1Department of Psychology,University of Georgia,Athens,Georgia.
J Int Neuropsychol Soc. 2018 Jan;24(1):77-90. doi: 10.1017/S1355617717000534. Epub 2017 Jul 11.
The present study constitutes the first randomized controlled trial to investigate the relation of lutein (L) and zeaxanthin (Z) to brain function using functional magnetic resonance imaging (fMRI). It was hypothesized that L and Z supplementation in older adults would enhance neural efficiency (i.e., reduce activation) and cognitive performance on a verbal learning task relative to placebo.
A total of 44 community-dwelling older adults (mean age=72 years) were randomly assigned to receive either placebo or L+Z supplementation (12 mg/daily) for 1 year. Neurocognitive performance was assessed at baseline and post-intervention on an fMRI-adapted task involving learning and recalling word pairs. Imaging contrasts of blood-oxygen-level-dependent (BOLD) signal were created by subtracting active control trials from learning and recall trials. A flexible factorial model was employed to investigate the expected group (placebo vs. supplement) by time (baseline vs. post-intervention) interaction in pre-specified regions-of-interest.
L and Z appeared to buffer cognitive decline on the verbal learning task (Cohen's d=.84). Significant interactions during learning were observed in left dorsolateral prefrontal cortex and anterior cingulate cortex (p < .05, family-wise-error corrected). However, these effects were in the direction of increased rather than decreased BOLD signal. Although the omnibus interaction was not significant during recall, within-group contrasts revealed significant increases in left prefrontal activation in the supplement group only.
L and Z supplementation appears to benefit neurocognitive function by enhancing cerebral perfusion, even if consumed for a discrete period of time in late life. (JINS, 2018, 24, 77-90).
本研究是首次利用功能磁共振成像（fMRI）研究叶黄素（L）和玉米黄质（Z）与大脑功能之间关系的随机对照试验。研究假设在老年人中补充 L 和 Z 会增强神经效率（即减少激活），并提高在言语学习任务上的认知表现，优于安慰剂。
共有 44 名居住在社区的老年人（平均年龄 72 岁）被随机分配接受安慰剂或 L+Z 补充剂（每日 12 毫克）治疗 1 年。在 fMRI 适应的学习和回忆单词对任务上进行神经认知表现评估，在干预前后进行。通过从学习和回忆试验中减去主动控制试验，创建血氧水平依赖（BOLD）信号的成像对比。采用灵活的因子模型，在预定的感兴趣区域中，按组（安慰剂与补充剂）和时间（基线与干预后）的预期进行交互作用的检验。
L 和 Z 似乎可以缓冲言语学习任务上的认知能力下降（Cohen's d=.84）。在学习过程中观察到左侧背外侧前额叶皮层和前扣带皮层的显著交互作用（p <.05，经家族性错误校正）。然而，这些作用是增加而不是减少 BOLD 信号。尽管在回忆期间总体交互作用不显著，但仅在补充剂组中，出现了左前额叶激活的显著增加。
即使在生命晚期的特定时间段内摄入，L 和 Z 的补充似乎也可以通过增强大脑灌注来改善神经认知功能。（JINS，2018，24，77-90）。
