Associations of n-3, n-6 Fatty Acids Intakes and n-6:n-3 Ratio with the Risk of Depressive Symptoms: NHANES 2009-2016

Associations of dietary flavonoid intake with the risk of all-cause and cardiovascular mortality in adults

BACKGROUND AND AIMS

Flavonoids are widely distributed polyphenolic compounds in the diet that possess various health-promoting effects. This study aimed to investigate the association between dietary flavonoid intake and all-cause and cardiovascular mortality in adults.

METHODS AND RESULTS

The data on the six main subclasses of flavonoids, including isoflavones, anthocyanidins, flavan-3-ols, flavanones, flavones, and flavonols, were obtained from the 2007-2010 National Health and Nutrition Examination Survey (NHANES) dataset of adults. The participants were followed up until December 30, 2019. Cox regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for dietary flavonoid intake and mortality. The study included a total of 8758 adults (mean age 44.00 years; 47.40% men). A median follow-up of 10.7 years yielded 1113 all-cause deaths and 261 cardiovascular deaths were recorded. In comparison to category 1, category 4 of flavan-3-ols, flavonols, and total flavonoids were associated with lower risks of all-cause mortality, with multivariable-adjusted HRs of 0.71 (95% CI: 0.55-0.92, Ptrend = 0.021), 0.58 (95% CI: 0.45-0.74, Ptrend<0.001), and 0.63 (95% CI: 0.50-0.80, Ptrend = 0.010), respectively. Similarly, higher intake of category 4 flavonoids was associated with a reduced risk of cardiovascular mortality, with HRs of 0.68 (95% CI: 0.29-0.89, Ptrend = 0.035) for flavones, 0.41 (95% CI: 0.22-0.78, Ptrend = 0.001) for flavonols, and 0.54 (95% CI: 0.36-0.80, Ptrend = 0.021) for total flavonoids.

CONCLUSION

Dietary flavonoid intake is associated with all-cause and cardiovascular mortality. Increasing dietary flavonoid intake may reduce the risk of death in adults.

The relationship between different fatty acids intake and the depressive symptoms: A population-based study

BACKGROUND

Depression is a common psychological disorder worldwide, affecting mental and physical health. Previous studies have explored the benefits of polyunsaturated fatty acids (PUFAs) intake in depressive symptoms; however, few studies have focused on the association between all types of fatty acids intake and depressive symptoms. Therefore, we explored the relationship between the intake of different fatty acids intake and the risk of depressive symptoms.

METHODS

The study was based on the data from the 2005-2018 National Health and Nutrition Examination Survey (NHANES), a large US-based database. We used a nutrient residual model and multi-nutrient density model for the analysis. We calculated the nutrient density and residual in men and women separately, and the fatty acids intake was divided into quartiles based on the sex distribution. The relationship between the depressive symptoms and the intake of different fatty acids was examined using logistic regression; furthermore, we explored the relationships separately in men and women.

RESULTS

The intake of monounsaturated fatty acids (MUFAs) and PUFAs, particularly n-3 and n-6 PUFAs, were associated with reduced odds ratios for depressive symptoms. The inverse relationship between the intake of MUFAs, PUFAs, n-3, and n-6 PUFAs and depressive symptoms was stronger in women. The inverse relationship between total fatty acid (TFAs) intake and depressive symptoms existed only in a single model. In contrast, saturated fatty acid (SFAs) intake was not related to depressive symptoms.

CONCLUSION

Consuming MUFAs and PUFAs can counteract the depressive symptoms, especially in women.

Fatty acid intake and prevalence of depression among Brazilian graduates and postgraduates (CUME Study)

BACKGROUND

Dietary fatty acids are related to the development of several inflammatory-related diseases, which may include depression. So, the association between fatty acids, culinary oils and fat intake and depression in highly educated Brazilians was evaluated.

METHODS

Multicenter cross-sectional study using baseline data from the Cohort of Universities of Minas Gerais. The diagnosis of depression was self-reported, and the daily intake of fatty acids was assessed using a 144-item food frequency questionnaire (FFQ).

RESULTS

A total of 7157 participants (68.83 % women) with a median age of 33 years were included. The prevalence of depression was 12.60 % (N = 902). In the adjusted analyses, it was observed that individuals with the highest intake of omega-6 fatty acids (n-6) (OR: 1.36, 95 % CI 1.11-1.67) had a higher prevalence of depression. This increased n-6 intake was identified as a risk factor for depression only among male participants, while among overweight participants, higher n-6 intake was also positively associated with depression. Conversely, a higher ratio of polyunsaturated to monounsaturated and saturated fatty acids (PM/S) was also found to be positively associated with depression, but this association was observed only among non-overweight participants. No associations were found between the consumption of culinary oils or fats and depression.

LIMITATIONS

Cross-sectional design limits the assessment of causality. The use of the FFQ can make estimates more difficult.

