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.

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.

Increased selenium intake in elderly high fish consumers may account for health benefits previously ascribed to omega-3 fatty acids.

OBJECTIVE: To examine relationships between fish consumption and plasma selenium (Se) and red blood-cell fatty acid (RBC FA) profile in aged subjects. We hypothesised that the importance of Se has been underestimated when interpreting the beneficial effect of fish consumption on health. DESIGN: Cross-sectional analysis of data from a prospective cohort study. SETTING: The EVA study in Nantes, France (1991-2002). SUBJECTS: 200 subjects aged > or = 69 y with information on RBC FAs, plasma Se and completed food frequency questionnaires. METHODS: We examined correlations between the most abundant FAs, Se and number of fish meals per week. Linear regression models were used. RESULTS: Plasma Se was negatively correlated with RBC omega6 poly-unsaturated FA (PUFAs) and positively with omega3 PUFAs. Plasma Se, RBC omega3 PUFAs, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) increased with fish consumption. Conversely, levels of omega6 PUFAs were lower in the highest fish consumption group. All associations between plasma Se and fish consumption remained significant when adjusting for omega6 PUFAs alone or additionally for age, sex, education, diabetes, hypertension, dyslipidemia, cardiovascular diseases, and broad food categories (meat, eggs, dairy products, cereals, fruit and vegetable). Associations between omega3 PUFAs and fish also remained significant in the same model independently of Se. In linear regression models adjusted for demographic indicators, fish consumption explained only 2.6% of the variance in RBC omega3 FAs (6.2% for omega6) but as much as 15% of the variance in plasma selenium. CONCLUSIONS: The observed health benefits of fish consumption in the elderly could be related not only to the increase in omega3 FA intake but also to other nutrients such as selenium. It is important to consider this observation when interpreting associations between fish consumption and health status in the elderly, particularly with regard to brain function.

Effect of zinc supplementation on vitamin status of middle-aged and older European adults: the ZENITH study.

OBJECTIVE: To assess the effects of zinc supplementation on vitamin status in middle-aged and older volunteers. SUBJECTS/METHODS: Three hundred and eighty-seven healthy middle-aged (55-70 years) and older (70-85 years) men and women, randomly allocated to three groups to receive 15 or 30 mg Zn/day or placebo for 6 months. Dietary intake was assessed by means of a validated 4-day recall record. Fasting blood samples were simultaneously analysed for levels of plasma retinol and alpha-tocopherol by high-performance liquid chromatography. Erythrocyte folates were measured by a competitive immunoassay with direct chemiluminescence detection on an automatized immunoanalyser. Biochemical measurements were performed at baseline and after 3 and 6 months of zinc supplementation. RESULTS: Plasma vitamin A levels were significantly increased proportionally with zinc dose and period of treatment, particularly at 6 months (for 15 mg Zn/day, P<0.05; for 30 mg Zn/day, P<0.0001); no significant changes were observed in the placebo group. There was no effect of zinc supplementation on vitamin E/cholesterol ratio and erythrocyte folates. CONCLUSIONS: Our results show that a long-term zinc supplementation increases plasma vitamin A levels in middle-aged and older people of similar characteristics to those involved in this study. Moreover, supplementation influences serum zinc levels but does not affect erythrocyte zinc concentration and both plasma vitamin E and erythrocyte folate status.

Age-Dependent Protective Effect of Selenium against UVA Irradiation in Primary Human Keratinocytes and the Associated DNA Repair Signature.

Few studies have focused on the protective role of selenium (Se) against skin aging and photoaging even though selenoproteins are essential for keratinocyte function and skin development. To the best of our knowledge, the impact of Se supplementation on skin cells from elderly and young donors has not been reported. Therefore, the main objective of our study was to evaluate the effects of Se supplementation on skin keratinocytes at baseline and after exposure to ultraviolet A (UVA) irradiation. Low doses of Se (30 nM) were very potently protective against UVA-induced cytotoxicity in young keratinocytes, whereas the protection efficiency of Se in old keratinocytes required higher concentrations (240 nM). Additionally, the DNA repair ability of the old keratinocytes drastically decreased compared with that of the young keratinocytes at baseline and after the UVA exposure. The Se supplementation significantly enhanced the DNA repair of 8-oxoguanine (8oxoG) only in the keratinocytes isolated from young donors. Therefore, aged keratinocytes have an increased vulnerability to oxidative DNA damage, and the Se needs in the elderly should be considered. Strengthening DNA repair activities with Se supplementation may represent a new strategy to combat aging and skin photoaging.

