Effects of supplementation with n-3 polyunsaturated fatty acids on cognitive performance and cardiometabolic risk markers in healthy 51 to 72 years old subjects: a randomized controlled cross-over study

Plasma Phospholipid Polyunsaturated Fatty Acid Associations with Neurocognition

Neurocognitive deficits are implicated in major depressive disorder (MDD) and suicidal behavior, and cognitive function may be affected by blood levels of polyunsaturated fatty acids (PUFAs). Neuroprotective functions have been described for omega-3 (n-3) PUFAs, while omega-6 (n-6) PUFAs exhibit broadly opposing activities. Both classes of PUFAs are linked to MDD and suicidal behavior. However, few studies have investigated the relationships between PUFAs and neurocognitive function with respect to MDD or suicidal behavior. Among participants with MDD (n = 45) and healthy volunteers (HV, n = 30) we assessed performance on tasks of attentional capacity and executive function and its relationship to plasma phospholipid PUFA levels, expressed as a percentage of total plasma phospholipids, for eicosapentaenoic acid (EPA%), docosahexaenoic acid (DHA%), and arachidonic acid (AA%). Regression models tested the correlations between PUFA levels and task performance in three groups: MDD with a history of suicide attempt (SA, n = 20), MDD with no attempts (NA, n = 25), and HV. Interaction testing indicated a significant positive correlation of EPA% with continuous performance test scores in the NA group (F = 4.883, df = 2,72, p = 0.01), a measure of sustained attention. The AA% correlated negatively with performance on two executive function tasks, object alternation (beta = -3.97, z-score = -2.67, p = 0.008) and the Wisconsin card sort (beta = 0.80, t-score = -2.16, df = 69, p = 0.035), after adjustment for group and age, with no group effects. Our findings suggest a role for PUFA imbalance in attentional functioning and executive performance; however, no MDD-specific effect was observed.

Omega-3 Fatty Acids, Cognition, and Brain Volume in Older Adults

The elderly population is growing at increased rates and is expected to double in size by 2050 in the United States and worldwide. The consumption of healthy foods and enriched diets have been associated with improved cognition and brain health. The key nutrients common to many healthy foods and diets are the omega-3 polyunsaturated fatty acids (omega-3 FAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). We explored whether omega-3 FA levels are associated with brain volume and cognition. Forty healthy, cognitively normal, Seventh-day Adventist older adults (mean age 76.3 years at MRI scan, 22 females) completed neurocognitive testing, a blood draw, and structural neuroimaging from 2016 to 2018. EPA and an overall omega-3 index were associated with individual measures of delayed recall (RAVLT-DR) and processing speed (Stroop Color) as well as entorhinal cortex thickness. EPA, DHA, and the omega-3 index were significantly correlated with the total white matter volume. The entorhinal cortex, frontal pole, and total white matter were associated with higher scores on delayed memory recall. This exploratory study found that among healthy, cognitively older adults, increased levels of omega-3 FAs are associated with better memory, processing speed, and structural brain measures.

A Systematic Review of Omega-3 Consumption and Neuroprotective Cognitive Outcomes

Context

While a great deal of interest has been accorded to the cognitive effects of n-3 long-chain polyunsaturated fatty acids (LC PUFAs), there is a need for systematic review data that assess this outcome across the lifespan, accounting for population differences and highlighting methodological limitations of extant studies.

Objective

This systematic review addresses the effects of n-3s on human cognition and provides an overview on the current state of research and recommendations for future efforts.

Data Sources

Based on a thorough review of highly powered articles from PubMed (MEDLINE), Web of Science, and ProQuest Central, the authors evaluated articles published between 2000 and 2020 assessing LC PUFA status on cognition as a primary outcome measure. Using the PRISMA guidelines, the researchers' primary aim was to provide a comprehensive overview of the articles.

Conclusions

The results indicate inconsistent effects of intervention, with benefits for specific groups on specific outcomes. Although results were rarely definitive across cognitive domains, and the majority of studies indicated the presence of a possible threshold effect in which LC PUFA needs were already being met, and supplementation did not have an additional effect, there is evidence for trends towards benefit in cognitive functions, in those experiencing early cognitive decline.

The Effect of Very-Long-Chain n-3 Polyunsaturated Fatty Acids in the Central Nervous System and Their Potential Benefits for Treating Alcohol Use Disorder: Reviewing Pre-Clinical and Clinical Data

Alcohol use poses a significant global health concern, leading to serious physical and socioeconomic issues worldwide. The current treatment options for problematic alcohol consumption are limited, leading to the exploration of alternative approaches, such as nutraceuticals. One promising target is very-long-chain n-3 polyunsaturated fatty acids (VLC n-3 PUFAs). This review aims to compile the most relevant pre-clinical and clinical evidence on the effect of VLC n-3 PUFAs on alcohol use disorders and related outcomes. The findings suggest that VLC n-3 PUFAs may alleviate the physiological changes induced by alcohol consumption, including neuroinflammation and neurotransmitter dysregulation. Additionally, they can reduce withdrawal symptoms, improve mood, and reduce stress level, all of which are closely associated with problematic alcohol consumption. However, more research is required to fully understand the precise mechanisms by which VLC n-3 PUFAs exert their function. Furthermore, PUFAs should not be considered a standalone solution, but as a complement to other therapeutic approaches. Although preliminary evidence supports the potential therapeutic effect of VLC n-3 PUFAs on problematic alcohol consumption, additional research is needed to validate these findings and determine the optimal use of PUFAs as part of a comprehensive approach to the treatment of alcohol use disorders.

New perspectives on randomized controlled trials with omega-3 fatty acid supplements and cognition: A scoping review

Long chain polyunsaturated omega-3 fatty acids (n-3 FA), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are known to be important components in a healthy diet and contribute to healthy functioning of the heart and the brain, among other organs. Although there are epidemiological studies on the strong relationship between fish or n-3 FA consumption and lower risk of cognitive decline, results from randomized controlled trials (RCTs) are less consistent. Here, we performed a scoping review on RCTs with n-3 FA supplementation where cognition was evaluated. Seventy-eight RCTs published before April 2022 were included in this review. Among these RCTs, 43.6% reported a positive cognitive outcome after the consumption of n-3 FA compared to the placebo. However, there was a large diversity of populations studied (age ranges and health status), wide range of doses of EPA + DHA supplemented (79 mg/day - 5200 mg/day) and a multitude of tests evaluating cognition, mainly diagnostic tests, that were used to assess cognitive scores and overall cognitive status. RCTs were thereafter categorized into non-cognitively impaired middle-aged adults (n = 24), non-cognitively impaired older adults (n = 24), adults with subjective memory complaints (n = 14), adults with mild cognitive impairments (MCI, n = 9) and people with diagnosed dementia or other cognitive changes (n = 7). Among these categories, 66.7% of RCTs conducted with MCI adults reported a positive cognitive outcome when supplemented with n-3 FA vs. the placebo. Therefore, this scoping review provides rationale and questions to a) strengthen the design of future RCTs with n-3 FA for cognitive outcomes, and b) generate more informative data to support clinicians in their practice in assessing cognition before and after a nutritional intervention.

