Prospective study of the association between grapefruit intake and risk of breast cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC).
ABSTRACT Grapefruit inhibits cytochrome P450 3A4 and may affect estrogen metabolism. In the European Prospective Investigation into Cancer and Nutrition (EPIC), we examined the relationships of grapefruit intake with risk of breast cancer and with serum sex hormone levels. 114,504 women with information on dietary intake of grapefruit and on reproductive and lifestyle risk factors were followed for a median 9.5 years and 3,747 incident breast cancers were identified. Fifty-nine percent of women reported eating grapefruit, 4% ate > or = 60 g/day. Cox proportional hazard models were used to estimate the hazard ratio (HR) for breast cancer according to grapefruit intake, adjusting for study centre, reproductive factors, body mass index, energy intake, and alcohol intake. Grapefruit intake was not related to the risk of breast cancer: compared with women who ate no grapefruit, women with the highest intake of > or =60 g/day had a HR of 0.93 (95% CI 0.77-1.13), p for linear trend = 0.5. There was no relationship between grapefruit intake and breast cancer risk among premenopausal women, all postmenopausal women, or postmenopausal women categorized by hormone replacement therapy use (all p>0.05). There was no association between grapefruit intake and estradiol or estrone among postmenopausal women. In this study, we found no evidence of an association between grapefruit intake and risk of breast cancer.
- SourceAvailable from: Anne C M Thiébaut[show abstract] [hide abstract]
ABSTRACT: The authors assessed the association between serum phospholipid fatty acids as biomarkers of fatty acid intake and breast cancer risk among women in the E3N Study (1989-2002), the French component of the European Prospective Investigation into Cancer and Nutrition. During an average of 7 years of follow-up, 363 cases of incident invasive breast cancer were documented among 19,934 women who, at baseline (1995-1998), had completed a diet history questionnaire and provided serum samples. Controls were randomly matched to cases by age, menopausal status at blood collection, fasting status at blood collection, date, and collection center. Serum phospholipid fatty acid composition was assessed by gas chromatography. Adjusted odds ratios for risk of breast cancer with increasing levels of fatty acids were calculated using conditional logistic regression. An increased risk of breast cancer was associated with increasing levels of the trans-monounsaturated fatty acids palmitoleic acid and elaidic acid (highest quintile vs. lowest: odds ratio = 1.75, 95% confidence interval: 1.08, 2.83; p-trend = 0.018). cis-Monounsaturated fatty acids were unrelated to breast cancer risk. A high serum level of trans-monounsaturated fatty acids, presumably reflecting a high intake of industrially processed foods, is probably one factor contributing to increased risk of invasive breast cancer in women.American journal of epidemiology 07/2008; 167(11):1312-20. · 5.59 Impact Factor
- British Journal of Cancer 02/2008; 98(1):240-1. · 5.08 Impact Factor
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ABSTRACT: Contrasting etiologic hypotheses about the role of endogenous sex steroids in breast cancer development among premenopausal women implicate ovarian androgen excess and progesterone deficiency, estrogen excess, estrogen and progesterone excess, and both an excess or lack of adrenal androgens (dehydroepiandrosterone [DHEA] or its sulfate [DHEAS]) as risk factors. We conducted a case-control study nested within the European Prospective Investigation into Cancer and Nutrition cohort to examine associations among premenopausal serum concentrations of sex steroids and subsequent breast cancer risk. Levels of DHEAS, (Delta4-)androstenedione, testosterone, and sex hormone binding globulin (SHBG) were measured in single prediagnostic serum samples from 370 premenopausal women who subsequently developed breast cancer (case patients) and from 726 matched cancer-free control subjects. Levels of progesterone, estrone, and estradiol were also measured for the 285 case patients and 555 matched control subjects who had provided information about the day of menstrual cycle at blood donation. Conditional logistic regression models were used to estimate relative risks of breast cancer by quartiles of hormone concentrations. All statistical tests were two-sided. Increased risks of breast cancer were associated with elevated serum concentrations of testosterone (odds ratio [OR] for highest versus lowest quartile = 1.73, 95% confidence interval [CI] = 1.16 to 2.57; P(trend) = .01), androstenedione (OR for highest versus lowest quartile = 1.56, 95% CI = 1.05 to 2.32; P(trend) = .01), and DHEAS (OR for highest versus lowest quartile = 1.48, 95% CI = 1.02 to 2.14; P(trend) = .10) but not SHBG. Elevated serum progesterone concentrations were associated with a statistically significant reduction in breast cancer risk (OR for highest versus lowest quartile = 0.61, 95% CI = 0.38 to 0.98; P(trend) = .06). The absolute risk of breast cancer for women younger than 40 followed up for 10 years was estimated at 2.6% for those in the highest quartile of serum testosterone versus 1.5% for those in the lowest quartile; for the highest and lowest quartiles of progesterone, these estimates were 1.7% and 2.6%, respectively. Breast cancer risk was not statistically significantly associated with serum levels of the other hormones. Our results support the hypothesis that elevated blood concentrations of androgens are associated with an increased risk of breast cancer in premenopausal women.CancerSpectrum Knowledge Environment 06/2005; 97(10):755-65. · 14.07 Impact Factor