根据纽约路透社的报导，一份来自法国的研究显示，吃银杏(Ginkgo biloba)也许能延长老人的寿命，但却无法降低他们痴呆(dementia)的风险。法国波尔多大学（University of Bordeaux）的科学家针对3534名年龄超过65岁的老人进行测试，发现在13 年之间有服用银杏的组别，其死亡率大约减少了24%，此研究由Jean-Francois Dartigues博士主导进行。
Dartigues研究团队表示：「银杏在法国销售已超过30年之久，作为加强记忆力的功用。迄今，大部份的研究都集中在银杏是否能预防老人痴呆症的议题，但是，老人死亡的风险似乎更高，因此，银杏是否能延长老人的寿命也应该列入考虑。」研究自1988年开始，有6.4%的人服用银杏萃取物，25.1%的人服用其它种能强化记忆功能的物质，每两年观测一次受测者预防痴呆的情况。13年后，有53.1%的人已经死亡，17.6%的人得到痴呆症。
在服用安慰剂的组别(以下称A组)中，大约有一半的人死亡，而服用他种强化记忆功能物质(以下称B组)以及服用银杏(以下称C组)的组别，其死亡率则分别为62.1%及46.7%，而A, B, C三组受试者得到老人痴呆症的比例则分别为15.5%, 22.4%以及21.4%。由研究结果显示：「银杏在延长老人寿命的情况有显著差异，但却没有实质预防痴呆的功效。」研究人员指出目前在美国及欧洲也有超过5800人参与类似的实验，结果将于2010年公布。
(资料来源 : Reuters)
英文原文:
"Memory" herb ginkgo may boost survival
Mon Apr 16, 2007 4:26PM EDT
NEW YORK (Reuters Health) - A study conducted in France provides preliminary evidence that older people who take Ginkgo biloba may be extending their lives, but are not reducing their risk of dementia
Among 3,534 men and women 65 and older, those who used the herb were 24 percent less likely to die over a 13-year period than their peers who didn't take ginkgo, Dr. Jean-Francois Dartigues at the University of Bordeaux and colleagues found.
Dartigues and his team note that Ginkgo biloba extract has been sold in France for more than three decades to enhance memory. To date, they add, most studies have focused on whether the herb prevents dementia, but because older people have a much greater risk of dying, dementia-free survival should also be included as an outcome.
The researchers looked at the effect of several different dementia prevention treatments on the study participants, collecting data when the study began, in 1988, and every 2 years thereafter.
At the start of the study, 6.4 percent of the participants were taking Ginkgo biloba extract, while 25.1 percent were taking some other type of memory enhancing treatment. After 13 years, 53.1 percent had died and 17.6 percent had developed dementia.
About half of people who took no memory enhancing treatment died, compared with 46.7 percent of those taking Gingko biloba and 62.1 percent of those taking some other type of memory-boosting drug. Among those on Gingko biloba, 21.4 percent developed dementia, compared with 22.4 percent of those on other memory treatments and 15.5 percent of those who were not taking memory enhancers.
The researchers found that while the effect of the herb on mortality risk remained significant, it had no effect on the likelihood of developing dementia. People taking other memory treatments were actually at increased risk of dementia, but did not have a greater risk of dying.
These results should be interpreted carefully, the researchers note, because people taking Gingko or other memory enhancers at the beginning of the study may have been at greater risk of dementia than those who weren't taking such treatment.
"Nevertheless, it cannot be excluded that Ginkgo biloba may have a beneficial effect on survival in the elderly population," they write.
The results must be confirmed in randomized, prospective clinical trials in which people taking the extract are compared to those who aren't, the researchers add. They point out that there are currently over 5,800 people taking part in such studies in the US and Europe, with results expected in 2010.
SOURCE: Journal of the American Geriatrics Society, March 2007.
