Vitamin D status and measures of cognitive function in healthy older European adults.

BACKGROUND/OBJECTIVES: Data from human studies that have investigated the association between vitamin D status and cognitive function in elderly adults are conflicting. The objective of this study was to assess vitamin D status (reflected by serum 25-hydroxyvitamin D (25(OH)D)) in older European subjects (n=387; aged 55-87 years) and examine its association with measures of cognitive function. SUBJECTS/METHODS: Serum 25(OH)D was assessed using enzyme-linked immunosorbent assay, whereas measures of cognitive function were assessed using a comprehensive Cambridge Neuropsychological Testing Automated Battery (CANTAB). RESULTS: In all, 12, 36 and 64% of subjects had serum 25(OH)D concentrations <30, <50 and <80 nmol/l, respectively, throughout the year. Serum 25(OH)D was significantly and inversely correlated with four assessments within the spatial working memory (SWM) test parameter (SWM between errors (r=-0.166; P=0.003); SWM between errors 8 boxes (r=-0.134; P=0.038); SWM strategy (r=-0.246; P<0.0001); and SWM total errors (r=-0.174; P<0.003)). When subjects were stratified on the basis of tertiles (T) of serum 25(OH)D (<47.6 (T(1)); 47.6-85.8 (T(2)); and >85.8 (T(3)) nmol/l), fewer errors in SWM test scores occurred in subjects in the third T when compared with the first T (P<0.05-0.084). Stratification by sex showed that these differences between tertiles strengthened (P<0.001-0.043) in the females, but the differences were not significant (P>0.6) in males. CONCLUSIONS: Vitamin D insufficiency, but not deficiency, is widespread in the older population of several European countries. Low vitamin D status was associated with a reduced capacity for SWM, particularly in women.

Health and lifestyle characteristics of older European adults: the ZENITH study.

OBJECTIVE: To describe health and lifestyle factors of participants in the ZENITH study. DESIGN: A prospective multicentre intervention study employing a randomised double-blind design. PARTICIPANTS: Community dwelling older adults (n = 387), aged 55-87 y were recruited from regions in France, Italy and the UK. INTERVENTION: A self-report questionnaire comprising socio-demographic variables, dietary habits, physical activity in the home, at work and recreation. RESULTS: Participants differed with regards dietary habits and physical activity for each region. Recreational activity was higher in France and women generally tend to perform less hours of recreational activity per week than men. CONCLUSIONS: The differences found for these regions of Europe in relation to lifestyle factors will affect health and well-being within these countries and may mediate the impact of zinc supplementation on various biological and psychological parameters.

Positive and negative mood in the elderly: the ZENITH study.

OBJECTIVE: To assess the quality of positive and negative affect (mood) in an ageing European sample. BACKGROUND: Mood quality has important implications for both physical and mental wellbeing. Poor quality moods are associated with deficits in the diverse areas of cognitive function, health, and social relationships. The ageing process presents a number of potential challenges to successful mood regulation that could have wider implications. DESIGN AND PARTICIPANTS: The current study examines the quality of positive and negative affect in 387 healthy participants from three European countries. Moods were measured four times a day for 4-7 d with the Positive and Negative Affect Schedule (PANAS) mood scales. Measures of zinc (Zn) status were taken also. SETTING: Two centres concentrated on 55-70 yr olds (Coleraine, N.Ireland, n = 93 and Clermont-Ferrand, France, n = 95), and two centres concentrated on 70-87 yr olds (Rome, Italy, n = 108, and Grenoble, France, n = 91). RESULTS: Positive affect scores for the centre in Rome were significantly (P < 0.01) lower than for the other three centres, and the Grenoble centre had significantly (P < 0.05) higher scores on negative affect than the other three centres. Mood was not related to measures of zinc status (all Ps > 0.05). CONCLUSIONS: The two centres with the oldest participants showed deficits in mood quality that may have implications for broader well-being.

Zinc status and taste acuity in older Europeans: the ZENITH study.

BACKGROUND: Age-related decline in taste acuity may be both a cause and an effect of depleted zinc and/or increased zinc requirement. OBJECTIVE: The aim of this study was to explore associations between zinc status and taste acuity in healthy older European adults aged 55-90 y. SAMPLE: Volunteers were recruited within Italy (n = 108 aged 70-90 y), the United Kingdom (UK) (n = 93 aged 55-70) and two regions of France (n = 186), Grenoble (aged 70-90 y) and Clermont-Ferrand (aged 55-70 y). METHODS: A signal detection theory approach was adopted, employing a three-alternative, forced-choice procedure. The data were converted to R-indices and bivariate correlations were computed to explore relationships between serum zinc, erythrocyte zinc and taste acuity. ANOVA was undertaken to determine regional differences in zinc status. RESULTS: Higher erythrocyte zinc status was associated with better acuity for salt (sodium chloride) taste in the sample as a whole (P = 0.012) (n = 385). Higher serum zinc levels were associated with greater sensitivity to sour taste (citric acid) (P = 0.015) only in the older groups (aged 70-90 y). There were no apparent associations between serum or erythrocyte zinc status and acuity for bitter (quinine) or sweet (sucrose) tastes irrespective of age. CONCLUSION: These results agree with those previously suggesting that age-related detriment in sensitivity for salt taste may be associated with depleted zinc.

Cognitive function in healthy older European adults: the ZENITH study.

OBJECTIVE: Baseline data are reported from a study of the effects of zinc supplementation on cognitive function in older adults as assessed by the CANTAB computerised test battery. DESIGN: This is a multicentre prospective intervention study employing a randomised double-blind design. SETTING: European community-based study. PARTICIPANTS: There are 387 healthy adults aged 55-87 y from centres in France, Italy and Northern Ireland. INTERVENTIONS: Measures of visual memory, working memory and attention were obtained at baseline (prior to supplementation). RESULTS: Younger adults (<70 y) performed significantly better than older adults (>70 y) on all tests, with minimal differences between centres. In addition, men outperformed women on tests of spatial span, pattern recognition memory and reaction times, although these gender differences varied somewhat between centres. CONCLUSIONS: The results are generally consistent with previous age- and gender-related effects on cognitive functioning.