Association of serum fatty acid pattern with depression in U.S. adults: analysis of NHANES 2011-2012

BACKGROUND

Exposure to different concentration levels of fatty acids (FAs) may have an impact on depression. However, previous studies using individual FAs may not reflect the performance of mixtures of various FAs, and the associations of FA patterns with depression remain unclear.

METHODS

We conducted the cross-sectional analysis in 792 adults aged 18 and older with available serum FAs and depression screening data in the National Health and Nutrition Examination Survey (NHANES) 2011-2012. The serum concentrations of thirty FAs were measured using gas chromatography-mass spectrometry and their percentage compositions were subsequently calculated. Depression was defined as the Patient Health Questionnaire-9 score ≥ 10. We employed principal component analysis to derive serum FA patterns. We examined the association between these patterns and depression in the overall population and various subgroups through survey-weighted logistic regression.

RESULTS

Four distinct patterns of serum FAs were identified: 'high eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA); low docosatetraenoic acid (DTA) and docosapentaenoic acid (DPA) n-6', 'high long-chain saturated FA and long chain FA', 'low median-chain saturated FA and myristoleic acid' and 'low capric acid and lauric acid; high gamma-linolenic acid (GLA) and stearidonic acid (SDA)' pattern. Individuals in the high tertile of 'high EPA and DHA; low DTA and DPA n-6' pattern score had 0.46 (95% CI: 0.22, 0.93) lower odds of developing depression compared to individuals in the lowest tertile after adjusting for confounders such as age, sex, physical activity and total energy intake, etc. The odds ratio (OR) of depression was increased in the population with the highest tertile of 'low capric acid and lauric acid; high GLA and SDA' pattern (OR: 2.45, 95% CI: 1.24, 4.83). In subgroup analyses, we observed that the association between 'high EPA and DHA; low DTA and DPA n-6' and depression persisted among specific demographic and lifestyle subgroups, including females, non-Mexican Americans, non-obese, those aged over 60 years, smokers and drinkers. Similarly, 'low capric acid and lauric acid; high GLA and SDA' showed stable associations in female, non-Mexican Americans and smokers.

CONCLUSIONS

Serum FA patterns are associated with depression, and their relationships vary across sex, race, BMI, age, smoking and drinking subgroups, highlighting the importance of considering specific FA patterns within these demographic and lifestyle categories. Utilization of combined FA administration may serve as a mitigation measure against depression in these specific populations.

Coconut oil ameliorates behavioral and biochemical alterations induced by D-GAL/AlCl3 in rats

Alzheimer's disease (AD) is a chronic, progressive neurodegenerative condition marked by cognitive impairment. Although coconut oil has been shown to be potentially beneficial in reducing AD-related cognitive deficits, information on its mechanism of action is limited. Thus, we investigated the effects of coconut oil on spatial cognitive ability and non-cognitive functions in a rat model of AD induced by G-galactose (D-GAL) and aluminum chloride (AlCl3), and examined the changes in synaptic transmission, cholinergic activity, neurotrophic factors and oxidative stress in this process. The AD model was established by administering D-GAL and AlCl3 for 90 days, while also supplementing with coconut oil during this time. Cognitive and non-cognitive abilities of the rats were evaluated at the end of the 90-day supplementation period. In addition, biochemical markers related to the pathogenesis of the AD were measures in the hippocampus tissue. Exposure to D-GAL/AlCl3 resulted in a reduction in locomotor activity, an elevation in anxiety-like behavior, and an impairment of spatial learning and memory (P < 0.05). The aforementioned behavioral disturbances were observed to coincide with increased oxidative stress and cholinergic impairment, as well as reduced synaptic transmission and levels of neurotrophins in the hippocampus (P < 0.05). Interestingly, treatment with coconut oil attenuated all the neuropathological changes mentioned above (P < 0.05). These findings suggest that coconut oil shows protective effects against cognitive and non-cognitive impairment, AD pathology markers, oxidative stress, synaptic transmission, and cholinergic function in a D-GAL/AlCl3-induced AD rat model.

