Dietary Intake of Lactose as a Strong Predictor for Secretor Status of Nipple Aspirate Fluid in Healthy Premenopausal Nonlactating Women

Abstract

Purpose-Nipple aspirate fluid (NAF) is considered a potential source for discovering breast cancer biomarkers. However, the success rate of obtaining NAF was reported to vary from 48 to 77%, and mechanisms for its secretion are not fully understood. The purpose of this study was to investigate dietary, demographic, reproductive, hormonal, and anthropometric factors that are associated with the ability to obtain NAF by aspiration (secretor status) from premenopausal women.Study Design-NAF procedures were attempted for women who were 30-40 years old, not pregnant, not breastfeeding, and not taking contraceptive medications.Results-Compared with non-secretors, secretors of NAF consumed significantly more dietary lactose (mainly from milk), were more likely to be parous, were older at first and last childbirth, breastfed their babies for a longer period of time, and had an earlier menarche and lower plasma concentrations of 17β-estradiol (P<0.05). Using multivariate logistic regression models, higher dietary intake of lactose [Odds Ratio (OR) =2.7; 95% Confidence Interval (CI): 1.5-4.8], earlier menarche (OR=0.8, CI: 0.7-1.0), being parous (OR=2.3, CI: 1.0-5.6), and older at first childbirth (OR=1.5, CI: 1.0-2.1) were found to be independent and positive predictors for being a secretor of NAF.Conclusions-These findings suggest that dietary intake of lactose, a modifiable factor, may be used to change the NAF secretor status of women. This finding may facilitate the use of NAF as a diagnostic material for detecting breast diseases.

Influence of diet on nipple aspirate fluid production and estrogen levels

“…Unlike previous studies that linked dietary intake with NAF producer status, 3,7,8,10 we observed no strong associations between selected nutrients and foods and NAF volume except for the inverse trend of isoflavones, among women who were able to produce NAF. A similar, non-significant relation was observed for soy consumption; however, the overall consumption of soy, as well as the corresponding intake of isoflavones, was low.…”

“…4–6 Dietary fat intake was associated with producing NAF especially epithelial cell containing NAF in two studies 7,8 and with circulating estrogen levels in a meta-analysis. 9 Similarly, intakes of lactose and soy were associated with NAF producer status in some studies 3,10 although our randomized crossover trial detected no effect of soy on NAF volume 2 and only a non-significant effect on NAF estrogens levels. 11 In contrast, dietary fiber, as well as fruits and vegetables, were inversely associated with yielding cellular NAF 8 while lowering circulating hormone levels.…”

“…In the past, a few published studies had examined NAF producer vs. non-producer status by FFQs and food records. 3,7 Strengths of the present study include the diverse ethnic backgrounds of the women and the use of an FFQ that was previously validated within Hawaii’s multiethnic population. 18 However, this study also had a number of limitations.…”

“…Interestingly, the ability to produce NAF as well as the volume produced varies across individuals. 1–3 Longitudinal studies have observed a higher breast cancer risk in NAF producing, premenopausal women, especially if abnormal cytology was detected. 4–6 Dietary fat intake was associated with producing NAF especially epithelial cell containing NAF in two studies 7,8 and with circulating estrogen levels in a meta-analysis.…”

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

“…Several studies have demonstrated that modification of the diet is able to alter both the NAF composition and secretory status of some women; for example, high dietary intake of lactose [23] (a milk disaccharide not absorbed intact but metabolized in the intestine to galactose and glucose, and re-synthesized in the mammary gland by lactose synthase) may significantly increase NAF secretion due to its main osmotic property [24], but may also stimulate apocrine breast ductal/lobular cells to increase the pathways of lactose synthase through lactalbumin and galactosyl transferase activities [40,43]. Although the enzymatic involvement of lactose synthase was found only in healthy subjects, several studies have highlighted that lactose intake and its presence in NAF were related to both the active secretory function of apocrine breast cells lining the ducts and to NAF colour [47].…”