Higher serum EPA or DHA, and lower ARA compositions with age independent fatty acid intake in Japanese aged 40 to 79

Association of open skill exercise and long-chain polyunsaturated fatty acid intake with brain volume changes among older community-dwelling Japanese individuals

Considering that a multifactorial lifestyle approach may prove more effective than a single factor approach to improve or maintain brain health, we evaluated the association of exercise (open skill exercise [OSE] or closed skill exercise [CSE]) combined with long-chain polyunsaturated fatty acid (LCPUFAs) (docosahexaenoic acid [C22:6n-3, DHA], eicosapentaenoic acid [C20:5n-3, EPA], and arachidonic acid [C20:4n-6, ARA]) intake with brain atrophy among older Japanese individuals (n = 795, aged 60-88 years) without a self-reported history of dementia based on the datasets of a two-year longitudinal study. Brain volumes were measured using three-dimensional T1-weighted brain magnetic resonance imaging for follow-up periods of two years. The associations between multivariate-adjusted changes in brain volumes and OSE or CSE frequency (≥ once/month and < once/month) along with LCPUFA intake (≥ median and < median) at the baseline were assessed using a general linear model. Subgroup analysis was performed by restricting DHA and EPA intakes (n = 263; median, 323 mg/d), which represented levels similar to those in countries with low fish consumption. Higher OSE frequencies, ARA intakes, and their combination were inversely associated with decreases in total gray matter and frontal cortex volumes. In subgroup analysis, a combination of higher OSE frequencies and DHA intakes was also associated with a smaller decrease in total gray matter volume. Overall, our findings suggest that regular OSE engagement and appropriate LCPUFA intake may contribute to preventing brain volume decreases in older individuals.

Effects of Long-Chain Polyunsaturated Fatty Acids in Combination with Lutein and Zeaxanthin on Episodic Memory in Healthy Older Adults

Arachidonic acid (ARA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), which are long-chain polyunsaturated fatty acids (LCPUFAs), as well as lutein (L) and zeaxanthin (Z), can potentially improve brain function. However, the effect of a combination of these components (LCPUFAs + LZ) on memory function in healthy older individuals remains unclear. This study aimed to determine if LCPUFAs + LZ-supplemented food could improve memory function. Exploratory and confirmatory trials (Trials 1 and 2, respectively) were conducted in healthy older Japanese individuals with memory complaints. We conducted randomized, double-blind, placebo-controlled, parallel-group trials. Participants were randomly allocated to two groups: placebo or LCPUFAs + LZ. LCPUFAs + LZ participants were provided with supplements containing ARA, DHA, EPA, L, and Z for 24 weeks in Trial 1 and 12 weeks in Trial 2. Memory functions were evaluated using Cognitrax before and after each trial. Combined analyses were performed for subgroups of participants with cognitive decline in Trials 1 and 2. The results showed that supplementation with LCPUFAs + LZ did not significantly affect memory function in healthy, non-demented, older individuals with memory complaints whereas it improved memory function in healthy, non-demented, older individuals with cognitive decline.

Characterization of the fatty acid profile in the ventral midbrain of mice exposed to dietary imbalance between omega-6 and omega-3 fatty acids during specific life stages

Objective

Omega-6 (n-6) and omega-3 (n-3) polyunsaturated fatty acids (PUFAs) are essential nutrients. Dietary imbalance between these PUFAs, in particular high in n-6 PUFAs and low in n-3 PUFAs (n-6^high/n-3^low), is common in modern society. We have previously reported that C57BL/6 mouse male offspring derived from mothers exposed to an n-6^high/n-3^low diet during the gestation had an augmented ventral midbrain dopamine system in adulthood; however, the fatty acid composition in this brain region has not yet been investigated. This follow-up study aims to characterize the fatty acid profile of the ventral midbrain of mice exposed to the n-6^high/n-3^low diet during specific life stages.

Results

n-6 PUFAs, especially linoleic acid, were increased in the ventral midbrain of offspring exposed to the n-6^high/n-3^low diet during the gestation compared to those exposed to a well-balanced control diet throughout life. On the other hand, n-3 PUFAs, especially docosahexaenoic acid, were decreased in the ventral midbrain of offspring exposed to the n-6^high/n-3^low diet during the gestation, lactation, or postweaning period compared to those exposed to the control diet throughout life. Thus, exposure to the n-6^high/n-3^low diet in pregnancy increases linoleic acid and that in any life stage decreases docosahexaenoic acid in the offspring's ventral midbrain.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-06175-0.

Relationship Between Serum Eicosapentaenoic Acid to Arachidonic Acid Ratio and Atherosclerotic Risk Factors in Patients With Peripheral Artery Disease

BACKGROUND

The eicosapentaenoic acid to arachidonic acid ratio (EPA/AA) is attracting attention as a risk factor for peripheral artery disease (PAD). However, there have been few studies investigating the relationship between the EPA/AA ratio and atherosclerotic risk factors in patients with PAD. The purpose of the present study was to analyze atherosclerotic risk factors in patients with PAD to identify those factors associated with a low EPA/AA ratio.

METHODS.

The data of patients treated for symptomatic PAD at Tokyo Medical University Hospital and Eniwa Midorino Clinic between April 2014 and March 2018 were retrospectively analyzed.

RESULTS.

