Dietary supplements shown to increase cancer risk

文：加思.桑德姆/2015.4.20

Tim Byers, MD, MPH, shows that taken in excess, dietary supplements can increase cancer risk.

蒂姆.拜尔，医务部的公共卫生硕士，证实如果摄入过量的膳食 补充剂将增加患癌风险。

While dietary supplements may be advertised to promote health, a forum at the American Association for Cancer Research (AACR) Annual Meeting 2015 by University of Colorado Cancer Center investigator Tim Byers, MD, MPH, describes research showing that over-the-counter supplements may actually increase cancer risk if taken in excess of the recommended daily amount.

尽管膳食补充剂因其可以增进健康而被刊登，在科罗拉多大学癌症研究中心举办的美国癌症研究协会（AACR）2015年年会的一个论坛上，研究员蒂姆.拜尔(医务部的公共卫生硕士）描述道，研究表明如果摄入过多地、超出推荐的每日供给量的非处方药补充剂，实际上可能增加患癌风险。

“We are not sure why this is happening at the molecular level but evidence shows that people who take more dietary supplements than needed tend to have a higher risk of developing cancer,” explains Byers, associate director for cancer prevention and control at the CU Cancer Center.

“在化学层面上，我们也不确定这一点为什么会发生，但是证据表明， 那些摄入超出人体所需的膳食补充剂的人，将有更高的患癌风险，” 科罗拉多大学癌症中心癌症预防与控制办公室副主任拜尔解释道。

The line of research started 20 years ago with the observation that people who ate more fruits and vegetables tended to have less cancer. Researchers including Byers wanted to see if taking extra vitamins and minerals would reduce cancer risk even further.

调查从20年前就开始了，我们观察到，那些平时爱吃水果和蔬菜的人患癌率明显更少。包括拜尔在内的研究者都希望了解如果摄入过多的维他命和矿物质是否会进一步减少患癌风险。

“When we first tested dietary supplements in animal models we found that the results were promising,” says Byers. “Eventually we were able to move on to the human populations. We studied thousands of patients for ten years who were taking dietary supplements and placebos.”

“当我们第一次用动物模型来测试膳食补充剂时，我们就发现测试结果值得我们继续下去、是有希望的。”拜尔说道，“最终我们可以将试验对象转移到人类.我们用长达十年的时间研究了成千上万的、摄入膳食补充剂和安慰剂的病人。

The results were not what they expected.

但试验的结果却并未达到他们的预期。

“We found that the supplements were actually not beneficial for their health. In fact, some people actually got more cancer while on the vitamins,” explains Byers.

“我们发现补充剂实际上对他们的健康并没有好处。事实上，那些摄入过多维他命的人往往更容易增加患癌风险，”拜尔继续补充道。

One trial exploring the effects of beta carotene supplements showed that taking more than the recommended dosage increased the risk for developing both lung cancer and heart disease by 20 percent. Folic acid, which was thought to help reduce the number of polyps in a colon, actually increased the number in another trial.

一次探索胡萝卜素补充剂的试验表明，如果摄入超出推荐剂量的补充剂，将增加20%的患肺癌和心脏病的风险。维生素B（叶酸），本以为其可以减少结肠中息肉的数量，但实际上在另外一次试验中，息肉的数量却增加了。

“This is not to say that people need to be afraid of taking vitamins and minerals,” says Byers. “If taken at the correct dosage, multivitamins can be good for you. But there is no substitute for good, nutritional food.”

”这不是说人们就应对维他命和矿物质的摄入感到恐惧，”拜尔说道，“如果摄入正确的剂量，多种维他命都会对你的健康有好处。但是维他命也不能代替那些优质的、有营养的食物。”

Byers says that people can get the daily recommended doses of vitamins and minerals in their diets by eating healthy meal and that many adults who take vitamin supplements may not need them.

拜尔说道，人们可以通过食用健康的膳食来获取每日所需和推荐剂量的维他命和矿物质，并且许多复用膳食补充剂的成年人根本不需要它们。

“At the end of the day we have discovered that taking extra vitamins and minerals do more harm than good,” says Byers.

"在一天快要结束的时候，我们发现摄入过量的维他命和矿物质是弊大于利的，” 拜尔说道。