您现在的位置: 纽约时报中英文网 >> 华尔街日报中英文版 >> 医疗 >> 正文

冥想有益健康但效果有限

更新时间:2014-1-14 20:31:21 来源:华尔街日报中文网 作者:佚名

Meditation Has Limited Benefits, Study Finds
冥想有益健康但效果有限

Certain types of meditation may provide some modest relief from anxiety, depression and pain, a new study found.

But the study found little evidence for other reported benefits of meditation, including help in curbing substance abuse, poor eating habits, sleep disorders and weight problems.

The report, published Monday in the journal JAMA Internal Medicine, reviewed the findings from 47 previous studies, all randomized clinical trials, with 3,515 adult participants in total.

Many people use meditation to ease stress and promote general health. The purpose of the report was to examine the accumulated evidence to help doctors determine how best to counsel patients on the possible benefits and limitations of meditation, said Madhav Goyal, assistant professor of general internal medicine at Johns Hopkins University in Baltimore and the report's lead researcher.

In each of the underlying studies, participants received professional instruction in one of two types of meditation: mantra meditation or mindfulness meditation. A popular form of mantra meditation is transcendental meditation, which involves repetition of a phrase 'in such a way that it transcends one to an effortless state where focused attention is absent,' the study said. By contrast, mindfulness meditation emphasizes training in 'present-focused awareness,' or mindfulness. The study noted that the distinctions between the meditation types aren't always clear.

Researchers found that only mindfulness meditation produced some benefits. For example, the improvement in patients with mild symptoms of depression was similar in magnitude to what might be expected from the use of an antidepressant, the study said. It also noted that there were few mantra-meditation studies to include in the JAMA review, which could help account for the lack of evidence of benefits from this type of meditation.

The study didn't find any evidence meditation was harmful.

Researchers culled through nearly 19,000 previous studies on meditation to select the most scientific. Dr. Goyal said his team used rigorous inclusion criteria. Each of the 47 included studies was a controlled trial in which at least one group received either a therapy with known psychological benefits, such as exercise, or a placebo instructional or educational session, he said. Studies that looked only at children or adolescents, or those without a control group, were excluded.

'Although uncontrolled studies have usually found a benefit of meditation, very few controlled studies have found a similar benefit for the effects of meditation programs on health-related behaviors affected by stress,' the JAMA report said.

The report's findings show that meditation is perhaps less effective in alleviating stress-related symptoms than is widely believed, said Allan H. Goroll, professor of medicine at Harvard Medical School-Massachusetts General Hospital, in invited commentary also published Monday in JAMA Internal Medicine. 'The studies overall failed to show much benefit from meditation with regard to relief of suffering or improvement in overall health, with the important exception that mindfulness meditation provided a small but possibly meaningful degree of relief from psychological distress,' he wrote.

Still, Dr. Goroll noted that participants only received 30 to 40 hours of training in meditation, which could indicate that 'meditation is a skill that takes time to master.' He also said more evidence is needed to draw more robust conclusions about any benefits to meditation.

'People come to a meditation class because they're suffering in some way,' said Jon Aaron, an instructor at New York Insight Meditation Center, which promotes mindfulness meditation. Through meditation, they learn to relate to their stress in a way that is more productive, he said.

一项最新研究发现,某些种类的冥想或许可以在一定程度上缓解焦虑、抑郁和痛苦。

不过这项研究还发现,几乎没有证据证明,冥想可以带来其他那些据称冥想可以带来的好处,比如说帮助抑制对药物的滥用、改善糟糕的饮食习惯、解决睡眠不规律问题和体重问题。

此项研究的报告发表在1月6日出版的《美国医学会杂志·内科学》(JAMA Internal Medicine)之上,报告对之前47项研究的结果进行了综合分析,这些研究均为随机安排的临床试验,共涉及3515名成年参与者。

许多人利用冥想来缓解压力并改善整体健康状况。巴尔的摩约翰霍普金斯大学(Johns Hopkins University)的普通内科医学助理教授马达夫·戈亚尔(Madhav Goyal)表示,这份报告旨在对以往积累的证据进行研究,以帮助医生们判断如何在冥想可能带来的益处和局限性方面给予患者最好的建议。戈亚尔是这份报告的首席研究者。

在报告涉及的每一项研究中,参与者会得到两类冥想方式中一种方式的专业指导,这两种冥想方式为:持咒冥想(mantra meditation)和正念冥想(mindfulness meditation)。报告称,持咒冥想的一种常见形式是超觉冥想(transcendental meditation),进行超觉冥想时,参与者需要重复一句话,“以这种方式,可以进入一种不存在专注之注意力的轻松状态”。与此不同的是,正念冥想强调以“意识要专注于当下”的状态来进行训练。报告指出,两种冥想类型之间的区别不一定都很清晰。

研究者发现,只有正念冥想能够带来一些好处。比方说,该报告指出,受到轻微抑郁症状困扰的患者,症状可以得到改善,其缓解程度与服用某种抗抑郁药的预期疗效相类似。研究还指出,极少有持咒冥想的研究得到过《美国医学会杂志》的评估,这或许有助于解释,为何缺乏有关这类冥想所带来益处方面的证据。

该研究没有发现任何证据证明冥想会造成伤害。

研究者们对早先进行过的近1.9万项针对冥想的研究进行了仔细筛选,从中挑选出最为系统科学的研究。戈亚尔博士表示,他的研究团队采用了最为严格的筛选标准。他说,被采纳的47项研究,每一项都是有对照控制的临床试验,其中至少有一组参与者会接受一种已知对心理健康有益的治疗方式,比如锻炼,或是接受安慰式的指导或培训课程。那些只观察儿童、青少年、或是没有设置受控对照组的研究,都被筛除出去了。

这份报告指出:“虽然没有受控对照组的研究通常会发现冥想存在某项好处,但很少有受控的研究发现,冥想对受压力影响的健康相关行为存在类似的好处。”

哈佛医学院附属麻省总医院(Harvard Medical School-Massachusetts General Hospital)的医学教授艾伦·H·戈罗尔(Allan H. Goroll)在受邀撰写并发表在同一期杂志上的评论文章中说,这份研究报告结果显示,冥想在缓解压力相关症状方面或许没有人们普遍认为的那样有效。他写道:“这些研究整体而言,没有显示出冥想在缓解痛苦或是改善整体健康状况方面能够带来很多好处,有一个重要的例外是,正念冥想能够在缓解心理压力方面带来很小程度上的改善,不过这样的改善可能是有意义的。”

不过,戈罗尔博士指出,参与者只接受了30到40小时的冥想训练,这可能意味着“冥想是一项需要花时间方能掌握的技巧”。他还表示,需要更多证据才能得出有关冥想所能带来益处的更具有说服力的结论。

纽约心灵禅修中心(New York Insight Meditation Center)的指导教练乔恩·阿龙(Jon Aaron)说:“人们来上冥想课是因为他们正经受着某种形式的痛苦。”这家机构推广正念冥想的方式。他说,通过冥想,人们学会了以某种更为有效的方式来应对自己的压力。

本文版权归道琼斯公司所有,未经许可不得翻译或转载。

相关文章列表