Willis Lauren M, Shukitt-Hale Barbara, Cheng Vivian, Joseph James A
USDA-ARS, Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA.
Br J Nutr. 2009 Apr;101(8):1140-4. doi: 10.1017/S0007114508059369.
Aged rats show decrements in performance on motor and cognitive tasks that require the use of spatial learning and memory. Previously we have shown that these deficits can be reversed by the polyphenolics in fruits and vegetables. Walnuts, which contain the n-3 fatty acids a-linolenic acid and linoleic acid, are a dietary source of polyphenols, antioxidants and lipids. Thus, the present study examined the effects of walnut supplementation on motor and cognitive ability in aged rats. Fischer 344 rats, aged 19 months, were fed a control, or a 2, 6 or 9% walnut diet for 8 weeks before motor and cognitive testing. Results for the motor testing showed that the 2% walnut diet improved performance on rod walking, while the 6% walnut diet improved performance on the medium plank walk; the higher dose of the 9% walnut diet did not improve psychomotor performance and on the large plank actually impaired performance. All of the walnut diets improved working memory in the Morris water maze, although the 9% diet showed impaired reference memory. These findings show for the first time that moderate dietary walnut supplementation can improve cognitive and motor performance in aged rats.
老年大鼠在需要运用空间学习和记忆的运动及认知任务中的表现会下降。此前我们已经表明，水果和蔬菜中的多酚类物质可以逆转这些缺陷。核桃含有n-3脂肪酸α-亚麻酸和亚油酸，是多酚、抗氧化剂和脂质的膳食来源。因此，本研究考察了补充核桃对老年大鼠运动和认知能力的影响。19个月大的Fischer 344大鼠在进行运动和认知测试前8周，分别喂食对照饮食、2%、6%或9%的核桃饮食。运动测试结果表明，2%的核桃饮食能改善杆上行走的表现，而6%的核桃饮食能改善中板行走的表现；9%的高剂量核桃饮食并未改善精神运动表现，实际上还损害了大板行走的表现。所有核桃饮食都改善了莫里斯水迷宫中的工作记忆，不过9%的饮食显示出参考记忆受损。这些发现首次表明，适度的膳食核桃补充可以改善老年大鼠的认知和运动表现。
