SEATTLE, WASHINGTON. A diet rich in fruits and vegetables is linked to a reduced risk of fibrocystic breast conditions (benign lumps), according to a study in Chinese women. This is important because factors that stimulate benign cell growth and replication (proliferation) may also enhance the likelihood of malignant change, so reducing the risk of fibrocystic conditions could possibly reduce the risk of breast cancer.
An international team of researchers conducted the study to identify reproductive and dietary factors associated with benign proliferative breast cell changes. The pool of subjects was derived from a trial of breast self-examination in Shanghai, China between 1989 and 1991, during which time they were interviewed, and in 1995-2000 were reinterviewed using a questionnaire detailing risk factors and diet. Women who developed fibrocystic breast conditions had biopsies and were then classified as nonproliferative (175 women), proliferative (181 women), or proliferative with atypia (33 women).
Analysis using conditional logistic regression showed that having more than one live-born child and consumption of fresh fruits and vegetables were more strongly associated with a reduced risk of proliferative and atypical lesions (abnormal tissue) than with nonproliferative conditions. Comparing women with the highest fruit intake (more than 435 times/year) to those with the lowest intake (less than 202 times/year) showed that the high intake women had a 60% lower incidence of nonproliferative lesions (abnormal tissue), an 80% lower incidence of proliferative lesions, and a 90% lower incidence of atypical proliferative lesions. The corresponding incidence reductions for high versus low vegetable intake (958 times/year or more versus 538 times/year or less) were 40%, 60%, and 90%. None of the 16 botanical families or specific micronutrients, which were considered individually, was appreciably more strongly associated with proliferative conditions than with nonproliferative conditions, after results were controlled for total fruit and vegetable intake.
The researchers believe that a strength of the study is the variety in and range of consumption of fruits and
vegetables in the study population, and conclude that a high intake of fruits and vegetables may reduce
cellular proliferation in breast tissue and thus potentially reduce the risk of breast cancer.