Xylooligosaccharides and aerobic training regulate metabolism and behavior in rats with streptozotocin-induced type 1 diabetes

Type 1 diabetes mellitus is characterized with decreased microbial diversity. Gut microbiota is essential for the normal physiological functioning of many organs, especially the brain. Prebiotics are selectively fermentable oligosaccharides [xylooligosaccharides (XOS), galactooligosaccharides, etc.] that promote the growth and activity of gut microbes and influence the gut-brain axis. Aerobic exercise is a non-pharmacological approach for the control of diabetes and could improve cognitive functions. The potential beneficial effect of XOS and/or aerobic training on cognition, the lipid profile and oxidative stress markers of experimental rats were evaluated in this study. Male Wistar rats were randomly divided into three streptozotocin-induced diabetic groups and a control group. Some of the rats, either on a XOS treatment or a standard diet, underwent aerobic training. The results showed that the aerobic training independently lowered the total cholesterol levels compared to the sedentary diabetic rats (p = 0.032), while XOS lowers the malondialdehyde levels in the trained diabetic rats (p = 0.034). What is more the exercise, independently or in combination with XOS beneficially affected all parameters of the behavioral tests. We conclude that aerobic exercises alone or in a combination with the prebiotic XOS could ameliorate the dyslipidemia, oxidative stress, and cognitive abilities in experimental type 1 diabetic animals.

Effect of Docosahexaenoic Acid and Eicosapentaenoic Acid Supplementation on Sleep Quality in Healthy Subjects: A Randomized, Double-Blinded, Placebo-Controlled Trial

Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)-omega-3 fatty acids with various functions-influence sleep in children and young adults. However, only limited studies on their effects on sleep in middle- and old-aged adults have been reported. Therefore, we investigated the effects of DHA and EPA on sleep quality in subjects aged ≥ 45 years. We performed a randomized, placebo-controlled, double-blinded, parallel-grouped study, in which we randomly assigned 66 healthy Japanese males and females. Each individual received six 480 mg capsules containing 576 mg DHA and 284 mg EPA per day (DHA/EPA group, n = 33), or corn oil (placebo group, n = 33), for 12 weeks. Before and after the intervention, the Oguri-Shirakawa-Azumi sleep inventory MA version (OSA-MA) and the sleep state test were conducted. In the DHA/EPA group, factor III (frequent dreaming) scores among the OSA-MA scores were significantly improved compared to the placebo group. Additionally, sleep state tests revealed that sleep efficiency improved in the DHA/EPA group. To our knowledge, this study is the first to report that DHA/EPA improves sleep quality in middle- and old-aged individuals, even at doses lower than those administered in previous studies.

The effects of docosahexaenoic acid supplementation on cognition and well-being in mild cognitive impairment: A 12-month randomised controlled trial

OBJECTIVES

Several recent clinical trials have shown that docosahexaenoic acid (DHA) supplements have a significant effect on cognition in cognitively impaired older adults. This randomised controlled trial aimed to investigate the cognitive effects of a DHA fish oil supplement in older adults with mild cognitive impairment, and to examine the moderating effect of the apolipoprotein E (APOE) ɛ4 allele on cognition and well-being.

METHODS/DESIGN

Seventy-two older adults between the ages of 60 and 90 from New Zealand were given a DHA supplement equivalent to 1491 mg DHA + 351 mg eicosapentaenoic acid per day or a placebo for a period of 12 months. Outcome measures included cognition, wellbeing and self-rated quality of life as well as height, weight, blood pressure and APOE genotyping.

RESULTS

The final analysis (n = 60) found no evidence of a treatment effect on cognitive measures, although did find a treatment effect on systolic blood pressure (p = 0.03, ƞ²  = 0.08), and a treatment interaction for APOE ɛ4 carriers on depression (p = 0.04, ƞ²  = 0.07) and anxiety (p = 0.02, ƞ²  = 0.09) scores in favour of the DHA supplement.

CONCLUSIONS

Despite no effect on cognition, the positive result in APOE ɛ4 carriers on depression and anxiety scores and on systolic blood pressure justifies further DHA trials. It may be a prudent step going forward for more studies to replicate the design elements (dose, duration and cognitive measures) of previous DHA trials to help understand why not all older adults appear to benefit from taking a fish oil supplement.

Long-chain Omega-3 fatty acids supplementation and cognitive performance throughout adulthood: A 6-month randomized controlled trial

OBJECTIVE

To investigate whether omega-3 polyunsaturated fatty acids (n-3 PUFA) supplementation improve cognitive performance and if apolipoprotein E (APOE) genotype or age were effect modifiers.

METHODS

Healthy adults of 20 to 80 years old (n = 193) were completed a 6-month double-blind randomized controlled trial with two groups: 2.5 g/day of n-3 PUFA or a placebo. Primary outcomes were visuospatial ability and working memory and secondary outcomes were episodic memory and executive function, measured at baseline and 6 months.

RESULTS

Cognitive performances did not significantly differ between groups on primary or secondary outcomes after 6 months of treatment. APOE carriers and age were not effect modifiers for any outcomes. Those with low episodic memory scores and taking the n-3 PUFA supplement, significantly improved their scores (p = 0.043).

CONCLUSIONS

A 6-month n-3 PUFA supplementation did not improve cognitive performance in cognitively healthy adults and APOE status or age were not effect modifiers.

Blood-Brain Barrier Disruption Mediated by FFA1 Receptor-Evidence Using Miniscope

Omega-3 polyunsaturated fatty acids (n-3 PUFAs), obtained from diet and dietary supplements, have been tested in clinical trials for the prevention or treatment of several diseases. n-3 PUFAs exert their effects by activation of free fatty acid (FFA) receptors. FFA1 receptor, expressed in the pancreas and brain, is activated by medium- to long-chain fatty acids. Despite some beneficial effects on cognition, the effects of n-3 PUFAs on the blood-brain barrier (BBB) are not clearly understood. We examined the effects of FFA1 activation on BBB permeability in vitro, using rat brain microvascular endothelial cells (RBMVEC), and in vivo, by assessing Evans Blue extravasation and by performing live imaging of brain microcirculation in adult rats. AMG837, a synthetic FFA1 agonist, produced a dose-dependent decrease in RBMVEC monolayer resistance assessed with Electric Cell-Substrate Impedance Sensing (ECIS); the effect was attenuated by the FFA1 antagonist, GW1100. Immunofluorescence studies revealed that AMG837 produced a disruption in tight and adherens junction proteins. AMG837 increased Evans Blue content in the rat brain in a dose-dependent manner. Live imaging studies of rat brain microcirculation with miniaturized fluorescence microscopy (miniscope) showed that AMG837 increased extravasation of sodium fluorescein. Taken together, our results demonstrate that FFA1 receptor activation reduced RBMVEC barrier function and produced a transient increase in BBB permeability.

Effects of Dietary Food Components on Cognitive Functions in Older Adults

Population aging has recently been an important issue as the number of elderly people is growing worldwide every year, and the extension of social security costs is financially costly. The increase in the number of elderly people with cognitive decline is a serious problem related to the aging of populations. Therefore, it is necessary to consider not only physical care but also cognitive patterns in the future care of older adults. Since food contains a variety of bioactive substances, dietary patterns may help improve age-related cognitive decline. However, the relationship between cognitive function and individual food components remains ambiguous as no clear efficacy or mechanism has been confirmed. Against this background, this review summarizes previous reports on the biological process of cognitive decline in the elderly and the relationship between individual compounds in foods and cognitive function, as well as the role of individual components of food in cognitive function, in the following order: lipids, carotenoids, vitamins, phenolic compounds, amino acids, peptides, and proteins. Based on the research presented in this review, a proper diet that preserves cognitive function has the potential to improve age-related cognitive decline, Alzheimer's disease, and Parkinson's disease. Hopefully, this review will help to trigger the development of new foods and technologies that improve aging and cognitive functions and extend the healthy life span.

