French adults' cognitive performance after daily supplementation with antioxidant vitamins and minerals at nutritional doses: a post hoc analysis of the Supplementation in Vitamins and Mineral Antioxidants (SU.VI.MAX) trial

Association between composite dietary antioxidant index and cognitive function impairment among the US older adults: a cross-sectional study based on the NHANES 2011-2014

Background

Cognitive function impairment (CFI) and the Composite Dietary Antioxidant Index (CDAI) were investigated in this study.

Methods

Participants from the 2011-2014 cycles of the National Health and Nutrition Examination Survey were chosen to assess cognitive function using the Consortium to Establish a Registry for Alzheimer's Disease Word Learning Test, the Animal Fluency Test, and the Digit Symbol Substitution Test. Participants scored below the 25% percentile of any of the three tests were defined as having cognitive function impairment. 24-h recalls of diet were collected to calculate CDAI.

Results

2,424 participants were included. The fully adjusted multivariate logistic regression model showed an increase of one CDAI unit reduced CFI risk by 5% (95% CI: 0.92 ~ 0.98, p = 0.004). When comparing individuals with the lowest CDAI in the first quartile (<-2.42), the adjusted odds ratio for CDAI and CFI were 0.81 (95% CI: 0.61 ~ 1.06, p = 0.125) in the second quartile, 0.69 (95% CI: 0.51 ~ 0.92, p = 0.012) in the third quartile, and 0.59 (95% CI: 0.43 ~ 0.82, p = 0.002) in the fourth quartile, respectively. Restricted cubic spline analysis revealed a steady negative linear correlation between CDAI and CFI, with a p-value for non-linearity of 0.122. Subgroup analysis did not reveal any significant interactions based on age, education level, family income, history of diabetes, hypertension, stroke, and depression.

Conclusion

CDAI was inversely associated with CFI in a large representative American population. Further longitudinal studies are needed for causal inference.

New horizons for the role of selenium on cognitive function: advances and challenges

Cognitive deficits associated with oxidative stress and the dysfunction of the central nervous system are present in some neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease. Selenium (Se), an essential microelement, exhibits cognition-associated functions through selenoproteins mainly owing to its antioxidant property. Due to the disproportionate distribution of Se in the soil, the amount of Se varies greatly in various foods, resulting in a large proportion of people with Se deficiency worldwide. Numerous cell and animal experiments demonstrate Se deficiency-induced cognitive deficits and Se supplementation-improved cognitive performances. However, human studies yield inconsistent results and the mechanism of Se in cognition still remains elusive, which hinder the further exploration of Se in human cognition. To address the urgent issue, the review summarizes Se-contained foods (plant-based foods, animal-based foods, and Se supplements), brain selenoproteins, mechanisms of Se in cognition (improvement of synaptic plasticity, regulation of Zn2+ level, inhibition of ferroptosis, modulation of autophagy and de novo synthesis of L-serine), and effects of Se on cognitive deficits, as well as consequently sheds light on great potentials of Se in the prevention and treatment of cognitive deficits.

Serum zinc concentration and dietary zinc intake in relation to cognitive function: an analysis of the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort

PURPOSE

There are several pathways by which zinc may be a modifiable factor to slow age-related cognitive decline. We investigated the associations between serum and dietary zinc and cognitive impairment in a longitudinal cohort.

METHODS

We used data from the REasons for Geographic and Racial Differences in Stroke (REGARDS) Cohort (n = 30,239) and the REGARDS Trace Element Study (n = 2666). Baseline serum zinc concentrations (2003-2007) were measured using inductively coupled plasma mass spectrometry. Baseline dietary zinc intake was measured via the Block food frequency questionnaire. Serum zinc concentrations and dietary zinc intake were categorized into quartiles. The outcome of interest was impairment on the Six-Item Screener (SIS), a measure of global cognitive functioning administered annually. The Enhanced Cognitive Battery (ECB), a more comprehensive series of tests assessing memory and fluency, was administered every two years and considered a secondary outcome. Associations between zinc and incident impairment were assessed using multivariable logistic regression.

RESULTS

Among 2065 participants with serum zinc data, 184 individuals developed impairment over 10 years of follow-up. In adjusted models, there was no significant association between serum zinc and impairment as assessed by the SIS or the ECB. Among 18,103 participants who had dietary data, 1424 experienced incident impairment on the SIS. Dietary zinc intake was not significantly associated with impairment as assessed by the SIS or the ECB in adjusted models.

CONCLUSION

Findings from this U.S. cohort did not support the hypothesis that serum zinc concentration or dietary zinc intake is associated with the risk of cognitive impairment.

Oxidative Stress in Military Missions-Impact and Management Strategies: A Narrative Analysis

This narrative review comprehensively examines the impact of oxidative stress on military personnel, highlighting the crucial role of physical exercise and tailored diets, particularly the ketogenic diet, in minimizing this stress. Through a meticulous analysis of the recent literature, the study emphasizes how regular physical exercise not only enhances cardiovascular, cognitive, and musculoskeletal health but is also essential in neutralizing the effects of oxidative stress, thereby improving endurance and performance during long-term missions. Furthermore, the implementation of the ketogenic diet provides an efficient and consistent energy source through ketone bodies, tailored to the specific energy requirements of military activities, and significantly contributes to the reduction in reactive oxygen species production, thus protecting against cellular deterioration under extreme stress. The study also underlines the importance of integrating advanced technologies, such as wearable devices and smart sensors that allow for the precise and real-time monitoring of oxidative stress and physiological responses, thus facilitating the customization of training and nutritional regimes. Observations from this review emphasize significant variability among individuals in responses to oxidative stress, highlighting the need for a personalized approach in formulating intervention strategies. It is crucial to develop and implement well-monitored, personalized supplementation protocols to ensure that each member of the military personnel receives a regimen tailored to their specific needs, thereby maximizing the effectiveness of measures to combat oxidative stress. This analysis makes a valuable contribution to the specialized literature, proposing a detailed framework for addressing oxidative stress in the armed forces and opening new directions for future research with the aim of optimizing clinical practices and improving the health and performance of military personnel under stress and specific challenges of the military field.

Effect of multivitamin-mineral supplementation versus placebo on cognitive function: results from the clinic subcohort of the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized clinical trial and meta-analysis of 3 cognitive studies within COSMOS

BACKGROUND

Longer effects of multivitamin-mineral (MVM) supplementation on late-life cognitive function remain untested using in-person, detailed neuropsychological assessments. Furthermore, insufficient evidence exists for healthcare providers to recommend daily MVM supplements to prevent cognitive decline.

OBJECTIVES

This study aimed to test MVM effects on cognitive change using in-person, detailed neuropsychological assessments and conduct a meta-analysis within COSMOS (COcoa Supplement and Multivitamin Outcomes Study) cognitive substudies for a robust evaluation of MVM effects on cognition.

METHODS

COSMOS is a 2 × 2 factorial trial of cocoa extract (500 mg flavanols/d) and/or a daily MVM supplement for cardiovascular disease and cancer prevention among 21,442 United States adults aged ≥60 y. There were 573 participants in the clinic subcohort of COSMOS (that is, COSMOS-Clinic) who completed all cognitive tests administered at baseline. For the meta-analysis, we included nonoverlapping participants across 3 COSMOS cognitive substudies: COSMOS-Clinic (n = 573); COSMOS-Mind (n = 2158); COSMOS-Web (n = 2472).

RESULTS

In COSMOS-Clinic, we observed a modest benefit of MVM compared with placebo on global cognition over 2 y {mean difference [95% confidence interval (CI)] = 0.06 SD units (SU) (-0.003, 0.13)}, with a significantly more favorable change in episodic memory [mean difference (95% CI) = 0.12 SU (0.002, 0.23)] but not in executive function or attention [mean difference (95% CI) = 0.04 SU (-0.04, 0.11)]. The meta-analysis of COSMOS substudies showed clear evidence of MVM benefits on global cognition [mean difference (95% CI) = 0.07 SU (0.03, 0.11); P = 0.0009] and episodic memory [mean difference (95% CI) = 0.06 SU (0.03, 0.10); P = 0.0007]; the magnitude of effect on global cognition was equivalent to reducing cognitive aging by 2 y.

CONCLUSIONS

In COSMOS-Clinic, daily MVM supplementation leads to a significantly more favorable 2-y change in episodic memory. The meta-analysis within COSMOS cognitive substudies indicates that daily MVM significantly benefits both global cognition and episodic memory. These findings within the COSMOS trial support the benefits of a daily MVM in preventing cognitive decline among older adults. This trial was registered at COSMOS-clinicaltrials.gov as NCT02422745, at COSMOS-Mind-clinicaltrials.gov as NCT03035201, and at COSMOS-Web-clinicaltrials.gov as NCT04582617.

Impact of multivitamin-mineral and cocoa extract on incidence of mild cognitive impairment and dementia: Results from the COcoa Supplement and Multivitamin Outcomes Study for the Mind (COSMOS-Mind)

INTRODUCTION

We assessed the effects of multivitamin-mineral and cocoa extract supplementation on incident mild cognitive impairment (MCI) and all-cause probable dementia.

METHODS

COSMOS-Mind (N = 2262), a 2 × 2 factorial, randomized-controlled clinical trial administered a telephone-based cognitive battery at baseline and annually for 3 years. Incidence rates of MCI, and separately dementia, were compared among treatment arms with proportional hazards regression.

