乳腺癌患者可以喝牛奶吗

许多研究发现饮用牛奶可以降低结肠癌发生的风险，其中原因似乎与牛奶中含钙有关。但是，研究也证实饮用牛奶会增加前列腺癌、子宫内膜癌、睾丸癌、卵巢癌发生的风险，不过，这种相关性并不太密切。全脂奶含有饱和脂肪酸，后者与心血管疾病以及诸多癌症发生相关。广东省中医院乳腺科陈前军

饮用牛奶与乳腺癌许多研究都试图探明饮用牛奶与乳腺癌发生发展的风险的关系，但遗憾的是研究结果相互矛盾。一些基于人口的研究发现饮用牛奶与乳腺癌发生风险无关，但是，几个大的基于人口的研究结果均显示牛奶摄入与乳腺癌发生风险肯定相关。这种矛盾的结果可能是因为牛奶同时含有对乳腺癌发生存在有益物质与有害物质有关。
   牛奶的主要成分包括钙、维生素D、硬脂酸盐、乳酶生、共轭亚油酸以及牛铁蛋白，这些成分在实验室中被发现有诱导乳腺癌细胞凋亡、降低乳腺肿瘤大小以及乳腺肿瘤发生率的作用。事实上，已经发现在婴幼儿、儿童期饮用牛奶对将来发生乳腺癌有拮抗作用，对乳房有些许保护作用。
  针对成年人是否适合饮用牛奶的研究似乎令人不能忽视。一个研究致癌物质诱发成年大鼠乳腺肿瘤的研究发现，如果去除大鼠的卵巢则大鼠乳腺肿瘤的数目、大小均会降低，但给卵巢切除的大鼠喂食牛奶，则致癌物质所诱发的乳腺肿瘤的发生率、肿瘤的数目以及大小均增加。不管是去脂牛奶还是全脂牛奶均会增加致癌物质所诱发的大鼠乳腺肿瘤的发生率与肿瘤大小。

在多个研究中发现，动物性脂肪的高摄入会增加乳腺密度，它也是乳腺癌发生与复发的风险因子。除此之外，一个研究发现一种在美国牛奶厂普遍存在的病毒，即牛白血病病毒，该病毒可诱发乳腺癌。许多研究者提醒我们，我们今天所引用的牛奶是由怀孕母牛生产的，这些牛奶中拥有非常高的雌激素与孕激素。值得提出的是牛奶中其它可疑促癌因子还有：饱和脂肪酸、重组牛生长因子(rBGH)、胰岛素生长因子、农药以及聚氯联苯等，这些成分也应该避免摄入。

附加注释
非巴氏消毒奶由于其可能受到致病菌污染，致其摄入而影响人类健康 ，但其似乎并未增加癌症发生风险。酸乳酒，一种发酵乳饮料，不会增加乳腺癌发生的风险。

主要参考研究
Proliferative effect of whey from cow"s milk obtained at two different stages of pregnancy measured in MCF-7 cells

 Mammographic Density and Intake of Selected Nutrients and Vitamins in Norwegian Women Dairy Products, Calcium Intake, and Breast Cancer Risk: A Case-Control Study in China Post-diagnosis dietary factors and survival after invasive breast cancer

 Prepubertal exposure to cow"s milk reduces susceptibility to carcinogen-induced mammary tumorigenesis in rats

Conjugated linoleic acid intake and breast cancer risk in a prospective cohort of Swedish women Meat, eggs, dairy products, and risk of breast cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort

 Dairy food, calcium, and risk of cancer in the NIH-AARP diet and health study Long-term dietary calcium intake and breast cancer risk in a prospective cohort of women

 Unpasteurized milk consumption and subsequent risk of cancer

 Milk Inhibits the Regression of 7,12-Dimethylbenz(a)anthracene-Induced Mammary Tumors in Ovariectomized Rats

Bovine leukemia virus infection is significantly associated with risk of breast cancer

The t10,c12 isomer of conjugated linoleic acid stimulates mammary tumorigenesis in transgenic mice over-expressing erbB2 in the mammary epithelium

 Naturally Occurring Estrogens in Processed Milk and in Raw Milk (from Gestated Cows) Dairy product consumption and the risk of breast cancer

Milk consumption in relation to incidence of prostate, breast, colon, and rectal cancers: is there an independent effect?

Milk and lactose intakes and ovarian cancer risk in the Swedish Mammography Cohort

Intake of conjugated linoleic acid, fat, and other fatty acids in relation to postmenopausal breast cancer: the Netherlands Cohort Study on Diet and Cancer