Yurko-Mauro Karin, Alexander Dominik D, Van Elswyk Mary E
Clinical Research, Nutritional Lipids, DSM Nutritional Products, Columbia, Maryland, United States of America.
Epidemiology, EpidStat Institute, Evergreen, Colorado, United States of America.
PLoS One. 2015 Mar 18;10(3):e0120391. doi: 10.1371/journal.pone.0120391. eCollection 2015.
Subjective memory complaints are common with aging. Docosahexaenoic acid (DHA; 22:6 n-3) is a long-chain polyunsaturated fatty acid (LCPUFA) and an integral part of neural membrane phospholipids that impacts brain structure and function. Past research demonstrates a positive association between DHA plasma status/dietary intake and cognitive function.
The current meta-analysis was designed to determine the effect of DHA intake, alone or combined with eicosapentaenoic acid (EPA; 20:5 n-3), on specific memory domains: episodic, working, and semantic in healthy adults aged 18 years and older. A secondary objective was to systematically review/summarize the related observational epidemiologic literature.
A systematic literature search of clinical trials and observational studies that examined the relationship between n-3 LCPUFA on memory outcomes in healthy adults was conducted in Ovid MEDLINE and EMBASE databases. Studies of subjects free of neurologic disease at baseline, with or without mild memory complaints (MMC), were included. Random effects meta-analyses were conducted to generate weighted group mean differences, standardized weighted group mean differences (Hedge's g), z-scores, and p-values for heterogeneity comparing DHA/EPA to a placebo. A priori sub-group analyses were conducted to evaluate the effect of age at enrollment, dose level, and memory type tested.
Episodic memory outcomes of adults with MMC were significantly (P<.004) improved with DHA/EPA supplementation. Regardless of cognitive status at baseline, > 1 g/day DHA/EPA improved episodic memory (P<.04). Semantic and working memory changes from baseline were significant with DHA but no between group differences were detected. Observational studies support a beneficial association between intake/blood levels of DHA/EPA and memory function in older adults.
DHA, alone or combined with EPA, contributes to improved memory function in older adults with mild memory complaints.
主观记忆主诉在衰老过程中很常见。二十二碳六烯酸（DHA；22:6 n-3）是一种长链多不饱和脂肪酸（LCPUFA），是神经膜磷脂的重要组成部分，会影响大脑结构和功能。过去的研究表明，DHA血浆水平/饮食摄入量与认知功能之间存在正相关。
本荟萃分析旨在确定DHA单独或与二十碳五烯酸（EPA；20:5 n-3）联合摄入对18岁及以上健康成年人特定记忆领域（情景记忆、工作记忆和语义记忆）的影响。第二个目的是系统回顾/总结相关的观察性流行病学文献。
在Ovid MEDLINE和EMBASE数据库中对临床试验和观察性研究进行系统文献检索，这些研究考察了n-3 LCPUFA与健康成年人记忆结果之间的关系。纳入了基线时无神经系统疾病的受试者的研究，无论有无轻度记忆主诉（MMC）。进行随机效应荟萃分析，以生成加权组均值差异、标准化加权组均值差异（Hedge's g）、z分数和p值，用于比较DHA/EPA与安慰剂的异质性。进行了预先设定的亚组分析，以评估入组年龄、剂量水平和测试的记忆类型的影响。
补充DHA/EPA可显著（P<.004）改善有MMC的成年人的情景记忆结果。无论基线时的认知状态如何，每天摄入>1 g的DHA/EPA可改善情景记忆（P<.04）。DHA使语义记忆和工作记忆与基线相比有显著变化，但未检测到组间差异。观察性研究支持DHA/EPA的摄入量/血液水平与老年人记忆功能之间存在有益关联。
DHA单独或与EPA联合使用，有助于改善有轻度记忆主诉的老年人的记忆功能。
