研究表明，进行适量的体育锻炼可以降低患癌症的风险

研究表明，进行适量的体育锻炼可以降低患癌症的风险

A new study sheds light on one potential health benefit of exercise: a lower risk of certain cancers.

一项新的研究揭示了运动的一个潜在的健康益处:降低患某些癌症的风险。

The study, published Thursday in the Journal of Clinical Oncology, analyzed data from more than 750.000 adults in the United States, Europe and Australia, and found that recommended amounts of physical activity correlated with lower risks of seven types of cancer, of the 15 types that researchers looked at.

周四发表在《临床肿瘤学杂志》上的这项研究分析了来自美国、欧洲和澳大利亚的75万多名成年人的数据，发现在研究人员观察的15种癌症中，推荐的运动量与降低7种癌症的风险相关。

These cancer types were colon, breast, kidney, myeloma, liver, non-Hodgkin lymphoma and endometrial.

这些癌症类型包括结肠癌、乳腺癌、肾癌、骨髓瘤、肝癌、非霍奇金淋巴瘤和子宫内膜癌。

A number of previous studies have come to similar conclusions about physical activity and cancer. In the latest analysis, the researchers dug deeper into the relationships between the amount of physical activity and how much lower the cancer risk became.

之前的一些研究也得出了类似的关于体育活动和癌症的结论。在最新的分析中，研究人员深入研究了运动量与降低癌症风险程度之间的关系。

Recommended levels of physical activity showed what could be a range of potential benefits, from a 6-10% lower risk of breast cancer to an 18-27% lower risk of liver cancer.

建议的身体活动水平显示了一系列潜在的好处，从降低6-10%的乳腺癌风险到降低18-27%的肝癌风险。

With some cancers, most of that reduced risk was seen with the recommended amounts of physical activity. With other cancers, the study found that physical activity well above current recommendations may correlate with the lowest risk levels.

对于某些癌症，大部分的风险降低是通过推荐的身体活动来实现的。对于其他癌症，研究发现，远高于目前建议的身体活动可能与最低风险水平相关。

The authors say this "may reflect important differences in the underlying biologic mechanisms for distinct cancer types."

作者说，这“可能反映了不同癌症类型潜在生物机制的重要差异”。

US health officials recommend that adults get at least 2½ hours of moderate-intensity aerobic exercise, 75 minutes of vigorous-intensity aerobic exercise, or a comparable combination of the two per week.

美国卫生官员建议成年人每周至少进行两个半小时的中等强度有氧运动，75分钟的大强度有氧运动，或每周两者结合。

The authors note their data come from self-reported physical activity at just one point in time and that the majority of people included were white, which could limit how applicable their findings are more broadly.

作者指出，他们的数据只来自于某个时间点上的自我报告的体育活动，而且其中的大多数人是白人，这可能会限制他们的发现在更广的范围内的适用性。

When adjusting for body mass index, or BMI, the link between endometrial cancer and physical activity disappeared. However, this had a "limited effect" on other types of cancer, the authors said. In addition, a significant association for non-Hodgkin lymphoma was seen only in women, and the same was true for colon cancer in men.

在对体重指数(BMI)进行调整后，子宫内膜癌与身体活动之间的联系消失了。然而，作者说，这对其他类型的癌症有“有限的影响”。此外，非霍奇金淋巴瘤的显著相关性仅限于女性，而结肠癌在男性中也是如此。

The researchers caution that the study doesn't definitively show that exercise directly causes cancer risk to drop. Health experts say there may be various other factors at play.

研究人员提醒说，这项研究并没有明确表明锻炼直接导致癌症风险下降。健康专家说，可能还有其他各种因素在起作用。

"There is substantial evidence that higher levels of physical activity are linked to lower risks of several cancers," explains the National Cancer Institute. However, "people who are not physically active may differ from active people in ways other than their level of physical activity.

“有大量证据表明，较高水平的体力活动与较低的患多种癌症的风险有关，”国家癌症研究所解释说。然而，“不运动的人可能与运动的人在身体活动水平以外的其他方面有所不同。

"These other differences, rather than the differences in physical activity, could explain their different cancer risk," according to the institute. "For example, if someone does not feel well, they may not exercise much, and sometimes people do not feel well because they have undiagnosed cancer."

“这些其他的差异，而不是身体活动的差异，可以解释他们不同的癌症风险，”该研究所说。“例如，如果有人感觉不舒服，他们可能不太运动，有时人们感觉不舒服是因为他们患有未确诊的癌症。”

A number of other factors have been linked to cancer risk, including smoking, diet and obesity.

其他一些因素也与癌症风险有关，包括吸烟、饮食和肥胖。

"We know there are many factors that are associated with both obesity and cancer, such as lack of exercise and poor diet," MD Anderson Cancer Center's Dr. George Chang previously told CNN. "How much each of those factors contribute to cancer is less clear."

MD安德森癌症中心的乔治·张医生之前告诉CNN:“我们知道有很多因素都与肥胖和癌症有关，比如缺乏锻炼和不良的饮食习惯。”“这些因素在多大程度上导致了癌症还不太清楚。”