Valentina A. Andreeva

Total and Specific Polyphenol Intakes in Midlife Are Associated with Cognitive Function Measured 13 Years Later

Polyphenols, and in particular flavonoids, are omnipresent plant-food components displaying biochemical properties possibly beneficial to brain health. We sought to evaluate the long-term association between total and class-specific polyphenol intake and cognitive performance. Polyphenol intake was estimated using the Phenol-Explorer database applied to at least six 24-h dietary records collected in 1994-1996 as part of the SU.VI.MAX (Supplémentation en Vitamines et Minéraux Antioxydants) study. The cognitive performance of 2574 middle-aged adults participating in the cohort was assessed in 2007-2009 using the following four neuropsychological tests: phonemic and semantic fluency, the RI-48 Cued Recall test, the Trail Making test, and Forward and Backward Digit Span. Inter-correlations among the test scores were estimated with principal component analysis. Associations between polyphenol intake and cognition were assessed by multivariate linear regression and ANCOVA. In multivariate models, high total polyphenol intake was associated with better language and verbal memory (P = 0.01) but not with executive functioning (P = 0.09). More specifically, intake of catechins (P = 0.001), theaflavins (P = 0.002), flavonols (P = 0.01), and hydroxybenzoic acids (P = 0.0004) was positively associated with language and verbal memory, especially with episodic memory assessed by the RI-48 test. In contrast, negative associations between scores on executive functioning and intake of dihydrochalcones (P = 0.01), catechins (P = 0.01), proanthocyanidins (P = 0.01), and flavonols (P = 0.01) were detected. High intake of specific polyphenols, including flavonoids and phenolic acids, may help to preserve verbal memory, which is a salient vulnerable domain in pathological brain aging. Further investigations are needed to clarify the observed negative associations regarding executive functioning.

Mediterranean diet and cognitive function: a French study

BACKGROUND Evidence on the association between Mediterranean diet (MedDiet) adherence and cognition is presently inconsistent. OBJECTIVES The aims of this study were to investigate the association between midlife MedDiet adherence and cognitive performance assessed 13 y later among participants in the SU.VI.MAX (Supplementation with Vitamins and Mineral Antioxidants) study and to test the hypothesis of effect modification by occupation and education as cognitive reserve markers. DESIGN A Mediterranean Diet Score (MDS) and a Mediterranean-Style Dietary Pattern Score (MSDPS) were estimated by using repeated 24-h dietary records (1994-1996) from 3083 middle-aged subjects. Cognitive performance was assessed in 2007-2009 by using 6 neuropsychological tests, and a composite score was built. Subgroup analyses were performed according to occupational and educational status. Mean differences and 95% CIs were estimated through covariance analyses. RESULTS After potential confounders were accounted for, no association between MDS or MSDPS and cognitive scores was detected except for a lower phonemic fluency score with decreasing MSDPS (P = 0.048) and a lower backward digit span score with decreasing MDS (P = 0.03). In turn, a low MDS was related to a lower composite cognitive score in the small subsample of manual workers (n = 178, P-interaction = 0.04) who could be hypothesized to have low cognitive reserve. MedDiet adherence did not interact with educational level in relation to cognitive function. CONCLUSION This study did not find support for a beneficial effect of MedDiet adherence on cognitive function, irrespective of educational level, which is the strongest indicator of cognitive reserve.

A Healthy Dietary Pattern at Midlife Is Associated with Subsequent Cognitive Performance