Association of dietary fat composition with cognitive performance and brain morphology in cognitively healthy individuals

BACKGROUND

Dietary lipids (omega-3 polyunsaturated fatty acids (n-3) PUFAs) and saturated fatty acids (SFA) seem to play an important role in brain health. (n-3) PUFAs have been shown to improve cerebral perfusion and to promote synaptogenesis. In this study, we investigated the relationship between dietary fat composition, cognitive performance and brain morphology in cognitively healthy individuals.

METHODS

A total of 101 cognitively healthy participants (age: 42.3 ± 21.3 years, 62 females) were included in this study. Verbal memory was assessed using the California Verbal Learning Test (CVLT). Intake of (n-3) PUFA and SFA was calculated from food-frequency questionnaire-derived data (EPIC-FFQ). Magnetic resonance imaging (MRI) data were obtained (Siemens Trio 3T scanner) and grey matter volumes (GMV) were assessed by voxel-based morphometry (VBM/SPM8). We examined the association of SFA/(n-3) PUFA ratio and memory performance as well as GMV using regression models adjusted for age, sex, education, body mass index, apolipoprotein E (APOE) status and alcohol consumption. For VBM data, a multiple regression analysis was performed using the same covariates as mentioned before with intracranial volume as an additional covariate.

RESULTS

A high SFA/(n-3) PUFA ratio was significantly (p < 0.05) correlated with poorer verbal memory performance and with lower GMV in areas of the left prefrontal cortex that support memory processes.

CONCLUSIONS

These findings suggest that a diet rich in PUFAs is likely to exert favourable effects on brain morphology in brain areas important for memory and executive functions. This could constitute a possible mechanism for maintaining cognitive health in older age.

Microglia and modifiable life factors: Potential contributions to cognitive resilience in aging

Given the increasing prevalence of age-related cognitive decline, it is relevant to consider the factors and mechanisms that might facilitate an individual's resiliency to such deficits. Growing evidence suggests a preeminent role of microglia, the prime mediator of innate immunity within the central nervous system. Human and animal investigations suggest aberrant microglial functioning and neuroinflammation are not only characteristic of the aged brain, but also might contribute to age-related dementia and Alzheimer's Disease. Conversely, accumulating data suggest that modifiable lifestyle factors (MLFs), such as healthy diet, exercise and cognitive engagement, can reliably afford cognitive benefits by potentially suppressing inflammation in the aging brain. The present review highlights recent advances in our understanding of the role for microglia in maintaining brain homeostasis and cognitive functioning in aging. Moreover, we propose an integrated, mechanistic model that postulates an individual's resiliency to cognitive decline afforded by MLFs might be mediated by the mitigation of aberrant microglia activation in aging, and subsequent suppression of neuroinflammation.

Associations of Omega-3 fatty acids with brain morphology and volume in cognitively healthy older adults: A narrative review

INTRODUCTION

Human neurodevelopment is complete by the 4th decade of life at which point brain atrophy ensues with variable rate and regionality into old age. Literally all regions of the brain experience atrophy with older age, however the pattern and rate of atrophy can dictate the behavioral consequences (i.e., cognitive impairment, Alzheimer's disease). Substantial research has aimed to discover the reasons why some people experience greater morphologic changes that produce undesirable consequences with aging and how it may be prevented. One possible explanation is diet, particularly fish consumption and the intake of omega-3 polyunsaturated fatty acids (omega 3) concentrated in fish oil. This narrative review examines the available evidence on the association between omega-3 and brain volume in non-demented older adults.

METHODS

A PubMed search of the literature was conducted in search of studies that investigated the associations of omega-3 on brain morphology and volume in cognitively intact older adults. Inclusion criteria were: populations of adults aged 45 years or over, who were cognitively intact, free of any central nervous system disease, and free of advanced structural brain atrophy. Study participants had to have DHA and EPA levels measured either by blood testing or scoring of dietary intake. There were no restrictions to dates of publication. Studies including demented participants, or participants with substantial white or grey matter atrophy visible on magnetic resonance imaging were excluded.

RESULTS AND CONCLUSION

The search identified only 12 studies, 8 of which were cross-sectional observational studies, 3 longitudinal observational studies, and 1 randomized controlled trial published between 2007 and 2019. The largest amount of evidence indicated that the hippocampus was most frequently involved in this association, with a higher volume associated with higher omega-3 levels. Larger total grey matter, total brain volume, and lower white matter lesion volume were also associated with higher omega-3 among four of the reviewed studies. However, most studies reviewed provided mixed findings regarding the presence or absence of the association of interest, and the findings were observed to be brain region-dependent. Current evidence is still insufficient to formulate recommendations for omega-3 intake to support brain health specifically.

Cognitive Improvement and Safety Assessment of a Dietary Supplement Containing Propolis Extract in Elderly Japanese: A Placebo-Controlled, Randomized, Parallel-Group, Double-Blind Human Clinical Study

Objectives. This study aimed to evaluate the effect of propolis on cognitive function in elderly Japanese with a placebo-controlled design. Material and Methods. This study was performed on 79 elderly Japanese. Participants orally received either a placebo or dietary supplement containing propolis extract for 24 weeks. Cognitive function assessed by Cognitrax and various blood or urine markers were measured at pre- and postadministration. Results and Conclusion. Eligible data from 68 subjects (placebo: 33, propolis: 35) who completed the study were analyzed. Compared to the placebo group, the propolis group showed significant improvement in verbal memory in Cognitrax (P=0.028). Total cholesterol, LDL cholesterol, urea nitrogen, creatinine, and uric acid were significantly improved in the propolis group compared to the placebo group (P = 0.011, P = 0.004, P = 0.048, P = 0.045, and P = 0.005, respectively). However, urea nitrogen, creatinine, and uric acid fluctuated within the normal level. Furthermore, a subgroup analysis was performed on those with higher than 100 of the standardized score of the neurocognitive index indicated by the overall Cognitrax score. Significant improvements in the propolis group compared to placebo were confirmed in verbal memory (P = 0.007) and processing speed as indications for information processing ability, complex attention, and concentration (P = 0.029). No side effects were observed in any of the groups. This study demonstrates that propolis is effective in improving cognitive functions such as memory, information processing, complex attention, and concentration in elderly Japanese.

