Taste acuity in response to zinc supplementation in older Europeans

Northern Ireland Centre for Food and Health, University of Ulster, Coleraine BT52 1SA, UK.
British Journal Of Nutrition (Impact Factor: 3.45). 02/2008; 99(1):129-36. DOI: 10.1017/S0007114507781485
Source: PubMed


Taste acuity declines with age and may be dependent upon Zn status. The aim of the present double-blind, randomised controlled intervention trial has been to determine taste acuity in response to Zn supplementation (placebo, or 15 or 30 mg Zn/d). Healthy older European adults aged 70-87 years were recruited within Italy (Rome) (n 108) and France (Grenoble) (n 91) to the European Commission-funded Zenith project. A signal detection theory approach was adopted for taste assessment. The data were converted to R indices and analysed by repeated-measures ANOVA controlling for baseline taste acuity as well as serum and erythrocyte Zn. Serum Zn increased post-intervention, indicating compliance with the intervention. Results differed across geographical region. Salt taste acuity was greater in response to Zn (30 mg) than placebo post-intervention among those recruited in Grenoble. There was no apparent change in acuity for sweet, sour or bitter taste in response to Zn. Supplemented Zn may have potential to enhance salt taste acuity in those over the age of 70 years. Further research is required to determine if enhanced salt taste acuity is reflected in the eating experiences of older individuals.

Download full-text


Available from: Heather Parr, Apr 08, 2014
  • Source
    • "As micronutrient deficiencies arise, decreased energy and motivation can further compromise dietary quality in a pathological cycle. For example, dietary zinc deficiency is known to decrease food intake in animal models and zinc supplementation improves taste acuity in elderly subjects (Pepersack et al. 2001; Stewart-Knox et al. 2008; Amani et al. 2010). Inadequate zinc intake certainly contributes to deficiency in many elderly patients (Singh et al. 1998; Pepersack et al. 2001) but effects of chronic inflammation and age-related decline in zinc transport mechanisms may also contribute to a functional zinc deficiency (Turnlund et al. 1986; Wong et al. 2012). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Alterations in trace element homeostasis could be involved in the pathology of dementia, and in particular of Alzheimer's disease (AD). Zinc is a structural or functional component of many proteins, being involved in numerous and relevant physiological functions. Zinc homeostasis is affected in the elderly, and current evidence points to alterations in the cellular and systemic distribution of zinc in AD. Although the association of zinc and other metals with AD pathology remains unclear, therapeutic approaches designed to restore trace element homeostasis are being tested in clinical trials. Not only could zinc supplementation potentially benefit individuals with AD, but zinc supplementation also improves glycemic control in the elderly suffering from diabetes mellitus. However, the findings that select genetic polymorphisms may alter an individual's zinc intake requirements should be taken into consideration when planning zinc supplementation. This review will focus on current knowledge regarding pathological and protective mechanisms involving brain zinc in AD to highlight areas where future research may enable development of new and improved therapies.
    Genes & Nutrition 01/2014; 9(1):379. DOI:10.1007/s12263-013-0379-x · 2.79 Impact Factor
  • Source
    • "Zinc supplementation has been shown to be effective in the treatment of taste and smell abnormalities observed among patients with taste disorders.[11] Even in healthy persons, zinc supplementation increased the recognition threshold for salty taste.[1213] Few reports are also available from clinical trials on the effects of zinc supplementation on taste perception in cancer patients. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Taste abnormalities are common among cancer patients after starting radiotherapy or chemotherapy. Considering the role of zinc and reports on its beneficial effects in taste perception, we evaluated the preventive effects of zinc sulfate on radiation-induced taste alterations. In a randomized, placebo-controlled trial, adult patients with head and neck cancers who were on schedule for radiotherapy, with or without chemotherapy, were allocated to receive zinc sulfate (50 mg, three times a day) or placebo; started with beginning of radiotherapy and continued for one month later. Taste acuity was determined by measuring detection and recognition thresholds for four taste qualities at baseline, at the end of radiotherapy, and a month later using the Henkin method. Thirty-five patients (mean age = 59.2 ± 16.5, 60% male) completed the trial. The two groups were similar at baseline. After radiotherapy, and one month later, there was a significant increase in taste perception threshold for bitter, salty, sweet, and sour tastes in the placebo group (P = 0.001). In those who received zinc, there was only slight increase in threshold for perception of the salty taste (P = 0.046). No relevant side effects due to zinc sulfate were reported. Zinc supplementation in head/neck cancer patients under radiotherapy can prevent radiation-induced taste alterations. Further studies with longer follow-ups and with different doses of zinc supplementation are warranted in this regard.
    Journal of research in medical sciences 02/2013; 18(2):123-6. · 0.65 Impact Factor
  • Source
    • "Moreover, in addition to changes associated with aging and aging-related diseases (Lang et al., 2006), several other factors may affect taste perception in the elderly leading to taste disorders that could be broadly classified as complete loss of taste, partial loss of taste, or taste distortion (Doty et al., 2003). These factors include oral health (Saunders et al., 2007), accumulative effects of drug administration (Ackerman and Kasbekar, 1997; Doty et al., 2008; Ikeda et al., 2008) and zinc deficiency (Stewart-Knox et al., 2008). Additionally , some individuals are genetically predisposed to certain tastes. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Taste, one of the major senses in humans, is the ability to detect the flavor of substances such as food, certain minerals, and poisons. Taste distortions in human beings have been attributed to various physiological and environmental factors including aging and disease conditions. Given the fact that taste is one of the most important factors in food preference, selection, and consumption, the decreased appetite in the elderly, probably due to disease conditions, may lead to dietary restrictions that could negatively impact nutritional and health status. The role of zinc on taste distortion in the elderly population and taste impairment are described. Although several studies demonstrate the associative nature of taste degeneration with age, additional investigations are required to clarify the mechanisms by which taste perception is altered with age.
    Critical Reviews in Food Science and Nutrition 01/2013; 53(3):245-50. DOI:10.1080/10408398.2010.527023 · 5.18 Impact Factor
Show more