Few studies have investigated the long-term impact of overall dietary patterns (DP) on cognition. We evaluated the association between empirically derived DP in midlife and cognitive performance 13 y later. Dietary data were based on 24-h dietary records obtained from a subsample of the Supplémentation en Vitamines et Minéraux Antioxydant Study. Cognitive performance was assessed via a battery of neuropsychological tests that included verbal fluency, the RI-48 cued recall test, the trail-making test, and forward and backward digit span. Three composite variables, for global cognitive function, verbal memory, and executive functioning, were built. The multivariate analyses were adjusted for baseline characteristics (age, gender, intervention group, education, alcohol and energy intake, number of dietary records, physical activity, BMI, tobacco use, self-reported memory troubles, diabetes, hypertension, and, for women, menopausal status and hormone therapy use), follow-up time, history of cardiovascular disease, and depressive symptoms. Adjusted means ± SEM of composite variables across quartiles (Q4 vs. Q1) of DP were estimated using ANCOVA. A healthy and a traditional DP were identified. In the multivariate model, the healthy pattern was associated with better global cognitive function (50.1 ± 0.7 vs. 48.9 ± 0.7; P-trend = 0.001) and verbal memory (49.7 ± 0.4 vs. 48.7 ± 0.4; P-trend = 0.01). These relationships were stronger in participants scoring below the gender-specific median values for energy intake (<2490 kcal for men and <1810 for women) than in those scoring at or above those values. Adherence to a healthy DP in middle life may help preserve global cognitive function, especially verbal memory, when total energy intake is regulated.

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

BACKGROUND Antioxidant properties of some vitamins and trace elements may help to prevent cognitive decline. OBJECTIVE The aim of the current study was to estimate the long-term effects of antioxidant nutrient supplementation on the cognitive performance of participants in the Supplementation in Vitamins and Mineral Antioxidants (SU.VI.MAX) study 6 y after the end of the trial. DESIGN This study included 4447 French participants aged 45-60 y who were enrolled in the SU.VI.MAX study (1994-2002), which was a double-blind, placebo-controlled, randomized trial. From 1994 to 2002, participants received daily vitamin C (120 mg), β-carotene (6 mg), vitamin E (30 mg), selenium (100 μg), and zinc (20 mg) in combination or as a placebo. In 2007-2009, the cognitive performance of participants was assessed with 4 neuropsychological tests (6 tasks). Principal components analysis (PCA) was performed to identify cognitive-function summary scores. Associations between antioxidant supplementation and cognitive functions, in the full sample and by subgroups, were estimated through ANOVA and expressed as mean differences and 95% CIs. Subgroup analyses were performed according to baseline characteristics. RESULTS Subjects receiving active antioxidant supplementation had better episodic memory scores (mean difference: 0.61; 95% CI: 0.02, 1.20). PCA indicated 2 factors that were interpreted as showing verbal memory and executive functioning. Verbal memory was improved by antioxidant supplementation only in subjects who were nonsmokers or who had low serum vitamin C concentrations at baseline. CONCLUSION This study supports the role of an adequate antioxidant nutrient status in the preservation of verbal memory under certain conditions. This trial was registered at clinicaltrials.gov as NCT00272428.

Cross-sectional and longitudinal associations of different sedentary behaviors with cognitive performance in older adults.

Background The deleterious health effects of sedentary behaviors, independent of physical activity, are increasingly being recognized. However, associations with cognitive performance are not known. Purpose To estimate the associations between different sedentary behaviors and cognitive performance in healthy older adults. Methods Computer use, time spent watching television (TV), time spent reading and habitual physical activity levels were self-reported twice (in 2001 and 2007) by participants in the SUpplémentation en Vitamines et MinérauX (SU.VI.MAX and SU.VI.MAX2) study. Cognitive performance was assessed at follow-up (in 2007–2009) via a battery of 6 neuropsychological tests used to derive verbal memory and executive functioning scores. Analyses (ANCOVA) were performed among 1425 men and 1154 women aged 65.6±4.5 at the time of the neuropsychological evaluation. We estimated mean differences with 95% confidence intervals (95%CI) in cognitive performance across categories of each type of sedentary behavior. Results In multivariable cross-sectional models, compared to non-users, participants using the computer for >1 h/day displayed better verbal memory (mean difference = 1.86; 95%CI: 0.95, 2.77) and executive functioning (mean difference = 2.15; 95%CI: 1.22, 3.08). A negative association was also observed between TV viewing and executive functioning. Additionally, participants who increased their computer use by more than 30 min between 2001 and 2007 showed better performance on both verbal memory (mean difference = 1.41; 95%CI: 0.55, 2.27) and executive functioning (mean difference = 1.41; 95%CI: 0.53, 2.28) compared to those who decreased their computer use during that period. Conclusion Specific sedentary behaviors are differentially associated with cognitive performance. In contrast to TV viewing, regular computer use may help maintain cognitive function during the aging process. Clinical Trial Registration clinicaltrial.gov (number NCT00272428).