CONCLUSION

Higher consumption of n-6, and higher PM/S ratios were associated with depression, and individual factors can interfere. The mental health care policies should include specific nutritional strategies.

Nutritional composition, health-promoting effects, bioavailability, and encapsulation of tree peony seed oil: a review

Tree peony is cultivated worldwide in large quantities due to its exceptional ornamental and medicinal value. In recent years, the edible value of tree peony seed oil (TPSO) has garnered significant attention for its high content of alpha-linolenic acid (ALA, >40%) and other beneficial minor components, including phytosterols, tocopherols, squalene, and phenolics. This review provides a systematic summary of the nutritional composition and health-promoting effects of TPSO, with a specific focus on its digestion, absorption, bioavailability, and encapsulation status. Additionally, information on techniques for extracting and identifying adulteration of TPSO, as well as its commercial applications and regulated policies, is included. Thanks to its unique nutrients, TPSO offers a wide range of health benefits, such as hypolipidemic, anti-obesity, cholesterol-lowering, antioxidant and hypoglycemic activities, and regulation of the intestinal microbiota. Consequently, TPSO shows promising potential in the food and cosmetic industries and should be cultivated in more countries. However, the application of TPSO is hindered by its low bioavailability, poor stability, and limited water dispersibility. Therefore, it is crucial to develop effective delivery strategies, such as microencapsulation and emulsion, to overcome these limitations. In conclusion, this review provides a comprehensive understanding of the nutritional value of TPSO and emphasizes the need for further research on its nutrition and product development.

Association of serum oleic acid level with depression in American adults: a cross-sectional study

BACKGROUND

As the most abundant fatty acid in plasma, oleic acid has been found to be associated with multiple neurological diseases; however, results from studies of the relationship between oleic acid and depression are inconsistent.

METHODS

This cross-sectional study analyzed 4,459 adults from the National Health and Nutrition Examination Survey 2011-2014. The following covariates were adjusted in multivariable logistic regression models: age, sex, race/ethnicity, education level, marital status, body mass index, physical activity, smoking status, alcohol status, metabolic syndrome, omega-3 polyunsaturated fatty acids, and total cholesterol.

RESULTS

Serum oleic acid levels were positively associated with depression. After adjusting for all covariates, for every 1 mmol/L increase in oleic acid levels, the prevalence of depression increased by 40% (unadjusted OR: 1.35, 95%CI: 1.16-1.57; adjusted OR: 1.40, 95% CI: 1.03-1.90).

CONCLUSIONS

Our study suggests that oleic acid may play a role in depression. Further research is needed to investigate the potential benefits of changing oleic acid levels for the treatment and prevention of depression.

Age-dependent association of high urinary iodine concentration with major depression in adults: NHANES 2007-2020

Excessive iodine exposure can have detrimental effects on thyroid function and overall health. This study aimed to investigate the age-dependent association between high urinary iodine concentration (UIC) and major depression symptoms in adults, using data from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2020. To perform stratified analysis by age, we utilized a rolling window method with a 15-year window width to examine the trend of the odds ratios (ORs) of UIC on depression symptoms with age. Full-factor and one-factor multinomial logistic regression models were employed to calculate the ORs, and violin plots were utilized to depict the ORs of UIC on major depression. The LASSO regression was applied to select variables for one-factor models. The bootstrap method was utilized to ensure the robustness of the results, and the Games-Howell test was applied to compare the differences in the bootstrapped ORs of different UIC groups. Our results indicate that, after age 46, the ORs of high UIC (≥ 300 μg/L) on major depression are significantly higher than those of normal UIC (100-199 μg/L). The bootstrapped ORs of high UIC on major depression calculated by the full-factor and one-factor multinomial logistic regression models are 1.9 (1.28, 2.82) and 1.42 (1.02, 1.93) among participants aged 46 and older, respectively. Based on these findings, we conclude that major depressive symptoms are significantly associated with high UIC among older individuals aged 46 and above.

Dietary niacin intake in relation to depression among adults: a population-based study

BACKGROUND

Previous studies have shown that an antioxidant diet is a protective factor against depression. However, the association between niacin, an important antioxidant consumed from the diet, and depression has received little attention. Therefore, we explored the association between niacin intake and depression through a cross-sectional analysis of the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2016.

METHODS

Depression was measured using the Patient Health Questionnaire (PHQ-9, score ≥ 10). Niacin intake was assessed through 24-h dietary recall interviews. The relationship of niacin intake with depression among adults in US was assessed by using a weighted multiple logistic regression model with subgroup analysis. Non-linear associations were explored using restricted cubic spline models. And we used a two-piece-wise logistic regression model with smoothing to explore the threshold for association between them.

