Nathalie Meunier

Zinc intake and status in middle-aged and older European subjects: the ZENITH study

Objective:Inadequate intakes of micronutrients in elderly negatively affect the nutritional status. Zinc is an essential micronutrient in the elderly, especially in relation to its impact on immune function, bone mass, cognitive function and oxidative stress. However, data are lacking on zinc intake and status during normal ageing. In this study, we evaluate the intake and status of zinc in late middle-aged and older free-living subjects.Design:Dietary zinc intake and zinc status in 188 middle-aged subjects from Clermont-Ferrand (Fr) and Coleraine (UK), and in 199 older subjects from Grenoble (Fr) and Roma (It) were assessed at the entry in the ZENITH study.Results:In relation to the zinc RDA for people older than 55 y, zinc intakes in most of the middle-aged and older subjects (more than 96%) in the present study were adequate. Older people had significantly lower (P<0.01) energy intakes as compared to middle-aged. Zinc intake expressed per MJ was also significantly (P<0.01) higher in older people compared to middle-aged. Erythrocyte and urinary zinc concentrations were significantly (P<0.001) higher in middle-aged subjects compared to older ones. The prevalence of biological Zn deficiency in free-living ageing European people was low (<5%).Conclusion:The results of the present study showed a relatively low prevalence of zinc deficiencies in healthy free-living late middle-age and older subjects. These results should be useful for health professionals to have reference data on zinc intake and status for a healthy ageing.Sponsorship:The ZENITH study is supported by the European Commission ‘Quality of Life and Management of Living Resources’ Fifth Framework Programme, Contract No: QLK1-CT-2001-00168.

Age-related oxidative stress and antioxidant parameters in middle-aged and older European subjects: the ZENITH study.

Objective:Oxidative stress has been reported to increase with ageing. However, the data in healthy humans remain controversial and studies in free-living elderly people are scarce. The objective of the present study was to compare age-related oxidative stress in late middle-aged and older free-living subjects.Design:The effect of ageing on oxidative stress and antioxidant parameters was investigated in 188 middle-aged subjects from Clermont-Ferrand (France) and Coleraine (UK), and in 199 older subjects from Grenoble (France) and Roma (Italy). Plasma thiol (SH) groups, define definition (TBARs) and total glutathione (GSH), define definition (FRAP), and superoxide dismutase (SOD) activity were measured at baseline of the ZENITH study.Results:Plasma SH groups and FRAP and, surprisingly, TBARs were significantly lower in free-living older subjects compared to younger subjects (P<0.001, P<0.001, P<0.01, respectively), but there was no significant differences in GSH levels.Conclusion:European free-living healthy older do not appear to be exposed to an acute oxidative stress. However, the highly significant positive correlation between plasma SH group oxidation or decreased FRAP and ageing is predictive of an increased risk of oxidative stress in older subjects. Moreover, the comparison between middle-aged and older subjects regarding oxidative stress parameters suggests also a progressive and slow decline of antioxidant status in healthy free-living older elderly and underline the impact on life-style factors on successful ageing.Sponsorship:The ZENITH study is supported by the European Commission ‘Quality of Life and Management of Living Resources’ Fifth Framework Programme, Contract No: QLK1-CT-2001-00168.

Importance of zinc in the elderly : the ZENITH study

The elderly are at nutritional risk as a result of multiple physiological, social, psychological, and economic factors. Physiological functions naturally decline with age, which may influence absorption and metabolism. Social and economic conditions can adversely affect dietary choices and eating patterns. However, at the same time, the nutrient needs of the elderly for certain nutrient (such as vitamins, minerals, proteins) is higher than for younger adults. This article reviews the importance of zinc (Zn) in elderly people, particularly for behavioural and mental function, micronutrient status, immune and antioxidant system, and bone metabolism.Sponsorship:The ZENITH Study is supported by the European Commission ‘Quality of Life and Management of Living Resources’ Fifth Framework Program, Contract No: QLK1-CT-2001-00168.