Omega 3 fatty acids and cognitive health in older people

Oily fish and other sources of long-chain n-3 polyunsaturated fatty acids (n-3 LCPs) have been proposed as protective against dementia and age related cognitive impairment. The basic mechanisms underlying these proposed benefits have been postulated and experimental studies supporting the plausibility of the putative effects have been published. Observational epidemiological and case control studies also largely support a protective role of fish consumption on cognitive function with advancing age, albeit with important unexplained heterogeneity in findings. In this review we report the findings of the latest Cochrane review on the benefits of n-3 LCP supplementation on cognitive function among cognitively healthy older people and expand the review by including trials conducted with individuals with prevalent poor cognitive function or dementia. We identified seven relevant trials, four among cognitively healthy older people, and three among individuals with pre-existing cognitive decline or dementia, and overall conclude that there is no evidence to support the routine use of n-3 LCPs supplements for the prevention, or amelioration, of cognitive decline in later life. We identified several challenges in the design of intervention studies for the prevention of dementia and cognitive decline in older people that require careful consideration especially in recruitment and retention in long-term trials. Whether the lack of agreement in findings from mechanistic and observational data and from intervention studies reflects a real absence of benefit on cognitive function from n-3 LCP supplementation, or whether it reflects intrinsic limitations in the design of published studies remains open to question.

Cognitive function after supplementation with B vitamins and long-chain omega-3 fatty acids: ancillary findings from the SU.FOL.OM3 randomized trial

BACKGROUND Rapid aging of the population worldwide necessitates a heightened concern about preventing cognitive decline. OBJECTIVE We investigated the effects of B vitamins and omega-3 (n-3) fatty acid supplementation on cognition in a high-risk population. DESIGN This was an ancillary study of the SU.FOL.OM3 (SUpplementation with FOLate, vitamins B-6 and B-12 and/or OMega-3 fatty acids) secondary prevention trial conducted in France between 2003 and 2009. The present sample included 1748 men and women aged 45-80 y with a history of myocardial infarction, unstable angina, or ischemic stroke and who were recruited via a network of 417 physicians. With the use of block randomization with stratification by sex, age, prior cardiovascular disease, and city of residence, participants were assigned in a 2 × 2 factorial design to 1 of 4 groups: 1) 5-methyltetrahydrofolate (folate, 0.56 mg) and vitamins B-6 (3 mg) and B-12 (0.02 mg), 2) eicosapentaenoic and docosahexaenoic acids (600 mg) in a 2:1 ratio, 3) B vitamins and omega-3 fatty acids, or 4) placebo. Cognitive function after 4 y of supplementation was assessed with the French version of the modified Telephone Interview for Cognitive Status. RESULTS No significant main effects of group assignment on cognitive function were found; however, we found some evidence of disease history- and age-specific effects. In the subgroup with prior stroke, for example, participants assigned to receive B vitamins plus omega-3 fatty acids were significantly less likely to have a decreased score on the temporal orientation task than were those assigned to receive placebo (odds ratio: 0.43; 95% CI: 0.21, 0.86). CONCLUSIONS If present, dietary effects on cognition are likely group-specific. These results could be useful in interventions aimed at preventing cognitive decline in high-risk individuals. This trial is registered at controlled-trials.com as ISRCTN41926726.

Association between dietary scores and 13-year weight change and obesity risk in a French prospective cohort