RESULTS

A total of 16,098 adults were included in this study. Compared with individuals with lowest niacin intake Q1 (≤ 15.96 mg/day), the adjusted OR values for dietary niacin intake and depression in Q2 (15.97-22.86 mg/day), Q3 (22.87-32.28 mg/day) and Q4 (≥ 32.29 mg/day), were 0.92 (95% CI: 0.70-1.20), 0.76 (95% CI: 0.56-0.99,) and 0.68 (95% CI: 0.48-0.98), respectively. The results were not modified by sex, by age and by BMI. Furthermore, the relationship between dietary niacin intake and depression exhibited a U-shaped curve (nonlinear, p < 0.001). And depression risk was lowest when dietary consumption of niacin was around 36 mg/day.

CONCLUSIONS

In present study, moderate niacin intake, but not high intake, was associated with lower odds of depression suggesting a U-shaped association.

Recent evidence and progress for developing precision nursing in symptomatology: A scoping review

AIM

To summarize the omics results of symptomatic research that can help nurses identify intervention targets and design precision interventions for pain, mental health, cognitive impairment, sleep disorder, fatigue, lymphedema, and quality of life, so as to provide a comprehensive summary of help and inspire to precision nursing.

METHODS

CINAHL, PubMed, Web of Science, and ScienceDirect databases were searched. Retrieval time was from January 2012 to December 2021. Symptomatology research applying omics that can be used to guide nurses in designing targeted interventions was included.

RESULTS

Forty-six studies were included in the final review. Symptomatology research that can be integrated with nursing science to develop precision nursing focused on pain, mental health, cognitive impairment, sleep disorder, fatigue, lymphedema, and quality of life. Most studies were related to cognitive impairment (n = 10; 21.74%), pain (n = 9; 19.57%), and mental health (n = 8; 17.39%). Moreover, the included studies involved various omics technologies, such as whole genome, epigenome, transcriptome, proteome, and metabolome.

CONCLUSION

The rapid development of various omic technologies promotes symptomatology research, which can help nurses fully understand the information of patients. Phenotypic characteristics and biomarkers shown in symptomatology research help nurses identify intervention targets and develop individualization interventions, so as to prevent and reduce symptoms and improve the quality of life.

IMPLICATION FOR NURSING AND HEALTH POLICY

This scoping review is the first synthesis of all peer-reviewed literature to summarize and provide important information and references from the omic results of symptomatology studies to develop precision nursing, highlighting the status and development of precision nursing. Nursing education policies should introduce the development and importance of precision nursing. Further research could consider investing more attention in precision nursing. Nursing researchers can carry out some studies applying omics technology to explore more biomarkers, helping guide the formulation of clinical intervention for symptoms.

Interaction of fatty acid quality indices and genes related to lipid homeostasis on mental health among overweight and obese women

The aim of this study is to investigate the interaction of fatty acid quality indices and genes related to lipid homeostasis on mental health among overweight and obese women. This cross-sectional study included 279 overweight and obese women for N6/N3 ratio and 378 overweight and obese women for CSI aged 18-58 years. Mental health were evaluated using Depression Anxiety Stress Scales (DASS-21). The anthropometric indices, biochemical parameters, body composition and dietary fat quality were measured. MC4R (rs17782313) and Caveolin-1 (CAV-1) (rs3807992) were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. The results of the study showed that after adjusting for age, energy intake, thyroid disease, physical activity, and BMI, a positive interaction between TC genotype of MC4R and CSI on depression (β = 0.39, CI = 0.12, 0.66, P = 0.004), and DASS-21 (β = 0.074, CI = 0.04, 1.44, P = 0.036). Also, there were a marginal significant interactions between AG genotype of CAV-1 and N6/N3 ratio on depression in adjustment model1 (β = 16.83, CI = - 0.19, 33.85, P = 0.053). Our findings showed that increasing adherence to fatty acid quality indices by considering genes related to lipid homeostasis was related to increasing depression in our population.

Dietary Nutrient Deficiencies and Risk of Depression (Review Article 2018-2023)

Depression is classified as one of the most common mental disorders. Its prevalence has recently increased, becoming a growing public health threat. This review focuses on clarifying the role and importance of individual nutrients in the diet and the impact of nutrient deficiencies on the risk of depression. Deficiencies in nutrients such as protein, B vitamins, vitamin D, magnesium, zinc, selenium, iron, calcium, and omega-3 fatty acids have a significant impact on brain and nervous system function, which can affect the appearance of depressive symptoms. However, it is important to remember that diet in itself is not the only factor influencing the risk of or helping to treat depression. There are many other aspects, such as physical activity, sleep, stress management, and social support, that also play an important role in maintaining mental health. The data review observed that most of the available analyses are based on cross-sectional studies. Further studies, including prospective cohort, case-control studies, are recommended to draw more reliable conclusions.

