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The effects of multi-nutrient formulas containing a combination of n-3 PUFA and B vitamins on cognition in the older adult: a systematic review and meta-analysis.
Fairbairn, P, Dyall, SC, Tsofliou, F
The British journal of nutrition. 2023;129(3):428-441
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Due to the insidious onset, cognitive impairment often goes unnoticed for several years, with clinical diagnosis being made late into the disease progression. Cognition is critical for functional independence as people age, and intact cognition is vital for humans to communicate effectively. The aims of this study were to (i) investigate whether supplementation with a combination of omega-3 polyunsaturated fatty acids (n-3 PUFA) and B vitamins alone or as part of a multi-nutrient formula can prevent cognitive decline in older adults, and (ii) determine whether the effects of a single nutrient intervention with either n-3 PUFA or B vitamins could be modified by the status of the other nutrient. This study is a systematic review and meta-analysis of fourteen studies of which eleven were randomised controlled trials and the rest were post hoc analysis of randomised controlled trials. Results show a benefit of supplementing with nutrient formulas that contain both n-3 PUFA and B vitamins on global cognition and episodic memory with small to moderate effect sizes. In fact, they can help preserve cognition in the older adults. Authors conclude that more experimental work providing a combination of nutrients including both n-3 PUFA and B vitamins, in healthy older adults or those showing early signs of cognitive decline, is clearly warranted to better explore how nutrition can impact the trajectory of cognition in older adults.
Abstract
There is now evidence to suggest that there may be an interaction between B vitamins and n-3 PUFA, with suggestions that increasing intake of both nutrients simultaneously may benefit cognition in older adults. The aim of this systematic review was to investigate whether supplementation with a combination of n-3 PUFA and B vitamins can prevent cognitive decline in older adults. Randomised controlled trials conducted in older adults that measured cognitive function were retrieved. The included trials provided a combination of n-3 PUFA and B vitamins alone, or in combination with other nutrients. Trials that provided n-3 PUFA alone and also measured B vitamin status or provided B vitamin supplementation alone and measured n-3 PUFA status were also included. The databases searched were The Cochrane Library, EMBASE, CINAHL, Scopus and MEDLINE. A total of 14 papers were included in the analysis (n 4913; age: 60-70 years; follow-up 24 weeks to 4 years). The meta-analysis results found a significant benefit of nutrient formulas, which included both n-3 PUFA and B vitamins alongside other nutrients, v. placebo on global cognition assessed using composite scores from a neuropsychological test battery (G = 0·23, P = 0·002), global cognition using single measures of cognition (G = 0·28, P = 0·004) and episodic memory (G = 0·32, P = 0·001). The results indicate that providing a combination of n-3 PUFA and B vitamins as part of a multi-nutrient formula benefits cognition in older adults v. a placebo, and the potential for an interaction between these key nutrients should be considered in future experimental work.
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Mediterranean diet and structural neuroimaging biomarkers of Alzheimer's and cerebrovascular disease: A systematic review.
Gregory, S, Pullen, H, Ritchie, CW, Shannon, OM, Stevenson, EJ, Muniz-Terrera, G
Experimental gerontology. 2023;172:112065
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Nearly a million people in the UK have Alzheimer's disease, the most common type of dementia. Mediterranean diet (MedDiet) adherence is associated with healthy brain ageing, a reduced stroke risk, and a lower incidence of dementia. Seven studies were included in this review to evaluate the effects of MedDiet on hippocampal volume and white matter hyperintensity volume, predictors of stroke and dementia. This systematic review did not reveal any associations between MedDiet adherence and hippocampal volume. However, there was a significant negative relationship between MedDiet adherence and white matter hyperintensity volume in two of the studies included. It is necessary to conduct more robust studies to investigate the associations between MedDiet adherence and structural brain imaging findings and understand the mechanisms behind dementia and other cerebrovascular diseases. This study could provide healthcare professionals with valuable information about the effects of increased MedDiet adherence on brain health, including its potential to delay neurodegenerative disease progression.
