Public Health Nutrition

Biological and behavioural determinants

Supplemented zinc does not alter mood in healthy older European adults – a randomised placebo-controlled trial: the Zenith study

Barbara J Stewart-Knoxa1 c1, Gordon Raea2, Ellen EA Simpsona2, Chris McConvillea2, Jacqueline O’Connora1, Angela Politoa3, Maud Andriollo-Sancheza4, Charles Coudraya5 and JJ Straina1

a1 Northern Ireland Centre for Food and Health, University of Ulster, Coleraine, BT521SA, Northern Ireland, UK

a2 Psychology Research Institute, University of Ulster, Coleraine, Northern Ireland, UK

a3 National Research Institute on Food and Nutrition, Department of Nutritional Science, Rome, Roma, Italy

a4 Faculté de Pharmacie, Laboratoire de Biologie de Stress Oxydant, Nutrition Vieillissement et Maladies Cardiovasculaires, University de Joseph Fourier, Grenoble, France

a5 Unité des Maladies Métaboliques et Micronutrients, INRA, Centre de Recherche en Nutrition Humaine d’Auvergne, Clermont-Ferrand/Theix, France

Abstract

Objective Older people are vulnerable to zinc deficiency, which may impact upon their mood. This randomised, placebo-controlled, double-blind intervention study aimed to investigate the effect of oral zinc gluconate supplementation (15 mg/d; 30 mg/d; and placebo) on subjective mood (affect) in older Europeans.

Subjects Healthy volunteers (n 387) aged 55–87 years were recruited.

Setting Volunteers in Rome (Italy; n 108) and Grenoble (France; n 91) were aged 70–87 years and those in Coleraine (Northern Ireland; n 93) and Clermont-Ferrand (France; n 95) were aged 55–70 years.

Design Mood was measured using the Positive and Negative Affect Scale on four occasions per day over 4 d at baseline, 3 and 6 months post-intervention.

Results Mixed ANOVA indicated that neither positive nor negative affect altered in response to zinc (15 mg/d or 30 mg/d) compared to placebo in either the 55–70 years or the ≥70 years age group.

Conclusions These results suggest that zinc does not benefit mood in healthy older people.

(Received October 23 2009)

(Accepted August 30 2010)

(Online publication January 28 2011)

Correspondence

c1 Corresponding author: Email b.knox@ulster.ac.uk

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