N.L. van der Zwaluw

Results of 2-year vitamin B treatment on cognitive performance; Secondary data from an RCT

Objective: We investigated the effects of 2-year folic acid and vitamin B12 supplementation on cognitive performance in elderly people with elevated homocysteine (Hcy) levels. Methods: This multicenter, double-blind, randomized, placebo-controlled trial included 2,919 elderly participants (65 years and older) with Hcy levels between 12 and 50 µmol/L. Participants received daily either a tablet with 400 µg folic acid and 500 µg vitamin B12 (B-vitamin group) or a placebo tablet. Both tablets contained 15 µg vitamin D3. Data were available for global cognitive functioning assessed by Mini-Mental State Examination (n = 2,556), episodic memory (n = 2,467), attention and working memory (n = 759), information processing speed (n = 731), and executive function (n = 721). Results: Mean age was 74.1 (SD 6.5) years. Hcy concentrations decreased 5.0 (95% confidence interval −5.3 to −4.7) µmol/L in the B-vitamin group and 1.3 (−1.6 to −0.9) µmol/L in the placebo group. Cognitive domain scores did not differ over time between the 2 groups, as determined by analysis of covariance. Mini-Mental State Examination score decreased with 0.1 (−0.2 to 0.0) in the B-vitamin group and 0.3 (−0.4 to −0.2) in the placebo group (p = 0.05), as determined by an independent t test. Conclusions: Two-year folic acid and vitamin B12 supplementation did not beneficially affect performance on 4 cognitive domains in elderly people with elevated Hcy levels. It may slightly slow the rate of decline of global cognition, but the reported small difference may be attributable to chance. Classification of evidence: This study provides Class I evidence that 2-year supplementation with folic acid and vitamin B12 in hyperhomocysteinemic elderly people does not affect cognitive performance.

Short-term effects of glucose and sucrose on cognitive performance and mood in elderly people

In this study we determined the short-term effects of a glucose drink and a sucrose drink compared to a placebo on cognitive performance and mood in elderly people with subjective, mild memory complaints using a randomized crossover study design. In total, 43 nondiabetic older adults with self-reported memory complaints were included. Drinks consisted of 250 ml with dissolved glucose (50 g), sucrose (100 g), or a mixture of artificial sweeteners (placebo). Multiple neuropsychological tests were performed and were combined by means of z scores into four cognitive domains: episodic memory, working memory, attention and information (processing speed), and executive functioning. Mood was assessed with the short Profile of Mood Status (s-POMS) questionnaire. Blood glucose concentrations were measured at five time points to divide participants into those with a better or poorer blood glucose recovery. Performance on the domain of attention and information processing speed was significantly better after consuming the sucrose drink (domain score of 0.06, SD = 0.91) than after the placebo drink (–0.08, SD = 0.92, p = .04). Sucrose had no effect on the other three domains, and glucose had no effect on any of the domains compared to the placebo. When dividing participants into poorer or better glucose recoverers, the beneficial effect of sucrose on attention and information processing speed was only seen in participants with a poorer recovery. After sucrose consumption, depressive feelings and tension were slightly higher than after the placebo. To conclude, 100 g sucrose, but not 50 g glucose, optimized attention and information processing speed in the short term in this study in elderly people with subjective, mild memory complaints.

Food sources of vitamin D and their association with 25-hydroxyvitamin D status in Dutch older adults

Various populations are at increased risk of developing a low vitamin D status, in particular older adults. Whereas sun exposure is considered the main source of vitamin D, especially during summer, dietary contributions should not be underestimated. This study aims to identify food sources of vitamin D that associate most strongly with serum vitamin D concentration. Data of 595 Dutch adults, aged ≥65 years, were analysed. Vitamin D intake was assessed with a food frequency questionnaire and 25-hydroxyvitamin D (25(OH)D) was determined in serum. Associations of total vitamin D intake and vitamin D intake from specific food groups with serum 25(OH)D status were examined by P-for trend analyses over tertiles of vitamin D intake, prevalence ratios (PRs), and spline regression. The prevalence of vitamin D deficiency was high, with 36% of the participants having a 25(OH)D status <50nmol/L. Participants with adequate 25(OH)D concentrations were more likely to be men and more likely to be younger than participants with vitamin D deficiency. Total median vitamin D intake was 4.3μg/day, of which 4.0μg/day was provided by foods. Butter and margarine were the leading contributors to total vitamin D intake with 1.8μg/day, followed by the intake of fish and shellfish with 0.56μg/day. Participants with higher intakes of butter and margarine were 21% more likely to have a sufficient 25(OH)D status after adjustment for covariates (T1 vs. T3: PR 1.0 vs. 1.21 (95%CI: 1.03-1.42), P-for trend 0.02). None of the other food groups showed a significant association with the probability of having a sufficient 25(OH)D status. This study shows that vitamin D intake was positively associated with total serum 25(OH)D concentration, with butter and margarine being the most important contributors to total vitamin D intake.

Effects of glucose and sucrose on mood: a systematic review of interventional studies

Context Glucose is the main energy source for the brain, and as such, manipulation of glucose supply may affect brain function. It has been suggested that a change in blood glucose may influence mood. Objective The aim of this review was to investigate the potential effects of glucose and sucrose, compared with placebo, on mood. Data Sources The electronic databases PubMed and Scopus were searched. Reference lists of selected articles were checked manually. Data Extraction Randomized controlled trials or crossover trials comparing the effects of glucose or sucrose on mood that were published up to May 2017 were eligible. Potentially eligible articles were selected independently by 2 reviewers. Results In total, 19 studies were found. Thirteen studies investigated the effects of glucose consumption compared with placebo on mood. Seven of these 13 studies found no effect of glucose on mood. The other 6 studies found small and partial effects that may also be due to other factors like palatability and expectation. Seven of the 19 studies investigated the effects of sucrose ingestion versus placebo on mood. None of these studies found a positive effect on mood, and 1 study observed an adverse effect. One of the studies investigated the effects of both glucose and sucrose. Conclusions The results from this review show limited effects of glucose ingestion on mood and no effect of sucrose on mood.

Dietary Protein, Cognitive Decline, and Dementia

As the population of elderly people is growing rapidly, the number of individuals with dementia and cognitive impairment is also increasing. One of the preventive measures against cognitive decline is diet, and different dietary factors have already been investigated. This chapter provides an overview of studies on dietary protein and dementia and cognitive decline. Also studies on some individual amino acids, the structural units that make up proteins, which may be related with cognitive functioning are discussed. Overall, the role of dietary protein intake on both dementia and cognitive decline has hardly been studied. Data are also limited on the role of individual amino acids, especially in elderly populations. More research is needed to come to definitive conclusions and specific recommendations regarding protein intake or intake of specific amino acids for maintaining optimal cognitive functioning.