Expert Review
Conflicts of interest:
None
Take Home Message:
Due to inconclusive results on the associations between MedDiet adherence and AD and cerebrovascular related structural neuroimaging findings, specific recommendations for the MedDiet cannot be made on the basis of this study until further research has been completed.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Background:
Changes in hippocampal volume (HV) and white matter intensity volume (WMIV) have been identified as structural neuroimaging biomarkers of neurodegenerative disease such as Alzheimer’s Disease (AD) and Cerebrovascular disease (CVD) respectively. Evidence has shown adherence to the Mediterranean Diet (MedDiet) has been associated with reduced risk for strokes. This review evaluated the MedDiet in relation to HV and WMIV.
Methods:
The review followed PRISMA guidelines and was registered on PROSPERO. Literature searching resulted in seven studies published between 2012 and 2022, which met the inclusion criteria. Six studies analysed cross-sectional data and one analysed longitudinal data. The NIH Quality Assessment Tool for Observational and Cross-Sectional Studies was used to assess risk of bias.
Overall, the studies were rated as low-risk of bias with details of the research question, participant group exposure and outcome variables included. Due to moderate to high heterogeneity in some studies, a meta-analysis was deemed unsuitable and narrative synthesis was conducted to present the results.
Results:
Mean participant age ranged from 53.19 to 80.3 years and volunteers were healthy or had subjective cognitive decline and a few participants had dementia (n=46).
Hippocampal Volume:
Four studies included 20,077 participants and found no significant associations between MedDiet adherence and hippocampal volume. All four studies were cross-sectional from larger cohort studies. To establish causative relationships longitudinal and RCT trials are required.
White Matter Hyperintensity Volumes:
Four studies included 1938 participants. Two studies found a significant negative association between MedDiet and WMHV, demonstrating higher Mediterranean Scores were associated with lower level of WHMV. The other two studies found no significant associations.
Although the review methodology with a piloted search strategy was considered a key strength, the lack of meta-analysis as planned in the a priori protocol, due to minimal eligible studies and high heterogeneity was a limitation as well as the restriction of brain imaging outcomes.
Conclusion:
Overall, these results are inconclusive on the associations between the MedDiet and HV and WMHV, and identify a gap in the knowledge, therefore further research such as RCT’s remains a priority to further understand the impact diet may have on neuroimaging markers of AD and CVD.
Clinical practice applications:
There were no significant associations between MedDiet adherence and HV, which was surprising given the evidence stating adherence to the MedDiet is associated with a lower incidence of dementia and stroke. However all four studies were cross-sectional studies and in order to detect causal associations, longitudinal and RCT’s are needed. Two studies did show a significant association between higher MedDiet adherence and lower WMHV, whereas two studies reported no significant associations.
Caution needs to be taken when recommending the MedDiet specifically for a reduction in HV and WMHV until further research has been undertaken.
Considerations for future research:
Future research should consider:
- larger cohorts and participants from the Mediterranean region where lifelong adherence to the MedDiet is more likely.
- looking at other risk factors to include obesity, lack of activity, poor sleep quality and stress.
- evaluating different socio-economic status, which has been shown to impact dietary behaviour.
- alternative imaging outcomes such as cortical thinning, PET amyloid and tau.
- . gold standard for methodology in particular dietary analysis and scanning and outcome derivation.
Abstract
Previous studies have demonstrated an association between adherence to the Mediterranean diet (MedDiet) and better cognitive performance, lower incidence of dementia and lower Alzheimer's disease biomarker burden. The aim of this systematic review was to evaluate the evidence base for MedDiet associations with hippocampal volume and white matter hyperintensity volume (WMHV). We searched systematically for studies reporting on MedDiet and hippocampal volume or WMHV in MedLine, EMBASE, CINAHL and PsycInfo. Searches were initially carried out on 21st July 2021 with final searches run on 23rd November 2022. Risk of bias was assessed using the NIH Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Of an initial 112 papers identified, seven papers were eligible for inclusion in the review reporting on 21,933 participants. Four studies reported on hippocampal volume, with inconclusive or no associations seen with MedDiet adherence. Two studies found a significant association between higher MedDiet adherence and lower WMHV, while two other studies found no significant associations. Overall these results highlight a gap in our knowledge about the associations between the MedDiet and AD and cerebrovascular related structural neuroimaging findings.
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Effects of Antioxidants on Pain Perception in Patients with Fibromyalgia-A Systematic Review.