RESULTS

Over 3 years, 110 incident MCI and 14 incident dementia cases were adjudicated. Incidence rates did not vary by assignment to multivitamin-mineral or cocoa extract (all p's ≥ 0.05); however, statistical power was low. When participants assigned to multivitamin-mineral versus placebo converted to MCI, their scores for global cognition (p = 0.03) and executive function (p < 0.001) were higher and had declined less relative to the previous year (p = 0.03 for global cognition; p = 0.004 for executive function).

DISCUSSION

Multivitamin-mineral therapy may provide cognitive resilience, countering conversion to MCI, but not significantly reduce its incidence over 3 years.

HIGHLIGHTS

Multivitamin-mineral supplementation did not reduce risks for cognitive impairment. Cocoa extract supplementation did not reduce risks for cognitive impairment. Multivitamin-mineral supplementation slowed cognitive declines for incident mild cognitive impairment.

The Effect of Beta-Carotene on Cognitive Function: A Systematic Review

β-carotene is a powerful antioxidant and dietary precursor of vitamin A whose role in maintaining mental health and cognitive performance, either alone or in combination with other dietary compounds, has been a topic of recent research. However, its effectiveness is still unclear. This systematic review, conducted according to the PRISMA guideline and assisted by the MySLR platform, addressed this issue. A total of 16 eligible original research articles were identified. Dietary intake or β-carotene serum levels were associated with improved measures of cognitive function in 7 out of 10 epidemiological studies included. In intervention studies, β-carotene consumption alone did not promote better cognitive function in the short term, but only in a long-term intervention with a mean duration of 18 years. However, all but one intervention study suggested the beneficial effects of β-carotene supplementation at doses ranging from 6 mg to 50 mg per day in combination with a multicomplex such as vitamin E, vitamin C, zinc, or selenium for a period of 16 weeks to 20 years. Despite the current limitations, the available evidence suggests a potential association between β-carotene dietary/supplementary intake and the maintenance of cognitive function. The β-carotene most probably does not act alone but in synergy with other micronutrients.

The Association Between Selenium, Selenoprotein P (SEPP1), Fluid Intelligence, and Exercise in the UK Biobank Cohort

BACKGROUND

In the mouse hippocampus, exercise boosts neurogenesis. Increased levels of the selenium transport protein selenoprotein P (SEPP1) in the serum of exercised animals may contribute to the impact of exercise. SEPP1 is a protein that aids in the delivery of selenium to the brain. The effect of exercise on mouse brain precursor cell proliferation was diminished when SEPP1 or its receptor were genetically depleted. Selenium supplementation in the diet had the same effect as exercise in reducing some of the cognitive impairments associated with aging.

METHODS

In the current analysis, we sought to determine the association of selenium, the SEPP1 gene, fluid intelligence, and exercise in the UK Biobank Cohort. We analyzed SEPP1 single nucleotide polymorphism (SNP) rs7579, a single nucleotide variation (SNV), position chr5:42800706, C > T, minor allele frequency T = 0.281. Its consequence is a 3'- UTR variant. The 3'-UTR contains regulatory regions that post-transcriptionally influence gene expression and is responsible for selenoprotein synthesis. SNP rs7579 has been implicated in multiple forms of cancer. The univariate general linear model of SPSS (IBM Corp., Armonk, NY) was used to rule out the effects of age, years of education, and vigorous activity on fluid intelligence score, with fluid intelligence score as the dependent variable, rs7579 genotype, and selenium supplements as fixed factors, and age, years of education, and vigorous activity as covariates.

RESULTS

The effect of rs7579 genotype on fluid intelligence score was insignificant (p = 0.702). The effect of selenium supplements on fluid intelligence score was insignificant (p = 0.107). The interaction of rs7579 genotype and selenium supplements was insignificant (p = 0.911) and unrelated to the significant effects of age (p < 0.001), years of education (p < 0.001), and vigorous activity (p < 0.001) on fluid intelligence score.  Conclusion: Our multivariate analysis of SEPP1 genotype, selenium supplement use, and fluid intelligence scores is consistent with the negligible effect selenium supplements seem to have on cognition. Selenium is found in nuts, dairy products, and grains. These foods can provide sufficient selenium for health. Selenium supplements are not recommended.

The Role of Selenium in Pathologies: An Updated Review

Selenium is an essential microelement required for a number of biological functions. Selenium—and more specifically the amino acid selenocysteine—is present in at least 25 human selenoproteins involved in a wide variety of essential biological functions, ranging from the regulation of reactive oxygen species (ROS) concentration to the biosynthesis of hormones. These processes also play a central role in preventing and modulating the clinical outcome of several diseases, including cancer, diabetes, Alzheimer’s disease, mental disorders, cardiovascular disorders, fertility impairments, inflammation, and infections (including SARS-CoV-2). Over the past years, a number of studies focusing on the relationship between selenium and such pathologies have been reported. Generally, an adequate selenium nutritional state—and in some cases selenium supplementation—have been related to improved prognostic outcome and reduced risk of developing several diseases. On the other hand, supra-nutritional levels might have adverse effects. The results of recent studies focusing on these topics are summarized and discussed in this review, with particular emphasis on advances achieved in the last decade.

Higher circulating α-carotene was associated with better cognitive function: an evaluation among the MIND trial participants

There is emerging evidence linking fruit and vegetable consumption and cognitive function. However, studies focusing on the nutrients underlying this relationship are lacking. We aim to examine the association between plasma nutrients and cognition in a population at risk for cognitive decline with a suboptimal diet. The Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) trial is a randomized controlled intervention that examines the effects of the MIND diet to prevent cognitive decline. The primary outcome is global cognition. A multivariate linear model was used to investigate the association between blood nutrients and global and/or domain-specific cognition. The model was adjusted for age, sex, education, study site, smoking status, cognitive activities and physical activities. High plasma α-carotene was associated with better global cognition. Participants in the highest tertile of plasma α-carotene had a higher global cognition z score of 0⋅17 when compared with individuals in the lowest tertile (P 0⋅002). Circulating α-carotene levels were also associated with higher semantic memory scores (P for trend 0⋅007). Lutein and zeaxanthin (combined) was positively associated with higher semantic memory scores (P for trend 0⋅009). Our study demonstrated that higher α-carotene levels in blood were associated with higher global cognition scores in a US population at risk for cognitive decline. The higher α-carotene levels in blood reflected greater intakes of fruits, other types of vegetables and lesser intakes of butter and margarine and meat. The higher circulating levels of lutein plus zeaxanthin reflected a dietary pattern with high intakes of fruits, green leafy, other vegetables and cheese, and low consumption of fried foods. Objective nutrient markers in the blood can better characterize dietary intake, which may facilitate the implementation of a tailored dietary intervention for the prevention of cognitive decline.

Walnut Kernel administration to mothers during pregnancy and lactation improve learning of their pups. Changes in number of neurons and gene expression of NMDA receptor and BDNF in hippocampus in 80 days rat pups

Walnut (Juglans regia) from the Juglandaceae family contains high levels of omega 3 fatty acid, vitamin E and melatonin, hence its consumption is beneficial to would be mothers and their offspring. The current study was designed to determine the possible mechanism of walnut consumption by mothers during pregnancy and lactation and the positive effects on learning and memory processes in their offspring. Wistar adult female rats were placed into three groups: control (fed with pellet, 20 g daily during pregnancy and lactation), CASE 1 [fed with Walnut Kernel (WK) 6% of food intake during pregnancy and lactation] and CASE 2 (fed with WK, 9% of food intake during gestation and lactation). In order to evaluate offspring learning and memory, the Morris Water Maze (MWM) test was performed for their adult offspring at 80 days of age. Histological and molecular studies were utilized in order to discover the protective mechanism and efficacy of WK consumption. The results revealed that learning was significantly improved in the females of CASE 2, in comparison to controls, while there was no difference in memory among the different groups. In addition, the number of neurons significantly increased in the CASE 2 group compared to the control group. However, the molecular study demonstrated that there was no significant difference among the study groups. The results herein show that feeding mothers with WK may improve the learning competence of their pups and increase the number of neurons in both sexes.

Association of Antioxidant Vitamins A, C, E and Carotenoids with Cognitive Performance over Time: A Cohort Study of Middle-Aged Adults

Carotenoids may strengthen the association of antioxidant vitamins A, C, and E with favorable cognitive outcomes over time, though a few prospective studies have examined this hypothesis. We evaluated the longitudinal data from 1251 participants in the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study (Age at visit 1 in 2004–2009 (v₁): 30–65 years). Vitamins A, C, and E dietary intakes and total and individual dietary carotenoids were computed using two 24-h recalls at v₁. Cognitive tests, covering global mental status and domains of memory/learning, attention, psychomotor speed, visuo-spatial, language/verbal, and executive function were conducted at v₁ and/or v₂ (2009–2013); mean ± SD follow-up: 4.66 ± 0.93 years. Mixed-effects linear regression models detected an interaction between vitamin E and total (and individual) carotenoids for three of 11 cognitive tests at v₁, with only one meeting the statistical significance upon multiple testing correction whereby vitamin E was linked with greater verbal memory performance in the uppermost total carotenoid tertile (γ_0a = +0.26 ± 0.08, p = 0.002), a synergism largely driven by carotenoid lycopene. Vitamins A and C showed no consistent interactions with carotenoids. In conclusion, we provide partial evidence for synergism between vitamin E and carotenoids in relation to better baseline cognitive performance, pending further studies with time-dependent exposures and randomized trials directly examining this synergism.

