Omega-3 polyunsaturated fatty acids and psychological intervention for workers with mild to moderate depression: A double-blind randomized controlled trial.

BACKGROUND: This study assessed whether a combined intervention of omega-3 polyunsaturated fatty acids (PUFAs) and psychoeducation better improved mild to moderate depression in workers compared to psychoeducation alone. METHODS: This study was a double-blinded, parallel group, randomized controlled trial that compared the intervention group, receiving omega-3 fatty acids, with a control group, receiving a placebo supplement. Participants receiving omega-3 fatty acids took 15 × 300 mg capsules per day for 12 weeks. The total daily dose of omega-3 PUFAs was 500 mg docosahexaenoic acid and 1000 mg eicosapentaenoic acid (EPA). The Beck Depression Inventory®-II (BDI-II) was used to assess the severity of depression after treatment. RESULTS: After 12 weeks of treatment, BDI-II scores were significantly lower in the placebo and omega-3 group, when compared to their respective baseline scores (Placebo: t = - 4.6, p < 0.01; Omega-3: t = - 7.3, p < 0.01). However, after 12 weeks of treatment, we found no significant difference between both groups with respect to changes in the BDI-II scores (0.7; 95% CI, - 0.7 to 2.1; p = 0.30). LIMITATIONS: This study did not measure blood omega-3 fatty acid concentration and presented a high-dropout rate. Moreover, our results may not be generalizable to other regions. CONCLUSIONS: The results show that a combination of omega-3 fatty acids and psychoeducation and psychoeducation alone can contribute to an improvement in symptoms in people with mild to moderate depression. However, there is no difference between the interventions in ameliorating symptoms of depression.

Association between blood omega-3 polyunsaturated fatty acids and the gut microbiota among breast cancer survivors.

Omega-3 polyunsaturated fatty acids (PUFAs) are essential nutrients demonstrated to have health benefits, such as decreasing the risk of coronary heart disease, improving parameters associated with metabolic syndrome, and decreasing anxiety symptoms and depression risk. Previous intervention studies indicated the association between blood or tissue PUFA levels and the gut microbiota; however, the details remain incompletely elucidated. We conducted a cross-sectional study to examine the association between PUFAs and the gut microbiota among breast cancer survivors. Adults who had been diagnosed with invasive breast cancer more than one year ago and were not currently undergoing chemotherapy were enrolled. Capillary blood and faecal samples were obtained to assess the blood PUFA levels and gut microbiota compositions. The mean age (n=124) was 58.7 years, and 46% of the participants had a history of chemotherapy. Multiple regression analysis controlling for possible confounders indicated that an increased relative abundance of Actinobacteria was significantly associated with increased levels of docosahexaenoic acid (DHA, beta=0.304, q<0.01). At the genus level, the abundance of Bifidobacterium was positively associated with the level of DHA (beta=0.307, q<0.01). No significant association between omega-6 PUFAs and the relative abundances of gut microbiota members was observed. In addition, analyses stratified by the history of chemotherapy indicated significant associations of PUFA levels with the abundance of some bacterial taxa, including the phylum Actinobacteria (DHA, beta=0.365, q<0.01) and Bacteroidetes (EPA, beta=-0.339, q<0.01) and the genus Bifidobacterium (DHA, beta=0.368, q<0.01) only among participants without a history of chemotherapy. These findings provide the first evidence of positive associations between the abundances of Bifidobacterium among the gut microbiota and the levels of omega-3 PUFAs in the blood. Further studies are required to gain additional insight into these associations in healthy subjects as well as into the causality of the relationship.

Mechanisms underlying the effects of n-3 polyunsaturated fatty acids on fear memory processing and their hypothetical effects on fear of cancer recurrence in cancer survivors.

