Intake of Fish and n-3 Fatty Acids and Future Risk of Metabolic Syndrome

The role for ω-3 polyunsaturated and short chain fatty acids in hypertension: An updated view on the interaction with gut microbiota

As of 2024, arterial hypertension is still considered the leading modifiable cardiovascular risk factor and, due to high rates of undertreatment and poor blood pressure control, the major contributor to human morbidity and mortality. Development of new treatment options and better interventions in lifestyle correction have become a priority of experimental and clinical research. In the last decades, dietary supplementation of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) and generation of gut microbiota-derived short chain fatty acids (SCFAs) have surged as potential and promising interventions for hypertension and cardiovascular prevention. ω-3 PUFAs are considered "essential" fatty acids that can be obtained only from dietary sources. Although previous intervention trials were not consistent in reporting a significant benefit of ω-3 PUFAs, the recent REDUCE-IT trial has provided robust evidence in support of their role in cardiovascular prevention. Recent studies have also identified the intestinal microbiota as a potential player in the pathophysiology and progression of hypertension. Although this might occur through many pathways, generation of SCFAs that is highly dependent on dietary fiber intake is primarily involved, providing an additional target for the development of novel therapeutic strategies. For these reasons, some scientific societies currently recommend dietary supplementation of ω-3 PUFAs and fiber-containing foods in patients with hypertension. In this narrative review, we summarize the results of studies that examined the effects of ω-3 PUFAs and SCFAs on blood pressure, highlighting the mechanisms of action on the vascular system and their possible impact on hypertension, hypertension-related organ damage and, ultimately, cardiovascular outcomes.

Fish oil supplementation in obese rats ameliorates metabolic syndrome response

Accumulation of visceral adipose tissue is associated with metabolic syndrome (MS), insulin resistance, and dyslipidemia. Here we examined several morphometric and biochemical parameters linked to MS in a rodent litter size reduction model, and how a 30-day fish oil (FO) supplementation affected these parameters. On day 3 post-birth, pups were divided into groups of ten or three. On day 22, rats were split into control (C) and small litter (SL) until 60 days old. Then, after metabolic disturbance and obesity were confirmed, FO supplementation started for 30 days and the new groups were named control (C), FO supplemented (FO), obese (Ob), and obese FO supplemented (ObFO). Comparison was performed by Student t-test or 2-way ANOVA followed by Tukey post hoc test. At the end of the 60-day period, SL rats were hyperphagic, obese, hypoinsulinemic, normoglycemic, and had high visceral fat depot and high interleukin (IL)-6 plasma concentration. Obese rats at 90 days of age were fatter, hyperphagic, hyperglycemic, hypertriacylgliceromic, hipoinsulinemic, with low innate immune response. IL-6 production ex vivo was higher, but in plasma it was not different from the control group. FO supplementation brought all biochemical changes to normal values, normalized food intake, and reduced body weight and fat mass in obese rats. The innate immune response was improved but still not as efficient as in lean animals. Our results suggested that as soon MS appears, FO supplementation must be used to ameliorate the morpho- and biochemical effects caused by MS and improve the innate immune response.

Interactions between physical activity and psychological factors in the association with the risk of lean type 2 diabetes mellitus

Background: The extent to which physical activity and psychological factors may affect the risk of diabetes mellitus among lean individuals remains unclear.Purpose: This study aimed to investigate the associations of total physical activity (TPA) and psychological factors with lean type 2 diabetes mellitus (T2DM) risk.Research Design: A prospective cohort study.Study Sample: The study population included 1,945 Korean adults who maintained a body mass index <23 kg/m2.Data Collection and Analysis: Baseline data on TPA and psychological factors were collected and T2DM incidence was assessed for 10 years. For analysis, a multivariable Cox proportional hazards regression model was used.Results: TPA was inversely associated with T2DM risk and this association was more pronounced in participants who were depressed or distressed; the top TPA quartile exhibited significant reductions in T2DM risk of 66% (95% confidence interval [CI]: 0.15, 0.78) and 65% (95% CI: 0.14, 0.88) among participants who reported depressed mood and those who perceived high distress, respectively, compared with the bottom TPA quartile.Conclusions: The current study demonstrated the preventive effects of physical activity on T2DM in lean adults through its interaction with psychological factors.

Adherence to the healthy eating index-2010 and alternative healthy eating index-2010 in relation to metabolic syndrome among African Americans in the Jackson heart study

OBJECTIVE

The primary objective of this study was to determine whether Healthy Eating Index (HEI) and Alternative Healthy Eating Index (AHEI) scores were associated with incident metabolic syndrome.

DESIGN

This study is a secondary analysis of data from the Jackson Heart Study. HEI and AHEI scores were divided into quintiles and Cox proportional hazards regression models were analysed for 1864 African American adults free from metabolic syndrome at Exam 1 to examine the incidence of metabolic syndrome by quintile of dietary quality score.

SETTING

Hinds, Madison and Rankin counties, Mississippi, USA.

PARTICIPANTS

African American adults, ages 21-94 years, 60·9 % female.

RESULTS

Over a mean follow-up time of 6·7 years, we observed 932 incident cases of metabolic syndrome. After adjusting for multiple covariates, a higher HEI score at Exam 1 was not associated with the risk of incident metabolic syndrome, except when looking at the trend analysis for the subgroup of adults with two metabolic syndrome components at Exam 1 (P-trend = 0·03). A higher AHEI score at Exam 1 was associated with the risk of incident metabolic syndrome (hazard ratio for those in the highest quintile compared to the lowest: 0·80 (95 % CI: 0·65, 0·99), P-trend = 0·03).

CONCLUSION

These findings suggest that a dietary pattern that scores higher on the AHEI may help reduce the risk of metabolic syndrome, even for adults who already have two of the minimum of three components required for a diagnosis of metabolic syndrome.

Dietary patterns derived by reduced rank regression are associated with lipid disorders among Korean adults: a cross-sectional analysis

BACKGROUND

Lipid disorders are a potent risk factor for cardiovascular diseases. Moreover, the intake of dietary fatty acids has been closely related to blood lipid levels. Therefore, this cross-sectional study examined the associations between dietary patterns related to fatty acid intake and lipid disorders in Korean adults.

METHODS

From the 2013-2019 Korea National Health and Nutrition Examination Surveys data, 8399 men and 11404 women (aged ≥ 19 years) were selected. Reduced rank regression was employed to identify dietary patterns from 26 food groups, aiming to explain the maximum variation in the intake of saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA), omega-3 fatty acids, and the PUFA/SFA ratio. Associations of quintiles (Q) of dietary pattern scores with lipid disorders were examined using multiple logistic regression stratified by sex.

RESULTS

Three dietary patterns were identified: dietary pattern 1 showed positive factor loadings for vegetable oils, seasonings, legumes, nuts, and fish; dietary pattern 2 was high in consumption of red meat, bread and snacks, and milk and dairy products; and dietary pattern 3 was rich in fish and milk and dairy products. In men, dietary pattern 3 was inversely associated with elevated triglycerides (Q5 vs. Q1: odds ratio [OR] = 0.82, 95% confidence interval [CI] = 0.69-0.97, P-trend = 0.008). In women, dietary pattern 2 was positively associated with elevated total cholesterol (OR = 1.31, 95% CI = 1.12-1.52, P-trend < 0.001) but inversely associated with low HDL-cholesterol (OR = 0.70, 95% CI = 0.59-0.83, P-trend < 0.001).

CONCLUSION

In this study, dietary patterns explaining the intake of various types of fatty acids were differentially associated with lipid disorders in Korean adults. Dietary pattern characterized by higher intakes of red meat, bread and snacks and milk and dairy products were positively associated with elevated total cholesterol, whereas dietary pattern rich in fish consumption showed an inverse association with elevated triglycerides. These findings could be instrumental in developing dietary guidelines and strategies for preventing and managing lipid disorders in this population.

Dietary fatty acid patterns and risk of metabolic syndrome: Tehran lipid and glucose study

BACKGROUND

The association between individual dietary fatty acids (FAs) and risk of metabolic syndrome (MetS) has been investigated in previous studies. However, synergistic or additive effects of multiple FA have received less attention. Hence, we aimed to determine the major dietary FA patterns and evaluate the association between FA patterns and risk of MetS.

METHODS

Dietary intakes of 1713 MetS-free adults who participated in the third phase of the Tehran Lipid and Glucose Study (TLGS) were assessed using a validated 168-items food frequency questionnaire. FA patterns were obtained by principal component analysis (PCA). Adjusted Hazard Ratios (HRs) and 95% confidence intervals (CIs) were calculated for the association of MetS incident with the extracted FA patterns.

RESULTS

Four major FA patterns were identified through PCA of the 24 FAs consumed: "short- and medium-chain saturated fatty acid (SFA) pattern", "long-chain FA pattern", "omega-3 PUFA pattern", and "long-chain SFA pattern". There was no significant association between dietary FA patterns and risk of MetS incidence.

CONCLUSIONS

We found no significant association between FA patterns and risk of MetS. More prospective cohort studies and clinical trials are needed to clarify the issue.