Glutathione Peroxidase-1 Knockout Facilitates Memory Impairment Induced by β-Amyloid (1-42) in Mice via Inhibition of PKC βII-Mediated ERK Signaling; Application with Glutathione Peroxidase-1 Gene-Encoded Adenovirus Vector

A growing body evidence suggests that selenium (Se) deficiency is associated with an increased risk of developing Alzheimer's disease (AD). Se-dependent glutathione peroxidase-1 (GPx-1) of a major antioxidant enzyme, and the most abundant isoform of GPx in the brain. In the present study, we investigated whether GPx-1 is protective against memory impairments induced by beta-amyloid (Aβ) (1-42) in mice. As the alteration of protein kinase C (PKC)-mediated ERK activation was recognized in the early stage of AD, we examined whether the GPx-1 gene modulates Aβ (1-42)-induced changes in PKC and ERK levels. We observed that Aβ (1-42) treatment (400 pmol, i.c.v.) significantly decreased PKC βII expression in the hippocampus of mice. Aβ (1-42)-induced neurotoxic changes [i.e., oxidative stress (i.e., reactive oxygen species, 4-hydroxy-2-noneal, and protein carbonyl), reduced PKC βII and phospho-ERK expressions, and memory impairment under Y-maze and passive avoidance test] were more pronounced in GPx-1 knockout than in wild type mice. Importantly, exposure to a GPx-1 gene-encoded adenovirus vector (Adv-GPx-1) significantly increased GPx-1 mRNA and GPx activity in the hippocampus of GPx-1 knockout mice. Adv-GPx-1 exposure also significantly blocked the neurotoxic changes induced by Aβ (1-42) in GPx-1 knockout mice. Treatment with ERK inhibitor U0126 did not significantly change Adv-GPx-1-mediated attenuation in PKC βII expression. In contrast, treatment with PKC inhibitor chelerythrine (CHE) reversed Adv-GPx-1-mediated attenuation in ERK phosphorylation, suggesting that PKC βII-mediated ERK signaling is important for Adv-GPx-1-mediated potentials against Aβ (1-42) insult. Our results suggest that treatment with the antioxidant gene GPx-1 rescues Aβ (1-42)-induced memory impairment via activating PKC βII-mediated ERK signaling.

[Selenium and zinc: "antioxidants" for healthy aging?]

Selenium and zinc are essential trace elements and an inadequate dietary intake has been implicated in the decline of immune and cognitive functions in aged persons and in the pathogenesis of age-related disorders. Both micronutrients are often marketed as "antioxidants" in mineral supplements; however, neither selenium nor zinc are antioxidants per se but they may exert beneficial effects as components of enzymes and other proteins that catalyze redox reactions and/or are involved in the maintenance of redox homeostasis. According to epidemiological data older individuals have an increased risk of developing deficiencies in the selenium and zinc status; however, such statistical correlations in epidemiological studies do not imply a causal association. Intervention trials are scarce and have yielded inconsistent and sometimes even adverse results. It should also be noted that the observed deficiencies in micronutrients may not necessarily be attributable to inadequate dietary intake as the absorption and distribution within the body might also be influenced by factors such as medications or interaction with other food ingredients. Thus, any dietary supplementation should be implemented with caution and persons who wish to take mineral supplements should first seek medical advice. This article discusses the role of selenium and zinc in biological antioxidant systems, summarizes findings on the supply and supplementation of aged persons with these trace elements and on the influence they may exert on aging-related health issues, such as cognitive decline and type 2 diabetes mellitus.

Effects of Lutein and Astaxanthin Intake on the Improvement of Cognitive Functions among Healthy Adults: A Systematic Review of Randomized Controlled Trials

Background: Fruits and vegetables are generally rich in antioxidants such as carotenoids. Consumption of carotenoids is expected to have benefits on cognitive functions in humans. However, previous randomized controlled trials (RCT) using carotenoids have reported inconsistent results. Therefore, this systematic review (SR) aimed to summarize the effect of carotenoid intake on cognitive functions in humans. Method: PubMed, Cochrane Library, Web of Science, and PsychoINFO were searched for research papers on carotenoid intake with the criteria that 1) oral carotenoid intake was evaluated using RCTs, 2) participants were healthy young, middle-aged, or older, and 3) cognitive functions were measured using RCTs. Results: Five studies using lutein and two studies using astaxanthin met the inclusion criteria. Consumption of lutein and its isomer showed consistent results in selective improvement of visual episodic memory in young and middle-aged adults while inhibition was observed in middle-aged and older adults. One of the two included astaxanthin studies reported a significant improvement of verbal episodic memory performance in middle-aged adults. Conclusion: This SR showed that the 10 mg lutein per day for twelve months can lead to improvement of cognitive functions. Due to the small number of studies, it is difficult to conclude whether astaxanthin would have a positive effect on cognitive functions.

Randomized placebo-controlled study of the memory effects of pomegranate juice in middle-aged and older adults

BACKGROUND

Antioxidant nutrients such as the polyphenols in pomegranate juice may prevent neuronal damage from the free radicals produced during normal metabolism. Previous research in animals and a short-term clinical trial in middle-aged and older adults support the potential memory benefits of pomegranate juice; however, the long-term effects of pomegranate juice consumption on cognition have not been studied.

OBJECTIVE

In this study, we investigated the long-term effect of pomegranate juice on memory in nondemented middle-aged and older adults.

METHODS

We performed a 12-month, randomized, double-blind, placebo-controlled trial of pomegranate juice in middle-aged and older adults. Two hundred and sixty-one subjects (aged 50-75 y) were randomly assigned to consume pomegranate juice [8 oz (236.5 mL) per day] or a placebo drink (8 oz, matched constituents of pomegranate juice except for pomegranate polyphenols). Memory measures [Brief Visuospatial Memory Test-Revised (BVMT-R) and Buschke Selective Reminding Test (SRT)] were assessed at 6 and 12 mo and analyzed using a mixed-effects general linear model.

RESULTS

Twenty-eight subjects in the pomegranate juice group and 33 subjects in the placebo group dropped out before completing the study. Baseline variables in the 98 pomegranate juice and 102 placebo group subjects who completed the study did not differ significantly. Group by time interaction was statistically significant for BVMT-R Learning (F[2, 257]= 5.90, P = 0.003; between-group effect size [ES] = 0.45): the change within the pomegranate group was not significant (ES = 0.15), whereas the placebo group showed a significant decline (ES = -0.35). Changes in the other BVMT-R scores as well as the SRT measures were not significantly different between groups.

CONCLUSIONS

Daily consumption of pomegranate juice may stabilize the ability to learn visual information over a 12-mo period. This trial was registered at clinicaltrials.gov as NCT02093130.

Deficiency but Not Supplementation of Selenium Impairs the Hippocampal Long-Term Potentiation and Hippocampus-Dependent Learning

Among the chemical factors that have been implicated in the etiology of dementia, recent concern has focused on both increased and decreased exposure to the metalloid selenium (Se). This report describes the molecular, behavioral, and electrophysiological analysis of rats that were fed with Se-free chow and Se-enriched tap water for 21 days. Three groups were produced, feeding them on a deficient diet with different Selenium content. Hippocampus-dependent spatial learning was measured using the water maze. Long-term potentiation (LTP) was recorded in the hippocampal dentate gyrus to assess how memory is formed at the cellular level. Hippocampal Se levels were measured in trained rats by using inductively coupled plasma mass spectrometry. Phosphorylated and total tau levels were measured in whole hippocampus by Western blot. An impairment of learning of rats feeding with Se-deficient diet was accompanied by attenuated LTP, and increased ratio of p²³¹Tau-to- and decreased ratio of p⁴¹⁶Tau-to-Tau in the non-stimulated hippocampus, despite no significant change was observed in Se levels of hippocampus and plasma. Se supplementation resulted in an increase in both tissues and an increase in the ratio of p²³¹Tau-to-Tau in the non-stimulated hippocampus but did not change learning performance and LTP. Despite impaired learning and LTP, no group differed in probe trial and in the fraction of phosphorylated tau in LTP-induced hippocampus. Reduced level of selenium would probably result in reduced synaptic plasticity as well as impairment of learning ability, suggesting requirement of Se for normal synaptic function.

Essential Amino Acids, Vitamins, and Minerals Moderate the Relationship between the Right Frontal Pole and Measures of Memory

SCOPE

Nutrition has increasingly been recognized for its ability to help prevent and protect against disease, inspiring new programs of research that translate findings from nutritional science into innovative assessment tools, technologies, and therapies to advance the practice of modern medicine. A central aim in this effort is to discover specific dietary patterns that promote healthy brain aging and moderate the engagement of neural systems known to facilitate cognitive performance in later life.

METHODS AND RESULTS

The present study therefore investigates estimates of nutrient intake derived from food frequency questionnaires, structural measures of brain volume via high-resolution magnetic resonance imaging, and standardized neuropsychological measures of memory performance in nondemented elders (n = 111) using a moderation analysis. The results reveal that the essential amino acids, vitamins, and minerals nutrient pattern moderates the positive relationship between the volume of the right frontal pole and measures of both delayed and auditory memory.

CONCLUSIONS

Our findings demonstrate that a nutrient pattern including macro- and micronutrients moderate the effect of brain structure on cognitive function in old age and support the efficacy of interdisciplinary methods in nutritional cognitive neuroscience for the study of healthy brain aging.