Genetic variants in FADS1 and ELOVL2 increase level of arachidonic acid and the risk of Alzheimer's disease in the Tunisian population

Polyunsaturated fatty acids (PUFAs) are closely related to various physiological conditions. In several age-related diseases including Alzheimer's disease (AD) altered PUFAs metabolism has been reported. However, the mechanism behind PUFAs impairment and AD developpement remains unclear. In humans, PUFAs biosynthesis requires delta-5 desaturase (D5D), delta-6 desaturase (D6D) and elongase 2 activities; which are encoded by fatty acid desaturase 1 (FADS1), fatty acid desaturase 2 (FADS2), and elongation of very-long-chain fatty acids-like 2 (ELOVL2) genes, respectively. In the present work, we aim to assess whether genetic variants in FADS1, FADS2 and ELOVL2 genes influence plasma and erythrocyte PUFA composition and AD risk. A case-control study was carried out in 113 AD patients and 161 healthy controls.Rs174556, rs174617, and rs3756963 of FADS1, FADS2, and ELOVL2 genes, respectively were genotyped using PCR-RFLP. PUFA levels were quantified using Gas Chromatography. Genotype distributions of rs174556 (FADS1) and rs3756963 (ELOVL2) were different between case and control groups. The genotype TT of rs174556 and rs3756963 single nucleotide polymorphism (SNP) increases significantly the risk of AD in our population. PUFA analysis showed higher plasma and erythrocyte arachidonic acid (AA) level in patients with AD, whereas only plasma docosahexaenoic acid (DHA) was significantly decreased in AD patients. The indexes AA/Dihomo-gamma-linolenic acid (DGLA) and C24:4n-6/Adrenic acid (AdA) were both higher in the AD group. Interestingly, patients with TT genotype of rs174556 presented higher AA level and AA/DGLA index in both plasma and erythrocyte. In addition, higher AA and AA/DGLA index were observed in erythrocyte of TT genotype ofrs3756963 carrier's patients. Along with, positive correlation between AA/DGLA index, age or Gamma-linolenic acid (GLA)/ Linoleic acid (LA) index was seen in erythrocyte and /or plasma of AD patients. After adjustment for confounding factors, the genotype TT of rs174556, erythrocyte AA and AA/DGLA index were found to be predictive risk factors for AD while plasma DHA was found associated with lower AD risk. Both rs174556 and rs3756963 influence AD risk in the Tunisian population and they are likely associated with high AA level. The combination of the two variants increases further the susceptibility to AD. We suggest that FADS1 and ELOVL2 variants could likely regulate the efficiency of AA biosynthesis which could be at the origin of inflammatory derivate.

Omega-3 fatty acids as adjunctive therapeutics: prospective of nanoparticles in its formulation development

Omega-3 polyunsaturated fatty acids (ω-3-PUFAs) are dietary components that have been extensively recognized for their therapeutic value and have shown diverse therapeutic effects including anti-inflammatory, antiarrhythmic, antithrombotic, immunomodulatory and antineoplastic activities. Most of the ω-3-PUFAs are obtained through diet or supplements because the body does not synthesize them. The high instability of ω-3-PUFAs to oxidative deterioration, lower bioavailability at the target tissues and reduced bioactivity of ω-3-PUFAs is an impediment for achieving their therapeutic potential. The present review provides an overview of potential therapeutic activities of ω-3-PUFAs and different novel technical approaches based on nanotechnology, which have been emphasized to overcome instability problems as well as enhance the bioactivity of ω-3-PUFAs. Future prospects related to this area of research are also provided.

Long-chain omega-3 polyunsaturated fatty acids and cognitive decline in non-demented adults: a systematic review and meta-analysis

Context

Long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFAs) are widely considered as nootropic agents that may be beneficial in reversing cognitive impairment.

Objective

The present systematic review of randomized controlled trials was conducted to determine the changes in cognitive function after intervention with LCn-3PUFA supplementation in non-demented adults, including those with mild cognitive impairment.

Data Sources

Five databases (MEDLINE, CINAHL, Scopus, EMBASE, and the Cochrane Library) were searched systematically along with reference lists of selected articles.

Study Selection

Studies were eligible for inclusion if they measured the effect of LCn-3PUFA supplementation on cognition in non-demented adults.

Data Extraction

A total of 787 records were screened, of which 25 studies were eligible for inclusion. Treatment effects were summarized as global cognitive function for primary outcome and measured using the Mini-Mental State Examination and individual cognitive domains for secondary outcome. The pooled effect sizes were estimated using Hedge’s g and random-effects modeling.

Data Analysis

Results from randomized controlled trials indicate that LCn-3PUFAs have no effect on global cognitive function (Hedge’s g = 0.02; 95% confidence interval, −0.12 to 0.154), and among the specific cognitive domains, only memory function showed a mild benefit (Hedge’s g = 0.31; P = 0.003; z = 2.945).

Conclusion

The existing literature suggests that LCn-3PUFA supplementation could provide a mild benefit in improving memory function in non-demented older adults.

Systematic Review Registration

PROSPERO registration no. CRD42017078664.

Effects of Mediterranean diet supplemented with lean pork on blood pressure and markers of cardiovascular risk: findings from the MedPork trial

The Mediterranean diet offers a range of health benefits. However, previous studies indicate that the restricted consumption of red meat in the diet may affect long-term sustainability in non-Mediterranean countries. A 24-week randomised controlled parallel cross-over design compared a Mediterranean diet supplemented with 2–3 serves per week of fresh, lean pork (MedPork) with a low-fat control diet (LF). Thirty-three participants at risk of CVD followed each intervention for 8 weeks, with an 8-week washout period separating interventions. The primary outcome was home-measured systolic blood pressure. Secondary outcomes included diastolic blood pressure, fasting lipids, glucose, insulin, C-reactive protein (CRP), body composition and dietary adherence. During the MedPork intervention, participants achieved high adherence to dietary guidelines. Compared with the MedPork intervention, the LF intervention led to greater reductions in weight (Δ = −0·65; 95 % CI −0·04, −1·25 kg, P = 0·04), BMI (Δ = −0·25; 95 % CI −0·03, −0·47 kg/m2, P = 0·01) and waist circumference (Δ = −1·40; 95 % CI −0·45, −2·34 cm, P < 0·01). No significant differences were observed for blood pressure, lipids, glucose, insulin or CRP. These findings indicate that Australians are capable of adhering to a Mediterranean diet with 2–3 weekly serves of fresh, lean pork. Larger intervention studies are now required to demonstrate clinical efficacy of the diet in populations with elevated blood pressure.

Effect of omega-3 fatty acids on cognition: an updated systematic review of randomized clinical trials

Context

The increasing number of studies on the effects of n-3 long-chain polyunsaturated fatty acids (LC-PUFAs) on health, particularly cognition, in the last 5 years reflects the growing interest in this area of research.

Objective

The aim for this systematic review was to evaluate the scientific evidence published in the last 5 years (2012-2017) on the effects of n-3 LC-PUFA intake on cognition, cognitive development, and cognitive decline to determine whether n-3 LC-PUFAs support cognitive development and prevent cognitive decline.

Data Sources

The PubMed database was searched.

Study Selection

The 51 articles included in this systematic review reported on healthy individuals with mild or moderate cognitive impairment and patients with Alzheimer's disease. Risk of bias was assessed using Cochrane methodology.

Data Extraction

The number of study participants, the type of study, the type and dose of n-3 LC-PUFAs, and the key results are reported here.

Results

Current evidence indicates that n-3 LC-PUFAs administered during pregnancy or breastfeeding have no effect on the skills or cognitive development of children in later stages of development. Evidence regarding the improvement of cognitive function during childhood and youth or in attention deficit/hyperactivity disorder is inconclusive. Moreover, it is still unclear if n-3 LC-PUFAs can improve cognitive development or prevent cognitive decline in young or older adults.