Omega-3 Fatty Acids in Arterial Hypertension: Is There Any Good News?

Omega-3 polyunsaturated fatty acids (ω-3 PUFAs), including alpha-linolenic acid (ALA) and its derivatives eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are "essential" fatty acids mainly obtained from diet sources comprising plant oils, marine blue fish, and commercially available fish oil supplements. Many epidemiological and retrospective studies suggested that ω-3 PUFA consumption decreases the risk of cardiovascular disease, but results of early intervention trials have not consistently confirmed this effect. In recent years, some large-scale randomized controlled trials have shed new light on the potential role of ω-3 PUFAs, particularly high-dose EPA-only formulations, in cardiovascular prevention, making them an attractive tool for the treatment of "residual" cardiovascular risk. ω-3 PUFAs' beneficial effects on cardiovascular outcomes go far beyond the reduction in triglyceride levels and are thought to be mediated by their broadly documented "pleiotropic" actions, most of which are directed to vascular protection. A considerable number of clinical studies and meta-analyses suggest the beneficial effects of ω-3 PUFAs in the regulation of blood pressure in hypertensive and normotensive subjects. These effects occur mostly through regulation of the vascular tone that could be mediated by both endothelium-dependent and independent mechanisms. In this narrative review, we summarize the results of both experimental and clinical studies that evaluated the effect of ω-3 PUFAs on blood pressure, highlighting the mechanisms of their action on the vascular system and their possible impact on hypertension, hypertension-related vascular damage, and, ultimately, cardiovascular outcomes.

Pragmatic applications of DNA barcoding markers in identification of fish species – a review

DNA barcoding and mini barcoding involve Cytochrome Oxidase Subunit I (COI) gene in mitochondrial genome and is used for accurate identification of species and biodiversity. The basic goal of the current study is to develop a complete reference database of fishes. It also evaluates the applicability of COI gene to identify fish at the species level with other aspects i.e., as Kimura 2 parameter (K2P) distance. The mean observed length of the sequence was ranging between 500 to 700 base pairs for fish species in DNA barcoding and 80 to 650 base pairs for DNA mini barcoding. This method describes the status of known to unknown samples but it also facilitates the detection of previously un-sampled species at distinct level. So, mini-barcoding is a method focuses on the analysis of short-length DNA markers has been demonstrated to be effective for species identification of processed food containing degraded DNA. While DNA meta-barcoding refers to the automated identification of multiple species from a single bulk sample. The may contain entire organisms or a single environmental sample containing degraded DNA. Despite DNA barcoding, mini barcoding and meta-barcoding are efficient methods for species identification which are helpful in conservation and proper management of biodiversity. It aids researchers to take an account of genetic as well as evolutionary relationships by collecting their morphological, distributional and molecular data. Overall, this paper discusses DNA barcoding technology and how it has been used to various fish species, as well as its universality, adaptability, and novel approach to DNA-based species identification.

Association of plant-based diets with adropin, atherogenic index of plasma, and metabolic syndrome and its components: A cross-sectional study on adults

Background

Little is known about the association of plant-based diet indices with metabolic syndrome (MetS) and its novel predictive biomarkers, including the atherogenic index of plasma (AIP) and adropin. We aimed to investigate the association of plant-based diets with adropin, atherogenic index of plasma, and MetS and its components in adults.

Methods

The present population-based cross-sectional study was conducted on a representative sample of adults aged 20-60 years in Isfahan, Iran. Dietary intake was obtained through a validated 168-item semi-quantitative food frequency questionnaire (FFQ). Peripheral blood was obtained after an overnight fast of at least 12 h from each participant. MetS was identified based on the Joint Interim Statement (JIS). AIP was calculated as a logarithmically transformed ratio of triglyceride (TG)/high-density lipoprotein cholesterol (HDL-c), and serum levels of adropin were measured by an ELISA kit.

Results

A total of 28.7% of subjects had MetS. No significant association was found between the overall plant-based diet index (PDI) and the healthful plant-based diet index (hPDI) with MetS. However, a non-linear association was observed between hPDI and MetS. Subjects in the third quartile of the unhealthful plant-based diet index (uPDI) had higher odds of MetS compared to the first quartile (OR: 2.39; 95% CI: 1.01, 5.66). The highest quartile of PDI (OR: 0.46; 95% CI: 0.21, 0.97) and the third quartile of hPDI (OR: 0.40; 95% CI: 0.18, 0.89) were associated with decreased odds of having high-risk AIP compared to the first quartile, after adjusting for potential confounders. No linear association was found between quartiles of plant-based diet indices and serum levels of adropin.

Conclusion

Plant-based diet index (PDI) and hPDI were not associated with the prevalence of MetS in adults, while moderate adherence to uPDI increased the prevalence of MetS. In addition, high adherence to PDI and moderate adherence to hPDI were associated with decreased odds of high-risk AIP. No significant association was found between plant-based diet indices and serum adropin levels. To confirm these findings, further studies with prospective designs are warranted.

Meat consumption and the risk of general and central obesity: the Shahedieh study

Objective

This study aimed to investigate the relations of total meat intake and its subtypes, including red and processed meat, white meat, poultry, fish, and organ meat to the risk of general/central obesity.

Methods

This cross-sectional study included a total of 7312 Iranian adults with the age range of 35–70 years from the Shahedieh cohort study, Yazd, Iran. Dietary intake of subjects was evaluated using a validated 120-item Food Frequency Questionnaire. General obesity was defined as body mass index ≥ 30 kg/m2 and central obesity as waist circumference ≥ 102 cm in men and ≥ 88 cm in women.

Results

After controlling for potential covariates including energy intake, age, marital status, gender, physical activity, supplement use, house possession, education, family size, current smoking, night shift working, history of thyroid disease and depression, and intakes of vegetables, legumes, nuts, fruits, whole grains, and dairy, a significant direct association was found between the higher consumption of white meat (OR = 1.31; 95% CI: 1.06–1.61) and poultry (OR = 1.23; 95% CI: 1.04–1.45) with odds of general obesity. Processed meat was a significant predictor for central obesity in the fully adjusted model, so that individuals in the fourth quartile of processed meat intake, compared with those in the first quartile, had a 22% (OR = 1.22; 95% CI: 1.04–1.43) increased risk to be centrally obese.

Conclusion

This study reveals that higher intakes of white meat and poultry are associated with increased risk of general obesity, while, processed meat consumption was associated with central obesity.

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.

Dietary determinants of healthy/unhealthy metabolic phenotype in individuals with normal weight or overweight/obesity: a systematic review

Objectives: Nutritional factors are amongst the major determinants in the onset and development of obesity and metabolic complications. Nevertheless, the dietary determinants of metabolic health are not completely elucidated. The aim of this systematic review is to investigate nutritional and dietary factors that may contribute to metabolic heterogeneity in individuals with obesity or normal weight. Methods: A literature search was performed in PubMed, Scopus, EMBASE, and google scholar databases until August 2021, to locate studies that examined metabolic health and its association with intakes of specific foods or food groups, nutrient intakes or status, as well as adherence to certain dietary patterns. Two researchers had independently screened titles and abstracts, examined full-text studies, conducted data extraction, and evaluated their quality using the Newcastle-Ottawa Scale. Results: Twenty-seven studies, with a total of 39518 subjects, were included. Of these studies, 11 articles evaluated the association between different dietary patterns and metabolic phenotypes, while 15 had investigated the association of single food/nutrients intakes or nutrient status with metabolic phenotype, and one paper evaluated the association of dietary inflammatory index with metabolic health. The findings of these studies propose that healthy dietary patterns such as the Mediterranean pattern, Dietary Approaches to Stop Hypertension, and population-derived patterns (such as the "Healthy" and "Fruit and vegetable" patterns) were associated with higher odds of the metabolically healthy phenotype. Higher intakes of fruits, vegetables, dairy products, coffee/tea, vitamin D, magnesium, and flavonoids, were suggested to lower the risk of developing metabolically unhealthy phenotype, while, higher consumption of saturated fat, carbohydrate and sugar-sweetened beverages, fast foods, organ meats, and a pro-inflammatory diet increased the risk. Conclusion: Results from published studies, which were mostly cross-sectional, suggest that higher adherence to unhealthier dietary patterns, characterized by the consumption of refined and processed foods, was associated with a lower likelihood of having a healthy metabolic phenotype, while the opposite was observed for healthier dietary patterns. Findings may be used in developing nutritional strategies aimed at improving metabolic health in the population.

