Serum folate, vitamin B-12 and cognitive function in middle and older age: The HAPIEE study

The Importance of Nutrition in Menopause and Perimenopause-A Review

Menopause is associated with an increased prevalence of obesity, metabolic syndrome, cardiovascular diseases, and osteoporosis. These diseases and unfavorable laboratory values, which are characteristic of this period in women, can be significantly improved by eliminating and reducing dietary risk factors. Changing dietary habits during perimenopause is most effectively achieved through nutrition counseling and intervention. To reduce the risk factors of all these diseases, and in the case of an already existing disease, dietary therapy led by a dietitian should be an integral part of the treatment. The following review summarizes the recommendations for a balanced diet and fluid intake, the dietary prevention of cardiovascular diseases, the role of sleep, and the key preventive nutrients in menopause, such as vitamin D, calcium, vitamin C, B vitamins, and protein intake. In summary, during the period of perimenopause and menopause, many lifestyle factors can reduce the risk of developing all the diseases (cardiovascular disease, insulin resistance, type 2 diabetes mellitus, osteoporosis, and tumors) and symptoms characteristic of this period.

Homocysteine, Cognitive Functions, and Degenerative Dementias: State of the Art

There is strong evidence that homocysteine is a risk factor not only for cerebrovascular diseases but also for degenerative dementias. A recent consensus statement renewed the importance and the role of high levels of homocysteine in cognitive decline in several forms of degenerative dementia, such as Alzheimer's disease. Although the molecular mechanisms by which homocysteine causes cell dysfunction are known, both the impact of homocysteine on specific cognitive functions and the relationship between homocysteine level and non-Alzheimer dementias have been poorly investigated. Most of the studies addressing the impact of hyperhomocysteinemia on dementias have not examined the profile of performance across different cognitive domains, and have only relied on screening tests, which provide a very general and coarse-grained picture of the cognitive status of the patients. Yet, trying to understand whether hyperhomocysteinemia is associated with the impairment of specific cognitive functions would be crucial, as it would be, in parallel, learning whether some brain circuits are particularly susceptible to the damage caused by hyperhomocysteinemia. These steps would allow one to (i) understand the actual role of homocysteine in the pathogenesis of cognitive decline and (ii) improve the diagnostic accuracy, differential diagnosis and prognostic implications. This review is aimed at exploring and revising the state of the art of these two strictly related domains. Suggestions for future research are provided.

Association between Intake of Total Dairy and Individual Dairy Foods and Markers of Folate, Vitamin B6 and Vitamin B12 Status in the U.S. Population

Vitamin B6, B12 and folate are required for energy metabolism and have been identified as nutrients of concern for certain population groups. This study examined the cross-sectional association between the consumption of dairy (total dairy, milk, yogurt and cheese) and biomarkers and adequacy for these nutrients in a nationally representative sample. Twenty-four-hour dietary recall data and concentrations of RBC folate (ng/mL), serum folate (ng/mL), and serum vitamins B6 (nmol/L) and B12 (pg/mL) were obtained from the National Health and Nutrition Examination Survey 2001−2018 (n = 72,831) and were analyzed by linear and logistic regression after adjusting for demographic variables. Significance was set at p < 0.01. Mean intakes of total dairy were 2.21, 2.17, 1.83 and 1.51 cups eq among consumers aged 2−8, 9−18, 19−50 and 51+ years, respectively. Higher intakes of total dairy as well as individual dairy foods (especially milk and yogurt) were positively associated with serum and RBC folate, serum vitamin B6 and serum B12, and generally, with 9−57% lower risk of inadequate or deficient levels of these vitamins. These findings suggest that encouraging dairy consumption may be an effective strategy for improving micronutrient status and provide continued evidence to support the current dietary recommendations for dairy and dairy products.

Aerobic Fitness, B-Vitamins, and Weight Status Are Related to Selective Attention in Children