A total of 149 patients were tested for blood levels of n-3 and n-6 polyunsaturated fatty acids, including EPA and AA. 73 patients had a low EPA/AA ratio (<0.4) and 76 patients had a high EPA/AA ratio (≥ 0.4). Univariate analysis showed that older age (≥ 75 years), female sex, smoking history, body mass index (BMI), and hemoglobin A_1C (HbA_1C) were associated with the low EPA/AA ratio. Multivariable analysis showed that older age (odds ratio [OR], 0.34; 95% confidential interval [CI], 0.15-0.76; p = 0.008), BMI (OR, 0.87; 95% CI, 0.77-0.98; p = 0.027), smoking history (OR, 2.67; 95% CI, 1.09-6.55; p = 0.007), and HbA_1C (OR, 0.46; 95% CI, 0.29-0.72; p = 0.020) were independently associated with the low EPA/AA ratio.

CONCLUSIONS.

The EPA/AA ratio was related to existing arteriosclerotic risk factors in patients with PAD; it was positively correlated with older age, increasing BMI, and higher HbA_1C, whereas it was negatively correlated with smoking history. These results suggest that the EPA/AA ratio may be closely intertwined with other atherosclerotic risk factors and have an influence on cardiovascular health.

Maternal dietary imbalance between omega-6 and omega-3 fatty acids triggers the offspring's overeating in mice

The increasing prevalence of obesity and its effects on our society warrant intensifying basic animal research for understanding why habitual intake of highly palatable foods has increased due to recent global environmental changes. Here, we report that pregnant mice that consume a diet high in omega-6 (n-6) polyunsaturated fatty acids (PUFAs) and low in omega-3 (n-3) PUFAs (an n-6^high/n-3^low diet), whose n-6/n-3 ratio is approximately 120, induces hedonic consumption in the offspring by upregulating the midbrain dopaminergic system. We found that exposure to the n-6^high/n-3^low diet specifically increases the consumption of palatable foods via increased mesolimbic dopamine release. In addition, neurodevelopmental analyses revealed that this induced hedonic consumption is programmed during embryogenesis, as dopaminergic neurogenesis is increased during in utero access to the n-6^high/n-3^low diet. Our findings reveal that maternal consumption of PUFAs can have long-lasting effects on the offspring’s pattern for consuming highly palatable foods.

Sakayori et al. show that feeding pregnant mice with a diet high in omega-6 polyunsaturated fatty acids (PUFAs) and low in omega-3 PUFAs triggers hedonic consumption in the offspring by increasing its dopaminergic neurogenesis. This study suggests that maternal consumption of diets with unbalanced PUFAs contributes to the offspring’s overconsumption of foods.

Effects of combining exercise with long-chain polyunsaturated fatty acid supplementation on cognitive function in the elderly: a randomised controlled trial

Multifactorial lifestyle intervention is known to be more effective for ameliorating cognitive decline than single factor intervention; however, the effects of combining exercise with long-chain polyunsaturated fatty acids (LCPUFA) on the elderlies' cognitive function remain unclear. We conducted a randomised, single-masked placebo-controlled trial in non-demented elderly Japanese individuals. Participants were randomly allocated to the exercise with LCPUFA, placebo, or no exercise with placebo (control) groups. Participants in the exercise groups performed 150 min of exercise per week, comprised resistance and aerobic training, for 24 weeks with supplements of either LCPUFA (docosahexaenoic acid, 300 mg/day; eicosapentaenoic acid, 100 mg/day; arachidonic acid, 120 mg/day) or placebo. Cognitive functions were evaluated by neuropsychological tests prior to and following the intervention. The per-protocol set analysis (n = 76) revealed no significant differences between the exercise and the control groups in changes of neuropsychological tests. Subgroup analysis for participants with low skeletal muscle mass index (SMI) corresponding to sarcopenia cut-off value showed changes in selective attention, while working memory in the exercise with LCPUFA group was better than in the control group. These findings suggest that exercise with LCPUFA supplementation potentially improves attention and working memory in the elderly with low SMI.

ISSFAL Official Statement Number 6: The importance of measuring blood omega-3 long chain polyunsaturated fatty acid levels in research

A statement on measuring blood omega-3 long chain polyunsaturated fatty acid levels was developed and edited based on input from ISSFAL members and accepted by vote of the ISSFAL Board of Directors. Summary of Statement: Omega-3 long chain polyunsaturated fatty acid (n-3 LCPUFA) levels at baseline and post-intervention should be assessed and reported in future research to evaluate the efficacy of n-3 LCPUFA supplementation: b ecause; 1. there are numerous factors that affect n-3 LCPUFA levels in humans as described in the systematic literature review [1]; 2. assessing intake of n-3 LCPUFA from the diet and/or supplements is not sufficient to accurately determine n-3 LCPUFA levels in humans; 3. some studies do not provide sufficient doses of n-3 LCPUFA to produce a significant impact on bloodstream/organ content and there is substantial variability in the uptake of n-3 LPCUFA into tissues between individuals. In secondary analyses, clinical trials should consider the influence of fatty acid status (baseline, endpoint and change from baseline to endpoint) on the outcome variables.

Epidemiological Features and Clinical Presentations of Acute Coronary Syndrome in Young Patients

Objective Although acute coronary syndrome (ACS) is an uncommon entity in young patients, it constitutes an important problem due to the devastating effects of the disease on the more active lifestyle of young patients. At present, there are no guidelines regarding the prevention of ACS in young patients. Methods We performed a retrospective study of ACS patients between 2014 and 2017. Epidemiological data, clinical findings, and short-term outcomes were evaluated between young ACS patients (≤50 years old) and elderly ACS patients (>50 years old). Results Of a total of 361 consecutive ACS patients, 37 were young ACS patients (10.2%). Compared with elderly ACS patients, young ACS patients showed a higher prevalence of males (94.6% vs. 73.8%, p<0.001), current smoking (70.3% vs. 29.9%; p<0.001), and overweight persons (67.6% vs. 27.8%, p<0.001). The eicosapentaenoic acid (EPA)/arachidonic acid (AA) ratio was significantly lower in young ACS patients than in elderly ACS patients [0.17 (0.12-0.25) vs. 0.25 (0.18-0.37), p=0.002]. The prevalence of cardio-pulmonary arrest and percutaneous cardiopulmonary support use was higher in young ACS patients than in elderly ACS patients (24.3% vs. 8.6%, p=0.003, 16.2% vs. 3.1%, p<0.001). Conclusion The features were markedly different between young ACS patients and elderly ACS patients. In young ACS patients, smoking, being overweight, and a low EPA/AA ratio were distinctive risk factors, and more serious clinical presentations were observed at the onset of ACS than in older patients.