The relationship of n-3 polyunsaturated fatty acids (PUFAs) and gut microbiota with brain function has been extensively reported. Here, we review how n-3 polyunsaturated fatty acids affect fear memory processing. n-3 PUFAs may improve dysfunctional fear memory processing via immunomodulation/anti-inflammation, increased BDNF, upregulated adult neurogenesis, modulated signal transduction, and microbiota-gut-brain axis normalization. We emphasize how n-3 PUFAs affect this axis and also focus on the hypothetical effects of PUFAs in fear of cancer recurrence (FCR), the primary psychological unmet need of cancer survivors. Its pathophysiology may be similar to that of post-traumatic stress disorder (PTSD), which involves dysfunctional fear memory processing. Due to fewer adverse effects than psychotropic drugs, nutritional interventions involving n-3 PUFAs should be acceptable for physically vulnerable cancer survivors. We are currently studying the relationship of FCR with n-3 PUFAs and gut microbiota in cancer survivors to provide them with a nutritional intervention that protects against FCR.

Dietary fish, n-3 polyunsaturated fatty acid consumption, and depression risk in Japan: a population-based prospective cohort study.

Systematic review of observational studies has revealed that fish consumption and levels of n-3 polyunsaturated fatty acids (PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid are associated with a reduced risk of depression. A reverse J-shaped effect of n-3 PUFAs was suggested. However, there is limited evidence from populations with high fish consumption and no studies have used a standard psychiatrist-based diagnosis of major depressive disorder (MDD). Therefore, this population-based, prospective study investigated the association of dietary fish, n-3 PUFA, and n-6 PUFA consumption with risk of psychiatrist-diagnosed MDD in Japan. A total of 12 219 subjects were enrolled from the Saku area in 1990. Of these, we extracted 1181 participants aged 63-82 years who completed food frequency questionnaires in both 1995 and 2000 and also underwent a mental health examination in 2014-2015. Odds ratios (ORs) and 95% confidence intervals (CIs) for MDD according to fish intake and PUFA quartiles were calculated. Current MDD was diagnosed in 95 patients. We found a reduced risk of MDD in the third quartile for fish intake (111.1 g per day, OR=0.44, 95% CI=0.23-0.84), second quartile for EPA (307.7 mg per day, OR=0.54, 95% CI=0.30-0.99) and third quartile for docosapentaenoic acid (DPA) (123.1 mg per day, OR=0.42, 95% CI=0.22-0.85). ORs adjusted for cancer, stroke, myocardial infarction and diabetes remained significant for fish and DPA intake. Our results suggest that moderate fish intake could be recommended for the prevention of MDD in aged Japanese individuals.

Polyunsaturated fatty acid deficiency during neurodevelopment in mice models the prodromal state of schizophrenia through epigenetic changes in nuclear receptor genes.

The risk of schizophrenia is increased in offspring whose mothers experience malnutrition during pregnancy. Polyunsaturated fatty acids (PUFAs) are dietary components that are crucial for the structural and functional integrity of neural cells, and PUFA deficiency has been shown to be a risk factor for schizophrenia. Here, we show that gestational and early postnatal dietary deprivation of two PUFAs-arachidonic acid (AA) and docosahexaenoic acid (DHA)-elicited schizophrenia-like phenotypes in mouse offspring at adulthood. In the PUFA-deprived mouse group, we observed lower motivation and higher sensitivity to a hallucinogenic drug resembling the prodromal symptoms in schizophrenia. Furthermore, a working-memory task-evoked hyper-neuronal activity in the medial prefrontal cortex was also observed, along with the downregulation of genes in the prefrontal cortex involved in oligodendrocyte integrity and the gamma-aminobutyric acid (GABA)-ergic system. Regulation of these genes was mediated by the nuclear receptor genes Rxr and Ppar, whose promoters were hyper-methylated by the deprivation of dietary AA and DHA. In addition, the RXR agonist bexarotene upregulated oligodendrocyte- and GABA-related gene expression and suppressed the sensitivity of mice to the hallucinogenic drug. Notably, the expression of these nuclear receptor genes were also downregulated in hair-follicle cells from schizophrenia patients. These results suggest that PUFA deficiency during the early neurodevelopmental period in mice could model the prodromal state of schizophrenia through changes in the epigenetic regulation of nuclear receptor genes.

Fatty acid composition of the postmortem corpus callosum of patients with schizophrenia, bipolar disorder, or major depressive disorder.

