Department of Psychiatry, Center for Imaging Research, Division of Bipolar Disorders Research, University of Cincinnati College of Medicine, Cincinnati, OH 45219-0516, USA.
Am J Clin Nutr. 2010 Apr;91(4):1060-7. doi: 10.3945/ajcn.2009.28549. Epub 2010 Feb 3.
Emerging evidence suggests that docosahexaenoic acid (DHA, 22:6n-3), the principal omega-3 (n-3) fatty acid in brain gray matter, positively regulates cortical metabolic function and cognitive development. However, the effects of DHA supplementation on functional cortical activity in human subjects are unknown.
The objective was to determine the effects of DHA supplementation on functional cortical activity during sustained attention in human subjects.
Healthy boys aged 8-10 y (n = 33) were randomly assigned to receive placebo or 1 of 2 doses of DHA (400 or 1200 mg/d) for 8 wk. Relative changes in cortical activation patterns during sustained attention at baseline and endpoint were determined by functional magnetic resonance imaging.
At 8 wk, erythrocyte membrane DHA composition increased significantly from baseline in subjects who received low-dose (by 47%) or high-dose (by 70%) DHA but not in those who received placebo (-11%). During sustained attention, both DHA dose groups had significantly greater changes from baseline in activation of the dorsolateral prefrontal cortex than did the placebo group, and the low-dose and high-dose DHA groups had greater decreases in the occipital cortex and cerebellar cortex, respectively. Relative to low-dose DHA, high-dose DHA resulted in greater decreases in activation of bilateral cerebellum. The erythrocyte DHA composition was positively correlated with dorsolateral prefrontal cortex activation and was inversely correlated with reaction time, at baseline and endpoint.
Dietary DHA intake and associated elevations in erythrocyte DHA composition are associated with alterations in functional activity in cortical attention networks during sustained attention in healthy boys. This trial was registered at clinicaltrials.gov as NCT00662142.
新出现的证据表明，二十二碳六烯酸（DHA，22:6n-3）是大脑灰质中主要的ω-3（n-3）脂肪酸，它可以正向调节皮质代谢功能和认知发育。然而，DHA 补充剂对人体功能性皮质活动的影响尚不清楚。
本研究旨在确定 DHA 补充剂对人体受试者持续注意力期间功能性皮质活动的影响。
8-10 岁健康男孩（n=33）被随机分为安慰剂组或 DHA 低剂量（400mg/d）、高剂量（1200mg/d）组，分别接受 8 周的补充。通过功能磁共振成像，在基线和终点时确定持续注意力期间皮质激活模式的相对变化。
8 周后，低剂量或高剂量 DHA 组的红细胞膜 DHA 组成比基线显著增加（分别增加 47%和 70%），而安慰剂组则减少 11%。在持续注意力期间，与安慰剂组相比，低剂量和高剂量 DHA 组的背外侧前额叶皮质的激活变化明显更大，而低剂量和高剂量 DHA 组的枕叶皮质和小脑皮质的激活变化分别更大。与低剂量 DHA 相比，高剂量 DHA 导致双侧小脑的激活降低更大。红细胞 DHA 组成与背外侧前额叶皮质的激活呈正相关，与反应时间呈负相关，无论在基线还是终点都是如此。
膳食 DHA 摄入和红细胞 DHA 组成的相应增加与健康男孩持续注意力期间皮质注意网络的功能性活动改变有关。本试验在 clinicaltrials.gov 上注册为 NCT00662142。