IANA task force on nutrition and cognitive decline with aging.

Cognitive impairment can be influenced by a number of factors. The potential effect of nutrition has become a topic of increasing scientific and public interest. In particular, there are arguments that nutrients (food and/or supplements) such as vitamins, trace minerals, lipids, can affect the risk of cognitive decline and dementia, especially in frail elderly people at risk of deficiencies. Our objective in this paper is to review data relating diet to risk of cognitive decline and dementia, especially Alzheimer's disease (AD). We chose to focus our statements on homocysteine-related vitamins (B-vitamins), antioxidant nutrients (vitamins E and C, carotenoids, flavonoids, enzymatic cofactors) and dietary lipids. Results of epidemiological studies may sometimes appeared conflicting; however, certain associations are frequently found. High intake of saturated and trans-unsaturated (hydrogenated) fats were positively associated with increased risk of AD, whereas intake of polyunsaturated and monounsaturated fats were protective against cognitive decline in the elderly in prospective studies. Fish consumption has been associated with lower risk of AD in longitudinal cohort studies. Moreover, epidemiologic data suggest a protective role of the B-vitamins, especially vitamins B9 and B12, on cognitive decline and dementia. Finally, the results on antioxidant nutrients may suggest the importance of having a balanced combination of several antioxidant nutrients to exert a significant effect on the prevention of cognitive decline and dementia, while taking into account the potential adverse effects of these nutrients. There is no lack of attractive hypotheses to support research on the relationships between nutrition and cognitive decline. It is important to stress the need to develop further prospective studies of sufficiently long duration, including subjects whose diet is monitored at a sufficiently early stage or at least before disease or cognitive decline exist. Meta analyses should be developed, and on the basis of their results the most appropriate interventional studies can be planned. These studies must control for the greatest number of known confounding factors and take into account the impact of the standard social determinants of food habits, such as the regional cultures, social status, and educational level.

Factors influencing blood concentration of retinol, alpha-tocopherol, vitamin C, and beta-carotene in the French participants of the SU.VI.MAX trial.

OBJECTIVES: The data was collected during the inclusion step of the SUpplémentation en VItamines et Minéraux AntioXydants (SU.VI.MAX) study. This article deals with the study's first stage before any supplementation. The collected data shows factors influencing blood vitamin concentrations and may reflect the vitamin status of volunteers. MATERIAL AND METHODS: A total of 12,741 volunteers were enrolled in the SU.VI.MAX study 7,713 women 35-60 years of age and 5,028 men 50-60 years of age. The serum concentrations of retinol, alpha-tocopherol, and beta-carotene were measured by HPLC, and vitamin C concentration was measured by spectrofluorimetry using a Technicon continuous flow analysis apparatus. The volunteers recorded their 24 h diet by means of a specific terminal that was connected to the main central computer of the SU.VI.MAX study. Volunteers recorded the food they consumed daily and estimated its quantity by comparing pictures of dishes. RESULTS: Retinol concentration was significantly higher in older volunteers, and was higher in male than in female volunteers. Smoking had no effect on serum retinol, but the latter was higher in the autumn than in the winter. Serum retinol concentrations were higher in the Southwest region and lower in the Ile-de-France and East-Centre regions. Serum alpha-tocopherol was slightly higher in older volunteers and also higher in male volunteers. Serum alpha-tocopherol was significantly lower in smokers, and former smokers showed intermediate levels. Like retinol, serum alpha-tocopherol was higher in the autumn, and higher in the Southwest as compared to the East-Centre Serum beta-carotene was slightly higher in younger volunteers, and concentrations were higher in female than in male volunteers. Tobacco smoking decreased serum beta-carotene, which was higher in the autumn, and higher in the East, West, and North regions. Serum vitamin C was higher in female volunteers, and was not age related. Serum vitamin C was lower in smokers, was season-dependant, but contrary to fat-soluble vitamins, concentrations were higher in the winter and spring. Serum vitamin C was higher in the Southeast and East-Centre, but lower in the North region. CONCLUSION: These results suggest that serum retinol concentrations depend on gender, age, seasons, and location of residence. Similarly, serum alpha-tocopherol concentrations were slightly influenced by age, but more by tobacco smoking, seasons, dietary intake, and location of residence. Serum concentrations of beta-carotene depend on gender, age, smoking status, dietary intake, and location of residence. Serum vitamin C concentrations depend on gender, age, smoking status, seasons, dietary intake, and location of residence. Contrary to beta-carotene, retinol concentrations were higher in male than in female volunteers. Such a reversed relation suggests a higher beta-carotene-retinol conversion in male volunteers.

