McNeill G, Winter J, Jia X
Division of Population Health Sciences, University of Aberdeen, Aberdeen, UK.
Eur J Clin Nutr. 2009 Feb;63 Suppl 1:S33-7. doi: 10.1038/ejcn.2008.62.
As the proportion of old and very old people in the population increases, new research on the influence of diet on health and nutritional needs in later life will be needed. Dietary assessment methods that rely on short-term memory or lengthy interviews, such as the 24-h recall and diet history methods, could have some limitations in this age group. There is some support for the use of food frequency questionnaires (FFQs) in older people, although their validity in the older old and in those with more advanced cognitive decline has not been extensively assessed.
SUBJECTS/METHODS: In a study designed to assess the validity of a modified FFQ in men and women over 65 years, 50 men and 47 women completed two FFQs, and 42 men and 41 women completed one FFQ followed by a 4-day weighed diet diary. Digit span forward (a test of short-term memory) and verbal fluency (a test of executive function) tests were used to assess the possible influence of cognitive function on repeatability and validity of the FFQ.
The FFQ was found to have good repeatability for most nutrients and reasonable validity for some but not all nutrients. Cognitive function assessed prior to the dietary assessment showed no relationship with repeatability, but there was some evidence that validity was lower in those with lower executive function.
Dietary assessment in healthy older people without overt cognitive decline can be achieved, but development and testing of methods of data collection for each target population and nutrient of interest are particularly important in this age group to ensure valid results. The possibility that cognitive decline influences dietary assessment needs to be borne in mind in the interpretation of observational studies of the influence of dietary intake on cognition in later life.
随着人口中老年和高龄人群比例的增加，需要开展关于饮食对晚年健康及营养需求影响的新研究。依赖短期记忆或冗长访谈的膳食评估方法，如24小时回顾法和饮食史法，在该年龄组可能存在一些局限性。虽然食物频率问卷（FFQ）在老年人中的有效性尚未得到广泛评估，但有一些证据支持在老年人中使用该方法，不过其在高龄老人以及认知功能衰退更严重者中的有效性尚未得到广泛评估。
对象/方法：在一项旨在评估改良FFQ在65岁以上男性和女性中有效性的研究中，50名男性和47名女性完成了两份FFQ，42名男性和41名女性完成了一份FFQ，随后是为期4天的称重饮食日记。采用数字广度顺背（短期记忆测试）和语言流畅性（执行功能测试）来评估认知功能对FFQ重复性和有效性的可能影响。
发现FFQ对大多数营养素具有良好的重复性，对一些但并非所有营养素具有合理的有效性。膳食评估前评估的认知功能与重复性无关，但有一些证据表明，执行功能较低者的有效性较低。
在没有明显认知衰退的健康老年人中可以进行膳食评估，但针对每个目标人群和感兴趣的营养素开发和测试数据收集方法在该年龄组尤为重要，以确保获得有效的结果。在解释饮食摄入对晚年认知影响的观察性研究时，需要考虑认知衰退影响膳食评估的可能性。