Caiman's fat enriched with n-3 fatty acids: potential food supplement

Broad-snouted caiman (Caiman latirostris) products (meat, fat and oil) are currently beginning to be valued as a food of special interest due to its high content of n-3 fatty acids. Thus, the objective of this study was to characterize the fats of caiman fed with diets enriched with flaxseeds (Linus usitatissimun) rich in n-3 fatty acids, lignans and antioxidants. Caimans were fed six days a week with: a control diet (C), and a diet enriched with ground flaxseed = 90% C + 10% flaxseed ground (FS), during 30 (FS30) and 60 (FS60) days. Animals fed the flaxseed-enriched diets increased linolenic acid content and reduced the n-6/n-3 ratio of fats relative to controls, and this improvement increased over time. The proportion of eicosapentaenoic acid also increased, but there was no difference at the time the enriched diets were offered. Caiman fat of the FS30 and FS60, showed a decrease in lipoperoxidation (24% and 40%) and reactive oxygen species (44% and 76%) accompanied by an increase in antioxidant systems. Consumption of a flax-enriched diet by caimans increases the content of essential fatty acids and improves the lipoperoxidative status of fat. This provides an enriched fat with potential for the development products for human consumption.

Associations of Serum Carotenoids With Risk of All-Cause and Cardiovascular Mortality in Hypertensive Adults

Background Systemic oxidative stress is involved in the development of hypertension, whereas carotenoids are a group of natural antioxidants. Our study aims to evaluate the relationships between the serum concentrations of major carotenoids and mortality in hypertensive adults. Methods and Results Data on 5 serum carotenoids from the National Health and Nutrition Examination Survey (NHANES) III and NHANES 2001-2006 were included. Outcome measures (all-cause and cardiovascular mortality) were identified from the National Death Index through December 31, 2019. Multiple Cox proportional hazards regression and restricted cubic spline analyses were performed to determine the association between carotenoid levels and outcomes. A total of 8390 hypertensive adults were included in the analysis. At a median follow-up duration of 16.6 years, all-cause and cardiovascular mortality occurred in 4005 (47.74%) and 1205 (14.36%) participants, respectively. Compared with the lowest quartiles, the highest quartiles of 5 major serum carotenoids were associated with lower risk of all-cause mortality, with multivariable-adjusted hazard ratios (HRs) of 0.63 (95% CI, 0.56-0.71) for α-carotene, 0.70 (95% CI, 0.61-0.80); for β-carotene, 0.67 (95% CI, 0.58-0.76); for β-cryptoxanthin, 0.74 (95% CI, 0.64-0.86) for lycopene; and 0.72 (95% CI, 0.63-0.83) for lutein/zeaxanthin. For cause-specific mortality, this association with the fourth quartile of serum carotenoids was evident for a reduced rate of cardiovascular mortality, with a 32% reduction for α-carotene (HR, 0.68 [95% CI, 0.55-0.86]), a 29% reduction for β-cryptoxanthin (HR, 0.71 [95% CI, 0.56-0.89]), and a 26% reduction for lycopene (HR, 0.74 [95% CI, 0.59-0.94]), but not for β-carotene and lutein/zeaxanthin. In addition, we found that serum α-carotene, β-carotene, β-cryptoxanthin, and lutein/zeaxanthin levels were nonlinearly related to all-cause mortality with inflection points of 2.43, 8.49, 5.12, and 14.17 μg/dL, respectively. Serum α-carotene, β-cryptoxanthin, and lutein/zeaxanthin concentrations showed nonlinear associations with cardiovascular mortality with inflection points of 2.31, 5.26, and 15.40 μg/dL, respectively. Conclusions Findings suggest that higher serum carotenoid concentrations were associated with lower risks of all-cause and cardiovascular mortality in hypertensive adults.

Effect of the Bleaching Process on Changes in the Fatty Acid Profile of Raw Hemp Seed Oil (Cannabis sativa)

Many refined oils from soybean, rapeseed, and sunflower, among others, are available on the food market, except olive oil. Refining, on the small production scale of niche oils, is not used due to the high cost of the refining process. Unrefined oils are characterized by intense taste, odor, color, and undesirable nutrients. The problem to be solved is determining the effects of incomplete refining of niche oils on their composition. One process, which does not require the use of complex apparatus, is the bleaching process. The results presented in this article relate to the research stage, in which the aim is to evaluate the changes occurring in the oil due to the low-temperature bleaching process with different process parameters. The presented research results provide evidence of the absence of adverse changes in the fatty acid profile of hemp oil of the varieties 'Finola', 'Earlina 8FC', and 'Secuieni Jubileu'. Seven different types of bleaching earth were used to bleach the oil in amounts of 2.5 and 5 g/100 g of vegetable oil. The fatty acid profile was obtained by gas chromatography (GC-FID). The obtained chromatograms were subjected to statistical analysis and principal component analysis (PCA). The results show that there was no effect of the type of bleaching earth and its amount on the change in the fatty acid profile of bleached oils. Only real differences between the types of hemp oils were observed. However, an overall positive effect of the bleaching process on hemp oil was found. The amount of saturated fatty acid (SFA) was reduced by 17.1% compared with the initial value, resulting in an increase in the proportion of polyunsaturated fatty acids (PUFA) by 4.4%, resulting in an unsaturated fatty acid (UFA) proportion of 90%. There was a significant improvement in the SFA/PUFA ratio by 26% over the baseline, and the omega-6/omega-3 ratio by 8.9% to a value of 3.1:1. The new knowledge from this study is evidence of the positive effect of the low-temperature bleaching process on the fatty acid profile. In contrast, the parameters of the bleaching process itself are not significant.