Altered dietary selenium influences brain iron content and behavioural outcomes

Selenium (Se) is an essential micronutrient that provides antioxidant defence through selenoproteins, but at high concentrations, deleterious effects have been reported. The present study examines the antioxidant response in brain regions and behavioural functions in mice under various dietary Se paradigms; Se-deficient, Se-adequate and Se-excess. Se levels were found to be reduced in the cortex and hippocampus of Se-deficient animals, whereas no change was observed in animals on Se-excess diet. In the hippocampus, iron (Fe) levels increased in animals on Se-deficient and Se-excess diets. Moreover, in Se-deficient animals, Fe levels increased in cortex also. Interestingly, Se content in the hair positively correlated with the dietary Se intake. Total and Se-dependent glutathione peroxidase activity decreased in the cortex, hippocampus and cerebellum of animals on Se-deficient diet. On the other hand, the activity of these enzymes decreased in the cortex of animals on Se-excess diet. Further, lipid peroxidation increased in the cortex of animals on Se-deficient diet and in the hippocampus of animals on Se-excess diet. Cognitive functions assessed by Morris water maze and Y-maze tests revealed deficits in Se-deficient state. However, in Se-excess state cognitive deficits were observed only in Y-maze test. These findings suggest that long-term dietary variation in Se influences oxidative stress that impacts cognitive functions. Therefore, it is suggested that maintenance of Se status during postnatal development may be crucial for mental health.

Improvement in Cognition Following Double-Blind Randomized Micronutrient Interventions in the General Population

The impact of poor nutrition on physiological health is well understood (Costarelli et al., 2013). Less is known about the effects of diet on brain function and cognition in the general population (Ames, 2010; Parletta et al., 2013; White et al., 2017) and we are still in the early stages of understanding the role of specific nutrients to normal and pathological neuronal functioning. In the present study, the putative effect of a multivitamin/mineral or vitamin D supplement on cognitive function over an 8-week period was compared with volunteers taking vitamin C. Healthy adults (N = 60) were recruited, age range 21-59 years ( x ¯ = 39.07 years, SD = 11.46), with participants randomly allocated to conditions in a double-blind protocol. Participants also completed a 14-day food diary to gather information on micronutrient intake. The cognitive test battery included measures from the Wechsler Adult Intelligence Scale-III (WAIS-III; Wechsler et al., 2008), Wechsler Memory Scale-IV (WMS-IV; Wechsler, 2009) and Delis-Kaplan Executive Function System (D-KEFS; Delis et al., 2001), along with the Doors and People (Baddeley et al., 1994) and a serial reaction time task. Analyses showed better performance on some tasks in all groups following the intervention period, notably on measures of verbal and visual memory and visuomotor processing speed. The Multivitamin group showed significant improvements on tasks of visual strategy generation (along with the Vitamin C group), motor planning, explicit and implicit learning, and working memory. This evidence suggests that sub-optimal micronutrient intake may have a negative effect on cognition across the lifespan.

Vitamin and mineral supplementation for maintaining cognitive function in cognitively healthy people in mid and late life

BACKGROUND

Vitamins and minerals play multiple functions within the central nervous system which may help to maintain brain health and optimal cognitive functioning. Supplementation of the diet with various vitamins and minerals has been suggested as a means of maintaining cognitive function, or even of preventing dementia, in later life.

OBJECTIVES

To evaluate the effects of vitamin and mineral supplementation on cognitive function in cognitively healthy people aged 40 years or more.

SEARCH METHODS

We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group's (CDCIG) specialised register, as well as MEDLINE, Embase, PsycINFO, CINAHL, ClinicalTrials.gov and the WHO Portal/ICTRP from inception to 26th January 2018.

SELECTION CRITERIA

We included randomised controlled trials that evaluated the cognitive effects on people aged 40 years or more of any vitamin or mineral supplements taken by mouth for at least three months.

DATA COLLECTION AND ANALYSIS

Study selection, data extraction, and quality assessments were done in duplicate. Vitamins were considered broadly in the categories of B vitamins, antioxidant vitamins, and combinations of both. Minerals were considered separately, where possible. If interventions and outcomes were considered sufficiently similar, then data were pooled. In order to separate short-term cognitive effects from possible longer-term effects on the trajectory of cognitive decline, data were pooled for various treatment durations from 3 months to 12 months and up to 10 years or more.

MAIN RESULTS

In total, we included 28 studies with more than 83,000 participants. There were some general limitations of the evidence. Most participants were enrolled in studies which were not designed primarily to assess cognition. These studies often had no baseline cognitive assessment and used only brief cognitive assessments at follow-up. Very few studies assessed the incidence of dementia. Most study reports did not mention adverse events or made only very general statements about them. Only 10 studies had a mean follow-up > 5 years. Only two studies had participants whose mean age was < 60 years at baseline. The risk of bias in the included studies was generally low, other than a risk of attrition bias for longer-term outcomes. We considered the certainty of the evidence behind almost all results to be moderate or low.We included 14 studies with 27,882 participants which compared folic acid, vitamin B12, vitamin B6, or a combination of these to placebo. The majority of participants were aged over 60 years and had a history of cardio- or cerebrovascular disease. We found that giving B vitamin supplements to cognitively healthy adults, mainly in their 60s and 70s, probably has little or no effect on global cognitive function at any time point up to 5 years (SMD values from -0.03 to 0.06) and may also have no effect at 5-10 years (SMD -0.01). There were very sparse data on adverse effects or on incidence of cognitive impairment or dementia.We included 8 studies with 47,840 participants in which the active intervention was one or more of the antioxidant vitamins: ß-carotene, vitamin C or vitamin E. Results were mixed. For overall cognitive function, there was low-certainty evidence of benefit associated with ß-carotene after a mean of 18 years of treatment (MD 0.18 TICS points, 95% CI 0.01 to 0.35) and of vitamin C after 5 years to 10 years (MD 0.46 TICS points, 95% CI 0.14 to 0.78), but not at earlier time points. From two studies which reported on dementia incidence, there was low-certainty evidence of no effect of an antioxidant vitamin combination or of vitamin E, either alone or combined with selenium. One of the included studies had been designed to look for effects on the incidence of prostate cancer; it found a statistically significant increase in prostate cancer diagnoses among men taking vitamin E.One trial with 4143 participants compared vitamin D3 (400 IU/day) and calcium supplements to placebo. We found low- to moderate-certainty evidence of no effect of vitamin D3 and calcium supplements at any time-point up to 10 years on overall cognitive function (MD after a mean of 7.8 years -0.1 MMSE points, 95% CI -0.81 to 0.61) or the incidence of dementia (HR 0.94, 95% CI 0.72 to 1.24). A pilot study with 60 participants used a higher dose of vitamin D3 (4000 IU on alternate days) and found preliminary evidence that this dose probably has no effect on cognitive function over six months.We included data from one trial of zinc and copper supplementation with 1072 participants. There was moderate-certainty evidence of little or no effect on overall cognitive function (MD 0.6 MMSE points, 95% CI -0.19 to 1.39) or on the incidence of cognitive impairment after 5 years to 10 years. A second smaller trial provided no usable data, but reported no cognitive effects of six months of supplementation with zinc gluconate.From one study with 3711 participants, there was low-certainty evidence of no effect of approximately five years of selenium supplementation on the incidence of dementia (HR 0.83, 95% CI 0.61 to 1.13).Finally, we included three trials of complex supplements (combinations of B vitamins, antioxidant vitamins, and minerals) with 6306 participants. From the one trial which assessed overall cognitive function, there was low-certainty evidence of little or no effect on the TICS (MD after a mean of 8.5 years 0.12, 95% CI -0.14 to 0.38).

AUTHORS' CONCLUSIONS

We did not find evidence that any vitamin or mineral supplementation strategy for cognitively healthy adults in mid or late life has a meaningful effect on cognitive decline or dementia, although the evidence does not permit definitive conclusions. There were very few data on supplementation starting in midlife (< 60 years); studies designed to assess cognitive outcomes tended to be too short to assess maintenance of cognitive function; longer studies often had other primary outcomes and used cognitive measures which may have lacked sensitivity. The only positive signals of effect came from studies of long-term supplementation with antioxidant vitamins. These may be the most promising for further research.

Unsaturated Fatty Acid Intakes During Midlife Are Positively Associated with Later Cognitive Function in Older Adults with Modulating Effects of Antioxidant Supplementation

Background

Given the drastic demographic changes characterized as "population aging," the disease burden related to dementia is a major public health problem. The scientific literature documenting the link between mono- and polyunsaturated fatty acids (MUFAs, PUFAs) and cognitive function during aging is plentiful, but findings are inconsistent.

Objectives

We aimed to evaluate the association between intakes of unsaturated fatty acids at midlife and cognitive performance 13 y later in French adults, and to test for a modulating effect of antioxidant supplementation.

Methods

Fatty acid intakes were estimated with the use of repeated 24-h records (1994-1996) among 3362 subjects (mean ± SD age: 65.5 ± 4.6 y) of the SU.VI.MAX (Supplementation with Antioxidant Vitamins and Minerals) study, including an intervention phase (1994-2002) during which participants were randomly assigned to an "antioxidant supplementation" or placebo group. Cognitive performance was assessed at follow-up only (in 2007-2009) via a battery of 6 standardized neuropsychological tests. A global cognitive score was calculated as the sum of T-scores of the 6 tests. Multivariable-adjusted regression analyses were performed to provide regression coefficients and 95% CIs.

Results

In multivariable models, total MUFAs, total PUFAs, and n-6 PUFAs (ω-6 PUFAs) were positively associated with overall cognitive functioning. n-3 PUFA (ω-3 PUFA) intakes showed positive associations among supplemented participants only (mean difference Tertile3 versus Tertile1: 1.40; 95% CI: 0.30, 2.51; P-trend = 0.01, P-interaction = 0.01). A detrimental role of arachidonic acid for cognitive functioning was only detected in the placebo group (mean difference Tertile3 versus Tertile1: -1.38; 95% CI: -2.57, -0.18; P-trend = 0.02, P-interaction = 0.07).