Global metabolic profiling to model biological processes of aging in twins

Aging is intimately linked to system-wide metabolic changes that can be captured in blood. Understanding biological processes of aging in humans could help maintain a healthy aging trajectory and promote longevity. We performed untargeted plasma metabolomics quantifying 770 metabolites on a cross-sectional cohort of 268 healthy individuals including 125 twin pairs covering human lifespan (from 6 months to 82 years). Unsupervised clustering of metabolic profiles revealed 6 main aging trajectories throughout life that were associated with key metabolic pathways such as progestin steroids, xanthine metabolism, and long-chain fatty acids. A random forest (RF) model was successful to predict age in adult subjects (≥16 years) using 52 metabolites (R²  = .97). Another RF model selected 54 metabolites to classify pediatric and adult participants (out-of-bag error = 8.58%). These RF models in combination with correlation network analysis were used to explore biological processes of healthy aging. The models highlighted established metabolites, like steroids, amino acids, and free fatty acids as well as novel metabolites and pathways. Finally, we show that metabolic profiles of twins become more dissimilar with age which provides insights into nongenetic age-related variability in metabolic profiles in response to environmental exposure.

Aging and FADS1 polymorphisms decrease the biosynthetic capacity of long-chain PUFAs: A human trial using [U-13C]linoleic acid

Long-chain polyunsaturated fatty acids (LCPUFAs) are important constituents of biomembranes. Observation of blood fatty acids indicated that LCPUFA biosynthesis is affected by aging and FADS polymorphisms. This study examined the effects of aging and FADS polymorphisms on LCPUFA biosynthetic capacity via direct quantification using [U-¹³C]linoleic acid. Healthy young (25-34 years) and elderly (65-74 years) participants were administered [U-¹³C]linoleate, and its metabolites were monitored for 14 days. The time of maximum plasma concentration of ¹³C-arachidonic acid (ARA) was 4-5 days. The area under the curve of the ¹³C-ARA concentration differed by FADS1 rs174547 polymorphism (TT [100%] > TC [57%] > CC [37%]). Among C allele carriers, ¹³C-ARA formation was 32% lower in elderly than in young participants. This is the first report to directly demonstrate that LCPUFA biosynthetic capacity is regulated by FADS1 polymorphisms and decreased by aging in FADS1 C allele carriers.

Fish and Meat Intake, Serum Eicosapentaenoic Acid and Docosahexaenoic Acid Levels, and Mortality in Community-Dwelling Japanese Older Persons

The associations between meat/fish consumption, docosahexaenoic acid (DHA)/eicosapentaenoic acid (EPA) intakes, and blood DHA/EPA levels, and mortality in Japan were examined as part of the National Institute for Longevity Sciences-Longitudinal Study of Aging: 520 men and 534 women (60–79 years at baseline) were followed from 1997–2017. Nutritional intakes were assessed using a 3-day dietary record and fasting venous blood samples were collected. Serum EPA/DHA concentrations, the EPA/arachidonic acid (ARA) ratio, EPA/DHA intakes, and fish/meat intakes were examined in tertiles as indicator variables, and hazard ratios (HR) were calculated to compare the risk of death across tertiles controlling for sex, age, body mass index, smoking status, alcohol drinking, physical activity, education, employment, and history of diseases. During follow-up (mean 11.7 years), 422 subjects (40.4%) died. The multivariate-adjusted HR for all-cause mortality in subjects in the highest tertile of serum DHA and EPA/ARA ratio was 0.73 (95% confidence intervals (CI): 0.53–0.99) and 0.71 (95% CI: 0.53–0.96) compared with subjects in the lowest tertile, respectively (trend p < 0.05). There were no significant associations between mortality and serum EPA/ARA and DHA/EPA intakes. An increased serum DHA level or EPA/ARA ratio might be recommended for longevity to Japanese community dwellers.

Intake of arachidonic acid-containing lipids in adult humans: dietary surveys and clinical trials

Long-chain polyunsaturated fatty acids (LCPUFAs) have important roles in physiological homeostasis. Numerous studies have provided extensive information about the roles of n-3 LCPUFA, such as docosahexaenoic acid and eicosapentaenoic acid. Arachidonic acid (ARA) is one of the major n-6 LCPUFAs and its biological aspects have been well studied. However, nutritional information for ARA is limited, especially in adult humans. This review presents a framework of dietary ARA intake and the effects of ARA supplementation on LCPUFA metabolism in adult humans, and the nutritional significance of ARA and LCPUFA is discussed.

