Comparing Calculated Nutrient Intakes Using Different Food Composition Databases: Results from the European Prospective Investigation into Cancer and Nutrition (EPIC) Cohort.

This study aimed to compare calculated nutrient intakes from two different food composition databases using data from the European prospective investigation into cancer and nutrition (EPIC) cohort. Dietary intake data of the EPIC cohort was recently matched to 150 food components from the U.S. nutrient database (USNDB). Twenty-eight of these nutrients were already included in the EPIC nutrient database (ENDB-based upon country specific food composition tables), and used for comparison. Paired sample t-tests, Pearson's correlations (r), weighted kappa's (κ) and Bland-Altman plots were used to compare the dietary intake of 28 nutrients estimated by the USNDB and the ENDB for 476,768 participants. Small but significant differences were shown between the USNDB and the ENDB for energy and macronutrient intakes. Moderate to very strong correlations (r = 0.60-1.00) were found for all macro- and micronutrients. A strong agreement (κ > 0.80) was found for energy, water, total fat, carbohydrates, sugar, alcohol, potassium and vitamin C, whereas a weak agreement (κ < 0.60) was found for starch, vitamin D and vitamin E. Dietary intakes estimated via the USNDB compare adequately with those obtained via the ENDB for most macro- and micronutrients, although the agreement was weak for starch, vitamin D and vitamin E. The USNDB will allow exposure assessments for 150 nutrients to investigate associations with disease outcomes within the EPIC cohort.

Mediation analysis of the alcohol-postmenopausal breast cancer relationship by sex hormones in the EPIC cohort.

Alcohol consumption is associated with higher risk of breast cancer (BC); however, the biological mechanisms underlying this association are not fully elucidated, particularly the extent to which this relationship is mediated by sex hormone levels. Circulating concentrations of estradiol, testosterone, their free fractions and sex-hormone binding globulin (SHBG), were examined in 430 incident BC cases and 645 matched controls among alcohol-consuming postmenopausal women nested within the European Prospective Investigation into Cancer and Nutrition. Mediation analysis was applied to assess whether individual hormone levels mediated the relationship between alcohol intake and BC risk. An alcohol-related hormonal signature, obtained by partial least square (PLS) regression, was evaluated as a potential mediator. Total (TE), natural direct and natural indirect effects (NIE) were estimated. Alcohol intake was positively associated with overall BC risk and specifically with estrogen receptor-positive tumors with respectively TE = 1.17(95%CI: 1.01,1.35) and 1.36(1.08,1.70) for a 1-standard deviation (1-SD) increase of intake. There was no evidence of mediation by sex steroids or SHBG separately except for a weak indirect effect through free estradiol where NIE = 1.03(1.00,1.06). However, an alcohol-related hormonal signature negatively associated with SHBG and positively with estradiol and testosterone was associated with BC risk (odds ratio [OR] = 1.25 [1.07,1.47]) for a 1-SD higher PLS score, and had a statistically significant NIE accounting for a mediated proportion of 24%. There was limited evidence of mediation of the alcohol-BC association by individual sex hormones. However, a hormonal signature, reflecting lower levels of SHBG and higher levels of sex steroids, mediated a substantial proportion of the association.

Fiber intake modulates the association of alcohol intake with breast cancer.

Alcohol intake has been related to an increased risk of breast cancer (BC) while dietary fiber intake has been inversely associated to BC risk. A beneficial effect of fibers on ethanol carcinogenesis through their impact on estrogen levels is still controversial. We investigated the role of dietary fiber as a modifying factor of the association of alcohol and BC using data from the European Prospective Investigation into Cancer and Nutrition (EPIC). This study included 334,850 women aged 35-70 years at baseline enrolled in the ten countries of the EPIC study and followed up for 11.0 years on average. Information on fiber and alcohol intake at baseline and average lifetime alcohol intake were calculated from country-specific dietary and lifestyle questionnaires. Hazard ratios (HR) of developing invasive BC according to different levels of alcohol and fiber intake were computed. During 3,670,439 person-years, 11,576 incident BC cases were diagnosed. For subjects with low intake of fiber (<18.5 g/day), the risk of BC per 10 g/day of alcohol intake was 1.06 (1.03-1.08) while among subjects with high intake of fiber (>24.2 g/day) the risk of BC was 1.02 (0.99-1.05) (test for interaction p = 0.011). This modulating effect was stronger for fiber from vegetables. Our results suggest that fiber intake may modulate the positive association of alcohol intake and BC. Alcohol is well known to increase the risk for BC, while a fiber-rich diet has the opposite effect. Here the authors find a significant interaction between both lifestyle factors indicating that high fiber intake can ease the adverse effects associated with alcohol consumption. Consequently, women with high alcohol intake and low fiber intake (<18.5 g/day) had the highest risk for BC. Specific benefits were associated with fibers from vegetable, warranting further investigations into specific fiber sources and their mechanistic interactions with alcohol-induced BC risk.