Fernández-Araque, A, Verde, Z, Torres-Ortega, C, Sainz-Gil, M, Velasco-Gonzalez, V, González-Bernal, JJ, Mielgo-Ayuso, J
Journal of clinical medicine. 2022;11(9)
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Fibromyalgia (FM) is characterised by widespread chronic pain, fatigue, sleep disturbances, and cognitive impairment. As a result of oxidative stress, reactive oxygen species (ROS) are produced and improperly disposed of, resulting in peripheral and central sensitisations, and a reduction of the pain threshold in FM patients. It is well known that antioxidants are protective against oxidative stress and that reducing antioxidant levels can result in increased pain in patients with FM. An overview of 17 studies was conducted to evaluate the effect of antioxidant supplementation on pain perception and the appropriate duration of treatment for FM patients in this systematic review. This systematic review found that supplementation with Fibromyalgine® (Fib) (that contains vitamin C, acerola ginger root, and freeze-dried royal jelly), 300-400 gm/d of coenzyme Q10 alone in combination with Pregabalin, ferric carboxymaltose, vitamin C, E, and Nigella sativa, magnesium + amitriptyline, acetyl L-carnitine, and Sun Chlorella™ green algae are effective in reducing pain perception in FM patients. In patients with FM, alpha-lipoic acid supplementation significantly reduced pain scores. 80% of FM patients reported reduced pain after supplement treatment for at least six weeks. There is a need for further robust long-term studies to confirm the effectiveness and clinical applicability of antioxidants in the management of FM, as well as to identify the pathophysiology of FM. This research may, however, be used by healthcare professionals to gain a better understanding of the potential benefits of antioxidants in the treatment of pain associated with FM.
Abstract
In recent years, antioxidant supplements have become popular to counteract the effects of oxidative stress in fibromyalgia and one of its most distressing symptoms, pain. The aim of this systematic review was to summarize the effects of antioxidant supplementation on pain levels perceived by patients diagnosed with fibromyalgia. The words used respected the medical search terms related to our objective including antioxidants, fibromyalgia, pain, and supplementation. Seventeen relevant articles were identified within Medline (PubMed), Scopus, Web of Science (WOS), the Cochrane Database of Systematic Review, and the Cochrane Central Register of Controlled Trials. This review found that antioxidant supplementation is efficient in reducing pain in nine of the studies reviewed. Studies with a duration of supplementation of at least 6 weeks showed a benefit on pain perception in 80% of the patients included in these studies. The benefits shown by vitamins and coenzyme Q10 are remarkable. Further research is needed to identify the effects of other types of antioxidants, such as extra virgin olive oil and turmeric. More homogeneous interventions in terms of antioxidant doses administered and duration would allow the effects on pain to be addressed more comprehensively.
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The Impact of Nutrients on Mental Health and Well-Being: Insights From the Literature.
Muscaritoli, M
Frontiers in nutrition. 2021;8:656290
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Diet, mental health, and well-being are linked through several biological pathways. In addition to a healthy diet, nutrient supplements may be of benefit due to their ability to influence these pathways. This review aimed to outline the relationship between specific nutrients and their beneficial effect on mental health. The review outlined the various benefits of polyunsaturated fats, vitamin E, magnesium and folic acid on stress, anxiety, sleep disorders, mild cognitive impairment, depression, bipolar disorders, and obsessive-compulsive disorder. With regards to stress, it was outlined that insufficient vitamins, excessive fat and nutritional imbalance can be contributory. Human research exists to support the benefits of magnesium and polyunsaturated fat for stress and these plus vitamin E for anxiety, however it appears that evidence is lacking for vitamin E and stress and the authors did not comment on folic acid for either condition. Extensive research exists for the use of polyunsaturated fats in mild cognitive impairment, and it was stated that high doses for long periods of time may be needed to show any benefits. The use of vitamin E in cognitive impairment is controversial and more studies may be needed. The authors did not comment on magnesium or folic acid supplementation. It was concluded that an unhealthy diet and lifestyle may be associated with poor mental health and well-being and the importance of a balanced, varied diet for normal brain function. This study could be used by healthcare professionals to understand the importance of recommending a healthy diet for mental well-being in individuals who are suffering from mental health disorders.