Non-dietary factors associated with n-3 long-chain PUFA levels in humans - a systematic literature review

Numerous health benefits are attributed to the n-3 long-chain PUFA (n-3 LCPUFA); EPA and DHA. A systematic literature review was conducted to investigate factors, other than diet, that are associated with the n-3 LCPUFA levels. The inclusion criteria were papers written in English, carried out in adult non-pregnant humans, n-3 LCPUFA measured in blood or tissue, data from cross-sectional studies, or baseline data from intervention studies. The search revealed 5076 unique articles of which seventy were included in the qualitative synthesis. Three main groups of factors potentially associated with n-3 LCPUFA levels were identified: (1) unmodifiable factors (sex, genetics, age), (2) modifiable factors (body size, physical activity, alcohol, smoking) and (3) bioavailability factors (chemically bound form of supplements, krill oil v. fish oil, and conversion of plant-derived α-linolenic acid (ALA) to n-3 LCPUFA). Results showed that factors positively associated with n-3 LCPUFA levels were age, female sex (women younger than 50 years), wine consumption and the TAG form. Factors negatively associated with n-3 LCPUFA levels were genetics, BMI (if erythrocyte EPA and DHA levels are &lt;5·6 %) and smoking. The evidence for girth, physical activity and krill oil v. fish oil associated with n-3 LCPUFA levels is inconclusive. There is also evidence that higher ALA consumption leads to increased levels of EPA but not DHA. In conclusion, sex, age, BMI, alcohol consumption, smoking and the form of n-3 LCPUFA are all factors that need to be taken into account in n-3 LCPUFA research.

Lower follicular n-3 polyunsaturated fatty acid levels are associated with a better response to ovarian stimulation

OBJECTIVES

To analyze in detail the fatty acid (FA) composition of follicular fluid (FF) from two-sized follicles at oocyte retrieval and to determine associations of the FAs from large follicles with the woman's age and the response to ovarian stimulation.

DESIGN

Observational study.

SETTING

University and fertility clinic.

PATIENTS

Sixty-four women (age 19-46), consisting of unfertile patients and oocyte donors, undergoing controlled ovarian stimulation.

INTERVENTIONS

None.

MAIN OUTCOME MEASURE(S)

FF from small (< 12 mm) and large (≥ 18 mm) follicles was collected at oocyte retrieval. FAs by gas chromatography-flame ionization detection.

RESULT

Thirty-two FAs with chain lengths ranging from 14 to 25 carbons were identified. There was a readjustment in FA distribution as follicle size increased, raising very long-chain saturated FAs, nervonic (24:1n-9), arachidonic (20:4n-6), and n-3 polyunsaturated FAs (PUFA, P < 0.001), the latter mainly due to an increase in docosahexaenoic acid (22:6n-3, DHA). In large follicles, double bond and peroxidizability indices and total n-3 PUFA, particularly DHA, correlated positively with the woman's age and negatively with the number of total and mature oocytes, total and top-quality embryos, and fertilization rate.

CONCLUSIONS

We have described 32 FAs in ovarian FF, of which 16 changed their distribution with follicle size. The results also indicate that lower n-3 PUFA levels in large follicles, which are associated with younger women, predict a better response to ovarian stimulation based on the recovery of total and mature oocytes, total and top-quality embryos, and fertilization rate per cycle.

KEY MESSAGE

The fatty acid profile of ovarian FF changes as the follicle grows and lower n-3 PUFA levels in large follicles, associated with younger women, predict a better response to ovarian stimulation.

Validation of repeated self-reported n-3 PUFA intake using serum phospholipid fatty acids as a biomarker in breast cancer patients during treatment

Background

The role of n-3 polyunsaturated fatty acids (PUFAs) in breast cancer is not clear and under debate. To explore this relationship it is important to have proper validated dietary assessment methods for measuring the intake of n-3 PUFAs. The aim of the current study is to validate two different methods used to assess the intake of selected n-3 PUFAs as well as food sources of long-chained n-3 PUFAs. Also, we aim to study how stable the intake of fatty acids is during breast cancer treatment.

Methods

The study-population was patients with breast cancer (Stages I-II) or ductal carcinoma in situ (DCIS-grade III) undergoing treatment (n = 49) in Norway. Dietary intake was assessed by two self-administered methods, a 256 food item food frequency questionnaire (FFQ) and a 7-day pre-coded food diary (PFD). The FFQ was administered presurgery and twelve months postsurgery, and the PFD was administered shortly after surgery (10 +/− 2 days), six and twelve months postsurgery. Fasting blood samples (presurgery, six and twelve months postsurgery) were analysed for serum phospholipid fatty acids, a biomarker for intake of n-3 PUFAs.

Results

Mean (SD) age was 54.2 (7.8) years at diagnosis, and the mean (SD) body mass index (BMI) was 24.8 (3.4) kg/m². Correlation coefficients between dietary intakes of n-3 PUFAs measured with the FFQ and the PFD ranged from 0.35 to 0.66. The correlation coefficients between the PFD and the biomarker (serum phospholipid n-3 PUFAs) as well as between the FFQ and the biomarker demonstrated stronger correlations twelve months after surgery (ρ 0.40–0.56 and 0.36–0.53, respectively) compared to around surgery (ρ 0.08–0.20 and 0.28–0.38, respectively). The same pattern was observed for intake of fatty fish. The intake of n-3 PUFAs did not change during treatment assessed by the FFQ, PFD or biomarker.

Conclusion

These results indicate that the FFQ and the PFD can be used to assess dietary intake of fish and n-3 PUFAs in breast cancer patients during breast cancer treatment. Still, the PFD shortly after surgery should be used with caution. The diet of patients undergoing breast cancer treatment was quite stable, and the intake of n-3 PUFAs did not change.

Electronic supplementary material

The online version of this article (10.1186/s12937-018-0402-6) contains supplementary material, which is available to authorized users.