Conclusion

Whereas higher total MUFA and n-6 PUFA intakes may be generally beneficial for maintaining cognitive health during aging, a higher consumption of n-3 fatty acids may only be beneficial among individuals with an adequate antioxidant status. These findings underline the importance of not only focusing on specific nutrients for dementia prevention, but also considering the complex interaction between consumed nutrients. This trial was registered at clinicaltrials.gov as NCT00272428.

Nutritional interventions and cognitive-related outcomes in patients with late-life cognitive disorders: A systematic review

There have been a large number of observational studies on the impact of nutrition on neuroprotection, however, there was a lack of evidence from randomized clinical trials (RCTs). In the present systematic review, from the 32 included RCTs published in the last four years (2014-2017) in patients aged 60 years and older with different late-life cognitive disorders, nutritional intervention through medical food/nutraceutical supplementation and multidomain approach improved magnetic resonance imaging findings and other cognitive-related biomarkers, but without clear effect on cognition in mild Alzheimer's disease (AD) and mild cognitive impairment (MCI). Antioxidant-rich foods (nuts, grapes, cherries) and fatty acid supplementation, mainly n-3 polyunsaturated fatty acids (PUFA), improved specific cognitive domains and cognitive-related outcomes in MCI, mild-to-moderate dementia, and AD. Antioxidant vitamin and trace element supplementations improved only cognitive-related outcomes and biomarkers, high-dose B vitamin supplementation in AD and MCI patients improved cognitive outcomes in the subjects with a high baseline plasma n-3 PUFA, while folic acid supplementation had positive impact on specific cognitive domains in those with high homocysteine.

Vitamin and mineral supplementation for preventing dementia or delaying cognitive decline in people with mild cognitive impairment

BACKGROUND

Vitamins and minerals have many functions in the nervous system which are important for brain health. It has been suggested that various different vitamin and mineral supplements might be useful in maintaining cognitive function and delaying the onset of dementia. In this review, we sought to examine the evidence for this in people who already had mild cognitive impairment (MCI).

OBJECTIVES

To evaluate the effects of vitamin and mineral supplementation on cognitive function and the incidence of dementia in people with mild cognitive impairment.

SEARCH METHODS

We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group's (CDCIG) specialised register, as well as MEDLINE, Embase, PsycINFO, CENTRAL, CINAHL, LILACs, Web of Science Core Collection, ClinicalTrials.gov, and the WHO Portal/ICTRP, from inception to 25 January 2018.

SELECTION CRITERIA

We included randomised or quasi-randomised, placebo-controlled trials which evaluated orally administered vitamin or mineral supplements in participants with a diagnosis of mild cognitive impairment and which assessed the incidence of dementia or cognitive outcomes, or both. We were interested in studies applicable to the general population of older people and therefore excluded studies in which participants had severe vitamin or mineral deficiencies.

DATA COLLECTION AND ANALYSIS

We sought data on our primary outcomes of dementia incidence and overall cognitive function and on secondary outcomes of episodic memory, executive function, speed of processing, quality of life, functional performance, clinical global impression, adverse events, and mortality. We conducted data collection and analysis according to standard Cochrane systematic review methods. We assessed the risk of bias of included studies using the Cochrane 'Risk of bias' assessment tool. We grouped vitamins and minerals according to their putative mechanism of action and, where we considered it to be clinically appropriate, we pooled data using random-effects methods. We used GRADE methods to assess the overall quality of evidence for each comparison and outcome.

MAIN RESULTS

We included five trials with 879 participants which investigated B vitamin supplements. In four trials, the intervention was a combination of vitamins B6, B12, and folic acid; in one, it was folic acid only. Doses varied. We considered there to be some risks of performance and attrition bias and of selective outcome reporting among these trials. Our primary efficacy outcomes were the incidence of dementia and scores on measures of overall cognitive function. None of the trials reported the incidence of dementia and the evidence on overall cognitive function was of very low-quality. There was probably little or no effect of B vitamins taken for six to 24 months on episodic memory, executive function, speed of processing, or quality of life. The evidence on our other secondary clinical outcomes, including harms, was very sparse or very low-quality. There was evidence from one study that there may be a slower rate of brain atrophy over two years in participants taking B vitamins. The same study reported subgroup analyses based on the level of serum homocysteine (tHcy) at baseline and found evidence that B vitamins may improve episodic memory in those with tHcy above the median at baseline.We included one trial (n = 516) of vitamin E supplementation. Vitamin E was given as 1000 IU of alpha-tocopherol twice daily. We considered this trial to be at risk of attrition and selective reporting bias. There was probably no effect of vitamin E on the probability of progression from MCI to Alzheimer's dementia over three years (HR 1.02; 95% CI 0.74 to 1.41; n = 516; 1 study, moderate-quality evidence). There was also no evidence of an effect at intermediate time points. The available data did not allow us to conduct analyses, but the authors reported no significant effect of three years of supplementation with vitamin E on overall cognitive function, episodic memory, speed of processing, clinical global impression, functional performance, adverse events, or mortality (five deaths in each group). We considered this to be low-quality evidence.We included one trial (n = 256) of combined vitamin E and vitamin C supplementation and one trial (n = 26) of supplementation with chromium picolinate. In both cases, there was a single eligible cognitive outcome, but we considered the evidence to be very low-quality and so could not be sure of any effects.

AUTHORS' CONCLUSIONS

The evidence on vitamin and mineral supplements as treatments for MCI is very limited. Three years of treatment with high-dose vitamin E probably does not reduce the risk of progression to dementia, but we have no data on this outcome for other supplements. Only B vitamins have been assessed in more than one RCT. There is no evidence for beneficial effects on cognition of supplementation with B vitamins for six to 24 months. Evidence from a single study of a reduced rate of brain atrophy in participants taking vitamin B and a beneficial effect of vitamin B on episodic memory in those with higher tHcy at baseline warrants attempted replication.

Effect of Sodium Selenate on Hippocampal Proteome of 3×Tg-AD Mice-Exploring the Antioxidant Dogma of Selenium against Alzheimer's Disease

Selenium (Se), an antioxidant trace element, is an important nutrient for maintaining brain functions and is reported to be involved in Alzheimer's disease (AD) pathologies. The present study has been designed to elucidate the protein changes in hippocampus of 3×Tg-AD mice after supplementing sodium selenate as an inorganic source of selenium. By using iTRAQ proteomics technology, 113 differentially expressed proteins (DEPs) are found in AD/WT mice with 37 upregulated and 76 downregulated proteins. Similarly, in selenate-treated 3×Tg-AD (ADSe/AD) mice, 115 DEPs are found with 98 upregulated and 17 downregulated proteins. The third group of mice (ADSe/WT) showed 75 DEPs with 46 upregulated and 29 downregulated proteins. Among these results, 42 proteins (40 downregulated and 2 upregulated) in the diseased group showed reverse expression when treated with selenate. These DEPs are analyzed with different bioinformatics tools and are found associated with various AD pathologies and pathways. Based on their functions, selenate-reversed proteins are classified as structural proteins, metabolic proteins, calcium regulating proteins, synaptic proteins, signaling proteins, stress related proteins, and transport proteins. Six altered AD associated proteins are successfully validated by Western blot analysis. This study shows that sodium selenate has a profound effect on the hippocampus of the triple transgenic AD mice. This might be established as an effective therapeutic agent after further investigation.

Selenium-enriched yeast inhibited β-amyloid production and modulated autophagy in a triple transgenic mouse model of Alzheimer's disease

Se-yeast reduced the burden of Aβ accumulation by both decreased the generation and inhibited the initiation of autophagy pathway, enhanced autophagic clearance of Aβ in the brains of AD mice.

Vitamin C Status Correlates with Markers of Metabolic and Cognitive Health in 50-Year-Olds: Findings of the CHALICE Cohort Study

A cohort of 50-year-olds from Canterbury, New Zealand (N = 404), representative of midlife adults, undertook comprehensive health and dietary assessments. Fasting plasma vitamin C concentrations (N = 369) and dietary vitamin C intake (N = 250) were determined. The mean plasma vitamin C concentration was 44.2 µmol/L (95% CI 42.4, 46.0); 62% of the cohort had inadequate plasma vitamin C concentrations (i.e., <50 µmol/L), 13% of the cohort had hypovitaminosis C (i.e., <23 µmol/L), and 2.4% had plasma vitamin C concentrations indicating deficiency (i.e., <11 µmol/L). Men had a lower mean plasma vitamin C concentration than women, and a higher percentage of vitamin C inadequacy and deficiency. A higher prevalence of hypovitaminosis C and deficiency was observed in those of lower socio-economic status and in current smokers. Adults with higher vitamin C levels exhibited lower weight, BMI and waist circumference, and better measures of metabolic health, including HbA1c, insulin and triglycerides, all risk factors for type 2 diabetes. Lower levels of mild cognitive impairment were observed in those with the highest plasma vitamin C concentrations. Plasma vitamin C showed a stronger correlation with markers of metabolic health and cognitive impairment than dietary vitamin C.

The effect of N-acetylcysteine (NAC) on human cognition - A systematic review

Oxidative stress, neuroinflammation and neurogenesis are commonly implicated as cognitive modulators across a range of disorders. N-acetylcysteine (NAC) is a glutathione precursor with potent antioxidant, pro-neurogenesis and anti-inflammatory properties and a favourable safety profile. A systematic review of the literature specifically examining the effect of NAC administration on human cognition revealed twelve suitable articles for inclusion: four examining Alzheimer's disease; three examining healthy participants; two examining physical trauma; one examining bipolar disorder, one examining schizophrenia, and one examining ketamine-induced psychosis. Heterogeneity of studies, insufficiently powered studies, infrequency of cognition as a primary outcome, heterogeneous methodologies, formulations, co-administered treatments, administration regimes, and assessment confounded the drawing of firm conclusions. The available data suggested statistically significant cognitive improvements following NAC treatment, though the paucity of NAC-specific research makes it difficult to determine if this effect is meaningful. While NAC may have a positive cognitive effect in a variety of contexts; larger, targeted studies are warranted, specifically evaluating its role in other clinical disorders with cognitive sequelae resulting from oxidative stress and neuroinflammation.

