Dietary fat, insulin sensitivity and the metabolic syndrome

Dietary Intake of Fatty Acids and Risk of Pancreatic Cancer: A Case-Control Study

BACKGROUND

Epidemiological findings on dietary fat intake and risk of pancreatic cancer (PanC) are inconsistent.

OBJECTIVES

This study aimed to determine the association between types of dietary fat intake and PanC.

METHODS

We conducted a hospital-based case-control study in 957 pathologically confirmed PanC cases and 938 cancer-free controls. Cases and controls were frequency matched by age, sex, and race. Dietary information was collected using a self-administered validated FFQ. Unconditional logistic regression models were used to estimate the ORs and 95% CIs of PanC risk by quintiles of fat intake with the lowest quintile as referent and with adjustment for other risk factors and dietary factors.

RESULTS

We observed no difference in (median) intake of total fat standardized for energy among cases versus controls. The multivariable-adjusted OR (95% CI) of the highest versus the lowest quintile of intake (ORQ5 compared with Q1) was 2.51 (1.68-3.72) for fat from animal sources and 0.41 (0.29-0.58) for fat from plant sources. Intakes of total MUFA, total PUFA, and linoleic (n-6) and long chain n-3 fatty acids were inversely associated with PanC (ORQ5 compared with Q1 and 95% CI: 0.55 [0.36-0.82], 0.59 [0.42-0.82], 0.64 [0.43-0.84], and 0.60 [0.42-0.84], respectively). Arachidonic acid (n-6) and several SFAs were positively associated with PanC.

CONCLUSION

Although some observed associations with pancreatic cancer risk could be explained by reverse causation, the potential protective associations with intakes of largely plant-derived PUFAs and MUFAs and fish-derived long chain n-3 PUFAs warrant further prospective investigation.

Role of hepatic PKCβ in nutritional regulation of hepatic glycogen synthesis

The signaling mechanisms by which dietary fat and cholesterol signals regulate central pathways of glucose homeostasis are not completely understood. By using a hepatocyte-specific PKCβ-deficient (PKCβHep-/-) mouse model, we demonstrated the role of hepatic PKCβ in slowing disposal of glucose overload by suppressing glycogenesis and increasing hepatic glucose output. PKCβHep-/- mice exhibited lower plasma glucose under the fed condition, modestly improved systemic glucose tolerance and mildly suppressed gluconeogenesis, increased hepatic glycogen accumulation and synthesis due to elevated glucokinase expression and activated glycogen synthase (GS), and suppressed glucose-6-phosphatase expression compared with controls. These events were independent of hepatic AKT/GSK-3α/β signaling and were accompanied by increased HNF-4α transactivation, reduced FoxO1 protein abundance, and elevated expression of GS targeting protein phosphatase 1 regulatory subunit 3C in the PKCβHep-/- liver compared with controls. The above data strongly imply that hepatic PKCβ deficiency causes hypoglycemia postprandially by promoting glucose phosphorylation via upregulating glucokinase and subsequently redirecting more glucose-6-phosphate to glycogen via activating GS. In summary, hepatic PKCβ has a unique and essential ability to induce a coordinated response that negatively affects glycogenesis at multiple levels under physiological postprandial conditions, thereby integrating nutritional fat intake with dysregulation of glucose homeostasis.

The association of dietary energy density and the risk of obesity, type 2 diabetes and metabolic syndrome: A systematic review and meta-analysis of observational studies

OBJECTIVES

There is a growing body of evidence linking dietary energy density (DED) with metabolic disorders like obesity, type 2 diabetes (T2D) and metabolic syndrome (MetS). However, according to our knowledge, there has been no systematic review and mate-analysis on T2D and MetS with DED. Therefore, this study aimed to investigate the association between DED with the risk of obesity, T2D and MetS in a systematic review and meta-analysis of observational studies.

METHODS

We searched all published studies according to the defined keywords up to march 2020 in the PubMed/Medline and Scopus databases. We excluded those that did not calculate DED for total intake, no observed association between obesity, T2D, MetS as the primary or one of the outcomes with DED, no reported odds ratio (OR), relative risk (RR) or hazard ratio (HR) estimates with 95% confidence intervals (CIs), studies in children under 2 years old, patients with cancer and pregnant women.

