A diet rich in certain foods such as nuts, fish and vegetables and low in high-fat dairy foods and red meat appears exert a preventative effect on the development of Alzheimer's disease, according to a study published online April 12 in the Archives of Neurology.
“Our findings provide support for further exploration of food-combination–based dietary behavior for the prevention of this important public health problem,” wrote Yian Gu, Ph.D., of the Taub Institute for Research in Alzheimer’s Disease and the Aging Brain at Columbia University, New York, and associates.
The researchers sought to assess food combinations rather than individual nutrients in relation to Alzheimer’s risk, so they studied dietary data obtained by food frequency questionnaires in two multiethnic cohorts: elderly subjects participating in the 1992 and the 1999 Washington Heights–Inwood Columbia Aging Project (WHICAP). Their study included 2,148 individuals who underwent serial batteries of neuropsychological tests, assessments of social and occupational function, and specific testing for cognitive deficits and dementia.
During an average follow-up of about 4 years, 253 of these subjects developed Alzheimer’s disease. Subjects were diagnosed for dementia using the criteria developed by the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer Disease and Related Disorders Association. Some of the patients may have had stroke in addition to Alzheimer’s.
The investigators calculated dietary patterns based on variations in the content of seven key nutrients that have been most consistently related to dementia risk in the literature. Only one dietary pattern was found to be strongly associated with AD prevention: a diet rich in omega-3 polyunsaturated fatty acids, omega-6 polyunsaturated fatty acids, vitamin E, and folate, and poor in saturated fatty acids and vitamin B12.
This pattern correlated with high intakes of salad dressing, nuts, fish, tomatoes, poultry, cruciferous and dark leafy green vegetables and low intakes of high-fat dairy foods, such as butter, red meats, and organ meats, Dr. Gu and colleagues said (Arch. Neurol. 2010 April 12 [doi:10.1001/archneurol.2010.84]).
The protective effect of such a diet did not change after the data were adjusted to account for age, level of education, ethnicity, and sex. Further analysis adjusting for smoking status, body mass index, caloric intake, comorbidities, and apolipoprotein E genotype only slightly attenuated the results.
Similarly, adding data on alcohol consumption and the use of nutritional supplements did not substantially change the association between this dietary pattern and lower risk of AD. In addition, the results were “essentially unchanged” when the analysis was repeated in the subgroup of subjects who developed AD without concomitant stroke.
The study was limited by the use of a single measurement of diet that did not capture long-term dietary habits.
This study was funded by the U.S. National Institute on Aging. No financial conflicts of interest were reported.
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4月12日在线发表于《神经病学纪要》(Archives of Neurology)上的一项研究显示，膳食中富含坚果、鱼及蔬菜且高脂乳制品和红肉含量较低时，可预防阿尔茨海默病(AD)的发生。
纽约哥伦比亚大学Taub阿尔茨海默病与脑老化研究所(Taub Institute for Research in Alzheimer’s Disease and the Aging Brain) 的Yian Gu博士及其同事写道：“我们的结果支持进一步探索以食物组合为基础的饮食行为，以达到预防这一重要公共卫生难题的目的。”
研究者旨在评价食物组合而非单种营养成分与AD风险之间的关系，故其对通过食物频率问卷获取的膳食数据进行了研究，有2个多种族队列参与了此问卷调查。队列中的受试者是参加了1992年和1999年华盛顿高地–哥伦比亚因伍德老龄化项目(WHICAP)的老年人，共计2,148名，这些受试者均完成了一系列神经心理学功能测试、社会及职业功能评估以及认知障碍和痴呆的专项测试。
在平均约4年的随访期间，有253名受试者发生AD。其诊断标准为美国国立神经疾病及交流障碍与卒中研究所-阿尔茨海默病及相关疾病学会(NINCDS-ADRDA)制定的标准。部分AD患者可能还合并卒中。
研究者根据文献中记载的与AD风险最有关联的7种主要营养成分含量的差异，计算膳食模式。只有以下一种膳食模式与预防AD呈强相关：富含ω-3多不饱和脂肪酸、ω-6多不饱和脂肪酸、维生素E以及叶酸，而饱和脂肪酸和维生素B12含量较低。
Gu博士及其同事指出，该膳食模式与色拉调料、坚果、鱼、番茄、家禽肉、十字花科中深绿色的叶类蔬菜摄入量高以及奶油等高脂乳制品、红肉和动物内脏摄入量低有关(Arch. Neurol. 2010 April 12 [doi:10.1001/archneurol.2010.84]) 。
在对年龄、教育程度、种族和性别进行调整后，该膳食模式的保护效应并未改变。在调整吸烟情况、体重指数、卡路里摄入量、合并症及载脂蛋白E基因型后进一步分析发现，上述效应并未显著减弱。
同样，补充有关饮酒量和营养补充剂使用等数据后，这种膳食模式与AD风险降低之间的相关性并无实质性改变。另外，在对发生AD而未并发卒中的亚组受试者进行同样的分析后，结果“基本未变”。
该研究仅单纯测定膳食成分而并未涉及长期的膳食习惯，故具有一定的局限性。
此研究由美国国立老化研究所(U.S. National Institute on Aging)资助。无经济利益冲突的报告。
爱思唯尔 版权所有
老年人膳食中红肉含量低但富含ω-3多不饱和脂肪酸、ω-6多不饱和脂肪酸、维生素E及叶酸可预防阿尔茨海默病(图: James Reinaker/爱思唯尔全球医学资讯)。