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 (T1); 47.6–85.8 (T2); and >85.8 (T3) 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.

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.Sponsorship:ZENITH is supported by the European Commission ‘Quality of Life and Management of Living Resources’, Fifth Framework Programme, Contract no. QLK1-CT-2001-00168.

Calcium and α-tocopherol suppress cured-meat promotion of chemically induced colon carcinogenesis in rats and reduce associated biomarkers in human volunteers

BACKGROUND Processed meat intake has been associated with increased colorectal cancer risk. We have shown that cured meat promotes carcinogen-induced preneoplastic lesions and increases specific biomarkers in the colon of rats. OBJECTIVES We investigated whether cured meat modulates biomarkers of cancer risk in human volunteers and whether specific agents can suppress cured meat-induced preneoplastic lesions in rats and associated biomarkers in rats and humans. DESIGN Six additives (calcium carbonate, inulin, rutin, carnosol, α-tocopherol, and trisodium pyrophosphate) were added to cured meat given to groups of rats for 14 d, and fecal biomarkers were measured. On the basis of these results, calcium and tocopherol were kept for the following additional experiments: cured meat, with or without calcium or tocopherol, was given to dimethylhydrazine-initiated rats (47% meat diet for 100 d) and to human volunteers in a crossover study (180 g/d for 4 d). Rat colons were scored for mucin-depleted foci, putative precancer lesions. Biomarkers of nitrosation, lipoperoxidation, and cytotoxicity were measured in the urine and feces of rats and volunteers. RESULTS Cured meat increased nitroso compounds and lipoperoxidation in human stools (both P < 0.05). Calcium normalized both biomarkers in rats and human feces, whereas tocopherol only decreased nitro compounds in rats and lipoperoxidation in feces of volunteers (all P < 0.05). Last, calcium and tocopherol reduced the number of mucin-depleted foci per colon in rats compared with nonsupplemented cured meat (P = 0.01). CONCLUSION Data suggest that the addition of calcium carbonate to the diet or α-tocopherol to cured meat may reduce colorectal cancer risk associated with cured-meat intake. This trial was registered at clinicaltrials.gov as NCT00994526.

Effects of zinc supplementation on cognitive function in healthy middle-aged and older adults: the ZENITH study

A randomised double-blind placebo-controlled design was employed to investigate the effects of Zn supplementation on cognitive function in 387 healthy adults aged 55-87 years. Several measures of visual memory, working memory, attention and reaction time were obtained using the Cambridge Automated Neuropsychological Test Battery at baseline and then after 3 and 6 months of 0 (placebo), 15 or 30 mg Zn/d. Younger adults (< 70 years) performed significantly better on all tests than older adults (> 70 years), and performance improved with practice on some measures. For two out of eight dependent variables, there were significant interactions indicating a beneficial effect (at 3 months only) of both 15 and 30 mg/d on one measure of spatial working memory and a detrimental effect of 15 mg/d on one measure of attention. Further work is required to establish whether these findings generalise to older adults in poorer mental and physical health and with less adequate Zn intake and status than the present sample.

Estimation of intake and status of vitamin A, vitamin E and folate in older European adults: the ZENITH