Serum concentrations of beta-carotene, vitamins C and E, zinc and selenium are influenced by sex, age, diet, smoking status, alcohol consumption and corpulence in a general French adult population.

OBJECTIVE: To assess relationships between energy, nutrient and food intakes, alcohol consumption, smoking status and body mass index (BMI), and serum concentrations of beta-carotene, alpha-tocopherol, vitamin C, selenium and zinc. METHODS: Data on health status, alcohol consumption, smoking habits, anthropometric data and biochemical measurements were obtained in 1821 women aged 35-60 y and 1307 men aged 45-60 y, participant to the SU.VI.MAX Study. Data on dietary intake were available on a subsample who reported six 24-h dietary records during the first 18 months of the study. RESULTS: Women had higher baseline serum beta-carotene and vitamin C concentrations and lower concentration for serum vitamin E, zinc and selenium than men. In women, younger age was associated with lowered mean concentration of serum beta-carotene, vitamin E and selenium. In men, only differences were observed for serum zinc, which was lower in older men. Current smokers of both sexes had significantly lower concentrations of serum beta-carotene, vitamin C and selenium, and, only in women, of vitamin E, than nonsmokers. Alcohol consumers had lower concentrations of serum beta-carotene and higher selenium concentrations. Serum beta-carotene and vitamin C concentrations were lower in obese subjects. There were positive associations of dietary beta-carotene, vitamin C and E with their serum concentrations. Age, nutrient and alcohol intakes, serum cholesterol, BMI and smoking status explained 15.2% of the variance of serum beta-carotene in men and 13.9% in women, and 10.8 and 10.0% for serum vitamin C, and 26.3 and 28.6% for serum vitamin E, respectively. CONCLUSION: Serum antioxidant nutrient concentrations are primarily influenced by sex, age, obesity, tobacco smoking, alcohol consumption and especially dietary intake of those antioxidant nutrients.

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.

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 alpha-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, alpha-tocopherol and folate appeared adequate.

Introduction to the ZENITH study and summary of baseline results.

Zinc is known to be essential for a great number of biochemical activities and physiological and cognitive functions. The objective of Zenith study was to investigate the effects of Zn, as a nutritional supplement, on psychological and behavioural factors and on surrogate markers that are indicative of trends towards better health in order to evaluate the need for dietary recommendations specific to the studied population. We report in this paper the summary of baseline results obtained before Zn supplementation.

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.

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 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.

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.

Alterations of antioxidant trace elements (Zn, Se, Cu) and related metallo-enzymes in plasma and tissues following burn injury in rats.

To improve the nutritional support for burn patients, we evaluated the alterations of selenium, zinc and copper (Se, Zn and Cu) and their possible contributions to an unbalanced antioxidant response to burn injury. These trace elements and the related antioxidant enzymes, glutathione peroxidase (GPx) and superoxide dismutase (SOD), were studied both in plasma (or serum) and tissues of 20% total body surface area (TBSA) burned rats for 10 days. While plasma Se and serum Zn levels significantly decreased 6 h after burn injury, serum Cu levels increased after 1 day and remained elevated the following 9 days. Selenium levels increased in kidney but decreased progressively in liver. The hepatic Zn and Cu concentrations followed a biphasic increase following burn injury. During the first day, GPx activity decreased in plasma and remained unchanged in the organs, except for a moderate diminution in the liver. Liver Cu/Zn SOD activity increased from 6 h to 4 days. In summary, following burn injury, copper and zinc were redistributed to the liver and selenium to the kidney with non-detectable changes in the muscle and brain. Changes in antioxidant enzyme activities following burn injury were significant mainly in the plasma. Early combined antioxidant supplementation to maintain and restore antioxidant status in burn patients requires further study.