RESULTS

From 2282, after deleting the duplicates and irrelevant studies, we entered 58 articles ( 47 systematic reviews and 11 meta-analyse). We indicated an increased risk of T2D in relation to DED (OR: 1.25, 95% CI: 1.18-1.33, P < .001). But studies reviewed were inconsistent. All studies which examined the relationship between DED and MetS showed a positive relationship with an increased significant risk (OR: 1.59, 95% CI: 1.22-2.07, P < .001). Most articles reported a direct association between DED and obesity but the relationship between DED and risk of obesity was not significant (OR: 1.04, 95% CI: 0.92-1.17, P = .543).

CONCLUSION

In this systematic review and meta-analysis of observational studies, we found that the DED increased the risk of T2D and MetS but was not significant with the risk of obesity.

Association between nutrition labelling awareness and the metabolic syndrome: results from the Korean National Health and Nutrition Examination Survey (KNHANES) 2016-2018

Healthy dietary habits reduce the likelihood for the metabolic syndrome (MS). The present study investigated whether awareness of nutrition information is associated with a decreased likelihood for the MS after adjusting for potential confounders among Korean adults aged 20 years and older. Data were obtained from the Korean National Health and Nutrition Examination Survey 2016-2018. Of the 14 490 participants, 4001 (27·6 %) participants had the MS. In total, 3815 (26·3 %) participants checked nutritional facts and made labelling-dependent purchasing decisions (aware + consider), 7001 (48·3 %) checked nutritional facts but did not make labelling-dependent purchasing decisions or were aware of nutrition facts but did not check them when making food purchasing decisions (aware + not consider) and 3674 (25·4 %) were unaware of nutritional facts (not aware). The aware + consider group was less likely to develop the MS than other groups. The aware + not consider, and not aware groups were at higher association with the MS compared with the aware + consider group. Statistically significant associations were observed between the MS and several demographic characteristics including sex, age, household income, education level, employment status, public health insurance status, smoking status, alcohol consumption and aerobic exercise.

Adipocyte-specific deletion of Depdc5 exacerbates insulin resistance and adipose tissue inflammation in mice

The mammalian target of rapamycin complex 1 (mTORC1) is a crucial regulator of adipogenesis and systemic energy metabolism. Its dysregulation leads to a diversity of metabolic diseases, including obesity and type 2 diabetes. DEP-domain containing 5 (DEPDC5) is a critical component of GATOR1 complex that functions as a key inhibitor of mTORC1. So far, its function in adipose tissue remains largely unknown. Herein we evaluated how persistent mTORC1 activation in adipocyte via Depdc5 knockout modulates adiposity in vivo. Our data indicated that adipocyte-specific knockout of Depdc5 in aged mice led to reduced visceral fat, aggravated insulin resistance and enhanced adipose tissue inflammation. Moreover, we found that Depdc5 ablation resulted in upregulation of adipose triglyceride lipase (ATGL) in adipocytes and elevated levels of serum free fatty acids (FFAs). Intriguingly, rapamycin treatment did not reverse insulin resistance but alleviated adipose tissue inflammation caused by Depdc5 deletion. Taken together, our findings revealed that mTORC1 activation caused by Depdc5 deletion promotes lipolysis process and further exacerbates insulin resistance and adipose tissue inflammation in mice.

Neck Circumference as a Predictor of Metabolic Syndrome in Koreans: A Cross-Sectional Study

Metabolic syndrome (MetS) is a complex metabolic disorder and a high-risk condition for type 2 diabetes and cardiovascular disease. Rapid screening of at-risk individuals using accurate and time-saving tools is effective in disease management. Using the Korea National Health and Nutrition Examination Survey (KNHANES) data, we collected data from 2234 participants suitable for the study design, of which 974 (43.6%) were men and 1260 (56.4%) were women. We used receiver operating characteristic (ROC) curve analysis to estimate the optimal sex-specific neck circumference (NC) cut-off point to predict the MetS risk. To analyze the risk of MetS according to the estimated NC, logistic regression analysis was performed to identify the confounding factors. The result of the ROC analysis showed that the optimal neck cut-off points for predicting the risk of MetS were 38.25 cm (AUC: 0.759, 95% CI: 0.729–0.790) in men and 33.65 cm (AUC: 0.811, 95% CI: 0.782–0.840) in women. In the upper NC cut-off point compared to the lower NC cut-off point, NC was associated with an increased MetS risk by 2.014-fold (p = 0.010) in men and 3.650-fold (p < 0.001) in women, after adjustments. The current study supports NC as an effective anthropometric indicator for predicting the risk of MetS. It is suggested that more studies should be conducted to analyze the disease prediction effect of the combined application of anthropometric indicators currently in use and NC.

