新托福阅读： Vitamin B12 tied to Alzheimer's

预防阿兹海默氏症，即老年痴呆症

Reuters Health - Vitamin B12 may help protect against Alzheimer's disease, according to a study out Monday.

路透社健康称 据悉，一份周一的研究报告显示，维他命B12可以帮助预防阿兹海默氏症症。

The study suggests that seniors with more of the active part of the vitamin in their blood have a lower risk of developing the disease, which eats away at the minds of one in eight Americans aged 65 and older, according to the Alzheimer's Association.

研究暗示，血液中含更多维他命活跃成分的老年人患阿兹海默氏症的风险更低，而全美65岁及以上的老人，有1/8的人群受此病困扰。阿兹海默症协会称。

However, the findings don't necessarily mean that taking B vitamin supplements will stave off mental decline.

然而，研究调查结果并不能切实证明服用维他命B12能避免认知能力减退。

Just last summer, for instance, a pair of studies deflated long-held hopes that B vitamins -- like B12 and folic acid -- would help patients who had suffered strokes or heart attack (see Reuters Health stories of June 22 and August 4, 2010).

就在去年夏天，有两份研究否定了，B族维生素，如：维他命B12和叶酸，有利于中风和心脏病病发患者(请参考2010-08-04和2010-06-22有关健康故事的报道。)。

"More research is needed before we can get a conclusion on the role of vitamin B12 supplements on neurodegenerative diseases such as Alzheimer's disease," said Dr. Babak Hooshmand from Karolinska Institutet in Stockholm, Sweden, whose findings appear in the journal Neurology.

瑞士斯德哥尔摩卡罗林斯卡医学院的博士Babak Hooshmand称：“我们尚不能得出结论，服用维他命B12在神经性退化疾病，如阿兹海默氏症，是否有利。

But he added that many elderly people suffer from B12 deficiency, so the results could turn out to be important.

但是他补充道，许多上年纪的人都缺乏维他命B12，所以研究结果至关重要。

"Our findings indicate that vitamin B12 and related metabolites may have an important role in Alzheimer's disease," Hooshmand told Reuters Health by e-mail.

Hooshmand发邮件告知路透社：“我们的调查显示，维他命B12及相关代谢分子在阿兹海默氏症中扮演重要角色。

The researchers took blood samples from 271 Finnish seniors without dementia. At a second examination about seven years later, they found 17 (six percent) had developed Alzheimer's.

研究人员从271位芬兰健康老人中抽取血样，七年后，再次测试，发现当中17人患病，即6%。

Those who did had higher levels of holotranscobalamin -- the active portion of vitamin B12 -- and lower levels of homocysteine, an amino acid tied to mental decline, stroke and heart disease. Folic acid was not linked to Alzheimer's.

人群中体内反钴胺素水平更高，反钴胺素是维他命B12的活跃成分，而体内高半胱氨基水平更低，高半胱氨基和认知能力退化，中风和心脏病病发相关的氨基酸。叶酸和阿兹海默氏症不相关。

B vitamins decrease homocysteine levels, and so have attracted a lot of attention as a potentially cheap and safe treatment. But it is unclear if they are just a sign of disease or have a causal role.

维他命B降低高半胱氨基水平，因此作为实惠可靠的治愈方式而大受关注。但是是否可以成为疾病征兆或者和疾病有因果关系，就不得而知了。

Neurologist Dr. Sudha Seshadri, of Boston University, said he wouldn't advise taking extra B vitamins unless a doctor had diagnosed signs of deficiency.

波士顿大学的神经科专家Sudha Seshadri称，除非病人被确诊维他命B缺乏，他是不会提倡服用过量维他命B。

"Too much folate in the presence of B12 deficiency can be harmful," he told Reuters Health by e-mail.

他发邮件告知路透社过多的叶酸也会有害身体健康。

However, he added, "A healthy diet with adequate B12 may still be useful in reducing risk despite the failure of initial clinical trials to show a benefit on cognition."

然而，他补充说：“含适量的维他命B的健康饮食有助于减低风险，尽管临床试验还未证明有助于认知能力。

Vitamin B12 is found in a variety of foods, including dairy, eggs, fish and meat.

科学发现维他命B12存在于多种食物，包括奶制品，蛋鱼肉类。