Acute and chronic effects of oral administration of a medium-chain fatty acid, capric acid, on locomotor activity and anxiety-like and depression-related behaviors in adult male C57BL/6J mice

Aim

Capric acid (also known as decanoic acid or C10) is one of the fatty acids in the medium‐chain triglycerides (MCTs) commonly found in dietary fats. Although dietary treatment with MCTs is recently of great interest for the potential therapeutic effects on neuropsychiatric disorders, the effects of oral administration of C10 on behavior remain to be examined. This study investigated acute and chronic effects of oral administration of C10 on locomotor activity and anxiety‐like and depression‐related behaviors in adult male C57BL/6J mice.

Methods

To explore the acute effects of C10 administration, mice were subjected to a series of behavioral tests in the following order: light/dark transition, open field, elevated plus maze, Porsolt forced swim, and tail suspension tests, 30 minutes after oral gavage of either vehicle or C10 solution (30 mmol/kg dose in Experiment 1; 0.1, 0.3, 1.0, 3.0 mmol/kg doses in Experiment 2). Next, to examine chronic effects of C10, mice repeatedly administered with either vehicle or C10 solution (0.3, 3.0 mmol/kg doses per day, for 21 days, in Experiment 3) were subjected to behavioral tests without oral administration immediately before each test.

Results

The mice administrated with the high dose of C10 (30 mmol/kg) showed lower body weights, shorter distance traveled, and more anxiety‐like behavior than vehicle‐treated mice, and the results reached study‐wide statistical significance. The C10 administration at a lower dose of 0.3 mmol/kg had no significant effects on body weights and induced nominally significantly longer distance traveled than vehicle administration. Repeated administration of C10 at a dose of 3.0 mmol/kg for more than 21 days caused lower body weights and decreased depression‐related behavior, although the behavioral differences did not reach study‐wide significance.

Conclusions

Although these results suggest dose‐dependent effects of oral administration of capric acid on locomotor activity and anxiety‐like and depression‐related behaviors, further study will be needed to replicate the findings and explore the underlying brain mechanisms.

Repeated oral administration of the medium‐chain fatty acid, capric acid, decreased depression‐related behavior in C57BL/6J mice. This study suggests that capric acid exerts an antidepressant effect.

Coconut oil supplementation during development reduces brain excitability in adult rats nourished and overnourished in lactation

INTRODUCTION

Coconut oil has been considered as a therapeutic alternative in several pathologies, but there is limited information regarding its effects on brain functioning.

OBJECTIVE

This study analyzed whether early virgin coconut oil (VCO) supplementation interferes with electrical activity of the adult rat brain and its lipid peroxidation. Moreover, it investigated whether the putative effect on brain electrophysiology could be affected by overnutrition occurring during lactation, and/or by environmental enrichment (EE). Electrophysiology was measured through cortical spreading depression (CSD), a phenomenon related to brain excitability.

METHODS

Wistar rats were suckled in litters of either nine or three pups, forming nourished (N) or overnourished (ON) groups, respectively. Between the 7th and 30th days of life, half of the animals in each group received VCO (10 mg kg^-1 d^-1; by gavage). The other half received an equivalent amount of vehicle (V, 0.009% cremophor). On day 36, animals from both groups were subjected to EE for 4 weeks. At 105 ± 15 days of life, each animal was subjected to CSD recordings and lipid peroxidation analyses.

RESULTS

Overnutrition during lactation enhanced body and brain weights. VCO decelerated the CSD propagation velocity (control - 3.57 ± 0.23 mm min^-1versus VCO - 3.27 ± 0.18 mm min^-1; p < 0.001), regardless of whether subjected to overnourishment or EE exposure. Neither VCO nor EE modified the cerebral lipid peroxidation (p > 0.05).

CONCLUSION

VCO supplementation impaired the spreading of CSD, indicating reduction of brain excitability. VCO effects occurred regardless of the nutritional state during lactation.