N-of-1 Clinical Trials in Nutritional Interventions Directed at Improving Cognitive Function

Longer life expectancy has led to an increase in the prevalence of age-related cognitive decline and dementia worldwide. Due to the current lack of effective treatment for these conditions, preventive strategies represent a research priority. A large body of evidence suggests that nutrition is involved in the pathogenesis of age-related cognitive decline, but also that it may play a critical role in slowing down its progression. At a population level, healthy dietary patterns interventions, such as the Mediterranean and the MIND diets, have been associated with improved cognitive performance and a decreased risk of neurodegenerative disease development. In the era of evidence-based medicine and patient-centered healthcare, personalized nutritional recommendations would offer a considerable opportunity in preventing cognitive decline progression. N-of-1 clinical trials have emerged as a fundamental design in evidence-based medicine. They consider each individual as the only unit of observation and intervention. The aggregation of series of N-of-1 clinical trials also enables population-level conclusions. This review provides a general view of the current scientific evidence regarding nutrition and cognitive decline, and critically states its limitations when translating results into the clinical practice. Furthermore, we suggest methodological strategies to develop N-of-1 clinical trials focused on nutrition and cognition in an older population. Finally, we evaluate the potential challenges that researchers may face when performing studies in precision nutrition and cognition.

Dietary Long-Chain Fatty Acids and Cognitive Performance in Older Australian Adults

Convincing evidence exists for the positive effect of an improvement in diet quality on age-related cognitive decline, in part due to dietary fatty acid intake. A cross-sectional analysis of data from the Hunter Community Study (HCS) (n = 2750) was conducted comparing dietary data from a validated Food Frequency Questionnaire (FFQ) with validated cognitive performance measures, Audio Recorded Cognitive Screen (ARCS) and Mini Mental State Examination (MMSE). Adjusted linear regression analysis found statistically significant associations between dietary intake of total n-6 fatty acids (FA), but no other FAs, and better cognitive performance as measured by the ARCS (RC = 0.0043; p = 0.0004; R² = 0.0084). Multivariate regression analyses of n-6 FA intakes in quartiles showed that, compared with the lowest quartile (179.8–1150.3 mg), those in the highest quartile (2315.0–7449.4 mg) had a total ARCS score 2.1 units greater (RC = 10.60466; p = 0.006; R² = 0.0081). Furthermore, when n-6 FA intake was tested against each of the ARCS domains, statistically significant associations were observed for the Fluency (RC = 0.0011432; p = 0.007; R² = 0.0057), Visual (RC = 0.0009889; p = 0.034; R² = 0.0050), Language (RC = 0.0010651; p = 0.047; R² = 0.0068) and Attention (RC = 0.0011605; p = 0.017; R² = 0.0099) domains, yet there was no association with Memory (RC = −0.000064; p = 0.889; R² = 0.0083). No statistically significant associations were observed between FA intakes and MMSE. A higher intake of total n-6 FA, but not other types of FA, was associated with better cognitive performance among a representative sample of older aged Australian adults.

Effects of exergame training combined with omega-3 fatty acids on the elderly brain: a randomized double-blind placebo-controlled trial

Background

Older adults often suffer from age- and behavior-related brain changes affecting neuronal functioning and, therefore, cognitive and motor functions. The improvement of these functions might decrease falls and improve mobility. Previous studies indicate that video game-based physical exercise, so-called exergames, or omega-3 fatty acids (FAs) improve motor and cognitive functioning through brain adaptations. The aim of this study was to assess the effects of exergame training combined with fish oil supplementation on neuronal system levels in the brain and behavioral measurements in older adults. We hypothesized that the combination would differently affect these factors compared to the sole administration of exergame.

Methods

Fifty-eight participants were randomly assigned to one of two groups (N = 29 each group) in a parallel, double-blind, randomized controlled trial lasting 26 weeks. The experimental group received daily fish oil, whereas the control group received daily olive oil. After 16 weeks, both groups started with an exergame training. Measurements were performed pre, during, and post intervention. Primary outcomes were recruitment curves using transcranial magnetic stimulation and response-locked potentials using electroencephalography. Secondary outcomes included executive functions and gait parameters. Blood samples were taken to control for FAs.

Results

Forty-three individuals (mean age 69.4 ± 4.6 years) completed the study (N_experimental = 22, N_control = 21). The results showed no significant time × group interaction effects for any parameters. Blood samples demonstrated significant time × group interaction effects. Post-hoc tests showed a significant increase of omega-3 FAs (p < .001) and a significant decrease of omega-6 FAs (p < .001) for the experimental group.

Conclusion

The combination of exergame training and fish oil did not lead to additional beneficial effects. To trigger possible effects, future studies should carefully consider study design aspects; e.g. study duration, individual nutritional supplementation dose, omega-3 FAs supplementation composition, and placebo. Furthermore, studies should consider neuroimaging methods as these might be more sensitive to assess early brain adaptations. Thus, future studies should be aware of several aspects running a combinatory study that includes omega-3 FAs according to their expected effects.

Trial registration

Swiss National Clinical Trials SNCTP000001623 and ISRCTN12084831 registered 30 November 2015.

Fish oil supplement use in New Zealand: A cross-sectional survey

OBJECTIVE

The aims of the survey were to determine: (i) the percentage of fish oil supplement users in a sample population; (ii) why people take fish oil supplements; (iii) where fish oil supplements are stored as well as the average daily dosage; (iv) what dietary and lifestyle behaviours are associated with fish oil supplement use.

DESIGN

An online cross-sectional survey.

SETTING

New Zealand.

RESPONDENTS

A total of 334 New Zealand residents over the age of 18.

RESULTS

Fish oil supplements were taken by 21.9% of respondents. Reasons for taking fish oil supplements were - 72.6% for 'general well-being', 54.8% to 'improve brain function', 31.5% for 'pain/inflammation', 12.3% to 'lower cholesterol levels' and 11% for 'a dietary insufficiency'. Approximately 26% of fish oil users reported taking a dose of fish oil supplements that would meet the recommended daily intake of 400-600 mg combined docosahexaenoic acid and eicosapentaenoic acid, and only 6.8% of fish oil users reported storing their fish oil supplements in the refrigerator. After controlling for other characteristics including age, gender, ethnicity and body mass index, fish oil supplementation use was most likely among respondents who already eat oily fish and least likely in respondents who regularly eat nuts and seeds.

CONCLUSIONS

Fish oil supplements are a commonly used supplement in New Zealand, yet questions remain about the role of these supplements in improving health outcomes. Safety issues related to manufacturing and storage conditions indicate that there is an urgency in answering these questions.

Impact of rye-based evening meals on cognitive functions, mood and cardiometabolic risk factors: a randomized controlled study in healthy middle-aged subjects

Background

Whole grain (WG) intake is associated with reduced risk of obesity, type 2 diabetes and cardiovascular disease, whereas type 2 diabetes increases the risk of cognitive decline and dementia. The purpose of this study was to investigate the effects of short-term intervention with WG rye on cognitive functions, mood and cardiometabolic risk markers in middle-aged test subjects.

Method

Rye-based breads were provided to 38 healthy test subjects (aged 52-70y) during three consecutive days in a crossover study design, using white wheat flour bread (WWB) as a reference. The rye-based bread consisted of a WG rye kernel/flour mixture (1:1 ratio) supplemented with resistant starch type 2 (RS2) (RB + RS2). The last bread portion was ingested at 2100 h, and cognitive function, mood and cardiometabolic risk markers were determined the following morning, 11 − 14 h post intake.