High Fat Diet and High Cholesterol Diet Reduce Hepatic Vitamin D-25-Hydroxylase Expression and Serum 25-Hydroxyvitamin D3 Level through Elevating Circulating Cholesterol, Glucose, and Insulin Levels

SCOPE

Low circulating 25-hydroxyvitamin D (25(OH)D) levels associate with obesity, diabetes, and hyperlipidemia, but the underlying mechanisms remain uncertain. As energy-dense diet contributes to these disorders, this study investigates whether diet could impair vitamin D metabolism.

METHODS AND RESULTS

Compared with control chow-fed mice, high fat diet (HFD)-fed mice show lower serum 25(OH)D₃ and 1,25(OH)₂ D₃ levels, lower hepatic vitamin D 25-hydroxylase Cyp2r1 expression but comparable renal vitamin D metabolic enzymes expression. Time course studies show that after HFD feeding, the serum concentrations of cholesterol, triglycerides, fatty acids, glucose, and insulin elevate sequentially and before the reduction of hepatic Cyp2r1 expression and serum 25(OH)D₃ levels. Hepatic Cyp2r1 expression also reduces after consuming high fat and high sucrose diet. After high cholesterol diet feeding, serum total cholesterol rises and hepatic Cyp2r1 expression decreases ahead of the reduction of serum 25(OH)D₃ . In vitro studies demonstrate that high concentrations of cholesterol, glucose, and insulin significantly inhibit Cyp2r1expression in primary murine hepatocytes. Further studies show that dietary restriction in HFD-fed mice ameliorates hypercholesterolemia, hyperglycemia, and hypertriglyceridemia, and elevates hepatic Cyp2r1 expression and serum 25(OH)D₃ level.

CONCLUSION

These findings suggest that diet-induced elevation of circulating cholesterol, glucose, and insulin reduces serum 25(OH)D₃ level through suppressing hepatic Cyp2r1 expression.

Dietary recommendations for prevention of atherosclerosis

This review aims at summarizing updated evidence on cardiovascular disease (CVD) risk associated with consumption of specific food items to substantiate dietary strategies for atherosclerosis prevention. A systematic search on PubMed was performed to identify meta-analyses of cohort studies and RCTs with CVD outcomes. The evidence is highly concordant in showing that, for the healthy adult population, low consumption of salt and foods of animal origin, and increased intake of plant-based foods-whole grains, fruits, vegetables, legumes, and nuts-are linked with reduced atherosclerosis risk. The same applies for the replacement of butter and other animal/tropical fats with olive oil and other unsaturated-fat-rich oil. Although the literature reviewed overall endorses scientific society dietary recommendations, some relevant novelties emerge. With regard to meat, new evidence differentiates processed and red meat-both associated with increased CVD risk-from poultry, showing a neutral relationship with CVD for moderate intakes. Moreover, the preferential use of low-fat dairies in the healthy population is not supported by recent data, since both full-fat and low-fat dairies, in moderate amounts and in the context of a balanced diet, are not associated with increased CVD risk; furthermore, small quantities of cheese and regular yogurt consumption are even linked with a protective effect. Among other animal protein sources, moderate fish consumption is also supported by the latest evidence, although there might be sustainability concerns. New data endorse the replacement of most high glycemic index (GI) foods with both whole grain and low GI cereal foods. As for beverages, low consumption not only of alcohol, but also of coffee and tea is associated with a reduced atherosclerosis risk while soft drinks show a direct relationship with CVD risk. This review provides evidence-based support for promoting appropriate food choices for atherosclerosis prevention in the general population.