There is an increasing prevalence of poor health behaviors during childhood, particularly in terms of physical activity and nutrition. This trend has occurred alongside a growing body of evidence linking these behaviors to cognitive function. B-vitamins are thought to be particularly important in the neural development that occurs during pregnancy, as well as in healthy cognitive aging. However, much less is known regarding the role of B-vitamins during childhood. Given that preadolescent childhood is a critical period for cognitive development, this study investigated the relationship between specific aspects of nutrition, particularly B-vitamins, and related health factors (e.g., body mass, fitness) on selective attention in children. Children (n = 85; 8-11 years) completed a selective attention task to assess inhibition. Participant's dietary intake was collected using the Automated Self-Administered 24-h dietary assessment tool. Correlations between specific nutrients, BMI, fitness, and task performance were investigated. After accounting for demographic variables and total caloric intake, increased B-vitamin intake (i.e., thiamin and folic acid) was associated with shorter reaction times (p's < 0.05), fitness was associated with greater response accuracy (p < 0.05), and increased BMI was related to increased variability in reaction times (p < 0.05). Together, these findings suggest that aspects of health may have unique contributions on cognitive performance. Proper physical health and nutrition are imperative for effective cognitive functioning in preadolescent children. Targeted efforts aimed at health education amongst this population could ensure proper cognitive development during school-age years, providing a strong foundation throughout life.

Risk and protective factors of neurocognitive disorders in older adults in Central and Eastern Europe: A systematic review of population-based studies

BACKGROUND

A wide range of potentially modifiable risk factors, indicating that the onset of neurocognitive disorders can be delayed or prevented, have been identified. The region of Central and Eastern Europe has cultural, political and economic specifics that may influence the occurrence of risk factors and their link to the cognitive health of the population.

OBJECTIVE

We aimed to systematically review population-based studies from Central and Eastern Europe to gather evidence on risk and protective factors for neurocognitive disorders.

METHODS

We searched the electronic databases PubMed, Cochrane Database of Systematic Reviews, PsycINFO, Web of Science, and Embase. The search was performed on 26th of February 2020 and repeated at the end of the review process on 20th May 2021.

RESULTS

We included 25 papers in a narrative synthesis of the evidence describing cardiovascular risk factors (n = 7), social factors (n = 5), oxidative stress (n = 2), vitamins (n = 2), genetic factors (n = 2) and other areas (n = 7). We found that there was a good body of evidence on the association between neurocognitive disorders and the history of cardiovascular disease while there were gaps in research of genetic and social risk factors.

CONCLUSION

We conclude that the epidemiological evidence from this region is insufficient and population-based prospectively followed cohorts should be established to allow the development of preventive strategies at national levels.

Serum folate levels and cognitive performance in the ELSA-Brasil baseline assessment

BACKGROUND

Most studies that analyze the association between serum folate levels and cognitive function either restrict their assessments to specific clinical scenarios or do not include middle-aged individuals, to whom strategies for preventing cognitive impairment may be more feasible.

OBJECTIVE

To examine the association between serum folate levels and cognitive function in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) baseline assessment.

METHODS

Data from 4,571 ELSA-Brasil participants who live in the state of São Paulo, aged 35-74 years, were analyzed. The word list learning, delayed recall, word recognition, verbal fluency, and Trail Making Test Part B consisted in the cognitive tests. For each test, age, sex, and education-specific standardized scores and a global cognitive score were calculated. Crude and adjusted linear regression models were used to examine the associations of serum folate levels with cognitive test scores.

RESULTS

In multivariable-adjusted models, serum folate was not associated with global cognitive score (β=-0.043; 95% confidence interval [95%CI] -0.135 to 0.050 for lowest vs. highest quintile group), nor with any cognitive test performance. We did not find associations between serum folate and global cognitive scores in subgroups stratified by age, sex, or use of vitamin supplements either.

CONCLUSIONS

We did not find significant associations between serum folate and cognitive performance in this large sample, which is characterized by a context of food fortification policies and a consequent low frequency of folate deficiency. Positive results from previous studies may not apply to the increasingly common contexts in which food fortification is implemented, or to younger individuals.

Novel genes associated with folic acid-mediated metabolism in mouse: A bioinformatics study

Folic acid plays an essential role in the central nervous system and cancer. This study aimed to screen genes related to folic acid metabolism. Datasets (GSE80587, GSE65267 and GSE116299) correlated to folic acid were screened in the Gene Expression Omnibus. Weighed gene co-expression network analysis was performed to identify modules associated with sample traits of folic acid and organs (brain, prostate and kidney). Functional enrichment analysis was performed for the eigengenes in modules that were significantly correlated with sample traits. Accordingly, the hub genes and key nodes in the modules were identified using the protein interaction network. A total of 17,252 genes in three datasets were identified. One module, which included 97 genes that were highly correlated with sample traits (including folic acid treatment [cor = -0.57, P = 3e-04] and kidney [cor = -0.68, p = 4e-06]), was screened out. Hub genes, including tetratricopeptide repeat protein 38 (Ttc38) and miR-185, as well as those (including Sema3A, Insl3, Dll1, Msh4 and Snai1) associated with "neuropilin binding", "regulation of reproductive process" and "vitamin D metabolic process", were identified. Genes, including Ttc38, Sema3A, Insl3, Dll1, Msh4 and Snai1, were the novel factors that may be associated with the development of the kidneys and related to folic acid treatment.