BACKGROUND: Studies investigating the relationship between n-3 polyunsaturated fatty acid (PUFA) levels and psychiatric disorders have thus far focused mainly on analyzing gray matter, rather than white matter, in the postmortem brain. In this study, we investigated whether PUFA levels showed abnormalities in the corpus callosum, the largest area of white matter, in the postmortem brain tissue of patients with schizophrenia, bipolar disorder, or major depressive disorder. METHODS: Fatty acids in the phospholipids of the postmortem corpus callosum were evaluated by thin-layer chromatography and gas chromatography. Specimens were evaluated for patients with schizophrenia (n=15), bipolar disorder (n=15), or major depressive disorder (n=15) and compared with unaffected controls (n=15). RESULTS: In contrast to some previous studies, no significant differences were found in the levels of PUFAs or other fatty acids in the corpus callosum between patients and controls. A subanalysis by sex gave the same results. No significant differences were found in any PUFAs between suicide completers and non-suicide cases regardless of psychiatric disorder diagnosis. CONCLUSIONS: Patients with psychiatric disorders did not exhibit n-3 PUFAs deficits in the postmortem corpus callosum relative to the unaffected controls, and the corpus callosum might not be involved in abnormalities of PUFA metabolism. This area of research is still at an early stage and requires further investigation.

Serum n-3 polyunsaturated fatty acids and psychological distress in early pregnancy: Adjunct Study of Japan Environment and Children's Study.

N-3 polyunsaturated fatty acids (PUFAs), especially long-chain types such as docosahexaenoic acid, are important nutrients in pregnancy, but the relationship between n-3 PUFA levels and perinatal and postnatal depression remains controversial. This study examined the possible relationship between serum n-3 PUFA levels and psychological distress among expectant mothers in early pregnancy. Data and specimen samples were obtained in a birth cohort study started at Toyama Regional Center in July 2012 as an adjunct study of the Japan Environment and Children's Study. Blood samples were collected at 9-14 weeks' gestation (75% of samples) or after 15 weeks (25%). Subjects with a Kessler Psychological Distress Scale score (K6) ⩾ 9 were assigned to the psychological distress group (n=283). The control group (n=283) was matched for age, educational level and family income. Fatty acid composition was determined from serum samples by gas chromatography. Associations between fatty acid levels and incident psychological distress were evaluated by logistic regression. After adjusting for possible confounders, eicosapentaenoic acid showed an inverse association with risk of psychological distress, with an odds ratio of 0.47 (95% confidence interval: 0.30, 0.73) for the highest tertile. This inverse association remained even after applying a higher cutoff score (K6 ⩾ 13) indicating severe psychological distress (74 pairs). We believe this is the first study to reveal the associations between serum n-3 PUFAs and risk of psychological distress in early pregnancy. Further research is required to verify the causality of these associations.

Fish consumption and depressive symptoms in undergraduate students: A cross-sectional analysis.

BACKGROUND: Emerging evidence suggests that fish consumption may have beneficial effects on mood disorders. However, no study has been reported on this issue in young adults to date. The aim of this study was to investigate the relationship between fish consumption and depressive symptoms in Japanese undergraduate students. METHODS: The 20-item Center for Epidemiologic Studies Depression Scale was used to measure depressive symptoms with a cut-off score of 16. A total of 4190 completed questionnaires (from 2124 men and 2066 women) were received for analysis. RESULTS: Multivariate logistic analysis showed that fish intake was inversely associated with risk of depressive symptoms in undergraduate students. After adjustment for possible confounders, the odds-ratios (95% confidence intervals) for fish intake 1-2 times/month, 1-2 times/week, 3-4 times/week, and almost every day (compared with "almost never") were 0.78 (0.62-0.99), 0.70 (0.56-0.87), 0.67 (0.53-0.85) and 0.65 (0.46-0.92), respectively. This association tended to be stronger in women than in men. CONCLUSIONS: Frequent fish consumption in undergraduate students seems to moderate depressive symptoms. Further research is warranted to clarify the causality.

Serum pro-BDNF/BDNF as a treatment biomarker for response to docosahexaenoic acid in traumatized people vulnerable to developing psychological distress: a randomized controlled trial.