Vitamin E for Alzheimer's dementia and mild cognitive impairment

BACKGROUND

Vitamin E occurs naturally in the diet. It has several biological activities, including functioning as an antioxidant to scavenge toxic free radicals. Evidence that free radicals may contribute to the pathological processes behind cognitive impairment has led to interest in the use of vitamin E supplements to treat mild cognitive impairment (MCI) and Alzheimer's disease (AD). This is an update of a Cochrane Review first published in 2000, and previously updated in 2006 and 2012.

OBJECTIVES

To assess the efficacy of vitamin E in the treatment of MCI and dementia due to AD.

SEARCH METHODS

We searched the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (ALOIS), the Cochrane Library, MEDLINE, Embase, PsycINFO, CINAHL, LILACS as well as many trials databases and grey literature sources on 22 April 2016 using the terms: "Vitamin E", vitamin-E, alpha-tocopherol.

SELECTION CRITERIA

We included all double-blind, randomised trials in which treatment with any dose of vitamin E was compared with placebo in people with AD or MCI.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures according to the Cochrane Handbook for Systematic Reviews of Interventions. We rated the quality of the evidence using the GRADE approach. Where appropriate we attempted to contact authors to obtain missing information.

MAIN RESULTS

Four trials met the inclusion criteria, but we could only extract outcome data in accordance with our protocol from two trials, one in an AD population (n = 304) and one in an MCI population (n = 516). Both trials had an overall low to unclear risk of bias. It was not possible to pool data across studies owing to a lack of comparable outcome measures.In people with AD, we found no evidence of any clinically important effect of vitamin E on cognition, measured with change from baseline in the Alzheimer's Disease Assessment Scale - Cognitive subscale (ADAS-Cog) over six to 48 months (mean difference (MD) -1.81, 95% confidence interval (CI) -3.75 to 0.13, P = 0.07, 1 study, n = 272; moderate quality evidence). There was no evidence of a difference between vitamin E and placebo groups in the risk of experiencing at least one serious adverse event over six to 48 months (risk ratio (RR) 0.86, 95% CI 0.71 to 1.05, P = 0.13, 1 study, n = 304; moderate quality evidence), or in the risk of death (RR 0.84, 95% CI 0.52 to 1.34, P = 0.46, 1 study, n = 304; moderate quality evidence). People with AD receiving vitamin E showed less functional decline on the Alzheimer's Disease Cooperative Study/Activities of Daily Living Inventory than people receiving placebo at six to 48 months (mean difference (MD) 3.15, 95% CI 0.07 to 6.23, P = 0.04, 1 study, n = 280; moderate quality evidence). There was no evidence of any clinically important effect on neuropsychiatric symptoms measured with the Neuropsychiatric Inventory (MD -1.47, 95% CI -4.26 to 1.32, P = 0.30, 1 study, n = 280; moderate quality evidence).We found no evidence that vitamin E affected the probability of progression from MCI to probable dementia due to AD over 36 months (RR 1.03, 95% CI 0.79 to 1.35, P = 0.81, 1 study, n = 516; moderate quality evidence). Five deaths occurred in each of the vitamin E and placebo groups over the 36 months (RR 1.01, 95% CI 0.30 to 3.44, P = 0.99, 1 study, n = 516; moderate quality evidence). We were unable to extract data in accordance with the review protocol for other outcomes. However, the study authors found no evidence that vitamin E differed from placebo in its effect on cognitive function, global severity or activities of daily living . There was also no evidence of a difference between groups in the more commonly reported adverse events.

AUTHORS' CONCLUSIONS

We found no evidence that the alpha-tocopherol form of vitamin E given to people with MCI prevents progression to dementia, or that it improves cognitive function in people with MCI or dementia due to AD. However, there is moderate quality evidence from a single study that it may slow functional decline in AD. Vitamin E was not associated with an increased risk of serious adverse events or mortality in the trials in this review. These conclusions have changed since the previous update, however they are still based on small numbers of trials and participants and further research is quite likely to affect the results.

Long-term associations between inflammatory dietary scores in relation to long-term C-reactive protein status measured 12 years later: findings from the Supplémentation en Vitamines et Minéraux Antioxydants (SU.VI.MAX) cohort

Chronic low-grade inflammation has been recognised as a key underlying mechanism for several chronic diseases, including cancer and CVD. Nutrition represents a host of key modifiable factors that influence chronic inflammation. Dietary inflammatory scores were developed to assess the inflammatory potential of the diet and have been associated with inflammatory biomarkers in cross-sectional and short-term longitudinal studies. The objective of this study was to investigate the relationship between the dietary inflammatory index (DII), the alternate dietary inflammatory index (ADII) and long-term C-reactive protein (CRP). We also tested age as an effect modifier of this relationship. Participants were selected in the Supplémentation en Vitamines et Minéraux Antioxydants study, which included subjects aged 45-60 years old for men and 35-60 years old for women in 1994. Participants with ≥3 24-h dietary records at baseline and a CRP measurement at the 12-year follow-up evaluation were included in the present study (n 1980). The relationships between the DII and ADII and elevated CRP (>3 mg/l) were investigated using logistic multivariable regression. All analyses were stratified by age (cut-off at median age=50 years old). The overall associations between DII and ADII and long-term CRP were not statistically significant (P trend across tertiles=0·16 for DII and 0·10 for ADII). A quantitative interaction was found between ADII score and age (P=0·16 for ADII, 0·36 for DII). In stratified analyses the ADII was significantly prospectively associated with CRP only in younger participants: OR tertile 3 v. tertile 1: 1·79 (95 % CI 1·04, 3·07). Pro-inflammatory diets may have long-term effect on CRP only in younger subjects.

Vitamin E for Alzheimer's dementia and mild cognitive impairment

BACKGROUND

Vitamin E occurs naturally in the diet. It has several biological activities, including functioning as an antioxidant to scavenge toxic free radicals. Evidence that free radicals may contribute to the pathological processes behind cognitive impairment has led to interest in the use of vitamin E supplements to treat mild cognitive impairment (MCI) and Alzheimer's disease (AD). This is an update of a Cochrane Review first published in 2000, and previously updated in 2006 and 2012.

OBJECTIVES

To assess the efficacy of vitamin E in the treatment of MCI and dementia due to AD.

SEARCH METHODS

We searched the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (ALOIS), the Cochrane Library, MEDLINE, Embase, PsycINFO, CINAHL, LILACS as well as many trials databases and grey literature sources on 22 April 2016 using the terms: "Vitamin E", vitamin-E, alpha-tocopherol.

SELECTION CRITERIA

We included all double-blind, randomised trials in which treatment with any dose of vitamin E was compared with placebo in people with AD or MCI.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures according to the Cochrane Handbook for Systematic Reviews of Interventions. We rated the quality of the evidence using the GRADE approach. Where appropriate we attempted to contact authors to obtain missing information.

MAIN RESULTS

Four trials met the inclusion criteria, but we could only extract outcome data in accordance with our protocol from two trials, one in an AD population (n = 304) and one in an MCI population (n = 516). Both trials had an overall low to unclear risk of bias. It was not possible to pool data across studies owing to a lack of comparable outcome measures.In people with AD, we found no evidence of any clinically important effect of vitamin E on cognition, measured with change from baseline in the Alzheimer's Disease Assessment Scale - Cognitive subscale (ADAS-Cog) over six to 48 months (mean difference (MD) -1.81, 95% confidence interval (CI) -3.75 to 0.13, P = 0.07, 1 study, n = 272; moderate quality evidence). There was no evidence of a difference between vitamin E and placebo groups in the risk of experiencing at least one serious adverse event over six to 48 months (risk ratio (RR) 0.86, 95% CI 0.71 to 1.05, P = 0.13, 1 study, n = 304; moderate quality evidence), or in the risk of death (RR 0.84, 95% CI 0.52 to 1.34, P = 0.46, 1 study, n = 304; moderate quality evidence). People with AD receiving vitamin E showed less functional decline on the Alzheimer's Disease Cooperative Study/Activities of Daily Living Inventory than people receiving placebo at six to 48 months (mean difference (MD) 3.15, 95% CI 0.07 to 6.23, P = 0.04, 1 study, n = 280; moderate quality evidence). There was no evidence of any clinically important effect on neuropsychiatric symptoms measured with the Neuropsychiatric Inventory (MD -1.47, 95% CI -4.26 to 1.32, P = 0.30, 1 study, n = 280; moderate quality evidence).We found no evidence that vitamin E affected the probability of progression from MCI to probable dementia due to AD over 36 months (RR 1.03, 95% CI 0.79 to 1.35, P = 0.81, 1 study, n = 516; moderate quality evidence). Five deaths occurred in each of the vitamin E and placebo groups over the 36 months (RR 1.01, 95% CI 0.30 to 3.44, P = 0.99, 1 study, n = 516; moderate quality evidence). We were unable to extract data in accordance with the review protocol for other outcomes. However, the study authors found no evidence that vitamin E differed from placebo in its effect on cognitive function, global severity or activities of daily living . There was also no evidence of a difference between groups in the more commonly reported adverse events.