Work, physical activity, and metabolic health: Understanding insulin sensitivity of long-haul truck drivers

BACKGROUND

Long-haul truck drivers are disproportionately exposed to metabolic risk; however, little is known about their metabolic health and the role of physical activity and other risk factors in metabolic outcomes.

OBJECTIVE

This study compares truck drivers' insulin sensitivity, and associations between metabolic risk factors and insulin sensitivity, with those of the general population.

METHODS

Survey, anthropometric, and biometric data were collected from 115 long-haul truckers, which were then compared to the general population data using the National Health and Nutrition Examination Survey (NHANES) dataset. The quantitative insulin sensitivity check index (QUICKI) was used to estimate insulin sensitivity.

RESULTS

Truck drivers had lower QUICKI scores than the general population cohort. Sagittal abdominal diameter and exercise were predictive for QUICKI among combined cohorts. Waist circumference and perceived health were more predictive for QUICKI among truck drivers, and sagittal abdominal diameter and income were more predictive for QUICKI among the general population.

CONCLUSIONS

Long-haul truckers appear to represent a subset of the general population regarding the impact of physical activity and other metabolic risk factors on QUICKI. Accordingly, comprehensive efforts which target these factors are needed to improve truckers' physical activity levels and other metabolic risks.

Structure-activity relationship of avocadyne

Avocado consumption is associated with numerous health benefits. Avocadyne is a terminally unsaturated, 17-carbon long acetogenin found almost exclusively in avocados with noted anti-leukemia and anti-viral properties. In this study, specific structural features such as the terminal triple bond, odd number of carbons, and stereochemistry are shown to be critical to its ability to suppress mitochondrial fatty acid oxidation and impart selective activity in vitro and in vivo. Together, this is the first study to conduct a structure-activity analysis on avocadyne and outline the chemical moieties critical to fatty acid oxidation suppression.

The Effect of Dietary Intake and Nutritional Status on Anthropometric Development and Systemic Inflammation: An Observational Study

(1) Background: Daily caloric intake should aim to reduce the risk of obesity or poor anthropometric development. Our study objective was to analyze the association between food consumption, inflammatory status and anthropometric development; (2) Methods: We performed a prospective observational analytical research during September 2020 and April 2021 on a group of 160 healthy subjects, aged between 6 and 12 years old, by analyzing food ingestion, the basal metabolic rate, anthropometric development and the inflammatory status; (3) Results: IL-6 was significantly correlated to the sum of skinfolds, along with both serum proteins and triglycerides. The skin folds were significantly correlated with the caloric intake and with total fat intake, next to saturated and trans fats. Unlike the skin folds, the body weight was significantly correlated with the caloric intake along with some vitamins, such as Vitamin A and Vitamin B12. Inactive mass increased with excessive folic acid, Vitamin E, Vitamin K and saturated fat intake; (4) Conclusions: The inflammatory status was influenced by the ingestion of micronutrients, total serum lipids and proteins. The anthropometric development was associated with the ingestion of carbohydrates, energy balance and energy intake. We can conclude that daily menu and nutrition imbalances can influence both the risk of obesity and the inflammatory status.

Seaweeds as Valuable Sources of Essential Fatty Acids for Human Nutrition

The overexploitation of terrestrial habitats, combined with the ever-growing demand for food, has led to the search for alternative food sources. The importance of seaweeds as food sources has been growing, and their potential as sources of fatty acids (FA) make seaweeds an interesting feedstock for the food and nutraceutical industries. The aim of this study is to assess the potential of five red seaweeds (Asparagospis armata, Calliblepharis jubata, Chondracanthus teedei var. lusitanicus, Gracilaria gracilis, and Grateloupia turuturu) and three brown seaweeds (Colpomenia peregrina, Sargassum muticum and Undaria pinnatifida), harvested in central Portugal, as effective sources of essential FA for food or as dietary supplements. FA were extracted from the biomass, transmethylated to methyl esters, and analyzed through gas chromatography-mass spectrometry. G. gracilis presented the highest content of saturated fatty acids (SFA) (41.49 mg·g-1), whereas C. jubata exhibited the highest content of highly unsaturated fatty acids (HUFA) (28.56 mg·g-1); the three G. turuturu life cycle stages presented prominent SFA and HUFA contents. Omega-6/omega-3 ratios were assessed and, in combination with PUFA+HUFA/SFA ratios, it is suggested that C. jubata and U. pinnatifida may be the algae with highest nutraceutical potential, promoting health benefits and contributing to a balanced dietary intake of fatty acids.

