Effects of High Fruit-Vegetable and/or Low-Fat Intervention on Breast Nipple Aspirate Fluid Micronutrient Levels

Abstract

Background: A change in diet is known to affect micronutrient levels in blood but to what extent diet can affect micronutrient levels in the breast is not yet well established. Methods: Healthy, premenopausal women with a family history of breast cancer were randomized across four diet arms for 1 year in a 2 Â 2 factorial design study: control, low-fat, high fruit-vegetable, and combination low-fat/high fruit-vegetable diets. Subjects were asked to collect breast nipple aspirate fluid (NAF) at 0, 6, and 12 months, and levels of micronutrients were measured in the fluid. Results: A total of 122 women were enrolled, 97 were retained for 12 months, and sufficient NAF for analysis was available from 59 women at baseline, 49 at 6 months, and 50 at 12 months. Repeated measures mixed-model ANOVA was used to model the data using cholesterol levels and lactation

Nutrients and nipple aspirate fluid composition: the breast microenvironment regulates protein expression and cancer aetiology

“…Several prospective or cohort studies have reported an inverse Vitamins [11,25] provitamin A [9] vitamin E [9] retinol [10,11,25] association between breast cancer risk and serum/plasma carotenoids, including a-and b-carotenes and lutein [59,60]. Despite being a relatively minor component among total carotenoids, it is intriguing that lutein showed a significant inverse association [25].…”

“…In this respect, a recent comprehensive study evaluates how a change in diet might affect micronutrient levels in the NAF breast microenvironment [10]. An important indication was that carotenoids in NAF increased with a high fruit and vegetable diet regardless of whether dietary fat intake was concomitantly decreased, but surprisingly little correlation between levels of micronutrients in NAF and plasma was found [10].…”

“…In this respect, a recent comprehensive study evaluates how a change in diet might affect micronutrient levels in the NAF breast microenvironment [10]. An important indication was that carotenoids in NAF increased with a high fruit and vegetable diet regardless of whether dietary fat intake was concomitantly decreased, but surprisingly little correlation between levels of micronutrients in NAF and plasma was found [10]. Dietary carotenoids were more strongly correlated with plasma levels than with adipose tissue levels [60], suggesting that plasma levels likely reflects absorption from the diet to a relatively greater degree, with the subsequent distribution of micronutrients within the body fluids.…”

“…In the Nutrition and Breast Health Study, it was also reported that plasma levels of c-tocopherol (but not b-tocopherol) decreased significantly in low-fat diet habit [25]. Based on the evidence that tocopherol and retinol levels found in NAF were not targeted by any intervention and did not show significant changes [10,11,25], it is possible that the breast tissue stores of tocopherols are less affected by diet than those of plasma. Previous studies indicate that a high fruit-vegetable diet can be useful to increase carotenoids in breast secretions (e.g., NAF and milk), which in turn may be useful for prevention of breast cancer, as increased plasma carotenoid levels have been associated with decreased BC risk [53,59].…”

“…While some nutrients (e.g., lipids, cholesterol, and some soy proteins) may be influenced by diet and metabolized in NAF producing mutagenic/genotoxic actions on the breast epithelium with final detrimental effects [30,31,46], others (like carotenoids, vegetable and fruit antioxidants) have been shown to be protective towards BC risk with final anticarcinogenic effects [10]: the balance between these effects may highlight mechanism(s) by which diet can affect breast cancer risk. All these substances, of both exogenous and endogenous origin, may be secreted and accumulated in NAF by the adult female breast.…”