Centre for Cardiovascular Sciences, University of Edinburgh, 49 Little France Crescent, Edinburgh, UK.
Eur J Clin Nutr. 2011 Feb;65(2):234-9. doi: 10.1038/ejcn.2010.233. Epub 2010 Nov 3.
BACKGROUND/OBJECTIVES: A large intake of walnuts may improve lipid profile and endothelial function. The effect of moderate walnut consumption is not known. We investigated whether a moderate intake of walnuts would affect lipid profile, arterial stiffness and platelet activation in healthy volunteers.
SUBJECTS/METHODS: A total of 30 healthy males were recruited into a single-blind randomized controlled crossover trial of 4 weeks of dietary walnut supplementation (15 g/day) and 4 weeks of control (no walnuts). Arterial stiffness was assessed using pulse waveform analysis to determine the augmentation index and augmented pressure. Platelet activation was determined using flow cytometry to measure circulating platelet-monocyte aggregates.
There were no differences in lipid profile after 4 weeks of walnut supplementation compared with control. Dietary intake of α-linolenic acid was increased during the walnut diet (2.1±0.4 g/day versus 0.7±0.4 g/day, P<0.0001). There were no differences in augmentation index or augmented pressure during walnut supplementation. Walnut supplementation did not affect platelet-monocyte aggregation.
Dietary intervention with a moderate intake of walnuts does not affect lipid profile, arterial stiffness or platelet activation in man. Our results suggest that the potentially beneficial cardiac effects of walnuts may not be apparent at lower and more practical levels of consumption.
背景/目的：大量摄入核桃可能会改善血脂状况和内皮功能。目前尚不清楚适量食用核桃的效果。我们研究了适量食用核桃是否会影响健康志愿者的血脂状况、动脉僵硬程度和血小板活化。
受试者/方法：共招募 30 名健康男性，他们参加了一项为期 4 周的单盲随机对照交叉试验，分别接受核桃补充饮食（每天 15 克）和 4 周对照饮食（不吃核桃）。通过脉搏波分析来评估动脉僵硬程度，以确定增强指数和增强压。通过流式细胞术来测量循环血小板-单核细胞聚集体来确定血小板活化。
与对照饮食相比，在摄入核桃 4 周后，血脂状况没有差异。在核桃饮食期间，α-亚麻酸的摄入量增加（每天 2.1±0.4 克，而每天 0.7±0.4 克，P<0.0001）。在摄入核桃期间，增强指数或增强压没有差异。核桃补充剂不会影响血小板-单核细胞聚集。
摄入适量核桃进行饮食干预不会影响人的血脂状况、动脉僵硬程度或血小板活化。我们的结果表明，核桃可能具有有益的心脏作用，但在较低和更实际的摄入量水平下可能不明显。