Association of folic acid, vitamin B12, and intelligence scores in epileptic children

Epilepsy is a serious childhood disease associated with cognitive impairment. Our aim was to investigate the possible association of serum folic acid, vitamin B12, and intelligence scores in epileptic children. A group of 30 children with established diagnosis of idiopathic epilepsy for at least one year as well as another group of 30 nonepileptic healthy children as the control group were recruited for analysis. Cognitive performance was assessed by a battery of psychological tests that covers verbal and nonverbal intelligence. Serum B12 level was significantly lower in patients than the control group (264.17 ± 58.07, 450.55 ± 134.9, respectively). No significant difference was detected between patients and the control group regarding serum folic acid level. Verbal, performance, and total IQ were significantly lower in patients than the control group (83.2 ± 3.08 vs. 95.8 ± 6.22, 78.4 ± 10.68 vs. 91.3 ± 2.45, and 180.6 ± 6.58 vs. 93.5 ± 3.02, respectively). However, no significant correlation was detected in folic acid, vitamin B 12, and cognitive scores. Epileptic children were five times more at risk of having low IQ (verbal, performance, and total) < 85 than the control group (OR = 4.754, 95% CI 13.047-1031.316, p = .000). In conclusion, children with epilepsy might be at higher risk for cognitive dysfunction than normal children. No significant association was detected between cognitive performance and either folic acid or vitamin B12 in epileptic children receiving sodium valproate. Supplementation of those vitamins should be restricted to those with documented deficiency.

Congruent relations between perceived neighbourhood social cohesion and depressive symptoms among older European adults: An East-West analysis

Rationale

Two gaps in the literature arise on the relationship between social cohesion and depressive disorders. Firstly, there is a lack of studies comparing countries with diverse communal bonds and population-level differences in depression. Secondly, most work on explanatory mechanisms has overwhelmingly focussed on social network and social support pathways.

Objectives

We compared the prospective association between perceived neighbourhood social cohesion and depressive symptoms among older adults in England, the Czech Republic, Poland and Russia; and examined whether psychological and health behavioural pathways mediated this association.

Methods

Harmonized data on 26,081 adults from the English Longitudinal Study of Ageing (ELSA), and the Health, Alcohol and Psychosocial factors In Eastern Europe (HAPIEE) studies were analysed. Prospective associations between perceived neighbourhood social cohesion at baseline and depressive symptoms at follow-up were assessed using multivariable negative binomial regression. The psychological (through control of life, and control at home) and health behavioural (through smoking and drinking) pathways were tested using path analysis.

Results

Low cohesion predicted a higher number of depressive symptoms at follow-up among English (b = 0.106, p = 0.001), Czech (b=0.203, p < 0.001), Polish (0.115, p < 0.001) and Russian adults (b = 0.087, p < 0.001). Indirect effects via psychological mechanisms were strong and explained 64% (Poland), 82% (Russia), 84% (England) and 95% (Czech Republic) of the total indirect effects from low cohesion to elevated symptoms in these populations. Indirect effects via health behaviours were much weaker by comparison.

Conclusions

Prospective associations between low social cohesion and increased depressive symptoms were largely congruent among older adults from England and three Central and Eastern European countries. These associations operated via a psychological, but not a health behavioural, pathway among ageing adults living in diverse parts of Europe.

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Social cohesion protects against depressive symptoms in older European adults.

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The association operates via psychological, but not health behavioural, mechanisms.

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Findings were highly consistent between English, Czech, Polish and Russian adults.

Suboptimal Baseline Serum Vitamin B12 Is Associated With Cognitive Decline in People With Alzheimer's Disease Undergoing Cholinesterase Inhibitor Treatment

Objectives

Cholinesterase inhibitors (ChEIs) are the mainstream treatment for delaying cognitive decline in Alzheimer’s disease (AD). Low vitamin B12 is associated with cognitive dysfunction, and its supplementation has been applied as the treatment for certain types of reversible dementia. The present study hypothesized that baseline serum vitamin B12 is associated with the deterioration of cognitive function in people with AD undergoing ChEI treatment.