Our open-label pilot study showed that supplementation with docosahexaenoic acid (DHA) increased serum brain-derived neurotrophic factor (BDNF) levels and that there might be an association between changes in serum BDNF levels and reduced psychological distress. Animal research has indicated that a DHA-enriched diet increases BDNF in the brain. In this randomized double-blind controlled trial of severely injured patients vulnerable to posttraumatic stress disorder (PTSD) and depression, we examined whether DHA increases serum BDNF levels and whether changes in BDNF levels are associated with subsequent symptoms of PTSD and depression. Patients received 1470 mg per day of DHA plus 147 mg per day of eicosapentaenoic acid (EPA; n = 53) or placebo (n = 57) for 12 weeks. Serum levels of mature BDNF and precursor pro-BDNF at baseline and 12-week follow-up were measured using enzyme-linked immunosorbent assay kits. At 12 weeks, we used the Clinician-Administered PTSD Scale to assess PTSD symptoms and depressive symptoms by the Montgomery-Åsberg Depression Rating Scale. We found a significant increase in serum BDNF levels during the trial in the DHA and placebo groups with no interaction between time and group. Changes in BDNF levels were not associated with PTSD severity but negatively associated with depression severity (Spearman's ρ = -0.257, P = 0.012). Changes in pro-BDNF were also negatively associated with depression severity (Spearman's ρ = -0.253, P = 0.013). We found no specific effects of DHA on increased serum levels of BDNF and pro-BDNF; however, evidence in this study suggests that increased BDNF and pro-BDNF have a protective effect by minimizing depression severity.

The role of high-density lipoprotein cholesterol in risk for posttraumatic stress disorder: taking a nutritional approach toward universal prevention.

Several cross-sectional studies, but no prospective studies, have reported an association between an abnormal lipid profile and posttraumatic stress disorder (PTSD). We hypothesized that an abnormal lipid profile might predict risk for developing PTSD. In this prospective study, we analyzed data from 237 antidepressant-naïve severely injured patients who participated in the Tachikawa Cohort of Motor Vehicle Accident Study. High-density lipoprotein cholesterol (HDL-C) levels at baseline were significantly lower in patients with PTSD than those without PTSD at 6 months after motor vehicle accident (MVA) and were inversely associated with risk for PTSD. In contrast, triglycerides (TG) at baseline were significantly higher in patients with PTSD than in those without PTSD at 6 months post-MVA and were positively associated with risk for PTSD. There was no clear association between low-density lipoprotein cholesterol or total cholesterol and risk for PTSD. In conclusion, low HDL-C and high TG may be risk factors for PTSD. Determining lipid profiles might help identify those at risk for PTSD after experiencing trauma.

Inhibitory effect of 5,8,11-eicosatrienoic acid on angiogenesis.

INTRODUCTION: Cartilage contains high levels of n-9 eicosatrienoic acid (20:3n-9) but no blood vessels. 20:3n-9 might inhibit angiogenesis. MATERIALS AND METHODS: Angiogenesis was measured in human umbilical vein endothelial cells and diploid fibroblasts. Co-culture was performed with vascular endothelial growth factor-A (VEGF-A, 10 ng/mL) and fatty acids (0.1-10 µmol/L). After 10 days of incubation and immunostaining for endothelial cells, vessel areas were calculated with image analyser software. RESULTS: Addition of 20:3n-9 and n-3 eicosatrienoic acid (20:3n-3) dose dependently inhibited VEGF-A-stimulated angiogenesis (more than the positive control suramin). Arachidonic, eicosapentaenoic, dihomo-γ-linolenic (20:3n-6) and oleic acids did not affect VEGF-A-stimulated angiogenesis even at 10 µmol/L. Arachidonic and dihomo-γ-linolenic acids enhanced angiogenesis without VEGF-A. DISCUSSION AND CONCLUSIONS: We suggest that the presence of 20:3n-9 in cartilage may be related to its vessel-free status and that 20:3n-9 may be useful for the treatment of disorders with excessive vasculature. ACKNOWLEDGEMENTS: This work was partly supported by Polyene Project, Inc.

The relationship between n-3 long-chain polyunsaturated fatty acids and pulse wave velocity in diabetic and non-diabetic patients under long-term hemodialysis. A horizontal study.