The association between meat consumption and the metabolic syndrome: a cross-sectional study and meta-analysis

The findings regarding the associations between red meat, fish and poultry consumption, and the metabolic syndrome (Mets) have been inconclusive, and evidence from Chinese populations is scarce. A cross-sectional study was performed to investigate the associations between red meat, fish and poultry consumption, and the prevalence of the Mets and its components among the residents of Suzhou Industrial Park, Suzhou, China. A total of 4424 participants were eligible for the analysis. A logistic regression model was used to estimate the OR and 95 % CI for the prevalence of the Mets and its components according to red meat, fish and poultry consumption. In addition, the data of our cross-sectional study were meta-analysed under a random effects model along with those of published observational studies to generate the summary relative risks (RR) of the associations between the highest v. lowest categories of red meat, fish and poultry consumption and the Mets and its components. In the cross-sectional study, the multivariable-adjusted OR for the highest v. lowest quartiles of consumption was 1·23 (95 % CI 1·02, 1·48) for red meat, 0·83 (95 % CI 0·72, 0·97) for fish and 0·93 (95 % CI 0·74, 1·18) for poultry. In the meta-analysis, the pooled RR for the highest v. lowest categories of consumption was 1·20 (95 % CI 1·06, 1·35) for red meat, 0·88 (95 % CI 0·81, 0·96) for fish and 0·97 (95 % CI 0·85, 1·10) for poultry. The findings of both cross-sectional studies and meta-analyses indicated that the association between fish consumption and the Mets may be partly driven by the inverse association of fish consumption with elevated TAG and reduced HDL-cholesterol and, to a lesser extent, fasting plasma glucose. No clear pattern of associations was observed between red meat or poultry consumption and the components of the Mets. The current findings add weight to the evidence that the Mets may be positively associated with red meat consumption, inversely associated with fish consumption and neutrally associated with poultry consumption.

Plasma glycerophospholipid profile, erythrocyte n-3 PUFAs, and metabolic syndrome incidence: a prospective study in Chinese men and women

BACKGROUND

Animal studies have highlighted critical roles of glycerophospholipid (GP) metabolism in various metabolic syndrome (MetS)-related features such as dyslipidemia, obesity, and insulin resistance. However, human prospective studies of associations between circulating GPs and risks of MetS are scarce.

OBJECTIVES

We aimed to investigate whether GPs are associated with incidence of MetS in a well-established cohort.

METHODS

A total of 1243 community-dwelling Chinese aged 50-70 y without MetS at baseline and followed up for 6 y were included in current analyses. A total of 145 plasma GPs were quantified by high-throughput targeted lipidomics. MetS was defined using the updated National Cholesterol Education Program Adult Treatment Panel III criteria for Asian Americans.

RESULTS

After 6 y, 429 participants developed MetS. Eleven GPs, especially those with long-chain polyunsaturated fatty acids (LCPUFAs) or very-long-chain polyunsaturated fatty acids (VLCPUFAs) at the sn-2 position, including 1 phosphatidylcholine (PC) [PC(18:0/22:6)], 9 phosphatidylethanolamines (PEs) [PE(16:0/22:6), PE(18:0/14:0), PE(18:0/18:1), PE(18:0/18:2), PE(18:0/20:3), PE(18:0/22:5), PE(18:0/22:6), PE(18:1/22:6), and PE(18:2/22:6)], and 1 phosphatidylserine (PS) [PS(18:0/18:0)], were positively associated with incident MetS (RRs: 1.16-1.30 per SD change; Bonferroni-corrected P < 0.05). In network analysis, the strongest positive association for MetS incidence was evidenced in a module mainly composed of PEs containing C22:6 and PSs [RR: 1.21; 95% CI: 1.12, 1.31 per SD change; Bonferroni-corrected P < 0.05]. This association was more pronounced in participants with lower erythrocyte total n-3 PUFA concentrations [Bonferroni-corrected Pinter(P value for the interaction)< 0.05].

CONCLUSIONS

Elevated plasma concentrations of GPs, especially PEs with LCPUFAs or VLCPUFAs at the sn-2 position, are associated with higher risk of incident MetS. Future studies are merited to confirm our findings.

Fish Consumption: A Review of Its Effects on Metabolic and Hormonal Health

Dietary habits are a major determinant of the risk of chronic disease, particularly metabolic and endocrine disorders. Fish as a food group are a unique source of nutrients with metabolic and hormonal importance including omega-3 fatty acids, iodine, selenium, vitamin D, taurine and carnitine. Fish are also a source of high quality protein and have in general low caloric density. The impact of these nutrients on cardiovascular risk has been extensively reviewed, but the impact of fish on the broader field of endocrine and metabolic health is sometimes not sufficiently appreciated. This article aimed to summarize the impact the effect of regular fish consumption on conditions like the metabolic syndrome, obesity, diabetes, hypothyroidism, polycystic ovary syndrome and the menopausal transition, which are in and of themselves significant causes of morbidity and mortality worldwide. The review revealed that scientific evidence from food science, translational research, epidemiologic studies and interventional trials shows that regular fish consumption has a positive impact on thyroid homeostasis, facilitates maintenance of a healthy body weight, reduces the magnitude of age-associated increases in blood pressure, improves glucose homeostasis helping prevent diabetes and the metabolic syndrome, and has a positive impact on muscle mass preservation among the elderly. These effects are mediated by multiple mechanisms, only some of which have been identified. For most of these effects it holds true that the potential benefits are more substantial when baseline fish consumption is low.

Gender differences in the associations among fish intake, lifestyle, and non-HDL-C level in Japanese subjects over the age of 50 years: Anti-atherosclerotic effect of fish consumption

BACKGROUND AND AIMS

Higher fish consumption may lead to the suppression of atherogenesis. The present study was aimed at investigating the gender differences in association with the frequency of fish intake, lifestyle behaviors and serum non-high-density lipoprotein cholesterol (non-HDL-C) levels.

METHODS AND RESULTS

This cross-sectional study was conducted in a cohort of 4320 (2479 males, 1570 females) healthy Japanese subjects over 50 years of age registered at the Health Planning Center of Nihon University Hospital between April 2018 and March 2019. The average weekly frequency of fish intake was 2.58 ± 1.39 days in males and 2.42 ± 1.36 days in females. In males, the serum non-HDL-C level decreased significantly as the weekly frequency of fish intake (0-1 days, 2-3 days, 4-5 days, or 6-7 days) increased (p < 0.0001). Multiple stepwise regression analysis identified the weekly frequency of fish intake (β = -0.056, p = 0.004) and habitual aerobic exercise (β = -0.063, p = 0.001) as independent determinants of the serum non-HDL-C level. On the other hand, no such associations were observed in females. However, the proportion of subjects engaging in habitual aerobic exercise increased as the frequency of fish intake increased even among females.

CONCLUSIONS

A higher frequency of fish intake may be associated with healthier lifestyle behaviors and lower non-HDL-C levels in males, but not in females. There appear to be gender differences in the relationships between the intake of fish and lifestyle behaviors on lipid metabolism.

CLINICAL TRIAL REGISTRATION

umin (http://www.umin.ac.jp/) Study ID: UMIN000035899.

Marinated Sea Bream Fillets Enriched with Lactiplantibacillus plantarum and Bifidobacterium animalis subsp. lactis: Brine Optimization and Product Design

This study aimed to design marinated sea bream fillets, inoculated with either Lactiplantibacillus plantarum (strains 11, 68, 69) or Bifidobacterium animalis subsp. lactis DSM 10140. In the first step, the optimization of brine composition was performed through a centroid; the factors of the design were citric acid, vinegar, and salt. As a result of optimization, the optimal composition of brine was set to 0.75% citric acid, 55% vinegar, and 3% NaCl. In the second step, sea bream fillets were inoculated with L. plantarum strain 69 and B. animalis subsp. lactis, marinated and then packed in a conditioning solution (oil or diluted brine); the samples were stored at 4 °C for 21 days. The viability of the strains and sensory scores were assessed. The bacteria retained a high viability throughout storage (21 days); however, the sensory scores were at their highest level for 4 days. In particular, sensory assessment suggested a preference for a conditioning solution with oil, rather than with a diluted brine. In addition, a slightly higher preference was found for B. animalis subsp. lactis.

Role of CaMKII in the regulation of fatty acids and lipid metabolism

BACKGROUND & AIMS

Previous studies have reported the beneficial roles of the activation of calmodulin-dependent protein kinase (CaMK)II to many cellular functions associated with human health. This review aims at discussing its activation by exercise as well as its roles in the regulation of unsaturated, saturated, omega 3 fatty acids, and lipid metabolism.

METHODS

A wide literature search was conducted using online database such as 'PubMed', 'Google Scholar', 'Researcher', 'Scopus' and the website of World Health Organization (WHO) as well as Control Disease and Prevention (CDC). The criteria for the search were mainly lipid and fatty acid metabolism, diabetes, and metabolic syndrome (MetS). A total of ninety-seven articles were included in the review.

RESULTS

Calmodulin-dependent protein kinase activation by exercise is helpful in controlling membrane lipids related with type 2 diabetes and obesity. CaMKII regulates many health beneficial cellular functions in individuals who exercise compared with those who do not exercise. Regulation of lipid metabolism and fatty acids are crucial in the improvement of metabolic syndrome.

CONCLUSIONS

Approaches that involve CaMKII could be a new avenue for designing novel and effective therapeutic modalities in the treatment or better management of metabolic diseases such as type 2 diabetes and obesity.