Long-chain Polyunsaturated Fatty Acid Supplementation Improves Mood in Elderly Japanese Men

Although several studies have reported the effects of long-chain polyunsaturated fatty acid (LCPUFA) supplementation on the mood in healthy adults, the effects of LCPUFA on elderly individuals remain unclear. Thus, we hypothesized that LCPUFA supplementation improves mood in the elderly. To address this hypothesis, 115 elderly Japanese men aged 55-64 years were assigned and randomly allocated to the LCPUFA or placebo group. Participants received 4 weeks of supplementation with LCPUFA-containing oil (docosahexaenoic acid (DHA) 300 mg/day, eicosapentaenoic acid (EPA) 100 mg/day, arachidonic acid (ARA) 120 mg/day) or a placebo oil. Mood was assessed using the Profile of Mood States (POMS) before and after supplementation as the secondary outcome in a previously performed randomized controlled trial on cognitive function. A total of 113 participants completed the supplementation period. One hundred participants (LCPUFA, n = 51; placebo, n = 49) who were eligible for evaluation of mood were analyzed. Increases in vigor scores on POMS, reflecting a positive mood, were significantly larger in the LCPUFA group than in the placebo group (LCPUFA, +1.8; placebo, -0.5). No significant differences were observed in changes in other negative mood scores between groups. DHA and ARA content in plasma phospholipids were increased by 0.8% and 0.7%, respectively, in the LCPUFA group, and were significantly larger than those in the placebo group. Dietary DHA, EPA, and ARA intake was unchanged during the study. These results suggest that LCPUFA supplementation may improve vigor (positive mood) in elderly Japanese men.

Plasma Lipidomics of Healthy Japanese Adults Reveals Gender- and Age-Related Differences

Lipid metabolites in the blood are expected to be biomarker candidates to reflect disease states and responses to therapeutic drugs. However, their profiles are influenced by subject background, which may lead to confounding results. This study aimed to evaluate whether age and gender affect lipid metabolite levels in the plasma of healthy Japanese adults. Comprehensive lipidomic analysis was performed using liquid chromatography-mass spectrometry for overnight fasted volunteers consisting of 4 groups of 15 subjects each: young males (25-35 years), elderly males (55-64 years), young females (25-35 years), and elderly females (55-65 years). Of 326 detected lipids, none showed significant gender-associated differences in the young groups and 3 metabolites showed significant gender-associated differences in the elderly groups, suggesting that age has little impact on plasma lipid levels in Japanese subjects. We found age-associated differences in 111 (34%) and 115 (35%) metabolites in males and females, respectively, indicating that the subjects' age should be considered an important confounding factor for lipid biomarker exploration and validation studies in Japanese populations. These findings provide fundamental information on biomarker discovery, validation, and qualification processes in Japanese populations, and facilitate the evaluation of biomarker candidates found in other populations.

Dietary alpha-linolenic acid/linoleic acid ratios modulate immune response, physical barrier and related signaling molecules mRNA expression in the gills of juvenile grass carp (Ctenopharyngodon idella)

This study was conducted to explore the possible effects of dietary ALA/LNA ratios on the gill immunity, tight junction and antioxidant capacity, and the related signaling factor mRNA levels of juvenile grass carp (Ctenopharyngodon idella). Fish were fed diets with different ALA/LNA ratios (0.01, 0.34, 0.68, 1.03, 1.41, 1.76 and 2.15) for 60 days. The present results showed that ALA/LNA ratio of 1.03 significantly enhanced lysozyme and acid phosphatase activities, complement 3 contents, promoted mRNA levels of antimicrobial peptides (Hepcidin and liver expression antimicrobial peptide-2), anti-inflammatory cytokines (interleukin 10 and transforming growth factor β1) and inhibitor protein κBα, whereas suppressed pro-inflammatory cytokines (interleukin 1β, interleukin 8, tumor necrosis factor a and interferon γ2), and signal molecules (IκB kinase β, IκB kines γ and nuclear factor κB p65) mRNA levels in the gill, indicating that optimal dietary ALA/LNA ratio improve gill immunity of juvenile fish. Besides, ALA/LNA ratio of 1.03 increased mRNA levels of the barrier functional proteins (occludin, zonula occludens-1, claudin-b, -c and -3), and reduced the pore-formation proteins (claudin-15a) and myosin light-chain kinase mRNA abundance in the gill of juvenile grass carp, indicating optimum ALA/LNA ratio strengthen gill tight junction of juvenile fish. Additionally, ALA/LNA ratio of 1.03 increased glutathione contents, copper/zinc superoxide dismutase, glutathione peroxidase, glutathione S-transferase and glutathione reductase activities and mRNA abundance, and nuclear factor erythoid 2-related factor 2 mRNA levels in the gill of fish, suggesting that optimal ALA/LNA ratio ameliorate gill antioxidant status of juvenile fish. Interestingly, dietary ALA/LNA ratios had no effect on IκB kinase α and catalase activities in fish gills. Collectively, optimal dietary ALA/LNA ratio could improve gill immunity and strengthen physical barrier of juvenile fish. Based on the quadratic regression analysis of complement 3 content in the gill, optimal dietary ALA/LNA ratio for maximum growth of juvenile grass carp was estimated to be 1.12.