Materials and methods

Between 2009 and 2016, medical records from 165 Taiwanese with mild to moderate AD who underwent ChEI treatment for at least 2 years were reviewed. Their baseline serum vitamin B12 levels were measured before treatment initiation. Their cognitive function was assessed using the Mini–Mental State Examination (MMSE) and Cognitive Abilities Screening Instrument (CASI). Student’s t test and multivariable logistic regression were used to analyze the association between cognitive decline and vitamin B12 level. Statistical analyses were performed using SPSS 19.0.

Results

Overall, 122 participants were women. Their median age was 76 years (ranging from 54 to 91). For people with optimal baseline vitamin B12 (above the median level of 436 ng/L), the rates of MMSE and CASI decline were 0.78 ± 1.28 and 2.84 ± 4.21 per year, respectively, which were significantly slower than those with suboptimal vitamin B12 (1.42 ± 1.67 and 4.94 ± 5.88 per year; p = 0.007 and 0.009, respectively). After adjustment for age, sex, education level, hypertension, diabetes, history of stroke, and baseline cognitive function, the baseline serum vitamin B12 level was negatively associated with MMSE and CASI decline.

Conclusion

Suboptimal baseline serum vitamin B12 level is associated with cognitive decline in people with AD undergoing ChEI treatment.

One-Carbon Metabolism Biomarkers and Cognitive Decline in the Very Old: The Newcastle 85+ Study

OBJECTIVES

Although the biological rationale for the association between folate, vitamin B12, and homocysteine with cognitive function seems plausible, conflicting results have been reported. This study aimed to determine the associations between 1-carbon (1-C) metabolism biomarkers (folate, vitamin B12, and homocysteine), and cognitive impairment at baseline and the rate of cognitive decline over 5 years in the very old.

DESIGN

The Newcastle 85+ Study was a prospective longitudinal study of people 85 years old and followed over 5 years in Northeast England.

SETTING

Community-dwelling and institutionalized.

PARTICIPANTS

The analytical sample included 765 very old participants with 1-C metabolism biomarkers and cognitive measures.

MEASUREMENTS

Global cognition was measured by the Standardized Mini-Mental State Examination (SMMSE) at baseline, and at 3 and 5 years of follow-up and, attention-specific cognition with the Cognitive Drug Research (CDR) System at baseline, and at 1.5 and 3.0 years of follow-up. Baseline red blood cell folate (RBC folate), plasma vitamin B12, and total homocysteine (tHcy) concentrations were determined by immunoassay. Linear mixed models were used to estimate the associations between quartiles of 1-C metabolism biomarkers and cognition over 3 (CDR) and 5 years (SMMSE).

RESULTS

Compared with participants in the lowest quartile of RBC folate concentrations (<612 nmol/L), those in the highest quartile of RBC folate concentrations (>1280 nmol/L) had 1 more point on the SMMSE at baseline (β = +1.02, SE = 0.43, P = .02). Those in quartile 4 of tHcy (>21.4 μmol/L) had 1 point less in the SMMSE at baseline than those in the lowest quartile (<13.5 μmol/L) (β = -1.05, SE = 0.46, P = .02). Plasma vitamin B12 was not predictive of global or attention-specific cognition at baseline and at follow-up. None of the 1-C metabolism biomarkers except tHcy was associated with the rate of decline in attention scores over 3 years.

CONCLUSION

RBC folate and tHcy, but not plasma vitamin B12, were associated with better global cognition in the very old at baseline but were not predictive of rate of decline over 5 years.

Folate intake in a Swedish adult population: Food sources and predictive factors

Introduction: Folate plays an important role in cell metabolism, but international studies show that intake is currently below recommendations, especially among women. The study objective was to identify folate food sources by food group, gender, and age group, and to identify factors influencing folate intake, based on food consumption data for Swedish adults in the 2010–11 Riksmaten study.

Methods: The sample included a representative Swedish population aged 18–80 years (n = 1657; 56.3% female). Food and nutrient intakes were estimated from self-reported food records during 4 consecutive days. Food consumption was categorized into 26 food groups. Stepwise regression was used to analyze food groups as folate sources for participants. Factors predicting the highest folate intake (third tertile) were determined by logistic regression analysis.

Results: Vegetables and pulses represented the most important folate source for all age groups and both genders, especially in women aged 45–64 years (49.7% of total folate intake). The next folate source in importance was dairy products for the youngest group (18–30 years), bread for men, and fruit and berries for women. The likelihood of being in the highest tertile of folate intake (odds ratio = 1.69, 95% confidence interval 1.354–2.104) was higher for men. Influencing factors for folate intake in the highest tertile were low body mass index and high educational level in the men, and high educational level, vegetarian diet, organic product consumption, non-smoking, and alcohol consumption within recommendations in the women.