AUTHORS' CONCLUSIONS

We found no evidence that the alpha-tocopherol form of vitamin E given to people with MCI prevents progression to dementia, or that it improves cognitive function in people with MCI or dementia due to AD. However, there is moderate quality evidence from a single study that it may slow functional decline in AD. Vitamin E was not associated with an increased risk of serious adverse events or mortality in the trials in this review. These conclusions have changed since the previous update, however they are still based on small numbers of trials and participants and further research is quite likely to affect the results.

Effect of Multimorbidity on Health-Related Quality of Life in Adults Aged 55 Years or Older: Results from the SU.VI.MAX 2 Cohort

Introduction

Multimorbid chronic diseases are usually considered separately in trials. Here, we aimed to describe overall multimorbidity patterns in adults aged 55 years or older and assess their effect on health-related quality of life (HRQoL).

Methods

We used data for 5,647 participants included in the SUpplémentation en VItamines et Minéraux AntioXydants 2 (SU.VI.MAX 2) population-based trial. HRQoL was assessed by the French versions of the Medical Outcome Study Short Form 36 and the Duke Health Profile. An exploratory factor analysis was used to determine multimorbidity patterns, and a multimorbidity score for each resulting pattern was calculated. Adjusted multiple linear regression was used to examine the association between the identified multimorbidity and HRQoL scores by gender and for each age group (55–59, 60–64, 65–69, ≥ 70 years).

Results

More than 63% of the sample reported two or more chronic conditions (from 55.8% for those 55–59 years to 74.4% for those ≥ 70 years). Multimorbidity was more common among women than men (67.3% vs 60%). Two different multimorbidity patterns were identified. Pattern A was represented mainly by mental illness and bone impairments. Pattern B was represented mainly by cardiovascular and metabolic disorders. After adjusting for covariates, a high pattern A score was associated with reduced HRQoL for the physical and mental components of each HRQoL questionnaire, and a high pattern B score was associated with reduced HRQoL for only the physical component of each questionnaire. These multimorbidity scores affected HRQoL differently by age group.

Conclusion

Our study used a novel methodological approach to account for multimorbidity patterns in determining the link with chronic conditions. These multimorbidity scores (counted and weighted) can be used in clinical research to control for the effect of multimorbidity on patients’ HRQoL and may be useful for clinical practice.

Clinical Trial Registration

Clinicaltrial.gov (number NCT00272428).

Treatment strategies in Alzheimer's disease: a review with focus on selenium supplementation

Alzheimer's disease (AD) is a neurodegenerative disorder presenting one of the biggest healthcare challenges in developed countries. No effective treatment exists. In recent years the main focus of AD research has been on the amyloid hypothesis, which postulates that extracellular precipitates of beta amyloid (Aβ) derived from amyloid precursor protein (APP) are responsible for the cognitive impairment seen in AD. Treatment strategies have been to reduce Aβ production through inhibition of enzymes responsible for its formation, or to promote resolution of existing cerebral Aβ plaques. However, these approaches have failed to demonstrate significant cognitive improvements. Intracellular rather than extracellular events may be fundamental in AD pathogenesis. Selenate is a potent inhibitor of tau hyperphosphorylation, a critical step in the formation of neurofibrillary tangles. Some selenium (Se) compounds e.g. selenoprotein P also appear to protect APP against excessive copper and iron deposition. Selenoproteins show anti-inflammatory properties, and protect microtubules in the neuronal cytoskeleton. Optimal function of these selenoenzymes requires higher Se intake than what is common in Europe and also higher intake than traditionally recommended. Supplementary treatment with N-acetylcysteine increases levels of the antioxidative cofactor glutathione and can mediate adjuvant protection. The present review discusses the role of Se in AD treatment and suggests strategies for AD prevention by optimizing selenium intake, in accordance with the metal dysregulation hypothesis. This includes in particular secondary prevention by selenium supplementation to elderly with mild cognitive impairment.

Dietary supplements and disease prevention - a global overview

Dietary supplements are widely used and offer the potential to improve health if appropriately targeted to those in need. Inadequate nutrition and micronutrient deficiencies are prevalent conditions that adversely affect global health. Although improvements in diet quality are essential to address these issues, dietary supplements and/or food fortification could help meet requirements for individuals at risk of deficiencies. For example, supplementation with vitamin A and iron in developing countries, where women of reproductive age, infants and children often have deficiencies; with folic acid among women of reproductive age and during pregnancy; with vitamin D among infants and children; and with calcium and vitamin D to ensure bone health among adults aged ≥65 years. Intense debate surrounds the benefits of individual high-dose micronutrient supplementation among well-nourished individuals because the alleged beneficial effects on chronic diseases are not consistently supported. Daily low-dose multivitamin supplementation has been linked to reductions in the incidence of cancer and cataracts, especially among men. Baseline nutrition is an important consideration in supplementation that is likely to modify its effects. Here, we provide a detailed summary of dietary supplements and health outcomes in both developing and developed countries to help guide decisions about dietary supplement recommendations.

Dietary scores at midlife and healthy ageing in a French prospective cohort

Although nutrition has been advocated as a major determinant of healthy ageing (HA), studies investigating the link between dietary quality and HA are scarce. We investigated the association between adherence to French food-based and nutrient-based guidelines at midlife, as assessed by three dietary scores, and HA. HA was assessed in 2007-2009, among 2329 participants of the SUpplémentation en Vitamines et Minéraux AntioXydants study aged 45-60 years at baseline (1994-1995) and initially free of diabetes, CVD and cancer. HA was defined as not developing any major chronic disease, good physical and cognitive functioning, no limitations in instrumental activities of daily living, no depressive symptoms, no health-related limitations in social life, good overall self-perceived health and no function-limiting pain. Data from repeated 24-h dietary records provided at baseline permitted the computation of the modified French Programme National Nutrition Santé-Guideline Score (mPNNS-GS), the Probability of Adequate Nutrient Intake Dietary Score (PANDiet) and the Diet Quality Index-International (DQI-I). Associations of these scores with HA were assessed by logistic regression. In 2007-2009, 42 % of men and 36 % of women met our criteria of HA. After adjustment for potential confounders, higher scores of the mPNNS-GS (ORquartile 4 v. quartile 1 1·44; 95 % CI 1·10, 1·87; P trend=0·006) and the PANDiet (1·28; 95 % CI 1·00, 1·64; P trend=0·03) were associated with higher odds of HA. We observed no association between DQI-I and HA. In conclusion, this study suggests a beneficial long-term role of high adherence to both food-based and nutrient-based French dietary guidelines for a HA process.

Prospective associations between a dietary index based on the British Food Standard Agency nutrient profiling system and 13-year weight gain in the SU.VI.MAX cohort

BACKGROUND/OBJECTIVES

The scoring of the nutritional quality of individual foods using nutrient profiling systems (NPS) has been suggested as a basis for public health preventive measures. Used for front-of-package labeling, such scoring would help consumers in making healthier food choices. An individual dietary score based on the Food Standards Agency NPS has been developed (FSA-NPS-DI), but its long term association with weight gain has not been investigated. Our objectives were to investigate long-term associations between the FSA-NPS DI and weight gain and overweight/obesity onset in a middle-aged French population.

SUBJECTS/METHODS

Subjects included in the French SU.VI.MAX cohort with at least three dietary records at baseline and available anthropometric measurements at baseline and at a 13-year follow-up examination were included in the study. FSA-NPS DI at baseline was computed for each subject. Association between FSA-NPS DI and weight and BMI gain were investigated with ANCOVA and associations with overweight/obesity onset with logistic regression models.

RESULTS

Higher baseline FSA-NPS DI (reflecting a poorer diet) was associated with higher weight and BMI gain (beta Q4 versus Q1=0.70; (95%CI 0.01; 1.38), P for trend=0.04). A 16% higher risk of obesity for a 1 point increase of FSA-NPS DI was observed only in men.

CONCLUSIONS

Our results suggest that a shift in nutritional quality of the foods and beverages within an individual's diet, as expressed by the FSA-NPS DI would be associated with lower weight gain in the long term. Using the FSA-NPS as a basis for food labeling might therefore contribute to tackle obesity.

Healthy Aging 5 Years After a Period of Daily Supplementation With Antioxidant Nutrients: A Post Hoc Analysis of the French Randomized Trial SU.VI.MAX

This study's objective was to investigate healthy aging in older French adults 5 years after a period of daily nutritional-dose supplementation with antioxidant nutrients. The study was based on the double-blind, randomized trial, Supplementation with Antioxidant Vitamins and Minerals (SU.VI.MAX) Study (1994-2002) and the SU.VI.MAX 2 Follow-up Study (2007-2009). During 1994-2002, participants received a daily combination of vitamin C (120 mg), β-carotene (6 mg), vitamin E (30 mg), selenium (100 µg), and zinc (20 mg) or placebo. Healthy aging was assessed in 2007-2009 by using multiple criteria, including the absence of major chronic disease and good physical and cognitive functioning. Data from a subsample of the SU.VI.MAX 2 cohort, initially free of major chronic disease, with a mean age of 65.3 years in 2007-2009 (n = 3,966), were used to calculate relative risks. Supplementation was associated with a greater healthy aging probability among men (relative risk = 1.16, 95% confidence interval: 1.04, 1.29) but not among women (relative risk = 0.98, 95% confidence interval: 0.86, 1.11) or all participants (relative risk = 1.07, 95% confidence interval: 0.99, 1.16). Moreover, exploratory subgroup analyses indicated effect modification by initial serum concentrations of zinc and vitamin C. In conclusion, an adequate supply of antioxidant nutrients (equivalent to quantities provided by a balanced diet rich in fruits and vegetables) may have a beneficial role for healthy aging.