Association of Urinary Iodine Concentration with Depressive Symptoms among Adults: NHANES 2007-2018

The association between iodine status and depressive symptoms has not been investigated in the general population. Therefore, we drew 8935 participants from the National Health and Nutrition Examination Survey (NHANES) 2007-2018 to explore their association. In NHANES, Inductively Coupled Plasma Dynamic Reaction Cell Mass Spectroscopy was utilized to measure urinary iodine concentration (UIC), and Patient Health Questionnaire-9 was used to assess depressive symptoms. Meanwhile, we fitted logistic regression and restricted cubic spline models. We found that high UIC was associated with a higher prevalence of depressive symptoms than the normal UIC group (OR: 1.50, 95% CI: 1.04-2.16). This association was particularly pronounced and further strengthened among females (OR: 1.90, 95% CI: 1.19-3.01) and participants aged 40-59 (OR: 1.90, 95% CI: 1.11-3.25). Moreover, we found that low UIC was associated with a high prevalence of depressive symptoms among females (OR: 1.50, 95% CI: 1.02-2.18). Moreover, the dose-response relationship between UIC and depressive symptoms presented a general trend of decreased, steady transiently, and then increased. We found that participants with high UIC had a higher prevalence of depressive symptoms than those with normal UIC. Meanwhile, we also found that females with low UIC had higher odds of reporting depressive symptoms.

The relationship between serum fatty acids and depressive symptoms in obese adolescents

Depression and obesity are highly prevalent and are considered inflammatory pathologies; in addition, they are also associated with dietary patterns including types of fatty acids (FA). Changes in the FA composition in the brain are determined by changes in the content and quality of dietary and serum FA. The aim of this study was to verify the relationships between serum-free FA, inflammatory processes and depressive symptoms in obese adolescents. This was a cross-sectional study that analysed a database composed of 138 post-pubertal adolescents. Data regarding the depressive symptoms, body composition, glucose metabolism, lipid profile, FA profile, leptin concentration, as well as adiponectin, IL-A, IL-6, IL-10, TNF-α, C-reactive protein and plasminogen activator inhibitor-1 levels of the subjects were collected. A total of 54·6 % of the adolescents presented with depressive symptoms, and there were positive correlations between depressive symptoms and serum saturated fatty acids (SFA) content, body fat, and inflammatory adipokines, such as leptin, IL-6, and the leptin/adiponectin ratio. Moreover, the content of n-3 polyunsaturated fatty acids (PUFA) was negatively correlated with depressive symptoms, suggesting that eicosatrienoic acid (C20:2n6) and dihomo-γ-linolenic acid (C20:3n-6) are independently associated with depressive symptom scores and can be critical predictors of poor mental health in humans. These results point to the relationship between SFA and depressive symptoms in obese adolescents. However, longitudinal studies are needed to confirm the causality between dietary SFA and depression in obese individuals.

Consumption of Omega-3 and Maintenance and Incidence of Depressive Episodes: The ELSA-Brasil Study

Depression affects 264 million persons in the world, accounting for some 4.3% of the global burden of disease. Current studies indicate that the decrease in the consumption of omega-3 food sources is associated with the increasing incidence of depression. The study aims to assess the association between the consumption of omega-3 and the maintenance and incidence of depressive episodes in adults (39−64 years) and elderly adults (>65 years). This was a longitudinal study using data from the baseline and first follow-up wave of the Longitudinal Study of Adult Health (ELSA-Brasil). Depressive episodes were obtained with the Clinical Interview Schedule Revised (CIS-R), and food consumption was measured with the Food Frequency Questionnaire (FFQ). Logistic regression was used to analyze associations between the consumption of omega-3 and depressive episodes. Fatty acids from the omega-3 family showed a protective effect against the maintenance of depressive episodes. In relation to incidence, the estimates suggest that the higher the consumption of omega-3 acids, the lower the risk of developing depressive episodes, and significant associations were found between the consumption of omega-3 and alpha-linolenic acid. Dietary consumption of omega-3, DHA, EPA, DPA, and alpha linolenic fatty acids may have a protective effect against the maintenance and incidence of depressive episodes.