Conclusion: This study describes the folate intake per food group of Swedish adults according to the 2010–11 Riksmaten survey, identifying vegetables and pulses as the most important source. Data obtained on factors related to folate consumption may be useful for the development of specific nutrition education programs to increase the intake of this vitamin in high-risk groups.

Dairy Intakes in Older Irish Adults and Effects on Vitamin Micronutrient Status: Data from the TUDA Study

BACKGROUND

Consumption of dairy products has been associated with positive health outcomes including a lower risk of hypertension, improved bone health and a reduction in the risk of type 2 diabetes. The suggested dairy intake for health in older adults is three servings per day but recent analysis of the NHANES data for older adults reported 98% were not meeting these recommendations. No studies have investigated the consequences of such declines in the dairy intakes of Irish older adults and the subsequent effects on vitamin micronutrient status.

OBJECTIVES

To study the daily dairy intakes of older Irish adults and to examine how the frequency of dairy food consumption affects vitamin micronutrient status.

METHODS

Participants (n 4,317) were from the Trinity Ulster Department of Agriculture (TUDA) Study, a large study of older Irish adults (aged >60 yrs) designed to investigate gene-nutrient interactions in the development of chronic diseases of aging. The daily intake portion for milk, cheese and yoghurt was calculated from food frequency questionnaire (FFQ) responses. Blood samples were analysed for vitamin biomarkers as follows: vitamin B12 (total serum cobalamin and holotranscobalamin (holoTC)), folate (red cell folate (RCF) and serum folate), vitamin B2 (erythrocyte glutathione reductase activation coefficient (EGRac)), vitamin B6 (serum pyridoxal phosphate) and vitamin D (serum 25(OH)D).

RESULTS

The mean total reported dairy intake was 1.16 (SD 0.79) portions per day with males consuming significantly fewer total dairy portions compared to females (1.07 vs 1.21 respectively) (P<0.05). There was no significant difference in total daily dairy serving intakes by age decade (60-69, 70-79, >80 yrs). Overall, only 3.5% of the total population (n 151) achieved the recommended daily dairy intake of three or more servings per day. A significantly higher proportion of females (4%) compared to males (2.4%) met these dairy requirements (P=0.011). Blood concentrations of vitamin B12 biomarkers, RCF, vitamin B2 and vitamin B6 were significantly worse in those with the lowest tertile of dairy intake (0-0.71 servings) compared to those in the highest tertile (1.50-4.50 servings) (P<0.05).

CONCLUSION

This study found that more than 96% of the older adults sampled did not meet current daily dairy intake recommendations. The study is the largest to-date examining dairy intakes in older Irish adults, and provides evidence that daily dairy intakes (in particular yogurt) contribute significantly to the B-vitamin and vitamin D biomarker status of older adults. These results suggest that older adults who are already vulnerable to micronutrient inadequacies, are forgoing the nutritional advantages of vitamin-rich dairy products.

Causes, Consequences and Public Health Implications of Low B-Vitamin Status in Ageing

The potential protective roles of folate and the metabolically related B-vitamins (vitamins B12, B6 and riboflavin) in diseases of ageing are of increasing research interest. The most common cause of folate and riboflavin deficiencies in older people is low dietary intake, whereas low B12 status is primarily associated with food-bound malabsorption, while sub-optimal vitamin B6 status is attributed to increased requirements in ageing. Observational evidence links low status of folate and the related B-vitamins (and/or elevated concentrations of homocysteine) with a higher risk of degenerative diseases including cardiovascular disease (CVD), cognitive dysfunction and osteoporosis. Deficient or low status of these B-vitamins alone or in combination with genetic polymorphisms, including the common MTHFR 677 C → T polymorphism, could contribute to greater disease risk in ageing by causing perturbations in one carbon metabolism. Moreover, interventions with the relevant B-vitamins to optimise status may have beneficial effects in preventing degenerative diseases. The precise mechanisms are unknown but many have been proposed involving the role of folate and the related B-vitamins as co-factors for one-carbon transfer reactions, which are fundamental for DNA and RNA biosynthesis and the maintenance of methylation reactions. This review will examine the evidence linking folate and related B-vitamins with health and disease in ageing, associated mechanisms and public health implications.