BACKGROUND/OBJECTIVES:The relationship between diet quality and development of obesity is complex and unresolved. The aim of this study was to assess and compare the predictive value of six different dietary scores on both relative weight change and the risk of obesity after 13 years of follow-up in adults aged 45 years and older.SUBJECTS/METHODS:Six scores reflecting adherence to different nutritional recommendations (the French Programme National Nutrition Santé-Guideline Score (PNNS-GS), the Dietary Guidelines for Americans Index (DGAI), the Diet Quality Index-International (DQI-I), the Mediterranean Diet Scale (MDS), the relative Mediterranean Diet Score (rMED) and the Mediterranean Style Dietary Pattern Score (MSDPS)) were estimated in 3151 participants in the French SU.VI.MAX (SUpplémentation en VItamines et Minéraux AntioXydants) study. Associations of dietary scores with 13-year weight change were assessed through multivariate linear regression models, and obesity risk was analyzed with logistic regression, providing odds ratios (OR) and 95% confidence intervals (CI).RESULTS:Except for the MSDPS, higher scores, that is, better adherence to nutritional guidelines or to a Mediterranean diet, were associated with lower weight gain in men (all P-value for trend <0.05). In addition, among men, ORs for becoming obese after 13 years associated with a 1 s.d. increase in dietary scores ranged from 0.63, 95% CI: 0.51, 0.78 for DGAI to 0.72, 95% CI: 0.59, 0.88 for MDS. These associations were weaker or not statistically significant in women.CONCLUSION:Overall, the six dietary scores predicted obesity risk equally well. Among French adults, strong adherence to dietary guidelines appears to be protective with regard to weight gain and obesity, especially in men.

Comparison of the sociodemographic characteristics of the large NutriNet-Santé e-cohort with French Census data: the issue of volunteer bias revisited

Background A recurring concern in traditional and in Web-based studies pertains to non-representativeness due to volunteer bias. We investigated this issue in an ongoing, large population-based e-cohort. Methods The sample included 122 912 individuals enrolled in the Internet-based, nutrition-focused NutriNet-Santé study between May 2009 and March 2014, with complete baseline data. Participants were recruited via recurrent multimedia campaigns and other traditional and online strategies. Individuals aged 18+ years, residing in France and having Internet access, were eligible for enrolment. Their sociodemographic characteristics were compared with the corresponding 2009 Census data via χ2 goodness-of-fit tests. The effectiveness of statistical weighting of the e-cohort data was also explored. Results The sample exhibited marked geographical and sociodemographic diversity, including volunteers belonging to typically under-represented subgroups in traditional surveys (unemployed, immigrants, the elderly). Nonetheless, the proportions of women, relatively well-educated individuals and those who are married or cohabiting, were notably larger compared with the corresponding national figures (women: 78.0% vs 52.4%; postsecondary education: 61.5% vs 24.9%; married or cohabiting: 70.8% vs 62.0%, respectively; all p<0.0001). Conclusions There were notable sociodemographic differences between the general French population and this general population-based e-cohort, some of which were corrected by statistical weighting. The findings bear on the potential generalisability of future investigations in the context of e-epidemiology.

Fruit and vegetable intake and cognitive function in the SU.VI.MAX 2 prospective study

BACKGROUND Current hypotheses suggest that intake of fruit and vegetables (FVs) protects against age-related cognitive impairment. OBJECTIVE We examined the 13-y association between FV intake and cognitive performance in a sample of French adults. DESIGN A total of 2533 subjects aged 45-60 y at baseline, who were part of the Supplementation with Antioxidant Vitamins and Minerals 2 (SU.VI.MAX 2) cohort, were selected. FV intake was estimated at baseline in participants who had completed at least six 24-h dietary records. Cognitive performance was assessed 13 y after baseline and included an evaluation of verbal memory (RI-48 cued recall, semantic, and phonemic fluency tests) and executive function (trail-making and forward and backward digit span tests). Principal components analysis was performed to account for correlations in test scores. The relation between cognitive performance and quartiles of FV intake was assessed by multivariate linear regression analyses. RESULTS Intakes of FVs (P-trend = 0.02), fruit alone (P-trend = 0.04), vitamin C-rich FVs (P-trend = 0.03), vitamin C (P-trend = 0.005), and vitamin E (P-trend = 0.04) were positively associated with verbal memory scores. In contrast, intakes of FVs (P-trend = 0.006), vegetables alone (P-trend = 0.03), and β-carotene-rich FVs (P-trend = 0.02) were negatively associated with executive functioning scores. CONCLUSIONS FVs might have a differential effect on cognition according to groups of FVs and type of cognitive function. Further research using sensitive and reliable measures of various types of cognitive function is needed to clarify the effect of individual FV groups and nutrients. This trial is registered at clinicaltrials.gov as NCT00272428.