Results

In comparison to WWB, the RB + RS2 product increased ratings of mood parameters (valance, P < 0.001; activation P < 0.05). No differences were seen in the cognitive tests depending on intervention (P > 0.05). RB + RS2 increased insulin sensitivity (P < 0.05), fasting levels of gut hormones (PYY, P < 0.05; GLP-2, P < 0.01) and fasting concentrations of plasma acetate, butyrate and total SCFA (P < 0.001). In contrast, fasting levels of IL − 1β were decreased (P < 0.05). Insulin sensitivity was positively correlated with working memory test performance (P < 0.05).

Conclusions

This study display novel findings regarding effects of WG rye products on mood, and glucose and appetite regulation in middle-aged subjects, indicating anti-diabetic properties of WG rye. The beneficial effects are suggested to be mediated through gut fermentation of dietary fiber in the RB + RS2 product.

Trial registration

The study was retrospectively registered at ClinicalTrials.gov, register number NCT03275948. Registered September 8 2017.

Impact of Dietary Fats on Brain Functions

BACKGROUND

Adequate dietary intake and nutritional status have important effects on brain functions and on brain health. Energy intake and specific nutrients excess or deficiency from diet differently affect cognitive processes, emotions, behaviour, neuroendocrine functions and synaptic plasticity with possible protective or detrimental effects on neuronal physiology. Lipids, in particular, play structural and functional roles in neurons. Here the importance of dietary fats and the need to understand the brain mechanisms activated by peripheral and central metabolic sensors. Thus, the manipulation of lifestyle factors such as dietary interventions may represent a successful therapeutic approach to maintain and preserve brain health along lifespan.

METHODS

This review aims at summarizing the impact of dietary fats on brain functions.

RESULTS

Starting from fat consumption, nutrient sensing and food-related reward, the impact of gut-brain communications will be discussed in brain health and disease. A specific focus will be on the impact of fats on the molecular pathways within the hypothalamus involved in the control of reproduction via the expression and the release of Gonadotropin-Releasing Hormone. Lastly, the effects of specific lipid classes such as polyunsaturated fatty acids and of the "fattest" of all diets, commonly known as "ketogenic diets", on brain functions will also be discussed.

CONCLUSION

Despite the knowledge of the molecular mechanisms is still a work in progress, the clinical relevance of the manipulation of dietary fats is well acknowledged and such manipulations are in fact currently in use for the treatment of brain diseases.

Association between cognitive function and supplementation with omega-3 PUFAs and other nutrients in ≥ 75 years old patients: A randomized multicenter study

A few studies have assessed the association between omega-3 polyunsaturated fatty acids (n-3 PUFA) and cognitive impairment (CI) in very old adults. The aim of this study was to evaluate the effect of a multinutrient supplementation rich in n-3 PUFA on the cognitive function in an institutionalized ≥75-year-old population without CI or with mild cognitive impairment (MCI). A multicenter placebo-controlled double-blind randomized trial was conducted between 2012 and 2013. Cognitive function was assessed at baseline and after one year using 4 neuropsychological tests. Nutritional status was assessed using Mini Nutritional Assessment (MNA). Interaction between Mini-Mental State Examination (MMSE) score and nutritional status were analyzed using linear regression models. A total of 99 participants were randomized to receive placebo or pills rich in n-3 PUFA. After 1-year follow-up, both groups decreased their MMSE score (-1.18, SD:0. 53 and -0.82, SD:0. 63, p = 0.67 for the control and the intervention group respectively). The memory subscale of the MMSE showed an improvement (+0.26, SD:0.18) in the intervention group against a worsening in the control group (-0.11, SD: 0.14; p = 0.09 for differences between groups). Patients at intervention group with normal nutritional status (MNA ≥24) showed an improvement in the MMSE (+1.03, p = 0.025 for differences between 1-y and baseline measurements) against a worsening in the group with malnutrition (MNA<24) (-0.4, p = 0.886 for differences between 1-y and baseline; p of interaction p = 0.05). Supplementation with n-3 PUFA did not show an improvement in the global cognitive function in institutionalized elderly people without CI or with MCI. They only suggest an apparent improvement in memory loss if previously they were well nourished.

Including pork in the Mediterranean diet for an Australian population: Protocol for a randomised controlled trial assessing cardiovascular risk and cognitive function

BACKGROUND

The Mediterranean diet is characterised by the high consumption of extra virgin olive oil, fruits, vegetables, grains, legumes and nuts; moderate consumption of fish, poultry, eggs and dairy; and low consumption of red meat and sweets. Cross sectional, longitudinal and intervention studies indicate that a Mediterranean diet may be effective for the prevention of cardiovascular disease and dementia. However, previous research suggests that an Australian population may find red meat restrictions difficult, which could affect long term sustainability of the diet.

METHODS

This paper outlines the protocol for a randomised controlled trial that will assess the cardiovascular and cognitive benefits of a Mediterranean diet modified to include 2-3 weekly serves of fresh, lean pork. A 24-week cross-over design trial will compare a modified Mediterranean diet with a low-fat control diet in at-risk men and women. Participants will follow each of the two diets for 8 weeks, with an 8-week washout period separating interventions. Home measured systolic blood pressure will be the primary outcome measure. Secondary outcomes will include body mass index, body composition, fasting blood lipids, C-reactive protein, fasting plasma glucose, fasting serum insulin, erythrocyte fatty acids, cognitive function, psychological health and well-being, and dementia risk.

DISCUSSION

To our knowledge this research is the first to investigate whether an alternate source of protein can be included in the Mediterranean diet to increase sustainability and feasibility for a non-Mediterranean population. Findings will be significant for the prevention of cardiovascular disease and age-related decline, and may inform individuals, clinicians and public health policy.

TRIAL REGISTRATION

ACTRN12616001046493 . Registered 5 August 2016.

Enriching Diet with n-3 PUFAs to Help Prevent Cardiovascular Diseases in Healthy Adults: Results from Clinical Trials

Omega-3 polyunsaturated fatty acids (n-3 PUFAs) are believed to be important for cardiovascular health. Many investigations have been carried out in an attempt to examine the effect of n-3 PUFAs intake, in the form of supplementation or fortified foods, for the management of cardiovascular disease (CVD) and risk factors for CVD, whereas less is known about the effect on healthy individuals. The present study reviews the available literature in order to examine the relationship between n-3 PUFAs intake, either via supplementation or enriched food, and the prevention of CVD among healthy adults. Interventional clinical trials on subjects aged >18 years old with none of the established risk factors for CVD have been considered for review. n-3 PUFAs supplementation or enriched food may positively regulate triglycerides and some lipoprotein subsets, as well as several vascular and coagulation parameters, even in healthy patients, presenting no risk factors for CVD, suggesting a protective effect. Diet enrichment with omega-3 is likely to be useful in helping to lower the risk of developing CVD in healthy individuals, but still offers no strong evidence of a tangible benefit on a population level. Additional studies are needed to determine the optimal daily intake, especially to prevent the unfavorable effects of PUFAs over-consumption.

Omega 3 fatty acids in cardiovascular disease risk factors: An updated systematic review of randomised clinical trials

Several studies and reviews regarding the supplementation of omega-3 LC-PUFAs have been developed during the last years. Indeed, the evidence states that high doses omega-3 LC-PUFAs produce a small but significant decrease in blood pressure in older and hypertensive subjects. Due to the increasing interest in the benefits of LC-PUFAs, we aimed to evaluate the scientific evidence provided in the past five years (2012-2016) on the effects of the intake of omega-3 LC-PUFAs on cardiovascular risk factors such as inflammation and oxidative stress, through a systematic review in PubMed database. Twenty-eight articles were related to cardiovascular disease (CVD) and are included in this systematic review. The studies included healthy subjects and CVD patients; we included the number of subjects, type of study, type and doses of omega-3 LC-PUFAs, primary outcomes, and results. The use of omega-3 LC-PUFAs for ameliorating CVD risk factors can be recommended. However, the administration of omega-3 does not seem to show any benefit for the management of CVD or associated complications.

