Eur J Nutr (2005) 44 : 485–498 DOI 10.1007/s00394-005-0583-6 Received: 10 February 2005 Accepted: 4 August 2005 D. Benton Dept. of Psychology University of Wales Swansea, UK K. W. Kallus Karl-Franzens-Universität Graz Institut für Psychologie Graz, Austria J. A. J. Schmitt Nestlé Research Center Nutrition & Health Dept. Lausanne, Switzerland ILSI Europe A.I.S.B.L. () 83 Avenue E. Mounier, Box 6 1200 Brussels, Belgium E-Mail: publications@ilsieurope.be ■ Summary There is a basic distinction between declarative memories, which can be stated ver- bally, and non-declarative memory, such as how to ride a bicycle, which cannot be expressed in words. With age it is the performance of declar- ative memory, particularly episodic memory that requires recall of events placed in time, that declines. As memory is not a unitary phe- nomenon, it should be ideally monitored using a range of tests that reflect theoretical conceptions of the topic. If circumstances de- mand the use of a single test then a measure of episodic memory is suggested. When it proves only possible to use a rating scale it should be ensured that memory is distinguished from other aspects of cognition and that different types of memory are not confused. The tests used, and the form in which they are used, need to be chosen to be of appropriate difficulty for the sample studied. A major conclusion is that the selection of the measure of memory used in the study of a dietary intervention should never be routine. It is inevitable that the form of the test used will need to be chosen carefully for the popula- tion being studied. ■ Key words aging – dementia – phosphatidylserine – memory – vitamin E ORIGINAL CONTRIBUTION David Benton K.Wolfgang Kallus Jeroen A. J. Schmitt How should we measure nutrition-induced improvements in memory? Introduction Can memory in young adults be improved by diet? Can the decline in memory that occurs with age be slowed or even prevented by appropriate nutrition? Although par- ticular nutrients have been studied in this context, and on occasions even marketed with the claim that a bene- ficial response is to be expected, it is an area character- ized by data limited both in quantity and methodologi- cal quality. One aspect of the methodology, the measurement of memory, is considered and ways that future studies might approach the topic are suggested. The many, varied and complex ways in which psy- chologists conceive memory contrast starkly with the often limited conceptions of such phenomena in many nutritionally inspired studies. Initially the most com- mon ways that memory is viewed and measured by psy- chologists are outlined and then related to the study of memory in nutritional studies. As a way of directing at- tention to potentially more informative tests, changes in those aspects of memory that typify the aging process are identified. Those aspects of memory that predict at an early stage the probable development of dementia are also considered, leading to recommendations of the types of memory tests that should be used in dietary studies. The conception of memory There are a number of stages at which diet may poten- tially influence memory and only a battery of carefully chosen tests will allow different mechanisms to be dis- tinguished. A common distinction is made between encoding – putting information into memory; storage – EJN 583