Putative metabolites involved in the beneficial effects of wholegrain cereal: Nontargeted metabolite profiling approach

BACKGROUND AND AIMS

Wholegrain cereals have been implicated in the reduction of lifestyle-related chronic diseases risk including cardiovascular diseases and type 2 diabetes. Molecular mechanisms responsible for the beneficial health effects are not entirely understood. The aims of this study were 1) to identify new potential plasma biomarker candidate metabolites of wholegrain cereal foods intake and 2) to examine whether some putative metabolites associated with wholegrain foods intake may play a role in the improvement of cardiometabolic risk factors.

METHODS AND RESULTS

Analysis have been conducted in 54 individuals with metabolic syndrome of both genders, age 40-65 years, randomly assigned to 2 dietary interventions lasting 12-week: 1) wholegrain enriched diet (n = 28), and 2) refined-wheat cereals diet (control diet) (n = 26). Nontargeted metabolite profiling analysis was performed on fasting plasma samples collected at baseline and at the end of the experimental diets. Our data show that, at the end of the intervention, a higher intake of wholegrain (tertile 3) was significantly associated with a marked increase in several lipid compounds, as PC (20:4/16:1), LPC (20:4), LPC (22:6), LPC (18:3), LPC (22:5), and a phenolic compound (P < .05 for all). In the wholegrain group, higher concentrations of these metabolites (tertile 3 vs tertile 1 of each metabolite) were significantly associated with lower postprandial insulin and triglyceride responses (P < .05) by 29% and 37%, respectively.

CONCLUSION

These observations suggest a possible role of lipid and polyphenol metabolites in the postprandial metabolic benefits of wholegrains in subjects at high risk of cardiovascular disease. In addition, they provide insight into the role of these metabolites as potential candidate biomarkers of wholegrain foods. The study was registered on ClinicalTrials.gov (identifier: NCT00945854).

Vegan Diet Health Benefits in Metabolic Syndrome

Plant-based diets (PBDs) are increasingly consumed by the Italian population and around the world. In particular, among PBDs, the vegan diet is a food pattern characterized by the exclusion of all animal-origin foods. What drives people to adopt this model are mainly ethical, health and environmental reasons. A vegan diet, if well-balanced and varied, can help in achieving and maintaining an optimal state of health. However, this nutritional approach, if not well-balanced, can cause deficiencies in proteins, ω-3 fatty acids, iron, vitamin D and calcium, zinc, iodine and, above all, vitamin B12. Oral food supplements especially fortified foods are recommended in these cases to restore the nutritional deficiencies. A vegan diet generally reduces the risk of developing chronic non-communicable degenerative diseases, such as metabolic syndrome (MetS) and, in addition, requires fewer natural resources for food production than an omnivorous diet. The aim of this review is to analyze the possible impact of the vegan diet on MetS onset and its treatment.

Pentadecanoic acid promotes basal and insulin-stimulated glucose uptake in C2C12 myotubes

Background

Saturated fatty acids (SFAs) generally have been thought to worsen insulin-resistance and increase the risk of developing type 2 diabetes mellitus (T2DM). Recently, accumulating evidence has revealed that SFAs are not a single homogeneous group, instead different SFAs are associated with T2DM in opposing directions. Pentadecanoic acid (C15:0, PA) is directly correlated with dairy products, and a negative association between circulating PA and metabolic disease risk was observed in epidemiological studies. Therefore, the role of PA in human health needs to be reinforced. Whether PA has a direct benefit on glucose metabolism and insulin sensitivity needs further investigation.

Objective

The present study aimed to investigate the effect and potential mechanism of action of PA on basal and insulin stimulated glucose uptake in C2C12 myotubes.

Methods

Glucose uptake was determined using a 2-(N-[7-nitrobenz-2-oxa-1,3-diazol-4-yl] amino)-2-deoxyglucose (2-NBDG) uptake assay. Cell membrane proteins were isolated and glucose transporter 4 (GLUT4) protein was detected by western blotting to examine the translocation of GLUT4 to the plasma membrane. The phosphorylation levels of proteins involved in the insulin and 5’-adenosine monophosphate-activated protein kinase (AMPK) pathways were examined by western blotting.