Effects of Long-Chain Omega-3 Polyunsaturated Fatty Acids on Endothelial Vasodilator Function and Cognition-Are They Interrelated?

Long-chain omega-3 polyunsaturated fatty acids (LCn-3 PUFA) may improve brain functions by acting on endothelial cells in the cerebrovasculature to facilitate vasodilatation and perfusion. The aim of this review is to explore this hypothesis by analyzing the effect of LCn-3 PUFA supplementation on systemic vasodilator and cognitive function and finding evidence to link LCn-3 PUFA intake, vasodilator function and cognition. Forty randomized controlled trials examining the effect of LCn-3 PUFA supplementation in humans on either endothelial vasodilator function or cognition were identified and pooled effects measured with a weighted analysis. Compared to placebo, LCn-3 PUFA tended to increase flow-mediated dilatation and significantly improved cognitive function. Emerging evidence links vasodilator dysfunction to cognitive impairment, but evidence that LCn-3 PUFA can improve cognition through enhancements of vasodilator function is still lacking. Further research is needed to determine: (1) whether LCn-3 PUFA can enhance dilatation of cerebral vessels; (2) if improvements in cerebrovascular responsiveness by LCn-3 PUFA are accompanied by cognitive benefits; and (3) the target population groups.

A Mediterranean Diet to Improve Cardiovascular and Cognitive Health: Protocol for a Randomised Controlled Intervention Study

The Mediterranean diet has demonstrated efficacy for improving cardiovascular and cognitive health. However, a traditional Mediterranean diet delivers fewer serves of dairy and less dietary calcium than is currently recommended in Australia, which may limit long-term sustainability. The present study aims to evaluate whether a Mediterranean diet with adequate dairy and calcium can improve cardiovascular and cognitive function in an at-risk population, and thereby reduce risk of cardiovascular disease (CVD) and cognitive decline. A randomised, controlled, parallel, crossover design trial will compare a Mediterranean diet supplemented with dairy foods against a low-fat control diet. Forty participants with systolic blood pressure above 120 mmHg and at least two other risk factors of CVD will undertake each dietary intervention for eight weeks, with an eight-week washout period between interventions. Systolic blood pressure will be the primary measure of interest. Secondary outcomes will include measures of cardiometabolic health, dietary compliance, cognitive function, assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB), psychological well-being and dementia risk. This research will provide empirical evidence as to whether the Mediterranean diet can be modified to provide recommended dairy and calcium intakes while continuing to deliver positive effects for cardiovascular and cognitive health. The findings will hold relevance for the field of preventative healthcare and may contribute to revisions of national dietary guidelines.

Nutrition and Cognition in Older Adults With Heart Failure: A Systematic Review

Cognitive impairment is commonly observed in older adults with heart failure; nutrition is a possible contributing factor. The purpose of the current systematic review is to examine the relationship between nutrition and cognition in older adults with heart failure. A literature review was performed through August 2015 that examined published, peer-reviewed studies from PubMed, PsycINFO, CINAHL, and Web of Science. Four articles were selected for inclusion. Findings revealed that poorer nutritional habits were associated with poorer attention, executive functioning, and memory in older adults with heart failure. Nutritional biomarkers, including anemia, hyponatremia, hypokalemia, hyperglycemia, and hypoalbuminemia, were also associated with cognitive impairment. More research is needed to explore the relationship between nutrition and cognition in this population. Descriptive studies will inform scientists as they design and test nutritional interventions to optimize cognitive function in older adults with heart failure.

Are Dietary Supplements and Nutraceuticals Effective for Musculoskeletal Health and Cognitive Function? A Scoping Review

OBJECTIVE

The aim of our scoping review was to summarize the state of the art regarding micronutrients in order to identify which of them might effectively improve health status in the areas typically impaired in older people: bone, skeletal muscle, and cognitive function.

DESIGN

Scoping review.

METHODS

The Italian Study Group on Healthy Aging by Nutraceuticals and Dietary Supplements (HANDS) performed this scoping review, based on the following steps: doing a list of micronutrients related with musculoskeletal or cognitive functions, included in dietary supplements and nutraceuticals commercialized in Italy; planning a research on PubMed, according to an evidence-based approach, in order to the most relevant positive study for each micronutrient into each of the three areas involved (bone, skeletal muscle and cognitive function); identifying the micronutrients effective in maintaining or achieving an adequate health status in older people, specifying the effective and safe daily doses, according to the selected studies.

RESULTS

In literature we found 12 relevant positive studies (1 international society guidelines/recommendations, 1 systematic review, 7 randomized controlled trials, and 3 prospective cohort studies). We showed that only 16 micronutrients resulted to have appropriate scientific evidences in terms of improving musculoskeletal health and/or cognitive function in older people: beta-alanine, calcium, creatine, fluorides, leucine, magnesium, omega-3 fatty acids, potassium, vitamin B6, vitamin B9, vitamin B12, vitamin C, vitamin D, vitamin E, vitamin K2, and zinc.

CONCLUSION

This scoping review showed that selected micronutrients in adequate doses might have an ancillary role in musculoskeletal health and cognitive functions in older people.

Impact of Omega-3 Fatty Acid Supplementation on Memory Functions in Healthy Older Adults

As the process of Alzheimer's disease (AD) begins years before disease onset, searching for prevention strategies is of major medical and economic importance. Nutritional supplementation with long-chain polyunsaturated omega-3 fatty acids (LC-n3-FA) may exert beneficial effects on brain structure and function. However, experimental evidence in older adults without clinical dementia is inconsistent, possibly due to low sensitivity of previously employed test batteries for detecting subtle improvements in cognition in healthy individuals. Here we used LOCATO, recently described as a robust and sensitive tool for assessing object-location memory (OLM) in older adults, to evaluate the impact of LC-n3-FA supplementation on learning and memory formation. In a double-blind placebo-controlled proof-of-concept study, 44 (20 female) cognitively healthy individuals aged 50-75 years received either LC-n3-FA (2,200 mg/day, n = 22) or placebo (n = 22) for 26 weeks. Before and after intervention, memory performance in the OLM-task (primary) was tested. As secondary outcome parameters, performance in Rey Auditory Verbal Learning Test (AVLT), dietary habits, omega-3-index, and other blood-derived parameters were assessed. Omega-3 index increased significantly in the LC-n3-FA group compared with the placebo group. Moreover, recall of object locations was significantly better after LC-n3-FA supplementation compared with placebo. Performance in the AVLT was not significantly affected by LC-n3-FA. This double-blind placebo-controlled proof-of-concept study provides further experimental evidence that LC-n3-FA exert positive effects on memory functions in healthy older adults. Our findings suggest novel strategies to maintain cognitive functions into old age.