Relation of Dietary n-3 and n-6 Fatty Acid Intakes to Metabolic Syndrome in Middle-Aged People Depending on the Level of HbA1c: A Review of National Health and Nutrition Survey Data from 2014 to 2016

Background and Objectives: The relation of dietary n-6 fatty acid to metabolic syndrome has not been examined and clearly defined. To improve health in the general population, this study was to investigate the role of n-3 and n-6 fatty acids in the reduction in metabolic syndrome and to observe changes in the effects of these fatty acids depending on the level of insulin resistance. Materials and Methods: This cross-sectional study utilized national health and nutrition survey data from 2014 to 2016. From the data, a relation of n-3 and n-6 fatty acid intakes to metabolic syndrome and Hemoglobin A1c (HbA1c)’s role in the relation was evaluated and analyzed for 4852 patients between 40 and 64 years old. Intake frequency of 112 nutrition and daily consumption amounts were identified, and intakes of n-3 and n-4 fatty acids were calculated from this data. Metabolic syndrome was determined for each participant using diagnostic standards for the Asian population published by the National Cholesterol Education Program. Results: Among the total 4852 subjects, 1583 (32.6%) had metabolic syndrome; 736 of 1875 (39.3%) males and 847 of 2977 (28.5%) females had the syndrome. In males, when their HbA1c was low (<5.4%), intakes of both n-3 and n-6 fatty acids were related to a 43−63% decreased prevalence of metabolic syndrome with significance, and a similar negative tendency was also observed in females. On the contrary, for both males and females, no statistically significant correlation was present when HbA1c was high. Conclusion: It was considered that consistent and regular dietary intakes of n-3 and n-6 fatty acids may contribute greatly to prevent or treat metabolic syndrome in healthy males with normal insulin sensitivity, but the effect of their dietary intakes was found to be limited in a group with strong insulin resistance. The conclusion of this study presents a valuable reference and knowledge to provide nutritional education to the general population.

My nutrition index: a method for measuring optimal daily nutrient intake

Background

Adequate nutrition is essential for individual and population level health. However, determining adequacy of daily nutrient intake in research studies is often challenging given the unique nutritional needs of individuals. Herein, we examine construct, predictive, criterion, content, and concurrent validity of a dietary analytic tool – My Nutrition Index (MNI) for measuring nutrient intake in relation to personalized daily nutrient intake guidelines. MNI gauges adequacy of an individual’s daily nutrient intake based on his or her unique demographic and lifestyle characteristics. MNI accounts for potential adverse effects of inadequate and excess nutrient consumption.

Methods

MNI, calculated based on 34 nutrients, provides an overall index score ranging from 0 to 100, with higher scores reflecting a more nutritious diet. We calculated MNI scores for 7154 participants ages 18-65 in the National Health and Nutrition Examination Surveys (2007-2014) by using average nutrient intakes from two 24-h dietary recalls. Survey-weighted binary logistic regression models were used to assess associations between MNI scores and obesity, depression, health perceptions, and past or present cardiovascular disease.

Results

Higher MNI scores were associated with lower prevalence of self-reported cardiovascular disease (OR = 0.69, CI: 0.52, 0.92, p = 0.012), depression (OR = 0.76, CI: 0.65, 0.90, p < 0.001), and obesity (OR = 0.92, CI: 0.87, 0.99, p = 0.016), as well as more favorable health perceptions (OR = 1.24, CI: 1.13, 1.37, p < 0.001).

Conclusions

MNI provides an individualized approach for measuring adequacy/sufficiency of daily nutrient intake that can validly be employed to assess relationships between nutrition and health outcomes in research studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40795-022-00497-9.

Relationship between the combination of polyunsaturated fatty acids intake and psychological distress during pregnancy: The Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study

No studies have examined the association of the combination of n-3 polyunsaturated fatty acids (PUFAs) and n-6 PUFAs intake with psychological distress during pregnancy. To examine these associations, we divided Japanese pregnant women into 25 groups based on combining quintiles of n-3 PUFAs intake and quintiles of n-6 PUFAs intake. We conducted multivariable logistic regression analyses to assess the risk of psychological distress during pregnancy (Kessler Psychological Distress Scale ≥ 5 or 13). Compared to the third quintile of both n-3 PUFAs and n-6 PUFAs intake, the groups with unbalanced intake, high intake of both, and low intake of both were associated with a higher risk of both Kessler Psychological Distress Scale ≥ 5 and 13 in early and mid-pregnancy. Further research is needed to identify the precise combination of n-3 PUFAs and n-6 PUFAs intake associated with the lowest psychological distress during pregnancy.

Independent Associations of Serum 25-hydroxyvitamin D3 and D2 with Depressive Symptoms in Females

BACKGROUND

The role of vitamin D in depression has been gaining increased research interest. However, little is known about the independent associations of serum 25-hydroxyvitamin D₃ (25(OH)D₃) and D₂ (25(OH)D₂) with depressive symptoms. The goal of this study was to examine the metabolites of vitamin D and their associations with depression.

METHODS

This study was conducted in US females using data from the National Health and Nutrition Examination Survey 2011-2014. Depressive symptoms were assessed using a nine-item Patient Health Questionnaire, and serum 25(OH)D₃ and 25(OH)D₂ levels were measured using liquid chromatography-tandem mass spectrometry. Linear regression and generalized additive models were applied to evaluate the associations between 25(OH)D₃, 25(OH)D₂ and depression.