A Three-Month Consumption of Eggs Enriched with ω-3, ω-5 and ω-7 Polyunsaturated Fatty Acids Significantly Decreases the Waist Circumference of Subjects at Risk of Developing Metabolic Syndrome: A Double-Blind Randomized Controlled Trial

Alpha-linolenic acid (ALA), docosahexaenoic acid (DHA), rumenic acid (RmA), and punicic acid (PunA) are claimed to influence several physiological functions including insulin sensitivity, lipid metabolism and inflammatory processes. In this double-blind randomized controlled trial, we investigated the combined effect of ALA, DHA, RmA and PunA on subjects at risk of developing metabolic syndrome. Twenty-four women and men were randomly assigned to two groups. Each day, they consumed two eggs enriched with oleic acid (control group) or enriched with ALA, DHA, RmA, and PunA (test group) for 3 months. The waist circumference decreased significantly (−3.17 cm; p < 0.001) in the test group. There were no major changes in plasma insulin and blood glucose in the two groups. The dietary treatments had no significant effect on endothelial function as measured by peripheral arterial tonometry, although erythrocyte nitrosylated hemoglobin concentrations tended to decrease. The high consumption of eggs induced significant elevations in plasma low-density lipoprotein (LDL)- and high-density lipoprotein (HDL)-cholesterol (p < 0.001), which did not result in any change in the LDL/HDL ratio in both groups. These results indicate that consumption of eggs enriched with ALA, DHA, RmA and PunA resulted in favorable changes in abdominal obesity without affecting other factors of the metabolic syndrome.

Association of Nutrient Patterns with Metabolic Syndrome and Its Components in Iranian Adults

We aimed to examine the association between nutrient patterns and metabolic syndrome (MetS) in Iranian adults. In a cross-sectional study of 850 self-certified healthy women and men aged 20-59 years old, dietary data were assessed using three 24-hour recall. Anthropometric measures were done and blood samples were collected to measure serum fasting serum glucose and lipid profile. The MetS was defined using the International Diabetes Federation. Major nutrient patterns were identified using principle competent analysis. In the first nutrient pattern, the individuals in the fifth quintile had a higher intake of vitamins B₁, B₂, B₃, B₅, B₆, B₁₂, zinc, iron, saturated fatty acids (SFAs), and protein. In the second nutrient pattern, individuals in the first quintile had lower consumption of zinc, SFAs, vitamin E, α-tocopherol, oleic acid, polyunsaturated fatty acids, β-carotene, linolenic acid, and monounsaturated fatty acids, compared to the fifth quintile. Furthermore, in the third nutrient pattern, the individuals in the fifth quintile had a higher intake of potassium, magnesium, phosphorous, calcium, protein, carbohydrate, vitamin C, and folate compared to other quintiles. We identified the second pattern had an indirect association with systolic and diastolic blood pressure, triglycerides, fasting blood sugar (p < 0.001 for all), and total cholesterol (p = 0.04) when it was controlled for body weight. Our findings showed that nutrient patterns may have an association with MetS components with mediating body weight.

Associations of alcohol consumption and physical activity with lean type 2 diabetes mellitus among Korean adults: A prospective cohort study

Data on the association between alcohol consumption and the risk of type 2 diabetes mellitus (T2DM) have accumulated, but little has been reported about this association in terms of lean T2DM. The present study analyzed 10-year longitudinal data to investigate the association between alcohol consumption and T2DM risk among lean individuals. This prospective study included 2,366 male and female Koreans aged 40–69 years who were free of DM and had a body mass index (BMI) <23 kg/m² during the baseline period between 2001 and 2012. Information on alcohol consumption, BMI, and incident cases of T2DM were identified by interviews and health examinations. To analyze the association between alcohol consumption and T2DM risk, Cox proportional hazard regression analysis was used. Alcohol drinkers consuming at least 16 g/day of alcohol (2 units/day) who maintained a BMI <23 kg/m² over 10 years had a significantly higher T2DM risk even after controlling for BMI and potential risk factors. Compared with lifetime abstainers, multivariate hazard ratios (HR) [95% confidence interval] of T2DM were 1.74 [1.02, 2.95] for 16–30 g/day, 2.09 [1.16, 3.77] for 31–60 g/day, and 1.94 [1.07, 3.51] for >60g/day among alcohol drinkers. No protective effect of moderate alcohol consumption <16 g/day on T2DM risk was observed. Age, parental history of DM, and physical inactivity were also significant risk factors for lean T2DM. Alcohol consumption of at least 2 units/day increased T2DM risk among lean individuals. Abstaining from alcohol and physical activity may be beneficial for the prevention of lean T2DM.

Association of nutrient patterns and metabolic syndrome and its components in adults living in Tehran, Iran

Purpose

Identification of nutrient patterns (NPs) may be helpful to evaluate the overall quality of diet and its relation to metabolic syndrome (MetS). We investigated the association of major nutrient patterns with MetS and its components among apparently healthy adults living in Tehran.

Methods

We included 522 adults (24-83 years old) who referred to health centers in Tehran. Fasting blood samples were collected to measure glycemic indicators and lipid profile. Principal component analysis (PCA) based on the 26 nutrient items were applied. Metabolic syndrome was defined based on the guidelines of the National Cholesterol Education Program Adult Treatment Panel III (ATP III).

Results

Three major nutrient patterns were identified: "Mono and disaccharides pattern", "Macronutrient pattern" and "Antioxidant pattern". After controlling for potential confounders, serum HDL (p < 0.001) increased across tertiles of "Antioxidant pattern". A significant inverse association was observed between adherence to "Antioxidant pattern" and odds of MetS (OR: 2.36, 95% CI: 1.51, 3.69) in crude model which was disappeared after adjusting for age, sex, education, physical activity, smoking, marital status, energy and BMI. Moreover, we found that adherence to "Antioxidant pattern" was inversely related to odds of reduced levels of serum high density lipoprotein (HDL) (OR: 0.09, 95% CI: 0.02, 0.35). No association was found between "Mono and disaccharides pattern", "Macronutrient pattern", MetS and its components.

Conclusions

In general, adherence to "Antioxidant pattern "resulted in lower level of HDL concentrations. More studies are needed to investigate the possible causal relationship of these results.

Fish and omega-3 fatty acid consumption and risk of hypertension

BACKGROUND

Experimental studies suggest that omega-3 fatty acid have favorable effects on blood pressure (BP). However, data on the association of long-term dietary intake of omega-3 fatty acid or fish with risk of hypertension in healthy subjects are sparse. We examined whether fish or omega-3 fatty acid consumption was associated with incident hypertension in the Physicians' Health Study (PHS).

METHODS

In a prospective cohort study, we analyzed data on 12 279 PHS participants (mean age: 53.0 ± 8.7 years) free of hypertension at baseline. Fish and omega-3 fatty acid consumption were assessed from a baseline semiquantitative food-frequency questionnaire. Incident hypertension was ascertained via self-reports on annual follow-up questionnaires.

RESULTS

During a mean follow-up of 15.8 years, 6299 men (51.3%) developed hypertension. In a multivariable model controlling for established risk factors for hypertension, fish and omega-3 fatty acid consumption was not significantly associated with incident hypertension. The hazard ratio (95% CI) of hypertension was 1.10 (0.93-1.30) for men who consumed at least five servings per week of fish compared with those who did not consume any fish (P for trend = 0.29). For the highest versus lowest quintile of omega-3 fatty acid intake, the hazard ratio of hypertension was 1.02 (0.94-1.11) (P for trend = 0.34). The associations did not vary by type of fish. There was also no evidence of effect modification by baseline BP, BMI, or history of hypercholesterolemia.

CONCLUSION

Overall, long-term dietary intake of fish and omega-3 fatty acid was not associated with incident hypertension in a cohort of middle-aged and older US men.

Erythrocyte Membrane Polyunsaturated Fatty Acids Are Associated with Incidence of Metabolic Syndrome in Middle-Aged and Elderly People-An 8.8-Year Prospective Study

BACKGROUND

The total and specific types of polyunsaturated fatty acids (PUFAs) related to metabolic syndrome (MetS) remain inconsistent.

OBJECTIVE

We assessed the association of erythrocyte n-3 and n-6 PUFAs with MetS and the components of MetS in a cohort population.

METHODS

This prospective analysis included 2754 participants (aged 40-75 y) from the Guangzhou Nutrition and Health Study (2008-2019) in China. Erythrocyte PUFAs at baseline were measured using gas chromatography. MetS was assessed every 3 y according to the updated National Cholesterol Education Program Adult Treatment Panel III criteria. Multivariable Cox proportional hazard models were used to evaluate HRs and 95% CIs.

RESULTS

We identified 716 incident cases of MetS. The primary analyses showed that the HRs (95% CIs) of MetS (tertile 3 versus 1) were 0.67 (0.56, 0.80) for n-3 PUFAs and 0.70 (0.58, 0.85) for n-6 PUFAs (all Ps trend <0.001). The secondary outcomes showed that, higher erythrocyte very-long-chain (VLC) PUFAs [20:3n-3, docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), arachidonic acid (ARA), and 22:4n-6], but lower α-linolenic acid (ALA) and γ-linolenic acid (GLA), tended to be associated with lower incidences of MetS and its components; among individual MetS components, the associations of PUFAs were more pronounced for hypertriglyceridemia (HTG) and hypertension, followed by low high-density lipoproten (HDL) cholesterol. Significantly higher concentrations of n-3 PUFAs (total, DPA, and DHA) and n-6 PUFAs (total, ARA, and 22:4) were observed in participants with improved (versus progressed) status of MetS (all Ps trend ≤0.003).

