Kramer M M, Wells C L
Department of Exercise Science and Physical Education, Arizona State University, Tempe 85287-0404, USA.
Med Sci Sports Exerc. 1996 Mar;28(3):322-34. doi: 10.1097/00005768-199603000-00008.
The estrogen-dependent cancers (breast, endometrial, and ovarian) are among the leading causes of morbidity and mortality in American women. Increased incidence of these cancers is predicted in the future, and the need for primary prevention is clear. Sufficient evidence has accumulated to warrant an analysis of the relationship between physical activity and estrogen-dependent cancer. Recent epidemiological studies confirm an inverse relationship between physical activity and estrogen-dependent cancer, with stronger associations appearing for occupational activity than for leisure time or nonoccupational activity. Several hypothesized mechanisms are described for the prevention of estrogen-dependent cancer by physical activity: 1) maintenance of low body fat and moderation of extraglandular estrogen, 2) reduction in number of ovulatory cycles and subsequent diminution of lifetime exposure to endogenous estrogen, 3) enhancement of natural immune function, and 4) the association of other healthy lifestyle habits. Although the mechanisms are not well defined, several lines of evidence support the inclusion of low-to-moderate physical activity as a preventive strategy for estrogen-dependent cancer.
雌激素依赖性癌症（乳腺癌、子宫内膜癌和卵巢癌）是美国女性发病和死亡的主要原因之一。预计这些癌症的发病率在未来将会增加，因此一级预防的必要性显而易见。已有足够的证据积累，足以对体育活动与雌激素依赖性癌症之间的关系进行分析。最近的流行病学研究证实，体育活动与雌激素依赖性癌症之间存在负相关关系，职业活动的相关性比休闲时间或非职业活动更强。文中描述了体育活动预防雌激素依赖性癌症的几种假设机制：1）维持低体脂并调节腺体外雌激素；2）减少排卵周期数量，从而减少一生当中内源性雌激素的暴露量；3）增强自然免疫功能；4）与其他健康生活方式习惯的关联。尽管这些机制尚未明确，但有几条证据支持将低至中等强度的体育活动作为预防雌激素依赖性癌症的一种策略。
