Zuivel en borstkanker*
Uit een studie onder bijna 1.900 vrouwen met borstkanker die 12 jaar gevolgd werden blijkt dat het eten van vetrijke
zuivelproducten de overlevingskansen doet verkleinen. Met het eten van vetarme zuivelproducten was er geen verband met een terugval of doodgaan. Bij het eten van vetrijke zuivelproducten daarentegen was er wel zeker een verband.
Dagelijks tot 1 portie vetrijke zuivel geeft 20% meer kans om dood te gaan en bij meerdere porties per dag loopt die kans op tot wel 49%. Wellicht is het oestrogeen in melk hiervoor verantwoordelijk. In vetrijke zuivelproducten zit in vergelijking met vetarme producten het meeste oestrogeen.
High- and Low-Fat Dairy Intake, Recurrence, and Mortality After Breast Cancer Diagnosis
1. Candyce H. Kroenke, 2. Marilyn L. Kwan, 3. Carol Sweeney, 4. Adrienne Castillo and
5. Bette J. Caan + Author Affiliations
1. Affiliations of authors: Division of Research, Kaiser Permanente, Oakland, CA (CHK, MLK, AC, BJC); Division of Epidemiology, University of Utah, Salt Lake City, UT (CS).
1. Correspondence to: Candyce Kroenke, ScD, MPH, Kaiser Permanente, Division of Research, 2101 Webster, Oakland, CA 94612 (e-mail:
candyce.h.kroenke@kp.org).
Abstract
Background Dietary fat in dairy is a source of estrogenic hormones and may be related to worse breast cancer survival. We evaluated associations between high- and low-fat dairy intake, recurrence, and mortality after breast cancer diagnosis.
Methods We included 1893 women from the Life After Cancer Epidemiology study diagnosed with early-stage invasive breast cancer from 1997 to 2000, who completed the Fred Hutchinson Cancer Research Center Food Frequency Questionnaire after diagnosis. A total of 349 women had a recurrence and 372 died during a median follow-up of 11.8 years, with 189 deaths from breast cancer. We used delayed entry Cox proportional hazards regression to evaluate associations between categories of the cumulative average of dairy fat at baseline and at follow-up 5 to 6 years later and subsequent outcomes. Tests of statistical significance were two-sided.
Results In multivariable-adjusted analyses, overall dairy intake was unrelated to breast cancer–specific outcomes, although it was positively related to overall mortality. Low-fat dairy intake was unrelated to recurrence or survival. However, high-fat dairy intake was positively associated with outcomes. Compared with the reference (0 to <0.5 servings/day), those consuming larger amounts of high-fat dairy had higher breast cancer mortality (0.5 to <1.0 servings/day: hazard ratio [HR] = 1.20, 95% confidence interval [CI] = 0.82 to 1.77; and ≥1.0 servings/day: HR = 1.49, 95% CI = 1.00 to 2.24, P trend = .05), higher all-cause mortality (P trend < .001), and higher non–breast cancer mortality (P trend = .007); the relationship with breast cancer recurrence was positive but not statistically significant. The higher risk appeared consistent across different types of high-fat dairy products.
Conclusions Intake of high-fat dairy, but not low-fat dairy, was related to a higher risk of mortality after breast cancer diagnosis.
(Maart 2013)
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