Jia X, McNeill G, Avenell A
Department of Environmental and Occupational Medicine, University of Aberdeen, Foresterhill Road, Aberdeen, UK.
J Hum Nutr Diet. 2008 Aug;21(4):317-36. doi: 10.1111/j.1365-277X.2008.00887.x.
Observational studies have shown associations between nutritional status and cognition in later life but evidence from intervention studies is unclear. The present study systematically reviewed the evidence on the effect of nutrient supplementation on cognitive function in people aged >or=65 years.
Databases including MEDLINE and EMBASE were searched up to 1 September 2006. Randomized controlled trials using at least one kind of vitamin, mineral or omega-3 fatty acid, evaluating standardized neuropsychological test(s), were included. There were no restrictions on participants' baseline nutritional status or cognitive function. Quality assessment and data abstraction were conducted by one author and checked by another.
Of 4229 articles retrieved, 22 trials (3442 participants) were identified. Many were small, short duration and of poor methodology. Only 16 out of 122 cognitive tests were significantly different between groups. A meta-analysis showed no significant effect of taking B vitamins or antioxidant vitamins on global cognitive function. There was insufficient evidence to evaluate the effect of omega-3 fatty acids on any cognitive domains.
There was little evidence of a beneficial effect from taking B vitamins or antioxidant supplements on global cognitive function in later life. Larger-scale randomized controlled trials of longer duration in selected age groups are needed.
观察性研究表明营养状况与晚年认知之间存在关联，但干预性研究的证据尚不清楚。本研究系统回顾了关于营养补充剂对65岁及以上人群认知功能影响的证据。
检索截至2006年9月1日的MEDLINE和EMBASE等数据库。纳入使用至少一种维生素、矿物质或ω-3脂肪酸的随机对照试验，这些试验评估标准化神经心理学测试。对参与者的基线营养状况或认知功能没有限制。由一位作者进行质量评估和数据提取，并由另一位作者进行检查。
在检索到的4229篇文章中，确定了22项试验（3442名参与者）。许多试验规模小、持续时间短且方法学质量差。122项认知测试中只有16项在组间存在显著差异。荟萃分析表明，服用B族维生素或抗氧化维生素对整体认知功能没有显著影响。没有足够的证据评估ω-3脂肪酸对任何认知领域的影响。
几乎没有证据表明服用B族维生素或抗氧化补充剂对晚年整体认知功能有有益影响。需要在选定年龄组中进行更大规模、持续时间更长的随机对照试验。