Modulation of Ras/ERK and Phosphoinositide Signaling by Long-Chain n-3 PUFA in Breast Cancer and Their Potential Complementary Role in Combination with Targeted Drugs

A potential complementary role of the dietary long-chain n-3 polyunsaturated fatty acids (LCn-3 PUFA) in combination with innovative mono-targeted therapies has recently been proposed. These compounds are thought to act pleiotropically to prevent the development and progression of a variety of cancers, including breast cancer. We hereinafter critically analyze the reports investigating the ability of LCn-3 PUFA to modulate the Ras/ERK and the phosphoinositide survival signaling pathways often aberrantly activated in breast cancer and representing the main targets of innovative therapies. The in vitro or in vivo animal and human interventional studies published up to January 2017 investigating the effects of LCn-3 PUFA on these pathways in normal and cancerous breast cells or tissues were identified through a systematic search of literature in the PubMed database. We found that, in most cases, both the in vitro and in vivo studies demonstrated the ability of LCn-3 PUFA to inhibit the activation of these pro-survival pathways. Altogether, the analyzed results strongly suggest a potential role of LCn-3 PUFA as complementary agents in combination with mono-targeted therapies. Moreover, the results indicate the need for further in vitro and human interventional studies designed to unequivocally prove the potential adjuvant role of these fatty acids.

Global survey of the omega-3 fatty acids, docosahexaenoic acid and eicosapentaenoic acid in the blood stream of healthy adults

Studies reporting blood levels of the omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), were systematically identified in order to create a global map identifying countries and regions with different blood levels. Included studies were those of healthy adults, published in 1980 or later. A total of 298 studies met all inclusion criteria. Studies reported fatty acids in various blood fractions including plasma total lipids (33%), plasma phospholipid (32%), erythrocytes (32%) and whole blood (3.0%). Fatty acid data from each blood fraction were converted to relative weight percentages (wt.%) and then assigned to one of four discrete ranges (high, moderate, low, very low) corresponding to wt.% EPA+DHA in erythrocyte equivalents. Regions with high EPA+DHA blood levels (>8%) included the Sea of Japan, Scandinavia, and areas with indigenous populations or populations not fully adapted to Westernized food habits. Very low blood levels (≤4%) were observed in North America, Central and South America, Europe, the Middle East, Southeast Asia, and Africa. The present review reveals considerable variability in blood levels of EPA+DHA and the very low to low range of blood EPA+DHA for most of the world may increase global risk for chronic disease.

Dietary alpha-linolenic acid/linoleic acid ratios modulate intestinal immunity, tight junctions, anti-oxidant status and mRNA levels of NF-κB p65, MLCK and Nrf2 in juvenile grass carp (Ctenopharyngodon idella)

This study was conducted to investigate the effects of dietary alpha-linolenic acid/linoleic acid (ALA/LNA) ratios on the immune response, tight junctions, antioxidant status and immune-related signaling molecules mRNA levels in the intestine of juvenile grass carp (Ctenopharyngodon idella). A total of 1260 juvenile grass carp with an average initial weight of 8.78 ± 0.03 g were fed diets with different ALA/LNA ratios (0.01, 0.34, 0.68, 1.03, 1.41, 1.76 and 2.15) for 60 days. Results indicated that ALA/LNA ratio of 1.03 significantly increased acid phosphatase, lysozyme activities and complement C3 contents, promoted interleukin 10, transforming growth factor β1 and κB inhibitor α mRNA abundance, whereas suppressed pro-inflammatory cytokines (interleukin 1β, interleukin 8, tumor necrosis factor α and interferon γ2) and signal molecules (IκB kinase β, IκB kinase γ and nuclear factor κB p65) mRNA levels in the intestine (P < 0.05), suggesting that optimal dietary ALA/LNA ratio improved intestinal immune response of juvenile fish. Additionally, ALA/LNA ratio of 1.03 significantly promoted Claudin-3, Claudin-b, Claudin-c, Occludin and ZO-1 gene transcription, whereas reduced Claudin-15a and myosin light-chain kinase mRNA levels in the intestine, suggesting that appropriate dietary ALA/LNA ratio strengthened tight junctions in the intestine of juvenile fish. Meanwhile, ALA/LNA ratio of 1.03 noticeably elevated glutathione contents, copper/zinc superoxide dismutase, glutathione peroxidase, glutathione S-transferase and glutathione reductase activities and mRNA levels, as well as signaling molecule nuclear factor erythoid 2-related factor 2 gene transcriptional abundance in the intestine, suggesting that proper ratio of dietary ALA/LNA ameliorate the intestinal antioxidant status of juvenile fish. Based on the quadratic regression analysis of the complement C3 content in the distal intestine and malondialdehyde content in the whole intestine, optimal ALA/LNA ratio for maximum growth of juvenile grass carp (8.78-72.00 g) were estimated to be 1.13 and 1.12, respectively.

Associations between a fatty acid desaturase gene polymorphism and blood arachidonic acid compositions in Japanese elderly

We investigated whether the single nucleotide polymorphism rs174547 (T/C) of the fatty acid desaturase-1 gene, FADS1, is associated with changes in erythrocyte membrane and plasma phospholipid (PL) long-chain polyunsaturated fatty acid (LCPUFA) composition in elderly Japanese participants (n=124; 65 years or older; self-feeding and oral intake). The rs174547 C-allele carriers had significantly lower arachidonic acid (ARA; n-6 PUFA) and higher linoleic acid (LA, n-6 PUFA precursor) levels in erythrocyte membrane and plasma PL (15% and 6% ARA reduction, respectively, per C-allele), suggesting a low LA to ARA conversion rate in erythrocyte membrane and plasma PL of C-allele carriers. α-linolenic acid (n-3 PUFA precursor) levels were higher in the plasma PL of C-allele carriers, whereas levels of the n-3 LCPUFAs eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) were unchanged in erythrocyte membrane and plasma PL. Thus, rs174547 genotypes were significantly associated with different ARA compositions of the blood of elderly Japanese.