Abstract
A good nutritional status is important for maintaining normal body function and preventing or mitigating the dysfunction induced by internal or external factors. Nutritional deficiencies often result in impaired function, and, conversely, intakes at recommended levels can resume or further enhance body functions. An increasing number of studies are revealing that diet and nutrition are critical not only for physiology and body composition, but also have significant effects on mood and mental well-being. In particular, Western dietary habits have been the object of several research studies focusing on the relationship between nutrition and mental health. This review aims to summarize the current knowledge about the relationship between the intake of specific micro- and macronutrients, including eicosapentaenoic acid, docosahexaenoic acid, alpha-tocopherol, magnesium and folic acid, and mental health, with particular reference to their beneficial effect on stress, sleep disorders, anxiety, mild cognitive impairment, as well as on neuropsychiatric disorders, all significantly affecting the quality of life of an increasing number of people. Overall data support a positive role for the nutrients mentioned above in the preservation of normal brain function and mental well-being, also through the control of neuroinflammation, and encourage their integration in a well-balanced and varied diet, accompanied by a healthy lifestyle. This strategy is of particular importance when considering the global human aging and that the brain suffers significantly from the life-long impact of stress factors.
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Quantifying dementia prevention potential in the FINGER randomized controlled trial using the LIBRA prevention index.
Deckers, K, Köhler, S, Ngandu, T, Antikainen, R, Laatikainen, T, Soininen, H, Strandberg, T, Verhey, F, Kivipelto, M, Solomon, A
Alzheimer's & dementia : the journal of the Alzheimer's Association. 2021;17(7):1205-1212
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Lifestyle interventions are being increasingly recognised to delay or prevent the onset of dementia. Scientific research targeting one lifestyle factor has continually failed to show any benefits and therefore interventions targeting several lifestyle factors, before disease onset may be more beneficial. The Lifestyle for BRAin Health (LIBRA) score is a tool which assesses peoples risk of dementia based on several lifestyle factors and this trial used this tool to determine the dementia risk of individuals who entered The Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER). This study was the first randomised control trial showing benefits to cognition following multi-domain lifestyle interventions. The results showed that higher LIBRA score at the start of the trial was associated with poorer brain function over time and that the multi-domain lifestyle intervention was effective at decreasing LIBRA score, regardless of the risk at the start of the trial. It was concluded that LIBRA may be a useful tool to determine risk of dementia and that the FINGER intervention was of benefit to individuals regardless of their risk of dementia.
Abstract
INTRODUCTION Individuals in early dementia prevention trials may differ in how much they benefit from interventions depending on their initial risk level. Additionally, modifiable dementia risk scores might be used as surrogate/intermediate outcomes. METHODS In the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER), we investigated in post hoc analyses (N = 1207) whether the cognitive benefits of the 2-year multi-domain lifestyle intervention differed by baseline dementia risk measured with the "LIfestyle for BRAin Health" (LIBRA) score. We also investigated intervention effects on change in LIBRA score over time. RESULTS Overall, higher baseline LIBRA was related to less cognitive improvement over time. This association did not differ between the intervention and control groups. The intervention was effective in decreasing LIBRA scores over time, regardless of baseline demographics or cognition. DISCUSSION The cognitive benefit of the FINGER intervention was similar across individuals with different LIBRA scores at baseline. Furthermore, LIBRA may be useful as a surrogate/intermediate endpoint and surveillance tool to monitor intervention success during trial execution.
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A ketogenic drink improves cognition in mild cognitive impairment: Results of a 6-month RCT.
Fortier, M, Castellano, CA, St-Pierre, V, Myette-Côté, É, Langlois, F, Roy, M, Morin, MC, Bocti, C, Fulop, T, Godin, JP, et al
Alzheimer's & dementia : the journal of the Alzheimer's Association. 2021;17(3):543-552
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Brain energy rescue is emerging as a potential strategy to reduce cognitive decline in mild cognitive impairment (MCI) and Alzheimer’s disease (AD). The main aim of this study was to report the complete cognitive outcomes of the BENEFIC (Brain Energy, Functional Imaging, and Cognition) trial. The secondary objectives are to report plasma ketones (free caprylic and capric acids) levels; as well as the metabolic response, safety, and tolerability after the 6-month intervention. This study is a 6-month randomised, placebo-controlled trial. A total of 122 participants were enrolled and randomised into one of the two arms: ketogenic medium chain triglyceride (kMCT) or placebo arm. Results show that performance on widely used tests of episodic memory, executive function, and language improved over 6 months in MCI when consuming 30g/day of a kMCT drink relative to a matching placebo. Moderate to large effect sizes were observed on four cognitive tests in the kMCT group. Furthermore, it is safe and feasible for an MCI population to consume a 15g kMCT supplement twice daily for 6 months. Authors conclude that formulation of a kMCT drink improved four cognitive outcomes in MCI by increasing blood ketone levels.