Objective:To report selected dietary intake and vitamin status at baseline of volunteers participating in the ZENITH study and the correlation of vitamin status with zinc.Design:A multicentre prospective intervention study employing a randomised double-blind design.Setting:Clermont-Ferrand, Theix (France), Coleraine (Northern Ireland), Grenoble (France), Rome (Italy).Participants:In total, 387 healthy middle-aged (55–70 y) and older (70–87 y) men and women participated in the study.Methods:Dietary intake was assessed by means of a validated 4-d recall record. Fasting blood samples were simultaneously analysed for retinol and α-tocopherol by the HLPC method. Erythrocyte folates were measured by a competitive immunoassay with direct chemiluminescence detection on an automatised immunoanalyser.Results:In all centres, men had a significantly (P<0.0001) higher mean nutrient intake than women. Comparison between age-groups showed that older individuals had significantly lower intakes of macro- and selected micronutrients than middle-aged subjects (P<0.0001). A high fat intake (from 36 to 40% of total energy) was observed in all examined groups. In relation to biochemical measures of vitamin status, all parameters were above their respective cut-off values for normality and, thus, none of the subjects had biochemical evidence of deficiency of these selected vitamins. A moderate correlation was found with plasma vitamin A and serum zinc (r=0.12, P<0.05) or red blood cell zinc (r=0.12, P<0.01) and with erythrocyte folates and red blood cell zinc (r=0.11, P<0.05).Conclusions:There were only moderate differences in the nutrient intake of the ZENITH study volunteers among the four European centres. Their biochemical status for retinol, α-tocopherol and folate appeared adequate.Sponsorship:The ZENITH study is supported by the European Commission ‘Quality of Life and Management of Living Resources’, Fifth Framework Programme, Contract no. QLK1-CT-2001-00168.

The relationship between the zinc nutritive status and biochemical markers of bone turnover in older European adults: the ZENITH study

Objective:To investigate the relationship between indices of zinc nutritive status and biochemical markers of bone turnover in older adult European subjects.Design:Use of baseline data from a multicentre prospective zinc intervention (ZENITH) study.Setting:Centres in France, Italy and Northern Ireland.Participants:A total of 387 healthy adults, aged 55–87 y.Methods:Zinc intake was assessed by 4-day recall records. Circulating and urinary biochemical zinc status measures were assessed by atomic absorption spectrophometry. Serum bone-specific alkaline phosphatase and osteocalcin were assessed by ELISA and urinary pyridinoline (Pyr) and deoxypyridinoline (Dpyr) by HPLC.Results:Zinc intake was negatively correlated with urinary Pyr and Dpyr (r=−0.298 and −0.304, respectively; P<0.0001), but was not correlated with bone formation markers. There was a tendency for serum zinc to be negatively correlated with urinary Dpyr (r=−0.211; P=0.080). Erythrocyte zinc was negatively correlated with serum osteocalcin (r=−0.090; P<0.0001). None of the other correlations were significant. After adjustment for confounder (age, gender and research centre) the only significant association that remained was between serum osteocalcin and erythrocyte zinc (β=−0.124; P=0.011).Conclusions:There was some, albeit inconsistent, evidence of a relationship between zinc nutritive status and bone turnover in the older adult participants of the ZENITH study.Sponsorship:ZENITH is supported by the European Commission ‘Quality of Life and Management of Living Resources’ Fifth Framework Programme, Contract No: QLK1-CT-2001-00168.

Screening and recruitment procedure of late-middle aged and older subjects: the ZENITH study.

Objective:To report the rational, design, recruitment, baseline characteristics and preliminary overview of volunteers in the ZENITH study.Design:A multicentre prospective intervention study employing a randomised double-blind design.Setting:Clermont-Ferrand, Theix (France), Coleraine (Northern Ireland), Grenoble (France), Rome (Italy).Participants:Healthy men and women middle-aged (55–70 y) and older volunteers (70–87 y).Interventions:At baseline (prior to zinc (Zn) supplementation), all volunteers underwent a full clinical examination, anthropometric measurements, health and lifestyle questionnaire, Mini Mental State Examination, Geriatric Depression Scale, and biochemistry profile.Results:In total, 842 volunteers (378 men and 464 women) were invited to take part in the study. A total of 49% of these volunteers were excluded on the basis of inclusion/exclusion criteria. In total, 433 participants were admitted to the Zn supplementation for 6 months. During this period, about 10% of volunteers dropped out from the study.Conclusions:A total of 387 subjects (197 male and 190 female subjects) successfully completed the supplementation phase of the ZENITH study.Sponsorship:The ZENITH study is supported by the European Commission ‘Quality of Life and Management of Living Resources’ Fifth Framework Programme, Contract No: QLK1-CT-2001-00168.