Loss of memory and other brain function can start as early as age 45, posing a big challenge to scientists looking for new ways to stave off dementia, researchers said, Reuters reported.

A research team followed more than 7,000 British government workers over a period of 10 years. Participants were assessed three times during the study, using tests for memory, vocabulary, and aural and visual comprehension skills.

Over the 10-year period, there was a 3.6 percent decline in mental reasoning in both men and women aged 45-49 at the start of the study, while the decline for men aged 65-70 was 9.6 percent and 7.4 percent for women.

Since the youngest individuals at the start of the study were 45, it is possible that the decline in cognition might have commenced even earlier.

The finding contradicts previous notions that cognitive decline does not begin before 60 years of age, and it could have far-reaching implications for dementia research.

Pinpointing the age at which memory, reasoning and comprehension skills start to deteriorate is important because drugs are most likely to work if given when people first start to experience mental impairment.

(China.org.cn January 26, 2012)

路透社報道，研究人員表示，記憶力及其它大腦功能最早從45歲便開始衰退了，這給尋找癡呆治療法的科學家提出了新的難題。

在過去10年中，一組科研人員跟蹤觀察了七千多名英國政府工作人員。期間，研究人員用記憶力、詞匯、視聽領悟力測試對參與人員進行了3次評估。

10年中，研究剛開始時，45至49歲男女的智力推理能力下降了3.6%，而65至70歲男子的能力下降9.6%，該年齡段女子的能力下降了7.4%。

由于研究開始時最年輕的個人為45歲，思維能力開始衰退的時間可能更早。

該發現有悖于以前的觀念，之前人們認為，認知能力下降不會在60歲前開始。該發現對癡呆研究會有長遠的影響。

明確記憶力、推理能力和理解力在哪個歲數開始衰退很重要，因為人們在開始感到智力衰退時便服藥，藥效最好。