RESULTS

A negative association between serum 25(OH)D₃ and depressive symptoms was observed in the fully adjusted model. This association was also found among widowed, divorced, separated, and never-married individuals. The association between 25(OH)D₂ and depressive symptoms was not statistically significant, but the dose-response analysis revealed an inverted U-shaped relationship between them with an inflection point at 56.2 nmol/L. To the left of the inflection point, we detected a positive association between 25(OH)D₂ and depressive symptoms, whereas a negative association was observed to the right of the inflection point.

LIMITATIONS

The study used a cross-sectional approach, so causation cannot be determined.

CONCLUSIONS

Our study shows an inverse linear association between serum 25(OH)D₃ and depressive symptoms in US females. The association between 25(OH)D₂ and depression follows an inverted U-shaped curve with the inflection point at 56.2 nmol/L.

Possible antidepressant mechanisms of omega-3 polyunsaturated fatty acids acting on the central nervous system

Omega-3 polyunsaturated fatty acids (PUFAs) can play important roles in maintaining mental health and resistance to stress, and omega-3 PUFAs supplementation can display beneficial effects on both the prevention and treatment of depressive disorders. Although the underlying mechanisms are still unclear, accumulated evidence indicates that omega-3 PUFAs can exhibit pleiotropic effects on the neural structure and function. Thus, they play fundamental roles in brain activities involved in the mood regulation. Since depressive symptoms have been assumed to be of central origin, this review aims to summarize the recently published studies to identify the potential neurobiological mechanisms underlying the anti-depressant effects of omega-3 PUFAs. These include that of (1) anti-neuroinflammatory; (2) hypothalamus-pituitary-adrenal (HPA) axis; (3) anti-oxidative stress; (4) anti-neurodegeneration; (5) neuroplasticity and synaptic plasticity; and (6) modulation of neurotransmitter systems. Despite many lines of evidence have hinted that these mechanisms may co-exist and work in concert to produce anti-depressive effects, the potentially multiple sites of action of omega-3 PUFAs need to be fully established. We also discussed the limitations of current studies and suggest future directions for preclinical and translational research in this field.

Dietary Vitamin C and Vitamin C Derived from Vegetables Are Inversely Associated with the Risk of Depressive Symptoms among the General Population

Vitamin C is a water-soluble antioxidant. Reducing the level of oxidative stress can alleviate depression. Therefore, we investigated the correlation between dietary vitamin C intake and the risk of depressive symptoms in the general population. Data from the 2007–2018 National Health and Nutrition Examination Survey were used in our study. The dietary intake of vitamin C was assessed by two 24-h dietary recalls. Depressive symptoms were assessed with the Patient Health Questionnaire-9. Logistic regression and restricted cubic spline models were applied to assess the relationship between dietary vitamin C intake and the risk of depressive symptoms. The multivariate adjusted odds ratio (95% confidence interval) of depressive symptoms for the highest vs. lowest category of dietary vitamin C intake and vitamin C intake derived from vegetables were 0.73 (0.58–0.91) and 0.73 (0.56–0.95). In subgroup analyses, dietary vitamin C intake was negatively correlated with the risk of depressive symptoms in females 18–39 years old and 40–59 year-old groups. A dose-response analysis showed that there was a nonlinear relationship between dietary vitamin C intake and the risk of depressive symptoms. Dietary vitamin C intake and vitamin C intake derived from vegetables were inversely associated with the risk of depressive symptoms among the general population. We recommend increasing the intake of vegetables in daily diet.

Exploring the therapeutic potential of omega-3 fatty acids in depression

Omega-3 fatty acids have been acknowledged for their number of holdings on an individual's health. Not only in physical valuation but also in managing psychiatric disorders, omega-3 fatty acids have been found to be a powerful formula. It is proclaimed that depressive patients suffer anomaly with the levels of omega-3 polyunsaturated fatty acids in the body, coupled with insignificant EPA and DHA. Enhancement in brain functioning, neuronal functions, and paying attention in interacting with the brain cells are some of the additional tasks, being performed by the supplementation of omega-3 fatty acids. The leading and primary source via dietary supplementation involves the involvement of fish and fish products. These are hypothesized to be the best and dominant source for omega-3 fatty acids. Consumption of omega-3 fatty acid is well safe, that physician highly favors intake of these supplements, remarkably in the case of pregnant women. However, treating this serious life-threatening mental disorder leads to many adverse effects when treated with antidepressants. The dose range includes 1g/d to 10g/d, which is to be incorporated by the patient. It is also tested that the combination of EPA and DHA is found to be more efficacious for a person in treating and preventing depressive symptoms. Some studies verify the supplementation of omega-3 fatty acids in diet was coequally productive and successful with minimal side effects when analyzed with antidepressants. Despite these facts, much research is still needed and presently in process for long-term safety and studying the role of omega-3 fatty acids in human health.