Systemic oxidative stress and cognitive performance in the population-based EVA study. Etude du Vieillissement Artériel.

The aim of this study was to examine the relationships between cognitive functioning and blood levels of antioxidants and lipoperoxidation products in an elderly population. In 1991-1992, 1389 volunteers (574 men and 815 women aged 59 to 71 years) were recruited from the general population. Levels of selenium, carotenoids, and thiobarbituric-reactive substances in plasma and of vitamin E, glutathione peroxidase, and Cu-Zn superoxide dismutase in red blood cells were measured. Cognitive functioning was assessed with various psychometric tests. We used logistic regression to estimate the risk of poor cognitive functioning (< 25th percentile of the score distribution) associated with low values of each antioxidants (< 25th percentile) including potential confounding factors. A low level of total carotenoids (< 1.86 mumol/l) was associated with poor cognitive performance in two tests assessing visual attention and logical reasoning: the Trail-Making Test part B [OR = 1.34 IC95% (0.99-1.81), p = .055] and the Digit Symbol Substitution from the WAIS-R [OR = 1.38 IC95% (1.02-1.89), p = .04]. Low levels of other antioxidants and high levels of thiobarbituric-reactive substances were not related to poor cognitive functioning. Results observed with plasma carotenoids are in accordance with previous data obtained mostly from dietary records.

Cognitive decline is associated with systemic oxidative stress: the EVA study. Etude du Vieillissement Artériel.

OBJECTIVE: To determine whether systemic oxidative stress status is associated with cognitive decline. DESIGN: A longitudinal population-based study. SETTING: A cohort study of older subjects in Nantes, France. PARTICIPANTS: A total of 1166 high cognitive functioning subjects aged 60 to 70 in the Etude du Vieillissement Arteriel (EVA) cohort with a 4 year follow-up. MEASUREMENTS: Subjects completed a baseline interview and a global cognitive test (Mini-Mental Status Examination (MMSE)). Blood samples were obtained at baseline to determine plasma levels of selenium, carotenoids, thiobarbituric acid reactant substances (TBARS), an indicator of lipoperoxidation, and red blood cell vitamin E. Risk of cognitive decline, defined as a loss of 3 points in MMSE score between baseline and the 4 year follow-up, was assessed by oxidative stress level. RESULTS: Subjects with the highest levels of TBARS show an increased risk of cognitive decline (adjusted odds ratio (OR) = 2.25; confidence interval (CI) 95% = 1.26-4.02). This result is reinforced in the lower antioxidant status subgroup. Subjects with low levels of selenium have an increased risk of cognitive decline (OR = 1.58; CI 95% = 1.08-2.31) after adjustment for various confounding factors. CONCLUSIONS: These results suggest that increased levels of oxidative stress and/or antioxidant deficiencies may pose risk factors for cognitive decline. The direct implication of oxidative stress in vascular and neurodegenerative mechanisms that lead to cognitive impairment should be further explored.

Effects of varying dietary proteins on plasma lipids and rabbit platelet function.

The aim of this paper was to study the effect of dietary proteins on rabbit platelet aggregation induced by ADP, collagen and thrombin. In addition, blood coagulation tests (Stypven, Stypven cephalin and cephalin kaolin plasma clotting times) were performed on these rabbits fed semi-synthetic diets containing animal protein (casein) or vegetable proteins (walnut or soybean). As part of this study, total cholesterol, HDL cholesterol, phospholipid and triglyceride plasma levels were determined and platelet fatty acid composition was analysed. The results show that the addition of walnut meal in the diet decreases platelet aggregability and total plasma cholesterol. The relative effects of casein, soybean and walnut protein on platelet aggregability best correlated with the ratio of lysine to arginine in the protein and the ratio of HDL to LDL. An increase in the ratio C20:5 n-3/C20:4 n-6 in platelet fatty acids was also seen in walnut and soybean protein-fed animals, but the changes were greatest in soybean protein-fed animals while inhibition of platelet aggregation was greatest in walnut protein-fed animals.

[Determination of normal levels of urinary xanthurenic acid as a function of age and sex (author's transl)]. / L'acide xanthurenique urinaire, détermination des taux normaux en fonction de l'âge et du sexe.

A quantitative determination of xanthurenic acid in human urine has made possible a statistical study of the secretion of this substance according to age and sex.