CONCLUSION

This study reveals that higher erythrocyte VLC n-3 and n-6 PUFAs, but lower 18-carbon PUFAs (ALA and GLA), are associated with lower risks of MetS components (HTG, hypertension, and low HDL cholesterol) and thereby lower MetS incidence in Chinese adults.

A systematic review and meta-analysis of the association between fish consumption and risk of metabolic syndrome

AIMS

Results regarding the association between fish intake and risk of metabolic syndrome (MetS) are ambiguous. Therefore, this study aims to evaluate whether there is an association between fish consumption and risk of MetS.

DATA SYNTHESIS

A comprehensive literature search was conducted of PubMed, Embase, ScienceDirect and Google Scholar up to August 2019. A random-effects model was used to pool the risk of MetS in the highest category of fish consumption compared with the lowest one. Subgroup analysis was conducted based on country of region, gender, dietary tool, MetS definition, energy adjustment and sample size. A dose-response of analysis of fish intake and risk of MetS was also conducted. Twelve studies with a total of 16 effect sizes (10 cross-sectional and six cohort) were included. An inverse association was observed between fish intake and risk of MetS in cohort (OR = 0.80, 95% CI: 0.66, 0.96; P = 0.017, I² = 62.9%) but not cross-sectional studies (OR = 0.80, 95% CI: 0.70, 1.02; P = 0.085, I² = 50.1%). Subgroup analysis suggested that the results were influenced by all the included variables but sample size. A significant non-linear association was observed between fish intake levels and risk of MetS (P-value for non-linearity = 0.010).

CONCLUSION

An inverse association existed between fish intake and risk of MetS when combining data from prospective cohort studies. Further studies are needed to confirm such an effect.

Associations of Dietary Intake with Cardiovascular Disease, Blood Pressure, and Lipid Profile in the Korean Population: a Systematic Review and Meta-Analysis

OBJECTIVE

Previous studies have separately reported the contributions of dietary factors to the risk of cardiovascular disease (CVD) and its markers, including blood pressure (BP) and lipid profile. This study systematically reviewed the current evidence on this issue in the Korean population.

METHODS

Sixty-two studies from PubMed and Embase were included in this meta-analysis. We performed a random-effects model to analyze pooled odds ratios (ORs) and hazard ratios (HRs) and their 95% confidence intervals (CIs) for the consumption of 14 food items, three macro- and eight micro-nutrients, two dietary patterns, and three dietary indices.

RESULTS

An analysis of pooled effect sizes from at least four individual study populations showed significant associations between coffee consumption and CVD (OR/HR, 0.71; 95% CI, 0.52-0.97) and elevated/high triglycerides (TG) (OR, 0.84; 95% CI, 0.78-0.90), sugar-sweetened beverage intake and elevated BP (OR/HR, 1.20; 95% CI, 1.09-1.33), and milk and dairy intake and elevated/high TG and low high-density lipoprotein cholesterol (HDL-C) (OR/HR, 0.82; 95% CI, 0.76-0.89 for both). Carbohydrate consumption and the low-carbohydrate-diet score were consistently related to an approximately 25% risk reduction for elevated TG and low HDL-C. A lower risk of elevated total cholesterol, but not low-density lipoprotein, was additionally observed for those with a higher low-carbohydrate-diet score. A healthy dietary pattern was only associated with a reduced risk of elevated TG in the Korea National Cancer Screenee Cohort (OR, 0.81; 95% CI, 0.67-0.98).

CONCLUSION

This study showed that milk and dairy and coffee had protective effects for CVD and its risk factors, such as BP and lipid profile, while sugar-sweetened beverages exerted harmful effects.

Association of Serum Uric Acid with Metabolic Syndrome and Its Components: A Cross-Sectional Study in Chinese Coastal Population

Objective: Few studies reported the association between serum uric acid and the prevalence of metabolic syndrome in China's coastal residents. We aimed to examine the association between serum uric acid and the prevalence of metabolic syndrome as well as its components in adults and elderly from Shenzhen (a China's coastal city). Methods: We conducted a survey in a community-based household population in Shenzhen, collecting data about 4049 participants aged 20-69 years. Based on the data, we determined the prevalence of metabolic syndrome in adults and elderly with different serum uric acid concentrations. Results: According to the revised National Cholesterol Education Program Adult Treatment Panel III, the prevalence of the metabolic syndrome in the surveyed participants was 24.69% [95% confidence interval (CI): 23.4%-26.0%]. The prevalence of metabolic syndrome in participants with serum uric acid levels <4, 4-4.9, 5-5.9, 6-6.9, 7-7.9, and ≥8 mg/dL is 10.12% (95% CI: 8.2%-12.0%), 17.92% (95% CI: 15.8%-20.1%), 31.05% (95% CI: 28.1%-34.0%), 39.47% (95% CI: 35.4%-43.8%), 49.39% (95% CI: 43.1%-55.7%), and 52.57% (95% CI: 42.5%-62.5%), respectively. Multivariable logistic regression analysis showed that participants with higher serum uric acid levels were at a higher risk of high triglycerides, low high-density lipoprotein, central obesity, high blood pressure, or high fasting glucose (P < 0.001). Conclusions: Serum uric acid levels were closely associated with metabolic syndrome and its components in Chinese coastal population.

The Omega-3 Fatty Acids EPA and DHA, as a Part of a Murine High-Fat Diet, Reduced Lipid Accumulation in Brown and White Adipose Tissues

Excess energy intake can trigger an uncontrolled inflammatory response, leading to systemic low-grade inflammation and metabolic disturbances that are hypothesised to contribute to cardiovascular disease and type 2 diabetes. The long chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are suggested to mitigate this inflammatory response, but the mechanisms are unclear, especially at the tissue level. Adipose tissues, the first tissues to give an inflammatory response, may be an important target site of action for EPA and DHA. To evaluate the effects of EPA and DHA in white and brown adipose tissues, we fed male C57Bl/6J mice either a high fat diet (HFD) with 5% corn oil, an HFD with 40% of the corn oil substituted for purified EPA and DHA triglycerides (HFD-ED), or normal chow, for 8 weeks. Fatty acid profiling and transcriptomics were used to study how EPA and DHA affect retroperitoneal white and brown adipose tissues. HFD-ED fed mice showed reduced lipid accumulation and levels of the pro-inflammatory fatty acid arachidonic acid in both white and brown adipose tissues, compared with HFD-corn oil fed animals. The transcriptomic analysis showed changes in β-oxidation pathways, supporting the decreased lipid accumulation in the HFD-ED fed mice. Therefore, our data suggests that EPA and DHA supplementation of a high fat diet may be anti-inflammatory, as well as reduce lipid accumulation in adipose tissues.

Adherence to the Mediterranean diet in metabolically healthy and unhealthy overweight and obese European adolescents: the HELENA study

PURPOSE

To examine the adherence to the Mediterranean dietary pattern (MDP) in metabolically healthy overweight or obese (MHO) and metabolically unhealthy obese (MUO) European adolescents.

METHODS

In this cross-sectional study, 137 overweight/obese adolescents aged 12-17 years old from the HELENA study were included. Height, weight, waist circumference and skinfold thickness were measured and body mass index and body fat percent were calculated. Systolic and diastolic blood pressure, glucose, HDL cholesterol, triglycerides and cardiorespiratory fitness (20 m shuttle run test) were measured. MHO and MUO phenotypes were categorized following the Jolliffe and Janssen criteria. Two non-consecutive 24 h recalls were used for dietary intake assessment and the adherence to the MDP was calculated using the Mediterranean dietary pattern score (MDP score) (range 0-9).

RESULTS

A total of 45 (22 girls) adolescents (32.8%) were categorized as MHO. The adherence to the MDP was significantly higher in MHO than in MUO adolescents regardless of age, sex, body fat percentage, energy intake and center (MDP score: 4.6 ± 1.6 vs. 3.9 ± 1.5, p = 0.036), but this difference became non-significant after further adjustment for cardiorespiratory fitness. Participants who had a low adherence to the MDP (MDP score ≤ 4) had a higher likelihood of having MUO phenotype regardless of sex, age, energy intake, center and body fat percentage (OR 2.2; 95% CI 1.01-4.81, p = 0.048).

CONCLUSIONS

Adherence to the MDP might be beneficial to maintain metabolic health in overweight/obese adolescents, yet cardiorespiratory fitness seems to play a key role on the metabolic phenotype.

Dietary fat intake and metabolic syndrome in adults: A systematic review

BACKGROUND AND AIMS

The metabolic syndrome (MetS) is a cluster of coexisting cardiovascular risk factors. The role of specific dietary fats was reemphasized by dietary recommendations. This systematic review aims to assess evidence for the effect of dietary fat intake on MetS occurrence and reversion in adults.