Important considerations when assessing the effect of essential fatty acids on cognitive performance

Over the past decade, there have been many studies determining the effect of dietary ω-3 and ω-6 fatty acids intake on cognitive performance; however, they have largely been inconsistent in their conclusions. In this letter, we provide context to the article by Dong et al., titled “Association of dietary ω-3 and ω-6 fatty acids intake with cognitive performance in older adults: National Health and nutrition examination Survey (NHANES) 2011–2014” and provide methodological considerations with regards to covariate measurement and inclusion that can be generalized to future cross-sectional studies. In particular, delineating 1) the type and source of fatty acid, in context of an individual’s overall dietary patterns, 2) sociobehavioral risk factors and physical & mental comorbidities, 3) and daily cognitive activity are important to adequately control for covariates.

Response to important considerations when assessing the effect of essential fatty acids on cognitive performance

In this letter, we respond to the comments raised by Visaria et al. in their letter to the editor about the publication “Association of dietary ω-3 and ω-6 fatty acids intake with cognitive performance in older adults: National Health and Nutrition Examination Survey (NHANES) 2011–2014”. We have further adjusted for some key covariates as the authors mentioned in the letter and performed sensitivity analysis by excluding vegetarians considering the bioavailability of fatty acids from different sources. In conclusion, the results were basically consistent with our previous results, which showed that the results were stable and reliable. We hope that our study could be helpful in further studies delineating the various intricacies of fatty acid nutrition and metabolism and control for covariates.

Associations of different types of dairy intakes with depressive symptoms in adults

BACKGROUND

Current evidence on the associations between different types of milk products and depressive symptoms is few and controversial, and there has been no study focusing on different types of milk (whole-fat, low-fat, and skim). This study aimed to appraise their associations.

METHODS

This cross-sectional study included adults (N=21,924) from the National Health and Nutrition Examination Survey 2007-2016. Patient Health Questionnaire was used to evaluate depressive symptoms. Logistic regression model was implemented to assess the association of dairy consumption with depressive symptoms.

RESULTS

After multivariate adjustment, compared to non-consumers, the odds ratios (95% confidence intervals) of depressive symptoms for intake < 175.38 g/d and 175.38 to < 321.56 g/d of skim milk were 0.48 (0.27-0.85) and 0.46 (0.29-0.75), and 0.70 (0.55-0.88) for intake < 81.00 g/d of milk desserts, while 1.61 (1.05-2.46), 1.70 (1.15-2.50) and 1.55 (1.11-2.16) for intake < 129.63 g/d, 129.63 to < 289.75 g/d and ≥ 289.75 g/d of whole milk, respectively. These associations remained significant in stratified analyses by gender and age. Additionally, yogurt was negatively associated with depressive symptoms in both females and the age group (≥ 60 years). Low-fat milk was inversely associated with depressive symptoms for both males and the age group (≥ 60 years). Moderate creams intake was negatively associated with depressive symptoms in males.

LIMITATIONS

It was difficult to infer causality for a cross-sectional study.

CONCLUSIONS

Intakes of skim milk and moderate milk desserts were negatively associated with depressive symptoms, while whole milk was positively associated with depressive symptoms among adults.

FADS2 polymorphisms are associated with plasma arachidonic acid and estimated desaturase-5 activity in a cross-sectional study

Polymorphisms in FADS genes are associated with plasma long-chain polyunsaturated fatty acids (LC-PUFA) and modulate omega-6/omega-3 balance. We hypothesized that the FADS2 gene variants will be associated with lower product-to-precursor ratio in the fatty acid metabolic pathways. Thus, we explored FADS2 rs174593, rs174616, and rs174576 effects on plasma phospholipid fatty acid profile, markers of desaturase activities, and risk factors in a sample of apparently healthy Serbian adults. Food and nutrient intake data were compiled through 24 h recalls. Plasma phospholipid fatty acid content was assessed by gas-chromatography. Estimated desaturase activities were calculated as conversion rates towards LC-PUFA in omega-6 pathway. During the selection of FADS2 polymorphisms, we accounted for their positional and functional aspect. Genotyping was performed by Real-Time PCR. Multivariable-adjusted general linear and hierarchical regression models were applied. Study subjects (mean age = 40 ± 7 years, 70% who were overweight) had a median dietary omega-6/omega-3 ratio of 16.29. Alternative allele frequencies were 33%, 36%, and 51% for rs174593, rs174576, and rs174616, respectively. Addition of FADS2 alternative alleles was associated with lower plasma arachidonic acid (AA, C20:4 n-6, P < .001) and estimated desaturase-5 activity (P < .001), irrespective of gender, age, daily polyunsaturated/saturated fatty acid intake, and obesity. The rs174576 association with AA withstood multiple testing and additional adjustments for other variants (multivariable-adjusted β = -1.14 [95% CI: -2.25, -0.43]). None of the variants was associated with dietary intake, serum lipids, or obesity. We observed inverse associations between FADS2 variants and plasma AA but not omega-3 fatty acids in Serbian subjects, with rs174576 exhibiting the strongest relation.