Hems G
Br J Cancer. 1978 Jun;37(6):974-82. doi: 10.1038/bjc.1978.142.
Mean, age-standardized breast-cancer mortality rates for women of 41 countries, during 1970-71, were closely correlated with diet for 1964-66. Partial correlation analysis indicated that breast-cancer rates were positively correlated with total fat, animal protein and animal calories, independently of other components of diet. These 3 components were correlated with one another so closely that it was not possible, with available data, to say whether any one was associated with breast cancer independently of the other 2. In addition to, and independently of, these correlations, breast cancer was associated with consumption of refined sugar.Breast-cancer mortality rates at 50-54 years during 1964-67 for 26 countries were closely correlated with childbearing, expressed as mean family size for women aged 45-49 years in 1960-61. However, this correlation was not independent of the correlations with diet, and it was concluded that variation of breast-cancer rates between countries arose predominantly from differences in diet. The variation of breast-cancer risk with childbearing, observed in clinial studies, seemed best regarded as a second gradient of risk, seen more readily as variation of breast-cancer rates within a population, where differences in diet would be relatively small.The physiological basis for the association between breast cancer and diet was not clear. The dietary associations did not correlate in an obvious way with height, obesity and oestrogen levels, factors observed in clinical studies to influence risk of breast cancer. That the observed statistical associations were real was supported by published findings on effects of diet on mammary cancer in experimental animals, as well as the lower rates of breast cancer amongst vegetarians.
1970 - 1971年期间，41个国家女性的年龄标准化乳腺癌死亡率均值与1964 - 1966年的饮食情况密切相关。偏相关分析表明，乳腺癌发病率与总脂肪、动物蛋白和动物热量呈正相关，且不受饮食其他成分的影响。这三种成分之间相互关联紧密，根据现有数据无法确定其中任何一种成分是否独立于其他两种成分与乳腺癌相关。除了这些相关性之外，且与之独立的是，乳腺癌还与精制糖的摄入量有关。1964 - 1967年期间，26个国家50 - 54岁女性的乳腺癌死亡率与生育情况密切相关，生育情况以1960 - 1961年45 - 49岁女性的平均家庭规模来表示。然而，这种相关性并非独立于与饮食的相关性，得出的结论是，各国乳腺癌发病率的差异主要源于饮食差异。临床研究中观察到的乳腺癌风险随生育情况的变化，似乎最好被视为第二种风险梯度，在人群中更容易表现为乳腺癌发病率的变化差异，因为在人群中饮食差异相对较小。乳腺癌与饮食之间关联的生理基础尚不清楚。饮食相关性与身高、肥胖和雌激素水平没有明显的关联，而这些因素在临床研究中被观察到会影响乳腺癌风险。饮食对实验动物乳腺癌影响的已发表研究结果，以及素食者中较低的乳腺癌发病率，都支持了所观察到的统计关联是真实存在的这一观点。
