英语沙龙：阳光致癌亦防癌（在线收听）

Sunshine ＆ Cancer

Although too much exposure to the sun’s ultraviolet rays can cause skin cancer，sunshine may have a protective effect against some cancers，U．S．scientists said in April．They suspect vitamin D，the so－called sunshine vitamin that is also found in fortified milk and dairy products，cod liver oil and some fatty fish，can help to slow down the speed at which cancer cells divide．“This study found inverse associations between both residential and occupational exposure to sunlight and mortality from female breast and colon cancers，”said Dr．Michael Freedman of the National Cancer Institute．

In research reported in Occupational and Environ－mental Medicine，Freedman and his team studied deaths from breast，ovarian，colon，prostate and skin cancers in ２４U．S．states between １９８４and １９９５to determine the impact of sunlight on t he diseases．Not surprisingly they found more deaths from skin cancer in sunnier states but the number of people who died from the other cancers was lower in the sunshine areas．Working outdoors in a sunny climate was also associated with fewer breast and colon cancer deaths but not with the other cancers．Freed man said more research is needed to explain the association between sunlight and certain cancers．

阳光致癌亦防癌

美国科学家今年４月说，尽管过多的太阳紫外线照射可能导致皮肤癌，但阳光对某些癌症却有一定预防作用。他们认为，维生素D，也就是所谓的阳光维生素有助于减缓癌症细胞分裂的速度。维生素D在强化牛奶和奶制品、鱼肝油和某些脂肪多的鱼类中的含量也较为丰富。国家癌症研究所迈克尔?弗里德曼博士说：“研究发现，在住宅和工作场所接受阳光照射的程度与女性乳腺和结肠癌死亡率成反比。”

在发表于《职业和环境医学》上的一项研究中，弗里德曼和他的小组调查了从１９８４年到１９９５年美国２４个州乳腺癌、卵巢癌、结肠癌、前列腺癌和皮肤癌的死亡率，以研究阳光对疾病的作用。不出意料，他们发现，阳光充足的州皮肤癌的死亡率较高，但这些地区其他癌症的死亡率却低得多。晴朗的天气中在户外工作也可以降低乳腺癌和结肠癌的死亡率，但对其他癌症没有类似作用。弗里德曼说，对于阳光与某些癌症的关系还需要进一步研究证实。