Protein supplementation has been proposed as an effective dietary strategy to augment the skeletal muscle adaptive response to prolonged resistance-type exercise training in elderly people. Our ...objective was to assess the impact of protein supplementation on muscle mass, strength, and physical performance during prolonged resistance-type exercise training in frail elderly men and women.
A randomized, double-blind, placebo-controlled trial with 2 arms in parallel among 62 frail elderly subjects (78 ± 1 year). These elderly subjects participated in a progressive resistance-type exercise training program (2 sessions per week for 24 weeks) during which they were supplemented twice daily with either protein (2 * 15 g) or a placebo.
Lean body mass (DXA), strength (1-RM), and physical performance (SPPB) were assessed at baseline, and after 12 and 24 weeks of intervention.
Lean body mass increased from 47.2 kg (95% CI, 43.5-50.9) to 48.5 kg (95% CI, 44.8-52.1) in the protein group and did not change in the placebo group (from 45.7 kg, 95% CI, 42.1-49.2 to 45.4 kg, 95% CI, 41.8-48.9) following the intervention (P value for treatment × time interaction = .006). Strength and physical performance improved significantly in both groups (P = .000) with no interaction effect of dietary protein supplementation.
Prolonged resistance-type exercise training represents an effective strategy to improve strength and physical performance in frail elderly people. Dietary protein supplementation is required to allow muscle mass gain during exercise training in frail elderly people.
clinicaltrials.gov identifier: NCT01110369.
Protein supplementation has been proposed as an effective dietary strategy to increase skeletal muscle mass and improve physical performance in frail elderly people. Our objective was to assess the ...impact of 24 weeks of dietary protein supplementation on muscle mass, strength, and physical performance in frail elderly people.
A total of 65 frail elderly subjects were included and randomly allocated to either daily protein or placebo supplementation (15 g protein at breakfast and lunch).
Skeletal muscle mass (DXA), muscle fiber size (muscle biopsy), strength (1-RM), and physical performance (SPPB) were assessed at baseline, and after 12 and 24 weeks of dietary intervention.
Skeletal muscle mass did not change in the protein- (from 45.8 ± 1.7 to 45.8 ± 1.7 kg) or placebo-supplemented group (from 46.7 ± 1.7 to 46.6 ± 1.7 kg) following 24 weeks of intervention (P > .05). In accordance, type I and II muscle fiber size did not change over time (P > .05). Muscle strength increased significantly in both groups (P < .01), with leg extension strength tending to increase to a greater extent in the protein (57 ± 5 to 68 ± 5 kg) compared with the placebo group (57 ± 5 to 63 ± 5 kg) (treatment × time interaction effect: P = .059). Physical performance improved significantly from 8.9 ± 0.6 to 10.0 ± 0.6 points in the protein group and did not change in the placebo group (from 7.8 ± 0.6 to 7.9 ± 0.6 points) (treatment × time interaction effect: P = .02).
Dietary protein supplementation improves physical performance, but does not increase skeletal muscle mass in frail elderly people.
As there is currently no cure for dementia, there is an urgent need for preventive strategies. The current review provides an overview of the existing evidence examining the associations of the ...Mediterranean, Dietary Approaches to Stop Hypertension (DASH), and Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diets and their dietary components with cognitive decline, dementia, and Alzheimer's disease (AD). A systematic search was conducted within Ovid Medline for studies published up to 27 March 2019 and reference lists from existing reviews and select articles were examined to supplement the electronic search results. In total, 56 articles were included. Higher adherence to the Mediterranean diet was associated with better cognitive scores in 9 of 12 cross-sectional studies, 17 of 25 longitudinal studies, and 1 of 3 trials. Higher adherence to the DASH diet was associated with better cognitive function in 1 cross-sectional study, 2 of 5 longitudinal studies, and 1 trial. Higher adherence to the MIND diet was associated with better cognitive scores in 1 cross-sectional study and 2 of 3 longitudinal studies. Evidence on the association of these dietary patterns with dementia in general was limited. However, higher adherence to the Mediterranean diet was associated with a lower risk of AD in 1 case-control study and 6 of 8 longitudinal studies. Moreover, higher adherence to the DASH or MIND diets was associated with a lower AD risk in 1 longitudinal study. With respect to the components of these dietary patterns, olive oil may be associated with less cognitive decline. In conclusion, current scientific evidence suggests that higher adherence to the Mediterranean, DASH, or MIND diets is associated with less cognitive decline and a lower risk of AD, where the strongest associations are observed for the MIND diet.