Changes in serum fatty acid and lipoprotein subclass concentrations from prepuberty to adulthood and during aging

Concentrations in serum were determined for 18 fatty acids (FAs) and 21 lipoprotein main and subclasses by chromatographic analyses and the average size was calculated for very low density (VLDL), low density (LDL) and high density (HDL) particles. 283 ethnic Norwegian children and adults from the rural Fjord region of Western Norway were compared with the objectives to reveal patterns and gender differences during the development from prepuberty to adulthood and during aging in adults. Both genders showed a large increase in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from child to adult. Males, but not females, show a significant increase in most C16-C18 FAs from prepuberty to adulthood. These changes in males correlate to a pattern of increased concentrations of triglycerides, VLDL and LDL particles, especially the atherogenic subclasses of small and very small LDL particles. Furthermore, concentrations of medium, large and very large HDL particles decrease, while concentration of very small HDL particles increase leading to reduced average size of HDL particles. Females only showed significant increase in concentrations of small and very small LDL particles, very small HDL particles and apolipoprotein B. While EPA and DHA continued to increase during aging in women, no validated model for connecting age to FA profile was obtained for men. Women showed significant increase in concentrations of all subclasses of LDL particles during aging, while men exhibited a more complex pattern with increase also in apolipoprotein A1 and HDL particles.

Cross-sectional association between serum concentrations of n-3 long-chain PUFA and depressive symptoms: results in Japanese community dwellers

The effect of n-3 long-chain PUFA (n-3 LCPUFA) on depression in healthy subjects is unclear, and most of the previous studies have focused on populations eating Western diets with lower fish intake. The present study investigated the association between blood levels of n-3 LCPUFA and depressive symptoms in Japanese community dwellers with higher n-3 LCPUFA blood levels. A cross-sectional study was conducted from 2006 to 2008, including 1050 men and 1073 women aged 40 years or older from the National Institute for Longevity Sciences – the Longitudinal Study of Aging. The Center for Epidemiologic Studies Depression Scale (CES-D) was used to assess depressive symptoms. Multiple logistic regression analysis was performed to estimate the OR and 95 % CI for a CES-D score ≥16. Serum concentrations of n-3 PUFA, but not n-6 PUFA, were inversely associated with depressive symptoms. Compared with the lowest quintile, the adjusted OR for serum EPA at the fourth and fifth quintiles were 0·55 (95 % CI 0·35, 0·85) and 0·64 (95 % CI 0·42, 0·98), respectively, and at the fifth quintile for DHA it was 0·58 (95 % CI 0·37, 0·92), for the presence of depressive symptoms (P_{for trend}=0·013 and 0·011, respectively). Serum levels of EPA and DHA were inversely associated with depressive symptoms in Japanese community dwellers with higher blood levels of n-3 LCPUFA, suggesting that n-3 LCPUFA intakes corresponding to higher levels in a Japanese population may have implications for a lower prevalence of depression.

Heterogeneity of the Fatty Acid Composition of Japanese Placentae for Determining the Perinatal Fatty Acid Status: a Methodological Study

Analysis of the placenta can be a useful way to determine the fatty acid (FA) status of pregnant women and neonates since this large organ can be obtained easily and non-invasively. Although several studies have been conducted on using placental tissue for FA analysis, the sampling methods have not been thoroughly examined. The aim of the present study was to determine a suitable method of sampling human placentae by focusing on their heterogeneity. Twenty-four placentae were collected from healthy pregnant Japanese women in the Miyagi Prefecture of Japan. Five of them were used to compare the FA composition between the peripheral area and the central area of the placentae. The other 19 were examined to determine differences in the FA composition between the fetal and maternal side. Placental tissue crude lipid was saponified, and methyl was esterified with 14% sodium boron trifluoride methanol for gas chromatography with flame ionization detector analysis. Fifty-six peaks were detected from the methyl esters of the placental total lipid, and 33 of those were identified as FA methyl esters. There were considerable variations in the FA composition, as the variation was low in the central parts and high in the peripheral parts of the placentae. The 18:1n-9 and 18:2n-6 levels were higher in the fetal side, whereas the 20:3n-6, 20:4n-6, and 22:6n-3 levels were higher in the maternal side. These findings indicate the presence of heterogeneity in the FA composition of human placenta, and they suggest the necessity for standardizing the sampling method so that the placental tissue can be used to determine the FA status.

Secular trend of serum docosahexaenoic acid, eicosapentaenoic acid, and arachidonic acid concentrations among Japanese-a 4- and 13-year descriptive epidemiologic study

Cross-sectional studies have shown age-related increases in blood docosahexaenoic and eicosapentaenoic acid and decreases in arachidonic acid. We describe serum docosahexaenoic, eicosapentaenoic, and arachidonic acid concentrations over 13 years (1997-2012) across four study waves and serum fatty acid composition over 4 years (2006-2012) between two study waves according to age groups by sex in the same subjects. We included 443 men and 435 women aged 40-79 years at baseline. Serum arachidonic acid concentrations increased in all sex and age groups over 13 years, and eicosapentaenoic or docosahexaenoic acid concentrations increased in males and females who were younger and middle-aged at baseline. Only serum arachidonic acid composition increased over 4 years in men and women who were 40-69 years at baseline, even after adjustment for arachidonic acid intake. These findings suggest a secular increase trend in serum arachidonic acid levels over 13 years among randomly selected community-dwelling middle-aged and elderly Japanese.

