Associations between Plasmatic Polyunsaturated Fatty Acids Concentrations and Cognitive Status and Decline in Neurocognitive Disorders

Overview of alkyl quercetin lipophenol synthesis and its protective effect against carbonyl stress involved in neurodegeneration

Oxidative stress and carbonyl stress resulting from the toxicity of small aldehydes are part of the detrimental mechanisms leading to neuronal cell loss involved in the progression of neurodegenerative diseases such as Alzheimer's disease. Polyunsaturated alkylated lipophenols represent a new class of hybrid molecules that combine the health benefits of anti-inflammatory omega-3 fatty acids with the anti-carbonyl and oxidative stress (anti-COS) properties of (poly)phenols in a single pharmacological entity. To investigate the therapeutic potential of quercetin-3-docosahexaenoic acid-7-isopropyl lipophenol in neurodegenerative diseases, three synthetic pathways using chemical or chemo-enzymatic strategies were developed to access milligram or gram scale quantities of this alkyl lipophenol. The protective effect of quercetin-3-DHA-7-iPr against cytotoxic concentrations of acrolein (a carbonyl stressor) was assessed in human SHSY-5Y neuroblastoma cells to underscore its ability to alleviate harmful mechanisms associated with carbonyl stress in the context of neurodegenerative diseases.

Association between the Erythrocyte Membrane Fatty Acid Profile and Cognitive Function in the Overweight and Obese Population Aged from 45 to 75 Years Old

Dietary fatty acid intake is closely related to the cognitive function of the overweight and obese population. However, few studies have specified the correlation between exact fatty acids and cognitive functions in different body mass index (BMI) groups. We aimed to explain these relationships and reference guiding principles for the fatty acid intake of the overweight and obese population. Normal weight, overweight, and obese participants were recruited to receive a cognitive function assessment and dietary survey, dietary fatty acids intake was calculated, and the erythrocyte membrane fatty acid profile was tested by performing a gas chromatography analysis. The percentages of saturated fatty acids (SFAs) in the obese group were higher, while monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) were lower than in the normal weight and overweight groups. In the erythrocyte membrane, the increase of n-3 PUFAs was accompanied by cognitive decline in the overweight group, which could be a protective factor for cognitive function in the obese group. High n-6 PUFAs intake could exacerbate the cognitive decline in the obese population. Dietary fatty acid intake had different effects on the cognitive function of overweight and obese people, especially the protective effect of n-3 PUFAs; more precise dietary advice is needed to prevent cognitive impairment.

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.

Childhood growth and neurocognition are associated with distinct sets of metabolites

BACKGROUND

Undernutrition is a serious global problem that contributes to increased child morbidity and mortality, impaired neurocognitive development, and decreased educational and economic attainment. Current interventions are only marginally effective, and identification of associated metabolic pathways can offer new strategies for intervention.

METHODS

Plasma samples were collected at 9 and 36 months from a subset of the PROVIDE child cohort (n = 130). Targeted metabolomics was performed on bile acids, acylcarnitines, amino acids, phosphatidylcholines, and sphingomyelins. Metabolic associations with linear growth and neurocognitive outcomes at four years were evaluated using correlation and penalized-linear regression analysis as well as conditional random forest modeling.

FINDINGS

Different metabolites were associated with growth and neurocognitive outcomes. Improved growth outcomes were associated with higher concentrations of hydroxy-sphingomyelin and essential amino acids and lower levels of acylcarnitines and bile acid conjugation. Neurocognitive scores were largely associated with phosphatidylcholine species and early metabolic indicators of inflammation. All metabolites identified explain ~45% of growth and neurocognitive variation.

INTERPRETATION

Growth outcomes were predominantly associated with metabolites measured early in life (9 months), many of which were biomarkers of insufficient diet, environmental enteric dysfunction, and microbiome disruption. Hydroxy-sphingomyelin was a significant predictor of improved growth. Neurocognitive outcome was predominantly associated with 36 month phosphatidylcholines and inflammatory metabolites, which may serve as important biomarkers of optimal neurodevelopment. The distinct sets of metabolites associated with growth and neurocognition suggest that intervention may require targeted approaches towards distinct metabolic pathways. FUND: Bill & Melinda Gates Foundation (OP1173478); National Institutes of Health (AI043596, CA044579).

Dietary supplement intake among the elderly: hazards and benefits

PURPOSE OF REVIEW

A large percentage of older adults do not receive recommended amounts of many nutrients from food alone. Accordingly, the routine use of dietary supplements has become common among older persons. Although supplement use provides potential benefits by increasing nutrient intakes, there are potential drawbacks.

RECENT FINDINGS

Clinical studies have pointed to potential reductions in the risk to develop age-related diseases among older people who reported long-term use of multivitamin supplements. Higher plasma levels of omega-3 polyunsaturated fatty acids were also associated with fewer cardiovascular deaths in older people consuming omega-3 supplements. Dietary protein supplementation combined with exercise had a strong effect in preventing age-related muscle mass attenuation and leg strength loss in older people. Finally, beneficial effects of purified flavonoids on cognitive functions have been reported in some studies, whereas in a significant number of other studies, no such effect could be observed.

SUMMARY

The use of dietary supplements among older people has increased over the years due to the expectation of reducing the risk of developing chronic diseases. Although some dietary supplements may indeed fulfill some of these expectations, it would be unwise to assume that they are all efficacious and safe to use.