a similar effect, but only among premenopausal women (high v. low tertile: OR = 0.32, 95 % CI 0.10, 0.99, P for trend = 0.051 and OR = 0.19, 95 % CI 0.06, 0.62, P for trend = 0.006, respectively).

Conclusions: Our results support a protective role of specific dietary phytochemicals in BC risk by menopausal status, independent of other reproductive factors.