BACKGROUND: Diabetes mellitus (DM) and deficiency in n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFAs) are known to increase the incidence of cardiovascular disease (CVD). However, it has not yet been reported whether n-3 LCPUFAs are related to arteriosclerosis in patients under long-term hemodialysis (HD). METHODS: Pulse wave velocity from the brachium to the ankle (baPWV) was measured as a marker of arteriosclerosis with a volume-plethysmographic apparatus in 147 long-term HD patients (non-diabetic (non-DM): 51 males/42 females, 62 +/- 14 y; and DM: 33 males/21 females, 67 +/- 9 y). The fatty acid composition of the total phospholipid fraction from washed RBCs was analyzed by gas chromatography. Analyses were adjusted for age, sex, diastolic blood pressure, pulse, body mass index, duration of HD treatment, smoking status, LDL/HDL-cholesterol ratios and diabetes mellitus (DM). RESULTS: The mean baPWV was 18.9 +/- 5.2 and 23.7 +/- 6.3 m/s in non-DM and DM patients, respectively. The mean baPWV in DM patients was significantly higher than that of non-DM patients after adjustment (p = 0.0002). Multiple regression analysis showed that there was a significant inverse association between baPWV and docosahexaenoic acid (DHA) levels (p = 0.017) and DHA/arachidonic acid (AA) ratios (p = 0.012) in RBC in non-DM patients after adjustment but not in DM patients. CONCLUSIONS: We suggest that n-3 LCPUFAs may be a negative risk factor of CVD also in non-DM HD patients. In DM patients the effects of n-3 PUFAs on the vascular system became undetectable probably because DM overwhelmingly affected PWV. Further studies in a prospective manner are necessary.

No effect of a traditional Chinese medicine, Hochu-ekki-to, on antibody titer after influenza vaccination in man: a randomized, placebo-controlled, double-blind trial.

BACKGROUND: It was shown that a traditional Chinese medicine, Hochu-ekki-to (HET), had adjuvant effects in influenza vaccination in an animal experiment. This, however, could not be assessed in a clinical study. METHODS: Thirty-two healthy subjects were randomly assigned to two groups (control and HET groups) in a double-blind manner. HET subjects (n=17) took 7.5 g of HET/day for two weeks; control subjects took the same amount of indistinguishable placebo. Then subjects were vaccinated against influenza (H1N1, H3N2 and B/Shandong). Hemagglutinin titers and natural killer (NK) activity were measured at weeks 0, 1, 2, 4, and 12. RESULTS: Antiinfluenza titers against the three viruses were increased continuously for the first two weeks and leveled off. However, there were no significant differences in any titers between the two groups. NK activity peaked at week 2 without any inter-group differences. CONCLUSION: We could not find any adjuvant effects of HET in this experimental condition.

Levels of omega-3 fatty acid in serum phospholipids and depression in patients with lung cancer.

Previous studies suggested that omega-3 fatty acids (FAs) have therapeutic effects against depression, but there is no evidence in the oncological setting. Our preliminary study reported the association between lower omega-3 FA intake and occurrence of depression in lung cancer patients. To explore the association further, the present study examined whether depression was associated with lower levels of omega-3 FAs in serum phospholipids. A total of 717 subjects in the Lung Cancer Database Project were divided into three groups by two cutoff points of the Hospital Anxiety and Depression Scale depression subscale (HADS-D). In all, 81 subjects of the nondepression and minor depression groups (HADS-D<5 and 510) for age, gender, clinical stage, and performance status. Fatty acids were assayed by gas chromatography and compared among the three matched groups. There were no differences between the major depression group and nondepression group in any FAs. The minor depression group had higher mean levels of docosahexaenoic acid (mean+/-s.d. (%), nondepression: 7.40+/-1.54; minor depression: 7.90+/-1.40; major depression: 7.25+/-1.52, P=0.017). These results suggested that serum FAs are associated with minor, but not major, depression in lung cancer patients.

The response of human T lymphocytes against alloantigens following Fas-mediated activation-induced cell death.