METHODS AND RESULTS

The MEDLINE database was used to search the existing literature. We included observational studies that analyzed dietary fat intake in adults with MetS and clinical trials that compared the effects of different dietary fat diets on MetS and/or its components. Thirty articles were selected (14 observational and 16 clinical trials), and we included information of dietary fat and fatty acids as well as MetS, body mass index, cholesterol, hypertension, and diabetes in adults. SFA intake was found to be positively associated with MetS components. Most of the observational reviewed studies found beneficial associations between MUFA and PUFA (including n-3 and n-6 subtypes) intake and MetS components. Clinical trials also supported the benefits of MUFA- or PUFA-enriched diets (including low-fat diets) in reducing MetS.

CONCLUSIONS

The effects of dietary SFAs on MetS will be influenced by other specific nutrients. Replacement of SFA by MUFA and PUFA has been associated with a decrease in MetS. Dietary recommendations should emphasize on different qualities of fat intake, not only to reduce total fat intake, to obtain health benefits in adults.

Dietary Fat Intake and Metabolic Syndrome in Older Adults

BACKGROUND

Metabolic Syndrome (MetS) is associated with higher rates of cardiovascular disease (CVD), type 2 diabetes mellitus, and cancer worldwide.

OBJECTIVE

To assess fat intake in older adults with or without MetS.

DESIGN

Cross-sectional nutritional survey in older adults living in the Balearic Islands (n = 477, 48% women, 55-80 years old) with no previous CVD.

METHODS

Assessment of fat (total fat, MUFA, PUFA, SFA, TFA, linoleic acid, α-linolenic acid, marine and non-marine ω-3 FA, animal fat and vegetable fat, cholesterol) and macronutrient intake using a validated food frequency questionnaire, and its comparison with recommendations of the US Institute of Medicine (IOM) and the Spanish Society of Community Nutrition (SENC).

RESULTS

Participants with MetS showed higher BMI, lower physical activity, higher total fat and MUFA intake, and lower intake of energy, carbohydrates, and fiber than participants without MetS. Men and women with MetS were below the Acceptable Macronutrient Distribution Range (AMDR) proposed by IOM for carbohydrates and above the AMDR for total fat and MUFAs, and women were below the AMDR proposed for α-linolenic acid (ALA) compared with participants without MetS.

CONCLUSIONS

Subjects with MetS were less likely to meet IOM and SENC recommendations for fat and macronutrient intakes as compared to non-MetS subjects.

Omega-3 and omega-6 polyunsaturated fatty acids and metabolic syndrome: A systematic review and meta-analysis

BACKGROUND & AIMS

Previous studies suggest that polyunsaturated fatty acids (PUFAs) may reduce the risk of metabolic diseases, but some have shown ambiguous results. The aim of this study was to systematically evaluate and summarize available evidence on the association between omega-3 and omega-6 PUFA levels and risk of metabolic syndrome (MetS).

METHODS

A systematic literature search of articles published until December 2017 was conducted in PubMed, Web of Science, and Cochrane Library databases. Meta-analyses of the highest vs. lowest categories of omega-3 and omega-6 PUFAs were conducted using the random effects models.

RESULTS

Thirteen studies (2 case-control, 9 cross-sectional, 1 nested case-control, and 1 prospective cohort) with 36,542 individuals were included. Higher omega-3 PUFA levels in diets or blood were associated with a 26% reduction in the risk of MetS (odds ratio (OR)/relative risk (RR) 0.74, 95% confidence interval (CI) 0.62-0.89). This inverse association was evident among studies with Asian populations (OR/RR 0.69, 95% CI 0.54-0.87), but not among those with American/European populations (OR/RR 0.84, 95% CI 0.55-1.28). Null results were found regarding the association between circulating/dietary omega-6 PUFAs and MetS.

CONCLUSION

The present meta-analysis indicates that higher intakes of omega-3 PUFAs, but not omega-6 PUFAs, was associated with lower MetS risk; adding to the current body of evidence on the metabolic health effects of circulating/dietary omega-3 PUFAs.

The Association between Fish Consumption and Risk of Metabolic Syndrome in Adults: Tehran Lipid and Glucose Study

Objective: Although fish consumption may play a role in prevention of the risk of metabolic syndrome (MetS), results of studies available on this topic are controversial. In this study, we have examined the association of fish consumption and 3.6-year incidence of MetS in Tehranian adults.

METHODS

We conducted a population based cohort study of 3382 adult subjects, aged 19-55 years, from the Tehran Lipid and Glucose Study (TLGS). Fish consumption data were collected using a valid and reliable food-frequency questionnaire. The consumption of fish, in the form of canned and non-canned fish was designated for all subjects, and was classified into three categories (< 30, 30-45, and > 45 g/week). Odds ratio (OR) for the occurrence of MetS according to categories of fish consumption was assessed by multivariable logistic regression.

RESULTS

The mean age of participants (35% male) at baseline was 35 years. Mean fish consumption was 11.3 g/d and incidence of MetS was 13.1%. In the fully adjusted model, subjects, who consumed > 45 g/week of fish had lower incidence of MetS, compared to those who consumed < 30 g/week (OR = 0.73; CI: 0.56-0.95). However, there were no associations between consumption of non-canned fish (OR = 0.86; 95% CI: 0.67-1.10) and canned fish (OR = 0.91; 95% CI: 0.64-1.29) and the incidence of MetS.

CONCLUSION

Our findings suggest that high consumption of fish can reduce the incidence of MetS among adults.

Food Groups and Risk of Overweight, Obesity, and Weight Gain: A Systematic Review and Dose-Response Meta-Analysis of Prospective Studies

This meta-analysis summarizes the evidence of a prospective association between the intake of foods [whole grains, refined grains, vegetables, fruit, nuts, legumes, eggs, dairy, fish, red meat, processed meat, and sugar-sweetened beverages (SSBs)] and risk of general overweight/obesity, abdominal obesity, and weight gain. PubMed and Web of Science were searched for prospective observational studies until August 2018. Summary RRs and 95% CIs were estimated from 43 reports for the highest compared with the lowest intake categories, as well as for linear and nonlinear relations focusing on each outcome separately: overweight/obesity, abdominal obesity, and weight gain. The quality of evidence was evaluated with use of the NutriGrade tool. In the dose-response meta-analysis, inverse associations were found for whole-grain (RRoverweight/obesity: 0.93; 95% CI: 0.89, 0.96), fruit (RRoverweight/obesity: 0.93; 95% CI: 0.86, 1.00; RRweight gain: 0.91; 95% CI: 0.86, 0.97), nut (RRabdominal obesity: 0.42; 95% CI: 0.31, 0.57), legume (RRoverweight/obesity: 0.88; 95% CI: 0.84, 0.93), and fish (RRabdominal obesity: 0.83; 95% CI: 0.71, 0.97) consumption and positive associations were found for refined grains (RRoverweight/obesity: 1.05; 95% CI: 1.00, 1.10), red meat (RRabdominal obesity: 1.10; 95% CI: 1.04, 1.16; RRweight gain: 1.14; 95% CI: 1.03, 1.26), and SSBs (RRoverweight/obesity: 1.05; 95% CI: 1.00, 1.11; RRabdominal obesity: 1.12; 95% CI: 1.04, 1.20). The dose-response meta-analytical findings provided very low to low quality of evidence that certain food groups have an impact on different measurements of adiposity risk. To improve the quality of evidence, better-designed observational studies, inclusion of intervention trials, and use of novel statistical methods (e.g., substitution analyses or network meta-analyses) are needed.

Association between Total Diet Quality and Metabolic Syndrome Incidence Risk in a Prospective Cohort of Korean Adults

The purpose of this study was to prospectively investigate the relation between total diet quality and metabolic syndrome in Korean adults. A community-based cohort of the Korean Genome and Epidemiology Study (KoGES) provided basis for this study. During the total follow-up period of 38,171 person-years of 5,549 subjects, a total of 1,891 metabolic syndrome incident cases were identified. Metabolic syndrome was defined by the criteria of the National Cholesterol Education Program Adult Treatment Panel. Mediterranean Diet Score (MDS), Dietary Approaches to Stop Hypertension diet, and Recommended Food Score (RFS) were used to assess total diet quality. Cox proportional hazards regression was used to estimate hazard ratios (HRs) for metabolic syndrome associated with total diet quality. In men, the incidence of metabolic syndrome in the 5th MDS quintile group decreased by approximately 25% compared to the 1st quintile group (p for trend < 0.01) after adjusting for age and energy intake. In women, significant decreasing trend of metabolic syndrome incidence risk was observed across the quintiles of RFS in an age and energy intake-adjusted model (HR [95% CI] of Q5 vs. Q1; 0.662 [0.521-0.842], p for trend < 0.01). However, such associations did not reach at a significance level when additional covariates were included. In this first study looking at prospective relation of metabolic syndrome with total diet quality in a Korean population, study findings suggest some protective role of better diet quality in preventing future metabolic syndrome. But no convincing evidence was observed in this study.

