流行病学调查结果表明，富含DHA 的饮食可降低AD的发生风险，然而DHA改善老年人认知功能的人群干预试验却未能获得预期结果。除干预剂量、时间等因素外，受试者的营养基线水平及遗传背景对干预结局的影响尚不清楚。课题组前期发现MCI患者每日鱼类摄入量及体内VE、n-3 PUFAs的水平明显低于对照组，提示VE及DHA在影响老年人认知功能过程中可能存在协同作用。此外，DHA干预效果的个体差异在人群及动物实验中均被观察到，提示了遗传因素对干预结局的影响。SRB1/CD36参与了脑内VE及长链脂肪酸的转运，且其基因变异可导致脑组织中VE及脂肪酸水平发生改变，推测VE、DHA及B类清道夫受体三者在影响脑功能过程中可能存在交互作用。本研究拟开展老年人现况调查、人群及动物饮食干预试验探讨VE、DHA、SRB1/CD36基因多态性与认知功能的关系，旨在为制定可预防AD的个性化DHA干预推荐量提供科学依据。

Epidemiology study indicated the inverse association of DHA rich diet intake and the risk of AD. However, up to date, no convincing results were derived from the treatment of AD by using DHA supplementation. Except for the DHA dosage and experimental period, the differences of nutrients baseline status and genetic background of the participants might contribute to the various outcome of DHA dietary intervention. Our previous population based study indicated that MCI patients consumed less fish daily than control subjects. And MCI subjects have lower serum VE and erythrocyte n-3 PUFAs levels than control subjects. Moreover, variety of responds to dietary DHA dietary intervention was observed in human being or experimental animals, which indicated the possible contribution of genetic background to the outcome of DHA dietary intervention. Class B scavenger receptor (CD36 and SR-B1) were reported participating in the absorption and transport of VE and DHA in brain. Increasing evidences suggested that the mutation of CD36 and SR-B1 gene caused the abnormal of brain VE and DHA levels. These results indicated the interaction of CD36/SR-B1 gene polymorphism, VE and DHA with cognition in the elderly. In the current study, cross-sectional, case-control and follow-up studies were carried out to investigate the correlation among SR-B1/CD36 gene polymorphism, dietary VE and DHA consumption and cognitive function in the elderly. Besides, human beings and animal dietary intervention studies were applied to explore the combine effects of SR-B1/CD36 gene mutation and dietary VE consumption on the outcome of DHA dietary intervention in improving cognition. The study will provide scientific supports for the personalized dietary recommendation of DHA in the prevention of AD in the elderly.