Lauric acid promotes neuronal maturation mediated by astrocytes in primary cortical cultures

Previous studies have suggested the potential efficacy of middle chain fatty acids (MCFAs) in the treatment of mood disorders and cognitive dysfunction. MCFAs are metabolized to ketone bodies in astrocytes; however, their effects on neuronal development including neurotrophic factor level are not well-understood. In the present study, we examined the effect of MCFAs on the mRNA expression of growth factors and cytokines in primary cultures of cortical astrocytes. The effect of MCFAs on neuron-astrocyte interaction in neuronal maturation was also determined using co-culture and astrocyte-conditioned medium. Lauric acid (LA) typically increased the mRNA expression of glial-derived neurotrophic factor (Gdnf), interleukin-6 (Il6), and C–C motif chemokine 2 (Ccl2) in astrocytes. LA-induced phosphorylation of extracellular signal-regulated kinase contributed to these changes. In primary cultures of cortical neurons containing astrocytes, LA enhanced the presynaptic protein levels. Astrocyte-conditioned medium after LA treatment also enhanced the presynaptic protein levels in the cortical neuron cultures. These results suggest that LA increase the mRNA expression of GDNF and cytokines in astrocytes, and thereby, enhances the presynaptic maturation.

Supplementation with Lactobacillus kefiranofaciens ZW3 from Tibetan Kefir improves depression-like behavior in stressed mice by modulating the gut microbiota

Increasing evidence indicates that probiotics can effectively improve depression-like behavior. However, the underlying mechanism is still unclear. In this study, the antidepressant effect of Lactobacillus kefiranofaciens CGMCC2809 (ZW3) isolated from Tibetan Kefir grains was investigated using a mouse model of chronic unpredictable mild stress (CUMS). ZW3 improved depression-like behavior and independent exploration ability in the CUMS group. Moreover, ZW3 regulated biochemical disorders in the hypothalamic-pituitary-adrenal axis, immune system and tryptophan metabolism caused by stress. Furthermore, ZW3 could modulate the composition of the gut microbiota, and alleviate constipation by improving the fecal water content in stressed mice. We found that the probiotic strain was present in the whole intestine, even 7 days after its administration was stopped. These results suggest that L. kefiranofaciens ZW3 might improve depression by regulating the gut microbiota as a probiotic food.

Protective and therapeutic effects of exercise on stress-induced memory impairment

The objective of this paper was to systematically evaluate the potential preventive and therapeutic effects of exercise in attenuating stress-induced memory impairment. A systematic review was employed, searching PubMed, PsychInfo, Sports Discus and Google Scholar databases. For eligibility, studies had to be published in English, employ an experimental design, have the acute or chronic bout of exercise occur prior to, during or after the stressor, implement a psychophysiological stressor, and have an assessment of memory function occurring after the stressor. In total, 23 studies were evaluated, all of which were conducted among animal models. All 23 studies employed a chronic exercise protocol and a chronic stress protocol. Eight studies evaluated a preventive model, three employed a concurrent model, ten studies employed a therapeutic model, and two studies evaluated both a preventive and therapeutic model within the same study. Among the eight studies employing a preventive model, all eight demonstrated that the stress regimen impaired memory function. In all eight of these studies, when exercise occurred prior to the stressor, exercise attenuated the stress-induced memory impairment effect. Among the ten studies employing a therapeutic model, one study showed that the stress protocol enhanced memory function, one showed that the stress protocol did not influence memory, and eight demonstrated that the stress regimen impaired memory function. Among the eight studies showing that the stress protocol impaired memory function, all eight studies demonstrated that exercise, after the stressor, attenuated stress-induced memory impairment. Within animal models, chronic stress is associated with memory impairment and chronic exercise has both a preventive and therapeutic effect in attenuating stress-induced memory impairment. Additional experimental work in human studies is needed. Such work should also examine acute exercise and stress protocols.