The etiology of breast cancer is complex and varied. Many of the major risk factors for breast cancer, including age, reproductive history, and family history of cancer, are not modifiable. There is a great need to provide women with evidence based advice on how they can reduce their risk of developing breast cancer. Research has shown that compounds in fruits and vegetables have anti-cancer properties and most people agree that a diet rich in nutritious fruits and vegetables may help prevent breast cancer. However, the ways in which such a diet reduces risk remain unknown. We propose that eating at least 8 daily servings of darkly pigmented, nutrient dense fruits and vegetables will reduce levels of biomarkers associated with breast cancer risk: inflammatory cytokines and cancer-associated DNA methylation patterns. Because we want to look at changes directly in breast tissue of young women, we will study breastmilk and conduct a diet intervention study in women who are nursing their first born child. Milk contains proteins and cells that will allow us to measure changes associated with the diet intervention. Nursing mothers will be randomized to a control group (continuing eating as they were) or an intervention in which they will receive weekly baskets of fruits and vegetables (for 12 weeks) and nutrition counseling. We will enroll 50 women per year for a period of five years. Milk will be collected at baseline (before the diet intervention) and at 12 weeks. We will measure markers of inflammation directly in the milk, and DNA methylation in the cells collected from the milk.
The goal of this study is to determine the extent to which a diet that includes at least eight daily servings of nutrient dense and deeply pigmented fruits and vegetables can alter 1) the inflammatory signals of the breast microenvironment, and 2) global DNA methylation of breast epithelium in a manner consistent with reducing breast cancer risk. Two hundred fifty primiparous nursing mothers will be randomly assigned to increase fruit and vegetable intake to at least eight daily servings of fruits and vegetables, or to a control condition in which participants receive a published diet guideline for breastfeeding mothers from the USDA.Women in the diet intervention arm will receive counseling and boxes of fruits and vegetables for the first 12 weeks. Milk collected before and after the women participate in the diet intervention will be analyzed for changes in inflammatory markers and global DNA methylation in breast epithelium. Human milk provides an ideal opportunity to assess the effects of a diet intervention on breast health as milk contains both secreted proteins and significant numbers of exfoliated breast epithelial cells