We examined the response of T lymphocytes activated with specific alloantigens following Fas-mediated apoptosis; using a mixed lymphocyte culture (MLC) system. Cells obtained from an MLC after 6 or 7 days of culture were incubated for are additional 24 hours in the presence or absence of the agonistic monoclonal antibody (MoAb), 7C11, or the antagonistic MoAb, ZB4. We assessed DNA fragmentation/specific cytotoxiy of the MoAb-treated cells. Cells harvested after 4 days of culture were sensitive to apoptosis induced by 7C11 with maximum DNA fragmentation observed on day 6. ZB4 slightly inhibited apoptosis of the cells compared with controls. The simultaneous addition of recombinant interleukin-2 (rIL-2) with the MoAbs significantly inhibited DNA fragmentation in control and ZB4-treated cells, but had little effect on the 7C11-treated cells. Control and ZB4-treated MLC cells showed cytotoxic activities against specific target cells, namely >10%. In contrast, the 7C11-treated cells showed <5% cytotoxicity. Although the addition of rIL-2 increased specific percentage cytotoxicity of control and ZB4-treated cells, it had little effect on the specific cytotoxic activity of the 7C11-treated MLC cells. These results suggest that specific cytotoxic T lymphocytes may be eliminated via apoptosis mediated by the Fas/Fas ligand system.

Potential remedy against Echinococcus multilocularis in wild red foxes using baits with anthelmintic distributed around fox breeding dens in Hokkaido, Japan.

The effect of bait-delivered anthelmintic to reduce the prevalence of Echinococcus multilocularis in wild red foxes was evaluated in Koshimizu, in the eastern part of Hokkaido, Japan. The study area (200 km2) was divided into baited and non-baited sections. The anthelmintic baits were distributed around fox den sites in the baited section every month for 13 months. After 1 year of the anthelmintic bait distribution, the prevalence of E. multilocularis in foxes, evaluated either by the parasite egg examination (from 27.1 to 5.6%) or coproantigen ELISA (from 59.6 to 29.7%), decreased in the baited section contrasting to that in the non-baited section (parasite egg: from 18.8 to 24.2%; ELISA: from 41.9 to 45.8%). The prevalence of E. multilocularis in grey red-backed vole Clethrionomys rufocanus, caught around fox dens, born after bait distribution also decreased and was significantly lower than that in non-baited section. However, within the study periods, the coproantigen-positive rate in fox faeces sporadically increased, while egg-positive rate constantly decreased. Since coproantigen ELISA can detect pre-patent infection, this observation indicates that reinfection pressure in the baited section was still high even after the 13 months of anthelmintic bait distribution. Therefore, the bait distribution longer than our study period is required for the efficient control of E. multilocularis in wild red fox population.

Evaluation of hepatic functional reserve in rats with obstructive jaundice by asyaloglycoprotein receptor.

BACKGROUND/AIMS: Until now, there has been no adequate means of evaluating the liver functional reserve in cases with obstructive jaundice. 99mTC-GSA (99mTechnetium-DTPA-Galactosyl-human serum albumin) is a new liver-imaging agent which binds specifically to the asyaloglycoprotein-receptor on the membrane of hepatocytes. So, the liver imaging by GSA excludes the influence of the reticuloendothelial system. Therefore, the uptake of 99mTC-GSA is considered to be a useful method for the estimation of liver functional reserve in cases with obstructive jaundice. METHODOLOGY: In this study, we examined the uptake rate and specific binding capacities of 99mTC-GSA to receptors on the membrane of hepatocytes following 1, and 2 weeks of bile-duct ligation and 1 week after reduction of jaundice using the rat model. RESULTS: The hepatic uptake rate decreased as the period of jaundice was prolonged and returned to nearly normal by the reduction of jaundice. The value of specific binding capacities at 2 weeks after bile-duct ligation decreased significantly compared to the value of the control and the reduced group (P < 0.05). The cause of decrease in specific binding capacities was indicated as the decrease of affinity constant especially in the high affinity part. These results coincide with the change of binding capacities of insulin and glucagon receptors with obstructive jaundice, which accurately reflect the severity of hepatocyte injury. CONCLUSIONS: Taking together these results, 99mTC-GSA liver scintigraphy is thought to be a useful method to evaluate the liver functional reserve in cases with jaundice.