Cutting calories may improve memory among healthy elderly men and women, a new study from Germany hints. In the study, researchers found that people who cut their calorie intake by approximately 30 percent performed better on standard memory tests after just three months.

    "Our study may help to generate novel prevention strategies to maintain cognitive functions into old age," Dr. A. Veronica Witte and colleagues from University of Munster wrote in the latest issue of Proceedings of the National Academy of Sciences.

    Animal studies have shown that diets low in calories and rich in unsaturated fatty acids - the kind found in olive oil and fish - are beneficial for brain function, helping to improve memory in aging rats.

    To see whether the same effects can be induced in humans, Witte's team divided 50 normal- to overweight individuals whose average age was 60 years into three groups. One group restricted by up to 30 percent the amount of calories they consumed; a second group increased their consumption of unsaturated fatty acids by up to 20 percent; and a third group, serving as the control group, made no changes.

    According to the investigators, the calorie-restricted group saw a significant 20 percent average increase in verbal memory scores after 3 months. In contrast, no significant changes in memory performance emerged in the two other groups.

    The investigators also noticed that memory improvements in the calorie-restricted group correlated with decreases in insulin levels and "biomarkers" of inflammation in the body, and that these changes were most pronounced in those individuals who stuck closest to the prescribed calorie-restricted diet.

    "To our knowledge, the current results provide the first experimental evidence in humans that caloric restriction improves memory in the elderly," Witte and colleagues note.

    The results of this study, they add, "may help to develop new prevention and treatment strategies for maintaining cognitive health into old age."

    來自德國建議的一項新的研究表明，在上了年紀的健康人當中，減少熱量可能提高他們的記憶力。在這個研究中，研究員發現那些減少了自己接近百分之30的熱量吸收的人在僅僅三個月之后就可以在標準的記憶測試中表現的比其他人好。

    “我們的研究可以幫助形成一種新的策略，可以防治老年人的記憶力衰退，保持認知能力。”A.Veronica Witte教授和他在閔斯特大學的同事在國家科學研究院最新一期的公報上如此寫道。

    動物上的研究已經表明了，多吃低熱量和多不飽和脂肪酸食物的日常飲食有利于大腦功能的發揮，能提高大老鼠的記憶力。

    為了證明在人類中能否產生一樣的效果，Witte的小組將50個平均年齡在60歲的從正常到超重的人分成了三組。一組限制了他們平時所消耗的熱量的30%；第二組增加他們所消耗的不飽和脂肪酸的20%；而第三組，作為參照，不需要做任何改變。

    根據這個調查，三個月后，熱量受限制的那組在非文字記憶測試中得到了分數高出20%的可觀結果。相比之下，在另外兩組卻沒有明顯的改變。

    在這個調查中還注意到，在熱量受限組，記憶力提升與身體里胰島素減少和出現炎癥的“生物標記”有關。這些改變在那些嚴格堅持熱量限制飲食方式的人中最為明顯。

    “據我們所知，目前的結果提供了第一個試驗證據，說明在人群中限制熱量可以提高上了年紀的人的記憶能力。”Witt和他的同事如是說。

    他們補充說:“這次研究的結果，有助于開發新的保護和治療策略來保持晚年健康的認知能力。”