As malnutrition is common in patients with Alzheimer's disease (AD), we evaluated nutritional status and body composition of patients with AD, mild cognitive impairment (MCI) and controls, and ...studied associations of AD biomarkers and cognitive performance with nutritional status and body composition. We included 552 participants, of which 198 patients had AD, 135 patients had MCI and 219 controls. We assessed nutritional status (mini nutritional assessment (MNA)) and body composition (body mass index (BMI), fat-free mass (FFM) and waist circumference). Linear regression analyses (adjusted for age, gender and education where appropriate) were applied to test associations of AD biomarkers and cognitive performance on five domains with nutritional parameters (dependent). Patients with MCI and AD had a lower BMI and MNA score than controls. Worse performance in all cognitive domains was associated with lower MNA score, but not with body composition. AD biomarkers were associated with MNA score, BMI and waist circumference, and associations with MNA score remained after adjustment for cognitive performance. Both AD biomarkers and cognitive performance were associated with nutritional status, associations with AD biomarkers remained after adjustment for cognition. Our data suggest that malnutrition is not only related to impaired cognition but also to AD pathology.
Nutrition is one of the modifiable risk factors for cognitive decline and Alzheimer's disease (AD) dementia, and is therefore highly relevant in the context of prevention. However, knowledge of ...dietary quality in clinical populations on the spectrum of AD dementia is lacking, therefore we studied the association between dietary quality and cognitive impairment in Alzheimer's disease (AD) dementia, mild cognitive impairment (MCI) and controls. We included 357 participants from the NUDAD project (134 AD dementia, 90 MCI, 133 controls). We assessed adherence to dietary guidelines (components: vegetables, fruit, fibers, fish, saturated fat, trans-fat, salt, and alcohol), and cognitive performance (domains: memory, language, visuospatial functioning, attention, and executive functioning). In the total population, linear regression analyses showed a lower vegetable intake is associated with poorer global cognition, visuospatial functioning, attention and executive functioning. In AD dementia, lower total adherence to dietary guidelines and higher alcohol intake were associated with poorer memory, a lower vegetable intake with poorer global cognition and executive functioning, and a higher trans-fat intake with poorer executive functioning. In conclusion, a suboptimal diet is associated with more severely impaired cognition-this association is mostly attributable to a lower vegetable intake and is most pronounced in AD dementia.
Protein and energy malnutrition and unintended weight loss are frequently reported in patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD). Possible underlying mechanisms ...include increased energy expenditure, altered uptake of nutrients, a reduced nutritional intake, or a combination of these 3. We aimed at systematically reviewing the literature to examine potential differences in energy and protein intake in patients with MCI and AD compared to controls as a possible mechanism for unintended weight loss.
Systematic review and meta-analysis.
PubMed and Cochrane Electronic databases were searched from inception to September 2017 for case control studies.
Patients with MCI or AD compared to cognitive healthy controls, all adhering to a Western dietary pattern.
Energy and protein intake.
The search resulted in 7 articles on patients with AD versus controls, and none on patients with MCI. Four articles found no differences in energy and protein intakes, 1 found higher intakes in patients with AD, and 1 article found lower intakes in patients with AD compared to controls. One article reported on intakes, but did not test differences. A meta-analysis of the results indicated no difference between patients with AD and controls in energy -8 kcal/d, 95% confidence interval (CI): -97, 81; P = .85, or protein intake (2 g/d, 95% CI: -4, 9; P = .47). However, heterogeneity was high (I
> 70%), and study methodology was generally poor or moderate.
Contrary to frequently reported unintended weight loss, our systematic review does not provide evidence for a lower energy or protein intake in patients with AD compared to controls. High heterogeneity of the results as well as of participant characteristics, setting, and study methods was observed. High-quality studies are needed to study energy and protein intake as a possible mechanism for unintended weight loss and malnutrition in both patients with MCI and AD.
The effects of tyrosine on plasma response and cognition in aging are unknown. We assessed the dose-dependent response to tyrosine administration in older adults in both plasma tyrosine ...concentrations and working memory performance. In this double blind randomized cross-over trial 17 older adults (aged 60-75 years) received a single administration of 100, 150, or 200 mg/kg body weight of tyrosine. For comparison, 17 young adults (aged 18-35 years) received a dose of 150 mg/kg body weight of tyrosine. Tyrosine plasma concentrations were determined before and 90, 120, 150, 180, 210, and 240 min after tyrosine intake. Working memory was assessed using the N-back task at 90 min after tyrosine administration. Older adults showed a dose-dependent increase in plasma tyrosine concentrations (
< 0.001), and the plasma response was higher than for young adults with the same dose (
< 0.001). Load-dependent working memory performance decreased with higher doses of tyrosine (
= 0.048), especially in older adults with greater dose-dependent plasma tyrosine responses (
= 0.035). Our results show an age-related increase in plasma tyrosine response, which was associated with a dose-dependent decline in cognitive functioning in older adults.
