Among women with a family history of breast or ovarian cancer, higher intake of vitamin D may be linked with lower breast density. These results were published in the journal Breast Cancer Research.
Breast density refers to the extent of glandular and connective tissue in the breast. Breasts with more glandular and connective tissue-and less fat-are denser. Women with higher breast density are at increased risk of developing breast cancer. In addition, dense breasts make it more difficult to detect breast cancer by mammography.
Some studies have suggested that diet may influence breast density. If this proves to be true, it may be possible to reduce the risk of breast cancer, or to facilitate the detection of breast cancer, by consuming a diet that reduces breast density.
To explore the effects of diet on breast density, researchers conducted a study among 157 women who had never had cancer themselves, but who had a family history of breast cancer or ovarian cancer.
The extent of the family history varied across study participants. In roughly 43% of the study participants, the family history reflected a known familial cancer syndrome or breast cancer predisposition gene (primarily BRCA1 and BRCA2 mutations).
Breast density was assessed by a standard screening mammogram. The four categories of breast density were 1) entirely fatty; 2) scattered fibroglandular tissue; 3) heterogeneously dense; and 4) extremely dense.
- Women with the highest intake of vitamin D had lower breast density than women with the lowest intake of vitamin D. Overall, no other dietary factors were linked with breast density.
- In the subset of women whose family history did not suggest a known familial cancer syndrome, higher intake of total protein and higher intake of animal protein were each linked with higher breast density. Among women whose family history did suggest a known familial cancer syndrome, there was no link between protein and breast density.
The researchers caution that these findings will need to be further evaluated in larger studies. While this study suggests that certain aspects of diet may influence breast density, the effects of dietary change on breast density and subsequent risk of breast cancer remain uncertain.