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."
紐約:來(lái)自德國(guó)建議的一項(xiàng)新的研究表明,在上了年紀(jì)的健康人當(dāng)中,減少熱量可能提高他們的記憶力。在這個(gè)研究中,研究員發(fā)現(xiàn)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(gè)月之后就可以在標(biāo)準(zhǔn)的記憶測(cè)試中表現(xiàn)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(rèn)知能力。”A.Veronica Witte教授和他在閔斯特大學(xué)的同事在國(guó)家科學(xué)研究院最新一期的公報(bào)上如此寫(xiě)道。
動(dòng)物上的研究已經(jīng)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(fā)揮,能提高大老鼠的記憶力。
為了證明在人類(lèi)中能否產(chǎn)生一樣的效果,Witte的小組將50個(gè)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(shí)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(jù)這個(gè)調(diào)查,三個(gè)月后,熱量受限制的那組在非文字記憶測(cè)試中得到了分?jǐn)?shù)高出20%的可觀結(jié)果。相比之下,在另外兩組卻沒(méi)有明顯的改變。
在這個(gè)調(diào)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(xiàn)炎癥的“生物標(biāo)記”有關(guān)。這些改變?cè)谀切﹪?yán)格堅(jiān)持熱量限制飲食方式的人中最為明顯。
“據(jù)我們所知,目前的結(jié)果提供了第一個(gè)試驗(yàn)證據(jù),說(shuō)明在人群中限制熱量可以提高上了年紀(jì)的人的記憶能力。”Witt和他的同事如是說(shuō)。
他們補(bǔ)充說(shuō):“這次研究的結(jié)果,有助于開(kāi)發(fā)新的保護(hù)和治療策略來(lái)保持晚年健康的認(rèn)知能力。”