Abstract Two distinct forms of response inhibition may underlie observed deficits in response inhibition in aging. We assessed whether age-related neuro-cognitive impairments in response inhibition ...reflect deficient reactive inhibition (outright stopping) or also deficient proactive inhibition (anticipatory response slowing), which might be particularly evident with high information load. We used fMRI in young (n=25, age range 18-32) and older adults (n=23, 61-74) with a stop-signal task. Relative to young adults, older adults exhibited impaired reactive inhibition (i.e. longer stop-signal reaction time) and increased BOLD signal for successful versus unsuccessful inhibition in the left frontal cortex and cerebellum. Furthermore, older adults also exhibited impaired proactive slowing, but only as a function of information load. This load-dependent behavioural deficit was accompanied by a failure to increase BOLD signal under high information load in lateral frontal cortex, pre-supplementary motor area and striatum. Our findings suggest that inhibitory deficits in older adults are caused both by reduced stopping abilities and by diminished preparation capacity during information overload.
Objective: To examine the association between consumption of seafood and long-chain n-3 fatty acids with change in 5 cognitive domains over an average of 4.9 years. Methods: From an ongoing ...longitudinal, community-based epidemiologic study of aging and dementia (the Rush Memory and Aging Project), we included 915 participants (age 81.4 6 7.2 years, 25% men) who had completed at least one follow-up cognitive assessment and dietary data. Diet was assessed by semiquantitative food frequency questionnaire. Scores for global cognitive function and 5 cognitive domains (episodic, semantic, and working memory, perceptual speed, and visuospatial ability) were assessed using 19 cognitive tests. Mixed models adjusted for multiple risk factors of cognitive change were used to assess the associations. Results: Consumption of seafood was associated with slower decline in semantic memory (b 5 0.024; p 5 0.03) and perceptual speed (b 5 0.020; p 5 0.05) in separate models adjusted for age, sex, education, participation in cognitive activities, physical activity, alcohol consumption, smoking, and total energy intake. In secondary analyses, APOE e4 carriers demonstrated slower rates of decline in global cognition and in multiple cognitive domains with weekly seafood consumption and with moderate to high long-chain n-3 fatty acid intake from food. These associations were not present in APOE e4 noncarriers. Higher intake levels of a-linolenic acid were associated with slower global cognitive decline, but also only in APOE e4 carriers. Conclusions: These results suggest protective relations of one meal per week of seafood and long-chain n-3 fatty acids against decline in multiple cognitive domains. The role of APOE e4 in this association needs further study.
BACKGROUND: Polyunsaturated fatty acids can have beneficial effects on human immune cells, such as peripheral blood mononuclear cells (PBMCs). However, the mechanisms of action of polyunsaturated ...fatty acids on immune cells are still largely unknown. OBJECTIVE: The objective was to examine the effects of supplementation with the polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on whole-genome PBMC gene expression profiles, in healthy Dutch elderly subjects participating in a double-blind trial, by using whole-genome transcriptomics analysis. DESIGN: The subjects were randomly allocated to 1 of 3 groups: 1) consumption of 1.8 g EPA+DHA/d (n = 36), 2) consumption of 0.4 g EPA+DHA/d (n = 37), or 3) consumption of 4.0 g high-oleic acid sunflower oil (HOSF)/d (n = 38). All supplements were given in capsules. Before and after 26 wk of intervention, blood samples were collected. Microarray analysis was performed on PBMC RNA from 23 subjects who received 1.8 g EPA+DHA/d and 25 subjects who received HOSF capsules. Quantitative real-time polymerase chain reaction was performed in all 111 subjects. RESULTS: A high EPA+DHA intake changed the expression of 1040 genes, whereas HOSF intake changed the expression of only 298 genes. EPA+DHA intake resulted in a decreased expression of genes involved in inflammatory- and atherogenic-related pathways, such as nuclear transcription factor κB signaling, eicosanoid synthesis, scavenger receptor activity, adipogenesis, and hypoxia signaling. CONCLUSION: These results are the first to show that intake of EPA+DHA for 26 wk can alter the gene expression profiles of PBMCs to a more antiinflammatory and antiatherogenic status. This trial was registered at clinicaltrials.gov as NCT00124852.
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