N-3 Polyunsaturated Fatty Acids through the Lifespan: Implication for Psychopathology

OBJECTIVE

The impact of lifetime dietary habits and their role in physical, mental, and social well-being has been the focus of considerable recent research. Omega-3 polyunsaturated fatty acids as a dietary constituent have been under the spotlight for decades. Omega-3 polyunsaturated fatty acids constitute key regulating factors of neurotransmission, neurogenesis, and neuroinflammation and are thereby fundamental for development, functioning, and aging of the CNS. Of note is the fact that these processes are altered in various psychiatric disorders, including attention deficit hyperactivity disorder, depression, and Alzheimer's disease.

DESIGN

Relevant literature was identified through a search of MEDLINE via PubMed using the following words, "n-3 PUFAs," "EPA," and "DHA" in combination with "stress," "cognition," "ADHD," "anxiety," "depression," "bipolar disorder," "schizophrenia," and "Alzheimer." The principal focus was on the role of omega-3 polyunsaturated fatty acids throughout the lifespan and their implication for psychopathologies. Recommendations for future investigation on the potential clinical value of omega-3 polyunsaturated fatty acids were examined.

RESULTS

The inconsistent and inconclusive results from randomized clinical trials limits the usage of omega-3 polyunsaturated fatty acids in clinical practice. However, a body of literature demonstrates an inverse correlation between omega-3 polyunsaturated fatty acid levels and quality of life/ psychiatric diseases. Specifically, older healthy adults showing low habitual intake of omega-3 polyunsaturated fatty acids benefit most from consuming them, showing improved age-related cognitive decline.

CONCLUSIONS

Although further studies are required, there is an exciting and growing body of research suggesting that omega-3 polyunsaturated fatty acids may have a potential clinical value in the prevention and treatment of psychopathologies.

Nutrition and Dementia: Evidence for Preventive Approaches?

In recent years, the possibility of favorably influencing the cognitive trajectory through promotion of lifestyle modifications has been increasingly investigated. In particular, the relationship between nutritional habits and cognitive health has attracted special attention. The present review is designed to retrieve and discuss recent evidence (published over the last 3 years) coming from randomized controlled trials (RCTs) investigating the efficacy of nutritional interventions aimed at improving cognitive functioning and/or preventing cognitive decline in non-demented older individuals. A systematic review of literature was conducted, leading to the identification of 11 studies of interest. Overall, most of the nutritional interventions tested by the selected RCTs were found to produce statistically significant cognitive benefits (defined as improved neuropsychological test scores). Nevertheless, the clinical meaningfulness of such findings was not adequately discussed and appears controversial. In parallel, only 2 studies investigated between-group differences concerning incident dementia and mild cognitive impairment cases, reporting conflicting results. Results of the present review suggest that several dietary patterns and nutritional components may constitute promising strategies in postponing, slowing, and preventing cognitive decline. However, supporting evidence is overall weak and further studies are needed.

Docosahexaenoic Acid and Cognition throughout the Lifespan

Docosahexaenoic acid (DHA) is the predominant omega-3 (n-3) polyunsaturated fatty acid (PUFA) found in the brain and can affect neurological function by modulating signal transduction pathways, neurotransmission, neurogenesis, myelination, membrane receptor function, synaptic plasticity, neuroinflammation, membrane integrity and membrane organization. DHA is rapidly accumulated in the brain during gestation and early infancy, and the availability of DHA via transfer from maternal stores impacts the degree of DHA incorporation into neural tissues. The consumption of DHA leads to many positive physiological and behavioral effects, including those on cognition. Advanced cognitive function is uniquely human, and the optimal development and aging of cognitive abilities has profound impacts on quality of life, productivity, and advancement of society in general. However, the modern diet typically lacks appreciable amounts of DHA. Therefore, in modern populations, maintaining optimal levels of DHA in the brain throughout the lifespan likely requires obtaining preformed DHA via dietary or supplemental sources. In this review, we examine the role of DHA in optimal cognition during development, adulthood, and aging with a focus on human evidence and putative mechanisms of action.

Docosahexaenoic Acid and Cognition throughout the Lifespan

Docosahexaenoic acid (DHA) is the predominant omega-3 (n-3) polyunsaturated fatty acid (PUFA) found in the brain and can affect neurological function by modulating signal transduction pathways, neurotransmission, neurogenesis, myelination, membrane receptor function, synaptic plasticity, neuroinflammation, membrane integrity and membrane organization. DHA is rapidly accumulated in the brain during gestation and early infancy, and the availability of DHA via transfer from maternal stores impacts the degree of DHA incorporation into neural tissues. The consumption of DHA leads to many positive physiological and behavioral effects, including those on cognition. Advanced cognitive function is uniquely human, and the optimal development and aging of cognitive abilities has profound impacts on quality of life, productivity, and advancement of society in general. However, the modern diet typically lacks appreciable amounts of DHA. Therefore, in modern populations, maintaining optimal levels of DHA in the brain throughout the lifespan likely requires obtaining preformed DHA via dietary or supplemental sources. In this review, we examine the role of DHA in optimal cognition during development, adulthood, and aging with a focus on human evidence and putative mechanisms of action.

Cognitive remission: a novel objective for the treatment of major depression?

BACKGROUND

Cognitive dysfunction in major depressive disorder (MDD) encompasses several domains, including but not limited to executive function, verbal memory, and attention. Furthermore, cognitive dysfunction is a frequent residual manifestation in depression and may persist during the remitted phase. Cognitive deficits may also impede functional recovery, including workforce performance, in patients with MDD. The overarching aims of this opinion article are to critically evaluate the effects of available antidepressants as well as novel therapeutic targets on neurocognitive dysfunction in MDD.

DISCUSSION

Conventional antidepressant drugs mitigate cognitive dysfunction in some people with MDD. However, a significant proportion of MDD patients continue to experience significant cognitive impairment. Two multicenter randomized controlled trials (RCTs) reported that vortioxetine, a multimodal antidepressant, has significant precognitive effects in MDD unrelated to mood improvement. Lisdexamfetamine dimesylate was shown to alleviate executive dysfunction in an RCT of adults after full or partial remission of MDD. Preliminary evidence also indicates that erythropoietin may alleviate cognitive dysfunction in MDD. Several other novel agents may be repurposed as cognitive enhancers for MDD treatment, including minocycline, insulin, antidiabetic agents, angiotensin-converting enzyme inhibitors, S-adenosyl methionine, acetyl-L-carnitine, alpha lipoic acid, omega-3 fatty acids, melatonin, modafinil, galantamine, scopolamine, N-acetylcysteine, curcumin, statins, and coenzyme Q10. The management of cognitive dysfunction remains an unmet need in the treatment of MDD. However, it is hoped that the development of novel therapeutic targets will contribute to 'cognitive remission', which may aid functional recovery in MDD.

Serum metabolic profiling in 29 patients with minimal hepatic encephalopathy

AIM: To screen the specific biomarkers for minimal hepatic encephalopathy (MHE).

METHODS: Serum samples were collected from 50 normal volunteers and 29 MHE patients from February 2014 to August 2014 and tested using gas chromatography-time-of-flight mass spectrometry. Principal components analysis and orthogonal partial least square discriminant analysis were performed to detect the specific metabolites of MHE.

RESULTS: Sixty different metabolites were found between MHE patients and normal volunteers, including homocysteine, taurine, docosahexaenoic acid, tyrosine, phenylalanine, valine, isoleucine, allo-isoleucine, etc.

CONCLUSION: Compared with normal controls, different serum metabolites were found in MHE patients. These metabolites might be specific biomarkers for MHE.