Quality, functionality, and microbiology of fermented fish: a review

Fermentation is a traditional food preservation method and is widely used for improving food safety, shelf life, and organoleptic and nutritional attributes. Fermented fish are produced and consumed in different parts of the world and are an integral part of many food cultures. Furthermore, fermented fish are a source of interesting microbes and are an important industry in many countries. This review tries to update the types and manufacturing processes for fermented fish around the world. The emphasis is on this work related to fermented fish and their health benefits, as well as the contribution of microorganisms to their fermentation. A variety of different approaches have been used to determine and understand microbial composition and functionality. Moreover, some challenges and future research directions regarding fermented fish are also discussed in this review. Further research into fermented fish products is of crucial importance not only for the food industry but also for human health. However, extensive in vivo and toxicological studies are essential before the application of bioactive-rich fermented fish products for human health benefits.

Nutrients in Fish and Possible Associations with Cardiovascular Disease Risk Factors in Metabolic Syndrome

Non-communicable diseases (NSDs) are responsible for two-thirds of all deaths globally, whereas cardiovascular disease (CVD) alone counts for nearly half of them. To reduce the impact of CVD, targeting modifiable risk factors comprised in metabolic syndrome (e.g., waist circumference, lipid profile, blood pressure, and blood glucose) is of great importance. Beneficial effects of fish consumption on CVD has been revealed over the past decades, and some studies suggest that fish consumption may have a protective role in preventing metabolic syndrome. Fish contains a variety of nutrients that may contribute to health benefits. This review examines current recommendations for fish intake as a source of various nutrients (proteins, n-3 fatty acids, vitamin D, iodine, selenium, and taurine), and their effects on metabolic syndrome and the CVD risk factors. Fatty fish is recommended due to its high levels of n-3 fatty acids, however lean fish also contains nutrients that may be beneficial in the prevention of CVD.

Application of a ω-3 Desaturase with an Arachidonic Acid Preference to Eicosapentaenoic Acid Production in Mortierella alpina

In the industrial oleaginous fungus Mortierella alpina, the arachidonic acid (AA; C20:4; ω-6) fraction can reach 50% of the total fatty acids (TFAs) in vivo. However, the eicosapentaenoic acid (EPA; C20:5; ω-3) fraction is less than 3% when this fungus is cultivated at a low temperature (12°C). Omega-3 fatty acid desaturase is a key enzyme in ω-3 long-chain polyunsaturated fatty acids biosynthesis pathways. To enhance EPA production, we transformed the ω-3 fatty acid desaturase (PaD17), which exhibits strong Δ-17 desaturase activity, into M. alpina, thus increasing the AA to EPA conversion rate to 49.8%. This PaD17-harboring M. alpina reconstruction strain produced 617 mg L⁻¹ of EPA at room temperature in broth medium, this yield was increased to 1.73 g L⁻¹ after culture medium optimization (i.e., about threefold higher than that under original culture conditions), with concomitant respective increases in dry cell weight and TFA content to 16.55 and 6.46 g L⁻¹. These findings suggest a new platform for the future industrial production of EPA.

Universal mini COI barcode for the identification of fish species in processed products

Species substitution, the use of a low value fish in place of a high value fish, is the biggest problem in international trade and the leading cause of fraud in the fisheries arena sector. Current DNA barcoding systems have partly solved this problem but also failed in many instances to amplify PCR targets from highly processed products because of the degradation of a longer barcode marker (~650bp). In the present study, a novel mini barcode marker (295bp) was developed to discriminate fish species in raw and processed states forms. The barcode primers were cross-tested against 33 fish species and 15 other animal species and found to be universal for all the tested fish varieties. When 20 commercial fish products of five different categories were screened, all commercial fish sample yielded positive bands for the novel fish barcode. PCR product was sequenced to retrieve the species IDs that reflected 55% (11/20) of Malaysian fish products were mislabeled.

Lifestyle recommendations for the prevention and management of metabolic syndrome: an international panel recommendation

The importance of metabolic syndrome (MetS) lies in its associated risk of cardiovascular disease and type 2 diabetes, as well as other harmful conditions such as nonalcoholic fatty liver disease. In this report, the available scientific evidence on the associations between lifestyle changes and MetS and its components is reviewed to derive recommendations for MetS prevention and management. Weight loss through an energy-restricted diet together with increased energy expenditure through physical activity contribute to the prevention and treatment of MetS. A Mediterranean-type diet, with or without energy restriction, is an effective treatment component. This dietary pattern should be built upon an increased intake of unsaturated fat, primarily from olive oil, and emphasize the consumption of legumes, cereals (whole grains), fruits, vegetables, nuts, fish, and low-fat dairy products, as well as moderate consumption of alcohol. Other dietary patterns (Dietary Approaches to Stop Hypertension, new Nordic, and vegetarian diets) have also been proposed as alternatives for preventing MetS. Quitting smoking and reducing intake of sugar-sweetened beverages and meat and meat products are mandatory. Nevertheless, there are inconsistencies and gaps in the evidence, and additional research is needed to define the most appropriate therapies for MetS. In conclusion, a healthy lifestyle is critical to prevent or delay the onset of MetS in susceptible individuals and to prevent cardiovascular disease and type 2 diabetes in those with existing MetS. The recommendations provided in this article should help patients and clinicians understand and implement the most effective approaches for lifestyle change to prevent MetS and improve cardiometabolic health.

Associations between fish intake and the metabolic syndrome and its components among middle-aged men and women: the Hordaland Health Study

In epidemiologic studies, the relationship between fish consumption and the metabolic syndrome (MetS) have been inconclusive and sex differences reported. The aim was to investigate associations between fish intake and the MetS in a cross-sectional study of men and women. Fish intake, waist circumference, triglycerides (TG), HDL-C, glucose and blood pressure were assessed among 2874 men and women (46–49 y) in the Hordaland Health Study (1997–1999). Fatty fish intake was inversely associated with TG in men only; mean difference in TG between highest and lowest quartile of fatty fish intake was –0.33 mmol/L (95% CI: –0.51, –0.15). Lean fish intake was inversely associated with TG in women only; mean difference in TG between highest and lowest quartile of lean fish intake was –0.23 mmol/L (95% CI: –0.34, –0.11). Fatty fish intake was positively associated with serum HDL-C in both men and women. Total fish intake was inversely associated with MetS; adjusted OR 0.75 (95% CI 0.57, 0.97). Higher fish intake was associated with lower odds of having MetS possibly driven by associations of higher fish intake with lower TG and higher HDL-C. The findings of differential associations by sex needs to be confirmed and possible biologic mechanisms explored.

n-3 Polyunsaturated Fatty Acids and Metabolic Syndrome Risk: A Meta-Analysis

The associations between n-3 polyunsaturated fatty acids (PUFAs) and metabolic syndrome (MetS) risk have demonstrated inconsistent results. The present study aimed to investigate whether higher circulating n-3 PUFAs and dietary n-3 PUFAs intake have a protective effect on MetS risk. A systematic literature search in the PubMed, Scopus, and Chinese National Knowledge Infrastructure (CNKI) databases was conducted up to March 2017. Odd ratios (ORs) from case-control and cross-sectional studies were combined using a random-effects model for the highest versus lowest category. The differences of n-3 PUFAs between healthy subjects and patients with MetS were calculated as weighted mean difference (WMD) by using a random-effects model. Seven case-control and 20 cross-sectional studies were included. A higher plasma/serum n-3 PUFAs was associated with a lower MetS risk (Pooled OR = 0.63, 95% CI: 0.49, 0.81). The plasma/serum n-3 PUFAs in controls was significantly higher than cases (WMD: 0.24; 95% CI: 0.04, 0.43), especially docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA). However, no significant association was found between dietary intake of n-3 PUFAs or fish and MetS risk. The present study provides substantial evidence of a higher circulating n-3 PUFAs associated with a lower MetS risk. The circulating n-3 PUFAs can be regarded as biomarkers indicating MetS risk, especially DPA and DHA.

Shrimp oil extracted from the shrimp processing waste reduces the development of insulin resistance and metabolic phenotypes in diet-induced obese rats

Diet-induced obesity, insulin resistance, impaired glucose tolerance, chronic inflammation, and oxidative stress represent the main features of type 2 diabetes mellitus. The present study was conducted to examine the efficacy and mechanisms of shrimp oil on glucose homeostasis in obese rats. Male CD rats fed a high-fat diet (52 kcal% fat) and 20% fructose drinking water were divided into 4 groups and treated with the dietary replacement of 0%, 10%, 15%, or 20% of lard with shrimp oil for 10 weeks. Age-matched rats fed a low-fat diet (10 kcal% fat) were used as the normal control. Rats on the high-fat diet showed impaired (p < 0.05) glucose tolerance and insulin resistance compared with rats fed the low-fat diet. Shrimp oil improved (p < 0.05) oral glucose tolerance, insulin response, and homeostatic model assessment-estimated insulin resistance index; decreased serum insulin, leptin, hemoglobin A1c, and free fatty acids; and increased adiponectin. Shrimp oil also increased (p < 0.05) antioxidant capacity and reduced oxidative stress and chronic inflammation. The results demonstrated that shrimp oil dose-dependently improved glycemic control in obese rats through multiple mechanisms.