Omega-3 polyunsaturated fatty acids and brain aging

PURPOSE OF REVIEW

The literature on the influence of dietary omega-3 polyunsaturated fatty acid (ω-3 PUFA) on brain aging has grown exponentially during the last decade. Many avenues have been explored but no global picture or clear evidence has emerged. Experimental studies have shown that ω-3 PUFA is involved in many neurobiological processes that are involved in neurotransmission and neuroprotection, indicating that these PUFAs may prevent age-related brain damage. Human studies have revealed only a weak link between ω-3 PUFA status and cognitive aging, whereas interventional studies have yet to confirm it. The purpose of this review is to analyze the developments in the area during the last 2 years.

RECENT FINDINGS

Human brain MRI studies have confirmed previous findings that ω-3 PUFA can protect the brain during aging; two intervention studies obtained clear evidence. We also analyzed the experimental data clarifying the involvement of ω-3 PUFA in neurotransmission, neuroprotection (including prevention of peroxidation, inflammation, and excitotoxicity), and neurogenesis, thereby helping the brain cope with aging.

SUMMARY

These recent human and experimental studies provide support for and clarification of how ω-3 PUFA protect against brain aging and highlight the main lines for future research.

Eicosapentaenoic acid/arachidonic acid ratio and smoking status in elderly patients with type 2 diabetes mellitus

BACKGROUND

A low ratio of eicosapentaenoic acid (EPA)/arachidonic acid (AA) is considered a risk factor for cardiovascular disease. Smoking is also a risk factor for cardiovascular disease even in an elderly population. This study investigated the relationship between EPA/AA ratio and smoking status among elderly patients with type 2 diabetes mellitus (T2DM).

FINDINGS

A total of 188 elderly patients with T2DM (men/women, 114/74; mean age, 65.0 ± 7.5 years) were studied in terms of their smoking status, diabetic conditions, and blood data, including EPA and AA. Current smokers showed a lower EPA/AA ratio than non-smokers (current smokers: 0.29, n = 49; non-smokers: 0.39, n = 139, p < 0.01). This relationship remained significant after adjusting for multiple variables.

CONCLUSIONS

Smoking may affect the EPA/AA ratio among elderly patients with T2DM, suggesting a possible mechanism of cardiovascular disease development and indicating the importance of smoking secession in such patients.

Monounsaturated and Saturated, but Not n-6 Polyunsaturated Fatty Acids Decrease Cartilage Destruction under Inflammatory Conditions: A Preliminary Study

PURPOSE

Osteoarthritis (OA) is associated with obesity in which altered fatty acid levels have been observed. We investigated whether the most common fatty acids in synovial fluid influence cartilage deterioration in OA.

DESIGN

Cartilage was obtained from OA patients undergoing total knee arthroplasty. Chondrocytes or cartilage explants were cultured with linoleic (n-6 polyunsaturated), oleic (monounsaturated), or palmitic (saturated) acid. After preculture, media were renewed and inflammation was simulated in half of the samples by addition of 10 ng/mL tumor necrosis factor-α (TNFα) with or without the fatty acids. Effects on lipid uptake (Oil-Red-O), cell toxicity (lactate dehydrogenase), prostaglandin-E2 (PGE2) release and gene expression for prostaglandin-endoperoxide synthase-2 (PTGS2), matrix metalloproteinase-1 (MMP1), and MMP13, and a disintegrin and metalloproteinase with thrombospondin motifs 4 were determined on chondrocytes in monolayer. Effects on glycosaminoglycan (GAG) release were evaluated on cartilage explants.

RESULTS

None of the fatty acids were cytotoxic and all were taken up by the cells, resulting in a higher amount of intracellular lipid in chondrocytes. Linoleic acid increased PGE2 production in the presence of TNFα. Oleic acid and palmitic acid inhibited MMP1 gene expression in chondrocytes stimulated with TNFα. In cartilage explants, GAG release was also inhibited by oleic acid and palmitic acid, and oleic acid decreased PTGS2 gene expression in stimulated chondrocytes.

CONCLUSIONS

Linoleic acid has a pro-inflammatory effect on cartilage whereas oleic acid and palmitic acid seem to inhibit cartilage destruction. These results indicate that altered fatty acid levels may influence loss of cartilage structure in OA.

Association of n-3 polyunsaturated fatty acid intake with bone mineral density in postmenopausal women

n-3 Polyunsaturated fatty acids (n-3 fatty acids) have been shown to have a beneficial effect on bone in animal studies, although little is known about their role in bone metabolism in humans. We investigated the association between bone mineral density (BMD) and daily n-3 fatty acid intake. This cross-sectional, community-based, epidemiologic study was conducted among 205 healthy postmenopausal women (mean age 63.5 years, range 46-79). We examined BMD, serum N-terminal propeptide of type I collagen (PINP), urinary type-I collagen cross-linked-N-telopeptide (uNTX), total cholesterol, triglycerides, and high-density lipoprotein cholesterol. Nutrient intake was calculated using a food-frequency questionnaire. BMD was measured at the lumbar spine and femoral neck by dual-energy X-ray absorptiometry. Simple regression analysis showed that intake of neither n-3 fatty acid nor n-6 fatty acid was associated with age or lipid metabolism indices. However, simple regression analysis showed that n-3 fatty acid intake was positively associated with both lumbar spine BMD and femoral neck BMD. n-6 fatty acid intake was positively associated with femoral neck BMD but not lumbar spine BMD. Multiple regression analysis showed that n-3 fatty acid intake was positively associated with lumbar spine BMD after adjustment for age, BMI, duration of menopausal state, grip strength, PINP, uNTX, and intakes of calcium, vitamin D, vitamin K, and n-6 fatty acid. In conclusion, n-3 fatty acid intake was positively associated with lumbar spine BMD independent of bone resorption and serum levels of cholesterol and triglycerides in postmenopausal women.