Expert Review
Conflicts of interest:
None
Take Home Message:
- MCT supplementation is a promising strategy to rescue energy metabolism in the brain for those with MCIs by providing an alternative energy source
- Improvements in cognition were associated with increased blood ketone levels from MCT supplementation
- Practitioners should be mindful that higher intakes of MCTs (>30g/d) may lead to negative GI effects in some individuals.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
This randomized controlled trial demonstrates that supplementation of a ketogenic drink containing medium-chain triglycerides (MCTs) is both safe and effective in improving cognitive outcomes in individuals with mild cognitive impairments (MCI), and does so through supporting energy metabolism in the brain.
Clinical practice applications:
These findings might be useful for Nutritional Therapists and Clinical Practitioners as follows:
- The results of this randomised controlled trial demonstrate that MCT supplementation (at 30g per day, split between two doses) is a viable strategy to support brain metabolism in individuals experiencing MCIs
- There was a dose-dependant response on elevated ketones and selected cognitive improvements which may have pertinent applications to therapeutic practice (either dietary or supplemental)
- The paper highlighted the involvement of energy metabolism in cognitive decline; this has potential therapeutic applications in terms of targeted nutritional support for mitochondrial function or energy signalling
- Some individuals experienced negative gastrointestinal effects when consuming MCTs at 30g/d for prolonged periods; practitioners should be mindful of this.
Considerations for future research:
Future research should consider:
- Whether dietary-induced ketosis can therapeutically impact MCI and support patient well-being
- Use of MCTs in those with severe cognitive impairments or those taking medication such as cholinesterase inhibitors
the role of glucose hypometabolism to determine alternative strategies for those who have GI issues with MCTs
- Whether APOE4 status has any impact on therapeutic outcomes to MCT supplementation
- Whether adjunct nutritional support for mitochondrial function alongside MCT could further impact on MCIs.
Abstract
INTRODUCTION Counteracting impaired brain glucose metabolism with ketones may improve cognition in mild cognitive impairment (MCI). METHODS Cognition, plasma ketone response, and metabolic profile were assessed before and 6 months after supplementation with a ketogenic drink containing medium chain triglyceride (ketogenic medium chain triglyceride [kMCT]; 15 g twice/day; n = 39) or placebo (n = 44). RESULTS Free and cued recall (Trial 1; P = .047), verbal fluency (categories; P = .024), Boston Naming Test (total correct answers; P = .033), and the Trail-Making Test (total errors; P = .017) improved significantly in the kMCT group compared to placebo (analysis of covariance; pre-intervention score, sex, age, education, and apolipoprotein E4 as covariates). Some cognitive outcomes also correlated positively with plasma ketones. Plasma metabolic profile and ketone response were unchanged. CONCLUSIONS This kMCT drink improved cognitive outcomes in MCI, at least in part by increasing blood ketone level. These data support further assessment of MCI progression to Alzheimer's disease.
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Green Tea Intake and Risks for Dementia, Alzheimer's Disease, Mild Cognitive Impairment, and Cognitive Impairment: A Systematic Review.
Kakutani, S, Watanabe, H, Murayama, N
Nutrients. 2019;11(5)
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Around 50 million people worldwide suffer from dementia, with 10 million new cases being diagnosed every year. Diet may play a role in the prevention of dementia. In this systematic review, the authors reviewed eight previous studies examining the effects of green tea on dementia. Six of the eight studies supported a preventative effect of green tea intake. The authors suggested that green tea might positively influence biological mechanisms such as oxidative stress, inflammation, accumulation of plaques in the brain and the maintenance of healthy blood vessels. The authors concluded that green tea intake might reduce the risk for dementia, Alzheimer's disease, mild cognitive impairment, or cognitive impairment, but further studies are needed.