Lean Fish Consumption Is Associated with Beneficial Changes in the Metabolic Syndrome Components: A 13-Year Follow-Up Study from the Norwegian Tromsø Study

BACKGROUND

Fish consumption may have beneficial effects on metabolic syndrome (MetS); however, limited information of such associations exists. This study investigated possible associations between fish consumption and changes in MetS components during a 13-year follow-up period.

METHODS

The sample included participants (26-69 years) from the Tromsø Study 4 (1994-1995, n = 23,907) and Tromsø Study 6 (2007-2008, n = 12,981). Data were collected using questionnaires including food frequency questions, non-fasting blood samples, and physical examinations. MetS was defined using the Joint Interim Societies (JIS) definition, in which one point was given for each MetS criteria fulfilled (metabolic score). Longitudinal analyses were performed using Linear mixed models.

RESULTS

For both genders, lean fish consumption once a week or more was significantly associated with decreased future metabolic score, decreased triglycerides, and increased high-density lipoprotein (HDL)-cholesterol, whereas decreased waist circumference and blood pressure was identified only for men (age adjusted models). Fatty fish consumption was significantly associated with increased waist circumference for both genders and increased HDL-cholesterol levels in men. Conclusion: The results suggest that fatty and lean fish consumption may influence MetS differently and that lean fish consumption in particular seems to be associated with beneficial changes in the MetS components.

Role of n-3 Polyunsaturated Fatty Acids in Ameliorating the Obesity-Induced Metabolic Syndrome in Animal Models and Humans

The incidence of obesity and its comorbidities, such as insulin resistance and type II diabetes, are increasing dramatically, perhaps caused by the change in the fatty acid composition of common human diets. Adipose tissue plays a role as the major energy reservoir in the body. An excess of adipose mass accumulation caused by chronic positive energy balance results in obesity. The n-3 polyunsaturated fatty acids (n-3 PUFA), DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) exert numerous beneficial effects to maintain physiological homeostasis. In the current review, the physiology of n-3 PUFA effects in the body is delineated from studies conducted in both human and animal experiments. Although mechanistic studies in human are limited, numerous studies conducted in animals and models in vitro provide potential molecular mechanisms of the effects of these fatty acids. Three aspects of n-3 PUFA in adipocyte regulation are discussed: (1) lipid metabolism, including adipocyte differentiation, lipolysis and lipogenesis; (2) energy expenditure, such as mitochondrial and peroxisomal fatty acid β-oxidation; and (3) inflammation, including adipokines and specialized pro-resolving lipid mediators. Additionally, the mechanisms by which n-3 PUFA regulate gene expression are highlighted. The beneficial effects of n-3 PUFA may help to reduce the incidence of obesity and its comorbidities.

Intake of fish and long-chain omega-3 polyunsaturated fatty acids and incidence of metabolic syndrome among American young adults: a 25-year follow-up study

PURPOSE

Studies suggest that long-chain ω-3 polyunsaturated fatty acid (LCω3PUFA) intake and its primary food source-fish-may have beneficial effects on the individual components of metabolic syndrome (MetS). We examined the longitudinal association between fish or LCω3PUFA intake and MetS incidence.

METHODS

We prospectively followed 4356 American young adults, free from MetS and diabetes at baseline, for incident MetS and its components in relation to fish and LCω3PUFA intake. MetS was defined by the National Cholesterol Education Program/Adult Treatment Panel III criteria. Cox proportional hazards model was used for analyses, controlling for socio-demographic, behavioral, and dietary factors.

RESULTS

During the 25-year follow-up, a total of 1069 incident cases of MetS were identified. LCω3PUFA intake was inversely associated with the incidence of MetS in a dose-response manner. The multivariable adjusted hazards ratio (HR) [95 % confidence interval (CI)] of incident MetS was 0.54 (95 % CI 0.44, 0.67; P for linear trend < 0.01) as compared the highest to the lowest quintile of LCω3PUFA intake. A threshold inverse association was found between non-fried fish consumption and the incidence of MetS. The multivariable adjusted HRs (95 % CIs) from the lowest to the highest quintile were 1.00, 0.70 (0.51, 0.95), 0.68 (0.52, 0.91), 0.67 (0.53, 0.86), and 0.71 (0.56, 0.89) (P for linear trend = 0.49). The observed inverse associations were independent of the status of baseline individual components of MetS.

CONCLUSIONS

Our findings suggest that intakes of LCω3PUFAs and non-fried fish in young adulthood are inversely associated with the incidence of MetS later in life.

Insulin-Sensitizing Effects of Omega-3 Fatty Acids: Lost in Translation?

Omega-3 polyunsaturated fatty acids (n-3 PUFA) of marine origin, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), have been long studied for their therapeutic potential in the context of type 2 diabetes, insulin resistance, and glucose homeostasis. Glaring discordance between observations in animal and human studies precludes, to date, any practical application of n-3 PUFA as nutritional therapeutics against insulin resistance in humans. Our objective in this review is to summarize current knowledge and provide an up-to-date commentary on the therapeutic value of EPA and DHA supplementation for improving insulin sensitivity in humans. We also sought to discuss potential mechanisms of n-3 PUFA action in target tissues, in specific skeletal muscle, based on our recent work, as well as in liver and adipose tissue. We conducted a literature search to include all preclinical and clinical studies performed within the last two years and to comment on representative studies published earlier. Recent studies support a growing consensus that there are beneficial effects of n-3 PUFA on insulin sensitivity in rodents. Observational studies in humans are encouraging, however, the vast majority of human intervention studies fail to demonstrate the benefit of n-3 PUFA in type 2 diabetes or insulin-resistant non-diabetic people. Nevertheless, there are still several unanswered questions regarding the potential impact of n-3 PUFA on metabolic function in humans.

Lean fish consumption is associated with lower risk of metabolic syndrome: a Norwegian cross sectional study

Background

Fish consumption may have a role in reducing the prevalence of metabolic syndrome (MetS). The aim of this study was to identify associations between fish consumption and MetS and its components, especially regarding differences concerning consumption of fatty and lean fish.

Methods

This cross sectional study uses data from the Tromsø 6 survey (2007–08), where a sample of 12 981 adults, aged 30–87 years (47 % men) from the Norwegian general population was included. Fish consumption was assessed using food frequency questionnaires (FFQ). Blood sample assessments, anthropometric and blood pressure measurements were carried out according to standard protocols. MetS was defined using the Joint Interim Societies (JIS) definition. All tests were two-sided. Analyses were performed using IBM SPSS Statistics 22 (Pearson’s correlation, Chi-Square tests, analysis of variance (ANOVA), linear and logistic regression models).

Results

Mean age was 57.5, and the prevalence of MetS was 22.6 %. Fish consumption once a week or more was associated with lower risk of having MetS among men (OR 0.85, CI 95 % 0.74 to 0.98, P = 0.03). In the adjusted models, lean fish consumption was associated with a decreased risk of having MetS, whereas fatty fish consumption was not associated with a decreased risk of having MetS. Both an increased fatty and lean fish consumption (0–1 times per month, 2–3 times per month, 1–3 times per week, 4–6 times per week, 1–2 times per day) were associated with decreased serum triglyceride (TG), and increased high-density lipoprotein cholesterol (HDL-C).

Conclusions

Fish consumption may be associated with a lower risk of having MetS and consumption of lean fish seems to be driving the association. Further investigation is warranted to establish associations between fish consumption and MetS.

Fish, Long-Chain n-3 PUFA and Incidence of Elevated Blood Pressure: A Meta-Analysis of Prospective Cohort Studies

Results from prospective cohort studies on fish or long-chain (LC) n-3 polyunsaturated fatty acid (PUFA) intake and elevated blood pressure (EBP) are inconsistent. We aimed to investigate the summary effects. Pertinent studies were identified from PubMed and EMBASE database through October 2015. Multivariate-adjusted risk ratios (RRs) for incidence of EBP in the highest verses the bottom category of baseline intake of fish or LC n-3 PUFA were pooled using a random-effects meta-analysis. Over the follow-up ranging from 3 to 20 years, 20,497 EBP events occurred among 56,204 adults from eight prospective cohort studies. The summary RR (SRR) was 0.96 (95% CI: 0.81, 1.14; I² = 44.70%) for fish in four studies, and 0.73 (95% CI: 0.60, 0.89; I² = 75.00%) for LC n-3 PUFA in six studies (three studies for biomarker vs. three studies for diet). Circulating LC n-3 PUFA as biomarker was inversely associated with incidence of EBP (SRR: 0.67; 95% CI: 0.55, 0.83), especially docosahexaenoic acid (SRR: 0.64; 95% CI: 0.45, 0.88), whereas no significant association was found for dietary intake (SRR: 0.80; 95% CI: 0.58, 1.10). The present finding suggests that increased intake of docosahexaenoic acid to improve its circulating levels may benefit primary prevention of EBP.