Fairfield Kathleen M, Hunter David J, Colditz Graham A, Fuchs Charles S, Cramer Daniel W, Speizer Frank E, Willett Walter C, Hankinson Susan E
Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
Int J Cancer. 2004 Jun 10;110(2):271-7. doi: 10.1002/ijc.20086.
The milk sugar lactose is an hypothesized risk factor for epithelial ovarian cancer because of possible direct toxic effects of its metabolites on oocytes or by compensatory gonadotropin stimulation. Women are presently encouraged to consume dairy products as a source of calcium to prevent osteoporosis. The objective of our study was to prospectively assess lactose, milk and milk product consumption in relation to ovarian cancer risk among 80326 participants in the Nurses' Health Study who had no history of cancer other than nonmelanoma skin cancer. Participants in the Nurses' Health Study reported on known and suspected ovarian cancer risk factors in questionnaires mailed biennially from 1976 to 1996. Food frequency questionnaires were included in the years 1980, 1984, 1986 and 1990. Newly reported ovarian cancer was documented by review of medical records. During 16 years of follow-up (1980-1996), 301 cases of invasive epithelial ovarian cancer were confirmed. Pooled logistic regression was used to control for age, body mass index (kg/m(2)), caffeine intake, oral contraceptive use, smoking history, parity and tubal ligation. For all subtypes of invasive ovarian cancer combined, we observed a nonsignificant 40% greater risk for women in the highest category of lactose consumption compared to the lowest (multivariate relative risk (RR) 1.40, 95% confidence interval (CI), 0.98-2.01). We observed a 2-fold higher risk of the serous ovarian cancer subtype among those in the highest category of lactose consumption compared to the lowest (RR 2.07, 95% CI, 1.27-3.40). For each 11-gram increase in lactose consumption (the approximate amount in one glass of milk), we observed a 20% increase in risk of serous cancers (RR 1.20, 95% CI, 1.04-1.39). Skim and low-fat milk were the largest contributors to dietary lactose. Women who consumed one or more servings of skim or low-fat milk daily had a 32% higher risk of any ovarian cancer (RR 1.32, 95% CI, 0.97-1.82) and a 69% higher risk of serous ovarian cancer (RR 1.69, 95% CI, 1.12-2.56) compared to women consuming 3 or less servings monthly. Controlling for fat intake did not change our findings. Our findings provide some support for the hypothesis that lactose intake increases risk of epithelial ovarian cancer. However, the observed excess risk appeared limited to the serous subtype of ovarian cancer in our study.
由于乳糖代谢产物可能对卵母细胞产生直接毒性作用，或通过代偿性促性腺激素刺激，因此乳类糖乳糖被认为是上皮性卵巢癌的一个风险因素。目前鼓励女性食用乳制品作为钙的来源以预防骨质疏松症。我们研究的目的是前瞻性评估护士健康研究中80326名除非黑素瘤皮肤癌外无其他癌症病史的参与者的乳糖、牛奶及奶制品摄入量与卵巢癌风险之间的关系。护士健康研究的参与者在1976年至1996年每两年邮寄一次的问卷中报告已知和疑似的卵巢癌风险因素。1980年、1984年、1986年和1990年的问卷中包含食物频率问卷。通过查阅病历记录新报告的卵巢癌病例。在16年的随访期（1980 - 1996年）内，确诊了301例浸润性上皮性卵巢癌病例。采用汇总逻辑回归分析来控制年龄、体重指数（kg/m²）、咖啡因摄入量、口服避孕药使用情况、吸烟史、生育史和输卵管结扎情况。对于所有合并的浸润性卵巢癌亚型，我们观察到乳糖摄入量最高组的女性相比最低组患癌风险高40%，但差异无统计学意义（多变量相对风险（RR）1.40，95%置信区间（CI），0.98 - 2.01）。我们观察到乳糖摄入量最高组的女性相比最低组患浆液性卵巢癌亚型的风险高2倍（RR 2.07，95% CI，1.27 - 3.40）。乳糖摄入量每增加11克（一杯牛奶中的大致含量），我们观察到浆液性癌症风险增加20%（RR 1.20，95% CI，1.04 - 1.39）。脱脂奶和低脂奶是膳食乳糖的最大来源。与每月食用3份或更少份脱脂或低脂奶的女性相比，每天食用1份或更多份脱脂或低脂奶的女性患任何卵巢癌的风险高32%（RR 1.32，95% CI，0.97 - 1.82），患浆液性卵巢癌的风险高69%（RR 1.69，95% CI，1.12 - 2.56）。控制脂肪摄入量并没有改变我们的研究结果。我们的研究结果为乳糖摄入增加上皮性卵巢癌风险这一假说提供了一些支持。然而，在我们的研究中，观察到的额外风险似乎仅限于卵巢癌的浆液性亚型。