Abstract
Dementia has become a major issue that requires urgent measures. The prevention of dementia may be influenced by dietary factors. We focused on green tea and performed a systematic review of observational studies that examined the association between green tea intake and dementia, Alzheimer's disease, mild cognitive impairment, or cognitive impairment. We searched for articles registered up to 23 August 2018, in the PubMed database and then for references of original articles or reviews that examined tea and cognition. Subsequently, the extracted articles were examined regarding whether they included original data assessing an association of green tea intake and dementia, Alzheimer's disease, mild cognitive impairment, or cognitive impairment. Finally, we included three cohort studies and five cross-sectional studies. One cohort study and three cross-sectional studies supported the positive effects of green tea intake. One cohort study and one cross-sectional study reported partial positive effects. The remaining one cohort study and one cross-sectional study showed no significant association of green tea intake. These results seem to support the hypothesis that green tea intake might reduce the risk for dementia, Alzheimer's disease, mild cognitive impairment, or cognitive impairment. Further results from well-designed and well-conducted cohort studies are required to derive robust evidence.
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Effect of Supplementation of a Whey Peptide Rich in Tryptophan-Tyrosine-Related Peptides on Cognitive Performance in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Study.
Kita, M, Obara, K, Kondo, S, Umeda, S, Ano, Y
Nutrients. 2018;10(7)
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Previous studies have suggested that consumption of dairy products may be related to a reduction in the risk of cognitive decline in later life. Studies in mice suggest that particular components of whey known as whey peptides may be partly responsible for improvements in cognitive performance. The aim of this randomised, double-blind, placebo-controlled study was to evaluate the effects of whey peptides on cognitive functions in healthy adults. 101 healthy Japanese adults (aged 45 to 64 years) with a tendency to forget names of people and places, took part in the study. They received either tablets containing 6g of whey peptide (including 1.6mg of glycine–threonine–tryptophan–tyrosine (GTWY) peptide) or placebo supplements for 12 weeks. Changes in cognitive function were assessed using memory and cognitive function tests at the start of the study and 6 and 12 weeks after supplementation. Whey peptide intake tended to improve the verbal fluency test (VFT) score. Further analysis showed that subjects with high-level fatigue from the whey peptide group improved their scores in the VFT as well as some other memory function tests significantly more compared to the placebo group. The authors concluded that intake of whey peptide might improve cognitive function in healthy middle- and older-aged adults with high subjective fatigue levels. Further studies are needed to examine the relationship among cognitive improvement, whey peptides, and psychological fatigue.
Abstract
Background: Previous epidemiological and clinical studies have shown that dairy products have beneficial effects on cognitive decline and dementia. Enzymatic digestion of whey protein produces a whey peptide rich in tryptophan-tyrosine-related peptides which improve cognitive performance in mice. We evaluated the effects of whey peptides on cognitive functions in healthy adults in a randomized, double-blind, placebo-controlled design. Methods: 101 healthy adults (45 to 64 years), with a self-awareness of cognitive decline received either whey peptide or placebo supplements for 12 weeks. Changes in cognitive function were assessed using neuropsychological tests at 6 and 12 weeks after the start of supplementation. Results: Verbal fluency test (VFT) score changes tended to be higher in the whey peptide group compared with the placebo at 12 weeks. Subgroup analysis classified by the degree of subjective fatigue showed that changes in the VFT as well as the Stroop and subjective memory function tests between baseline and 6 weeks of intervention were significantly better in subjects with high-level fatigue from the whey peptide group as compared to the placebo group. CONCLUSIONS Intake of whey peptide might improve cognitive function in healthy middle- and older-aged adults with high subjective fatigue levels. Further studies will elucidate the relationship among cognitive improvement, whey peptides, and psychological fatigue.
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Omega-3 Fatty Acid Status Enhances the Prevention of Cognitive Decline by B Vitamins in Mild Cognitive Impairment.
Oulhaj, A, Jernerén, F, Refsum, H, Smith, AD, de Jager, CA
Journal of Alzheimer's disease : JAD. 2016;50(2):547-57
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Many studies are exploring preventative measures to delay or prevent mild cognitive impairment (MCI) and Alzheimer’s disease. A recent trial (VITACOG) demonstrated that omega-3 fatty acid status enhances the protective effects of B-vitamins on brain atrophy. The present study uses the VITACOG data to investigate whether there is an association on cognitive function. This study revealed that a higher baseline omega-3 fatty acid status enhances the beneficial effects of B vitamins on both brain atrophy and cognitive decline. The authors conclude that this interaction may slow down the disease process in MCI and warrants further clinical trials investigating this relationship.