Improving Cognition in the Elderly With Nutritional Supplements

With increasing life expectancies in most Western populations, the number of people experiencing age-associated cognitive impairment is increasing. Research is needed to identify factors that may help the elderly maintain or even improve cognitive function in the face of advancing age. This review evaluates whether dietary supplementation with natural pharmaceuticals can be used as a means to improve cognitive function or limit cognitive decline. The evidence surrounding popular supplements such as Ginkgo biloba, fish oils, Bacopa monnieri, polyphenol extracts, and vitamins is reviewed briefly. Potential mechanisms of action are also highlighted. This review also discusses challenges surrounding cognitive testing in psychopharmacological research, highlighting discrepancies between the domains of human cognition as described by contemporary models and as measured in clinical trials.

Improved blood biomarkers but no cognitive effects from 16 weeks of multivitamin supplementation in healthy older adults

Supplementation with vitamins, minerals and phytonutrients may be beneficial for cognition, especially in older adults. The aim of this study was to assess the effects of multivitamin supplementation in older adults on cognitive function and associated blood biomarkers. In a randomised, double blind, placebo-controlled trial, healthy women (n = 68) and men (n = 48) aged 55–65 years were supplemented daily for 16 weeks with women’s and men’s formula multivitamin supplements. Assessments at baseline and post-supplementation included computerised cognitive tasks and blood biomarkers relevant to cognitive aging. No cognitive improvements were observed after supplementation with either formula; however, several significant improvements were observed in blood biomarkers including increased levels of vitamins B₆ and B₁₂ in women and men; reduced C-reactive protein in women; reduced homocysteine and marginally reduced oxidative stress in men; as well as improvements to the lipid profile in men. In healthy older people, multivitamin supplementation improved a number of blood biomarkers that are relevant to cognition, but these biomarker changes were not accompanied by improved cognitive function.

Midlife plasma vitamin D concentrations and performance in different cognitive domains assessed 13 years later

25-Hydroxyvitamin D (25(OH)D) insufficiency is very common in many countries. Yet, the extent to which 25(OH)D status affects cognitive performance remains unclear. The objective of the present study was to evaluate the cross-time association between midlife plasma 25(OH)D concentrations and subsequent cognitive performance, using a subsample from the French 'SUpplémentation en Vitamines et Minéraux AntioXydants' randomised trial (SU.VI.MAX, 1994-2002) and the SU.VI.MAX 2 observational follow-up study (2007-9). 25(OH)D concentrations were measured in plasma samples drawn in 1994-5, using an electrochemoluminescent immunoassay. Cognitive performance was evaluated in 2007-9 with a neuropsychological battery including phonemic and semantic fluency tasks, the RI-48 (rappel indicé-48 items) cued recall test, the Trail Making Test and the forward and backward digit span. Cognitive factors were extracted via principal component analysis (PCA). Data from 1009 individuals, aged 45-60 years at baseline, with available 25(OH)D and cognitive measurements were analysed by multivariable linear regression models and ANCOVA, stratified by educational level. PCA yielded two factors, designated as 'verbal memory' (strongly correlated with the RI-48 and phonemic/semantic fluency tasks) and 'short-term/working memory' (strongly correlated with the digit span tasks). In the fully adjusted regression model, among individuals with low education, there was a positive association between 25(OH)D concentrations and the 'short-term/working memory' factor (P=0.02), mainly driven by the backward digit span (P=0.004). No association with either cognitive factor was found among better educated participants. In conclusion, higher midlife 25(OH)D concentrations were linked to better outcomes concerning short-term and working memory. However, these results were specific to subjects with low education, suggesting a modifying effect of cognitive reserve.

Diet and cognitive decline at middle age: the role of antioxidants

To assess the relationship between dietary intake of antioxidants (vitamin C, vitamin E, β-carotene, lutein, flavonoids and lignans) and cognitive decline at middle age, analyses were performed on data from the population based Doetinchem Cohort Study. Habitual diet and cognitive function were assessed twice with a 5-year interval in 2613 persons aged 43–70 year at baseline (1995–2002). Diet was assessed with a validated 178-item semi-quantitative FFQ. Cognitive function was assessed with a neuropsychological test battery, consisting of the 15 Words Learning Test, the Stroop Test, the Word Fluency test, and the Letter Digit Substitution Test. Scores on global cognitive function, memory, processing speed, and cognitive flexibility were calculated. In regression analyses, quintiles of antioxidant intake were associated with change in cognitive domain scores. Results showed that higher lignan intake was linearly associated with less decline in global cognitive function (P= 0·01), memory (P< 0·01) and processing speed (P= 0·04), with about two times less declines in the highest v. the lowest quintile. In the lowest quintile of vitamin E intake, decline in memory was twice as fast as in all higher quintiles (P< 0·01). Global cognitive decline in the highest lutein intake group was greater than in the lowest intake group (P< 0·05). Higher flavonoid intake was associated with greater decline in cognitive flexibility (P for trend = 0·04). Intakes of other antioxidants were not associated with cognitive decline. We conclude that within the range of a habitual dietary intake, higher intake of lignans is associated with less cognitive decline at middle age.

Dietary antioxidant intake and its association with cognitive function in an ethnically diverse sample of US adults

BACKGROUND

Dietary antioxidants can inhibit reactions accompanying neurodegeneration and thus prevent cognitive impairment. We describe associations of dietary antioxidants with cognitive function in a large biracial population, while testing moderation by sex, race, and age and mediation by depressive symptoms.

METHODS

This was a cross-sectional analysis of 1274 adults (541 men and 733 women) aged 30 to 64 years at baseline (mean [standard deviation] = 47.5 [9.3]) in the Healthy Aging in Neighborhoods of Diversity Across the Lifespan Study, Baltimore city, MD. Cognitive performance in the domains of memory, language/verbal, attention, spatial, psychomotor speed, executive function, and global mental status were assessed. The 20-item Center for Epidemiologic Studies Depression Scale was used to measure depressive symptoms. Dietary intake was assessed with two 24-hour recalls, estimating daily consumption of total carotenoids and vitamins A, C, and E per 1000 kcal.

RESULTS

Among key findings, 1 standard deviation (∼ 2.02 mg/1000 kcal) higher vitamin E was associated with a higher score on verbal memory, immediate recall (β = +0.64 [0.19], p = .001), and better language/verbal fluency performance (β = +0.53 [0.16], p = .001), particularly among the younger age group. Women with higher vitamin E intake (β = +0.68 [0.21], p = .001) had better performance on a psychomotor speed test. The vitamin E-verbal memory association was partially mediated by depressive symptoms (proportion mediated = 13%-16%).

CONCLUSIONS

In sum, future cohort studies and dietary interventions should focus on associations of dietary vitamin E with cognitive decline, specifically for domains of verbal memory, verbal fluency, and psychomotor speed.

Selenium, selenoproteins and neurodegenerative diseases

A review of selenium's essential role in normal brain function and its potential involvement in neurodegenerative diseases.

Midlife dietary vitamin D intake and subsequent performance in different cognitive domains

BACKGROUND/AIMS

We evaluated the cross-time association between midlife dietary vitamin D intake and subsequent cognitive performance in a French general-population sample.

METHODS

Data from participants in both the SU.VI.MAX trial (1994-2002) and the SU.VI.MAX 2 observational study (2007-2009) were used. Dietary intake was estimated at baseline from 6 or more 24-hour records. Cognitive performance was evaluated 13 years later with a comprehensive neuropsychological battery. Parameter estimates of cognitive performance according to quartiles (Q) of vitamin D intake were estimated via ANCOVA.

RESULTS

In a sample of 1,990 aging adults, principal component analyses yielded two cognitive factors - for episodic/semantic memory and short-term memory/executive function; however, neither one displayed associations with dietary vitamin D intake. Midlife vitamin D intake was significantly and positively associated with scores on the forward digit span task measuring short-term memory (fully adjusted model: mean difference, Q4 vs. Q1 = 1.95; 95% CI 0.37-3.53; p(trend) = 0.03). No significant interaction with either sex or lifetime sun exposure was found.

CONCLUSIONS

Midlife vitamin D intake exhibited a cross-time and domain-specific association with cognition in the context of aging. Further investigations in this area of prevention are warranted given the rapidly expanding elderly population and the absence of curative treatment for dementia.

Clustering of midlife lifestyle behaviors and subsequent cognitive function: a longitudinal study

OBJECTIVES

We examined the association between individual and clustered lifestyle behaviors in middle age and later in cognitive functioning.

METHODS

Middle-aged participants (n = 2430) in the Supplémentation en Vitamines et Minéraux Antioxydant study self-reported their low physical activity, sedentary behavior, alcohol use, smoking, low fruit and vegetable consumption, and low fish consumption. We assessed cognition 13 years later via 6 neuropsychological tests. After standardization, we summed the scores for a composite cognitive measure. We estimated executive functioning and verbal memory scores using principal component analysis. We estimated the mean differences (95% confidence intervals [CIs]) in cognitive performance by the number of unhealthy behaviors using analysis of covariance. We identified latent unhealthy behavior factor via structural equation modeling.

RESULTS

Global cognitive function and verbal memory were linearly, negatively associated with the number of unhealthy behaviors: adjusted mean differences = -0.36 (95% CI = -0.69, -0.03) and -0.46 (95% CI = -0.80, -0.11), respectively, per unit increase in the number of unhealthy behaviors. The latent unhealthy behavior factor with low fruit and vegetable consumption and low physical activity as main contributors was associated with reduced verbal memory (RMSEA = 0.02; CFI = 0.96; P = .004). No association was found with executive functioning.

CONCLUSIONS

Comprehensive public health strategies promoting healthy lifestyles might help deter cognitive aging.