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."
德國的一項新研究表明,削減卡路里可以改善健康老年男女的記憶力.研究人員在研究中發(fā)現(xiàn),那些減少卡路里攝入約30%的人,僅僅3個月后, 在標準記憶力測試中的表現(xiàn)就要好得多.
“我們的研究有助于形成新穎的預防策略,來保持老年人的認知能力,” 蒙斯特大學的A.維羅妮卡.威特博士在最近一期的國家科學院學報中這樣表述.
動物實驗顯示,低卡路里和富含不飽和脂肪酸的食物--橄欖油和魚中發(fā)現(xiàn)的那種--對大腦的官能有利,有助于改善衰老的老鼠的記憶力
為了弄清楚在人類中是否會產(chǎn)生同樣的效果,威特研究小組將50名平均年齡60歲、體格從正常到超重的研究對象分成了3組。第一組的卡路里攝入被控制在原有水平的30%,第二組不飽和脂肪酸的攝入量增加到原有水平的20%,第三組作為控制組,不作任何改變。
據(jù)研究人員說,3個月后,卡路里限制組單詞記憶的分數(shù)有了一個顯著的20%的平均增長。相反,其他兩組表現(xiàn)出的記憶成績沒有顯著的變化。
研究人員還注意到,卡路里限制組的記憶改善與體內(nèi)胰島素水平和炎癥的生物標記物的降低是相關(guān)聯(lián)的,并且這些變化在那些嚴格遵守指定的卡路里限制食譜的研究對象身上最為明顯。
“就我們所知,目前的結(jié)果提供了卡路里限制可以改善老年人記憶力的第一個人類實驗證據(jù),”
這項研究成果,他們補充說:“有助于開發(fā)新的預防和治療策略,以保持老年人的認知健康。”