Acute emotional stress and high fat/high fructose diet modulate brain oxidative damage through NrF2 and uric acid in rats.

Studies focusing on the interaction of dietary and acute emotional stress on oxidative stress in cortex frontal and in brain mitochondria are scarce. Dietary-induced insulin resistance, as observed in Western diets, has been associated with increased oxidative stress causing mitochondrial dysfunction. We hypothesized that acute emotional stress could be an aggravating factor by impacting redox status in cortex and brain mitochondria. Thus, the aim of the present study was to evaluate the combination of an insulin resistance inducing high-fat/high-fructose (HF/HFr) diet and acute emotional stress on brain oxidative stress in rats. We measured several oxidative stress parameters (carbonyls, FRAP, TBARS assays, GSH, GSSG, oxidized DNA, mRNA expression of redox proteins (Nrf2), and uric acid). The HF/HFr diet resulted in increased oxidative stress both in the brain mitochondria and in the frontal cortex and decreased expression of the Nrf2 gene. The emotional stress induced an oxidative response in plasma and in brain mitochondria of the control group. In the HF/HFr group it triggered an increase expression of the redox transcription factor Nrf2 and its downstream antioxidant genes. This suggests an improvement of the redox stress tolerance in response to an enhanced production of reactive oxygen species. Accordingly, a blunted oxidative effect on several markers was observed in plasma and brain of HF/HFr-stressed group. This was confirmed in a parallel study using lipopolysaccharide as a stress model. Beside the Nrf2 increase, the stress induced a stronger UA release in HF/HFr which could take a part in the redox stress.

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.

Cinnamon improves insulin sensitivity and alters the body composition in an animal model of the metabolic syndrome.

Polyphenols from cinnamon (CN) have been described recently as insulin sensitizers and antioxidants but their effects on the glucose/insulin system in vivo have not been totally investigated. The aim of this study was to determine the effects of CN on insulin resistance and body composition, using an animal model of the metabolic syndrome, the high fat/high fructose (HF/HF) fed rat. Four groups of 22 male Wistar rats were fed for 12 weeks with: (i) (HF/HF) diet to induce insulin resistance, (ii) HF/HF diet containing 20 g cinnamon/kg of diet (HF/HF + CN), (iii) Control diet (C) and (iv) Control diet containing 20 g cinnamon/kg of diet (C + CN). Data from hyperinsulinemic euglycemic clamps showed a significant decrease of the glucose infusion rates in rats fed the HF/HF diet. Addition of cinnamon to the HF/HF diet increased the glucose infusion rates to those of the control rats. The HF/HF diet induced a reduction in pancreas weight which was prevented in HF/HF+CN group (p<0.01). Mesenteric white fat accumulation was observed in HF/HF rats vs. control rats (p<0.01). This deleterious effect was alleviated when cinnamon was added to the diet. In summary, these results suggest that in animals fed a high fat/high fructose diet to induce insulin resistance, CN alters body composition in association with improved insulin sensitivity.

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.

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 (TBAR's) 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, TBAR's 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.

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 (beta = -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.

[Zinc and pregnancy]. / Zinc et grossesse.

Zinc, an essential trace element, plays a critical role in normal growth and development, cellular integrity and many biological functions, including protein synthesis and nucleic acid metabolism. Since all these are involved in cell division and growth, zinc is believed to be important for foetal growth and development. Zinc requirement is increased during pregnancy but the lack of a valid indicator precludes a true estimate of zinc deficiency in pregnancy even in developed countries. This review examines the possibility that a gestational deficiency of zinc can adversely affect the pregnancy outcome. Preliminary human data suggest a beneficial effect of prenatal zinc supplementation trials in particular on infant's neurobehavioral development. In the light of the currently available information, zinc supplementation at therapeutic load (30 mg/day) as it is proposed for the treatment of hormonal skin disorders to adolescents, cannot be toxic.

[Is systematic iron supplementation justified during pregnancy?]. / Faut-il supplémenter en fer les femmes enceintes?

Considering that young women have a high risk of iron store deficiency, the iron supplementation is largely proposed during pregnancy. However, a selective supplementation reserved to anaemia women, must be preferred to a systematic supplementation which improves biological parameters of mothers but have no effect on newborns. Iron is a potentially toxic element and a not justified, supplementation could expose to high iron level and to an oxidative stress which is also observed in pregnancy pathologies (preeclamptia, gestational diabetes). Furthermore a non controlled increase of erythrocyte mass by iron supplementation could also alter the placenta exchange. As a precaution, iron supplementation may be reserved to anaemia women or with high anaemia risk. For others, nutritional advises must permit to reach iron recommendation.

Food and fluid intake of the SENECA population residing in Romans, France.

OBJECTIVES: to provide information and data on food and fluid intake of free-living elderly aged of 81-86 years old residing in the south of France. METHODS: using standardised methods data were collected from a random sample born between 1913 and 1918. The French study protocol again included data collection on dietary intake using a standardised modified dietary history consisting of a food frequency list and a 3-day estimated dietary record. RESULTS: Total dietary intake was generally low as compared to the recommended daily intake for elderly subjects. CONCLUSION: This descriptive part of the SENECA study gives the opportunity to have information on this growing segment of the population. These results should help to adapt the dietary guidelines for this category of the population.