前情提要
之前，我们讨论了大豆和豆制品，例如豆浆或豆奶，现在再来谈谈真正的奶制品。奶制品是复杂的混合物，包括可能影响癌症病因（例如乳腺癌）的营养素和非营养物质。
2017年2月16日（周四）美国营养学会官方期刊《当代营养学进展》在线发表罗斯维尔·帕克癌症研究所、康奈尔大学尼亚加拉县合作推广组织、德尤维尔学院的队列研究报告，调查了奶制品摄入类型和数量与乳腺癌之间的相关性，发现日常摄入特定奶制品与乳腺癌有相关性。
罗斯维尔·帕克癌症研究所位于美国纽约州布法罗（又称水牛城），由外科医生罗斯维尔·帕克（Roswell Park）成立于1898年，是美国国家癌症研究所（NCI）指定的八大综合癌症中心之一，也是美国最早成立的癌症研究中心。因此，帕克是姓，以后请大家不要翻译成公园。
该研究存档的临床和问卷数据来自2003年12月～2014年10月罗斯维尔·帕克癌症研究所数据银行生物库1941位诊断为乳腺癌的女性和1237位对照参与者，对奶制品摄入量自行完成食物频次问卷调查，并按每月摄入量分为所有奶制品、鲜奶、酸奶、低脂奶酪、其他奶酪（美式奶酪、英式切达干酪、稀奶油制新鲜软质奶酪）、甜奶制品。通过无条件逻辑回归估算比值比和95%置信区间，并根据年龄、种族、体重指数、是否绝经、能量摄入、日常摄入奶类、是否吸烟、乳腺癌家族史等影响因素进行校正。
结果发现：
所有奶制品的总摄入量大，可使乳腺癌风险减少15%，但无统计学意义（P=0.11）
酸奶摄入量大，可使乳腺癌风险显著减少39%（比值比：0.61，95%置信区间：0.46～0.82）
其他奶酪摄入量大，可使乳腺癌风险增加53%（比值比：1.53，95%置信区间：0.99～2.34，P=0.05）
此外，根据雌激素受体状态进行分层，发现：
所有奶制品摄入量大，可使雌激素受体阴性乳腺癌风险增加58%（比值比：1.58，95%置信区间：1.05～2.37）
甜奶制品摄入量大，可使雌激素受体阳性乳腺癌风险减少48%（比值比：0.52，95%置信区间：0.29～0.95）。
奶制品既有优点也有缺点，虽然是钙的良好来源，但是同时脂肪较高。在谈及奶制品对乳腺癌风险的影响时，该研究发现可能存在矛盾之处：摄入大量奶酪可能增加女性乳腺癌风险，但是摄入大量酸奶可能减少乳腺癌风险。众所周知，饮食对乳腺癌风险有关键作用，青春期和成年早期的不良饮食习惯与绝经前乳腺癌风险增加有相关性。虽然某些奶制品可能处于健康饮食的保护伞之下，那些对奶类如何影响乳腺癌风险的研究已经得出不一致的结果；某些研究认为奶制品摄入增加乳腺癌风险，而另一些刚好相反。出现这种错综复杂的结果并不特别出人意料，因为奶制品是一类复杂的混合物，包括多种营养素和非营养物质，可能通过增加或降低风险而影响癌症病因。该研究结果已经揭示了一些端倪，还需要进一步研究以深入了解奶制品如何影响乳腺癌风险。虽然饮食与30%的癌症有关，但是希望未来的研究将有助于更充分地了解哪些食物对于减少癌症风险最有价值。
总之，对于经常被问到还要不要喝奶？回答只能是：我不能马上告诉你，需要具体情况具体分析，无法一概而论，因为奶有很多类型，乳腺癌也有很多类型，懂我的意思——识得唔识得啊？
Curr Dev Nutr. 2017 Feb 16. [Epub ahead of print]
Usual consumption of specific dairy foods is associated with breast cancer in the Roswell Park Cancer Institute Databank and BioRepository.
McCann SE, Hays J, Baumgart CW, Weiss EH, Yao S, Ambrosone CB.
Roswell Park Cancer Institute, United States; Cornell Cooperative Extension of Niagara County, United States; D'Youville College, United States.
BACKGROUND: Dairy foods are complex mixtures which include nutrients and non-nutrient substances that could potentially influence cancer etiology, including breast cancer.
OBJECTIVE: The purpose of this study was to examine the associations between the types and quantity of dairy foods consumed and breast cancer among women participating in the Roswell Park Cancer Institute (RPCI) Data Bank and BioRepository (DBBR) between 2003 and 2014.
METHODS: Archived clinical and questionnaire data were obtained from the DBBR from 1,941 women diagnosed with breast cancer between December 2003 and October 2014, and 1237 control participants. Intakes of dairy foods were queried with a self-administered food frequency questionnaire and grouped into monthly intakes of total dairy, milk, yogurt, low-fat cheese, other cheese, and sweet dairy. Odds ratios (OR) and 95% confidence intervals (CI) were estimated with unconditional logistic regression adjusting for age, race, BMI, menopausal status, energy intake, type of milk usually consumed, cigarette smoking status, and family history of breast cancer.
RESULTS: Total dairy intakes were associated with a non-significant 15% reduction in breast cancer risk (p=0.11). Higher intakes of yogurt were associated with reduced risk of breast cancer (OR 0.61, 95% CI 0.46-0.82) and higher intakes of other cheese was associated with a marginally significant increased risk (OR 1.53, 95% CI 0.99-2.34; p=0.05). Associations with dairy foods were mixed when stratified by estrogen receptor status, and in general reflected those of overall breast cancer. However, we observed positive associations between milk intake and risk of ER- breast cancer (OR 1.58, 95% CI 1.05-2.37) and inverse associations between sweet dairy and ER+ breast cancer (OR 0.52, 95% CI 0.29-0.95).
CONCLUSIONS: Specific dairy foods may contribute to breast cancer risk in women, although risk varies by source of dairy. Future studies are warranted to confirm the protective potential of yogurt in this cancer.
DOI: 10.3945/cdn.117.000422
联系客服
