Alcance

As a part of my MSc in Psychology in 2010 I investigated dietary correlates of cognition in the HE with the aim of determining whether certain foodstuffs and/or lifestyle habits were associated with cognitive performance. Using a separate cohort of participants Walters et al., (2011) further investigated preliminary findings from this study of an association between non-oily fish and MMSE score. This showed that increased consumption was associated with improved performance on this test.

Non-oily fish consumption was investigated in 70 participants with a mean age of 72.09 (SD ± 6.24) years and mean years spent in education of 15.57 (SD ±4.86) years. A FFQ was used to assess various aspects of lifestyle and diet and specifically asked participants about their medical history, current medical

118

conditions, medication use and lifestyle habits [including alcohol consumption, smoking status, levels of exercise and interests and hobbies]. The remainder of the questionnaire asked participants to estimate their daily, weekly or monthly consumption of a variety of different foods and drinks and included a small specific section on fish including non-oily and oily types. A short cognitive battery consisting of the MMSE (Folstein et al., 1975), the Stroop Test (Trenerry et al., 1989), digit span (Wechsler et al., 1981) and immediate word recall was administered. The results revealed that portions of non-oily fish intake was trending towards significance as a predictor of MMSE score (p = 0.08). As consumption of non-oily fish increased MMSE score also increased. There was no effect of any variety of oily fish on MMSE score (Walters et al., 2011).

6.2 The present study: research aims

This chapter will further investigate whether non-oily fish consumption is a dietary factor which may influence cognitive performance in the elderly using a more controlled method of collecting dietary information, a four week food diary. This will allow the investigation of whether the same effect as seen in Walters et al., (2011) is present in a different cohort of participants.

6.3 Methods 6.3.1 Participants

All participants from the University of Bradford, Division of Psychology Participant Pool were invited to take part in the study and of these individuals 38 participants were recruited to take part in the study. The inclusion criteria specified that participants must be 60 years of age or older and must not possess an existing diagnosis of any neurological condition or a cognitive impairment. A novel cohort was recruited for the purpose of this study and, therefore, none of the participants had taken part in the previous pilot studies which had investigated trends between non-oily fish and cognitive performance. Data from four participants could not be included in the study due to failure to correctly complete the food diary. The final sample consisted of 11 males and 23 females. The mean age of participants was 72.59 (S.D ±6.09) years and the

119

mean years in education was 14.84 (S.D ±4.69). Ethical approval was obtained from the University of Bradford Ethics Committee and all participants gave their informed written consent to take part.

6.3.2 Materials

6.3.2.1 Food diary

A four week food diary was created to allow the recording of dietary information for a period of one month. The diary consisted of a 17 page A4 landscape booklet which contained an information sheet, a detailed instruction section, an example of a completed diary sheet and a four week blank diary. The diary was designed to be easy to complete and consisted of a tabular grid format which included a column for the day of the week and four columns for breakfast, lunch, dinner and snacks respectively.

Participants were instructed to record any meal that they consumed which contained a fish item. They were also required to note the type of fish, the weight as stated on the packet or scales, the brand make or the location the fish was purchased from e.g. Morrisons fishmonger. They were also required to note all foods eaten alongside the fish, condiments that were added and how the fish was prepared.

6.3.2.2 Neuropsychological tests

A neuropsychological assessment battery was used to assess cognition and this included the following tests. Further details of each test can be found in Chapter four ‘Neuropsychological testing’.

MoCA - an assessment of general cognitive function (Nasreddine et al., 2005). MMSE - an assessment of general cognitive ability (Folstein et al., 1975). DT - an assessment of EF (Baddeley et al., 1997).

120

PCS and LCS - assessments of processing speed (Salthouse and Babcock,

1991).

Stroop Test - an assessment of processing speed and EF (Trenerry et al.,

1989).

Digit span - an assessment of working memory (Wechsler, 1981).

6.3.3 Procedure

Participants were invited to take part in the study via a postal invitation letter. Those who accepted were invited to attend a brief meeting where they were given the opportunity to ask any questions, sign the consent form and were provided with a copy of the food diary to take home. During this appointment the researcher explained how to complete the diary and what information was required. Participants were asked to complete the diary for a period of four continuous weeks and it was specified that this must be a ‘’typical’’ four week period and must not be completed if the participant was going on holiday for example. Another appointment was then arranged for the week after the diary had been completed where the cognitive assessment could be carried out. Participants were also instructed not to alter their habitual consumption of fish and provide an honest recall of their fish intake. They were asked to note any supplements that they may take but were not specifically asked to record their medications. A sample of a completed week was provided as a guide and participants were instructed to contact the researcher if they experienced any problems or required assistance in the completion of the food diary. After they had completed the diary for a period of one month they were invited back to the university to complete a cognitive assessment (see section 6.3.2.2 for details).

6.4 Results