Abstract
A randomized trial (VITACOG) in people with mild cognitive impairment (MCI) found that B vitamin treatment to lower homocysteine slowed the rate of cognitive and clinical decline. We have used data from this trial to see whether baseline omega-3 fatty acid status interacts with the effects of B vitamin treatment. 266 participants with MCI aged ≥70 years were randomized to B vitamins (folic acid, vitamins B6 and B12) or placebo for 2 years. Baseline cognitive test performance, clinical dementia rating (CDR) scale, and plasma concentrations of total homocysteine, total docosahexaenoic and eicosapentaenoic acids (omega-3 fatty acids) were measured. Final scores for verbal delayed recall, global cognition, and CDR sum-of-boxes were better in the B vitamin-treated group according to increasing baseline concentrations of omega-3 fatty acids, whereas scores in the placebo group were similar across these concentrations. Among those with good omega-3 status, 33% of those on B vitamin treatment had global CDR scores >0 compared with 59% among those on placebo. For all three outcome measures, higher concentrations of docosahexaenoic acid alone significantly enhanced the cognitive effects of B vitamins, while eicosapentaenoic acid appeared less effective. When omega-3 fatty acid concentrations are low, B vitamin treatment has no effect on cognitive decline in MCI, but when omega-3 levels are in the upper normal range, B vitamins interact to slow cognitive decline. A clinical trial of B vitamins combined with omega-3 fatty acids is needed to see whether it is possible to slow the conversion from MCI to AD.
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Cognitive Effects of Intentional Weight Loss in Elderly Obese Individuals With Mild Cognitive Impairment.
Horie, NC, Serrao, VT, Simon, SS, Gascon, MR, Dos Santos, AX, Zambone, MA, Del Bigio de Freitas, MM, Cunha-Neto, E, Marques, EL, Halpern, A, et al
The Journal of clinical endocrinology and metabolism. 2016;101(3):1104-12
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Several studies have elucidated that midlife obesity increases the risk of dementia later in life. While the neuroprotective effects of caloric restriction have been widely demonstrated, they have not yet been investigated in patients with mild cognitive impairment (MCI). The aim of this trial was to evaluate the effect of intentional weight loss in elderly adults with mild cognitive impairment (MCI). Eighty participants aged over 60 were randomly allocated to receive either nutritional counselling or medical care alone for 12 months. The findings of this study indicated that intentional weight loss through diet was associated with cognitive improvement in patients with MCI, and this association was strongest in younger adults and APOE4 carriers. As this was the first clinical trial exploring these effects in patients with MCI further research is warranted.
Abstract
CONTEXT Obesity in midlife is a risk factor for dementia, but it is unknown if caloric restriction-induced weight loss could prevent cognitive decline and therefore dementia in elderly patients with cognitive impairment. OBJECTIVE To evaluate the cognitive effect of intentional weight loss in obese elderly patients with mild cognitive impairment (MCI), considering the influence of age, apolipoprotein E (APOE) genotype, physical activity, biochemical markers, and diet. DESIGN Single-center, prospective controlled trial. SETTING Academic medical center. PARTICIPANTS Eighty obese patients with MCI, aged 60 or older (68.1 ± 4.9 y, body mass index [BMI] 35.5 ± 4.4 kg/m(2), 83.7% women, 26.3% APOE allele ϵ4 carriers). INTERVENTION Random allocation to conventional medical care alone (n = 40) or together with nutritional counselling (n = 40) in group meetings aiming to promote weight loss through caloric restriction for 12 months. OUTCOME MEASUREMENTS clinical data, body composition, neuropsychological tests (main outcome), serum biomarkers, APOE genotype, physical performance, dietary recalls. RESULTS Seventy-five patients completed the follow-up. BMI, on average, decreased 1.7 ± 1.8 kg/m(2) (P = .021), and most of the cognitive tests improved, without difference between the groups. In analysis with linear generalized models, the BMI decrease was associated with improvements in verbal memory, verbal fluency, executive function, and global cognition, after adjustment for education, gender, physical activity, and baseline tests. This association was strongest in younger seniors (for memory and fluency) and in APOE allele ϵ4 carriers (for executive function). Changes in homeostasis model assessment-estimated insulin resistance, C-reactive protein, leptin and intake of energy, carbohydrates, and fats were associated with improvement in cognitive tests. CONCLUSIONS Intentional weight loss through diet was associated with cognitive improvement in patients with MCI.