Results

We found that PA significantly promoted glucose uptake and GLUT4 translocation to the plasma membrane. PA had no effect on the insulin-dependent pathway involving insulin receptor substrate 1 (Tyr632) and protein kinase B (PKB/Akt), but increased phosphorylation of AMPK and Akt substrate of 160 kDa (AS160). Compound C (an AMPK inhibitor) blocked PA-induced AMPK activation and reversed PA-induced GLUT4 translocation, indicating that PA promotes glucose uptake via the AMPK pathway in vitro. Moreover, PA significantly promoted insulin-stimulated glucose uptake in myotubes. Under insulin stimulation, PA did not affect the insulin-dependent pathway, but still activated AMPK.

Conclusion

PA, an odd-chain SFA, significantly stimulates glucose uptake via the AMPK-AS160 pathway and exhibits an insulin-sensitizing effect in myotubes.

Transgenerational supplementation with eicosapentaenoic acid reduced the metabolic consequences on the whole body and skeletal muscle in mice receiving an obesogenic diet

PURPOSE

The effect of manipulating the fatty acid profile of the diet over generations could affect the susceptibility to develop obesity and metabolic disorders. Although some acute effects were described, the impact of transgenerational continuous supplementation with omega 3 fatty acids on metabolic homeostasis and skeletal muscle metabolic flexibility during a nutritional stress is unknown.

METHODS

We analyzed the effect of an obesogenic diet in mice after transgenerational supplementation with an omega-3 rich oil (mainly EPA) or a control oil. Young F3 animals received a high fat and high sucrose diet for 4 months. Whole-body biometric data were recorded and lipidomic/transcriptomic adaptations were explored in the skeletal muscle.

RESULTS

F3 mice from the lineage supplemented with EPA gained less weight, fat mass, and exhibited better metabolic parameters after the obesogenic diet compared to mice from the control lineage. Transcriptomic exploration of skeletal muscle showed differential regulation of biological processes such as fibrosis, fatty acid catabolism, and inflammation between lineages. These adaptations were associated to subtle lipid remodeling of cellular membranes with an enrichment in phospholipids with omega 3 fatty acid in mice from the EPA lineage.

CONCLUSION

Transgenerational and continuous intake of EPA could help to reduce cardiovascular and metabolic risks related to an unbalanced diet by the modulation of insulin sensitivity, fatty acid metabolism, and fibrosis in skeletal muscle.

Subcellular localisation and composition of intramuscular triacylglycerol influence insulin sensitivity in humans

AIMS/HYPOTHESIS

Subcellular localisation is an important factor in the known impact of bioactive lipids, such as diacylglycerol and sphingolipids, on insulin sensitivity in skeletal muscle; yet, the role of localised intramuscular triacylglycerol (IMTG) is yet to be described. Excess accumulation of IMTG in skeletal muscle is associated with insulin resistance, and we hypothesised that differences in subcellular localisation and composition of IMTG would relate to metabolic health status in humans.

METHODS

We evaluated subcellular localisation of IMTG in lean participants, endurance-trained athletes, individuals with obesity and individuals with type 2 diabetes using LC-MS/MS of fractionated muscle biopsies and insulin clamps.

RESULTS

Insulin sensitivity was significantly different between each group (athletes>lean>obese>type 2 diabetes; p < 0.001). Sarcolemmal IMTG was significantly greater in individuals with obesity and type 2 diabetes compared with lean control participants and athletes, but individuals with type 2 diabetes were the only group with significantly increased saturated IMTG. Sarcolemmal IMTG was inversely related to insulin sensitivity. Nuclear IMTG was significantly greater in individuals with type 2 diabetes compared with lean control participants and athletes, and total and saturated IMTG localised in the nucleus had a significant inverse relationship with insulin sensitivity. Total cytosolic IMTG was not different between groups, but saturated cytosolic IMTG species were significantly increased in individuals with type 2 diabetes compared with all other groups. There were no significant differences between groups for IMTG concentration in the mitochondria/endoplasmic reticulum.

CONCLUSIONS/INTERPRETATION

These data reveal previously unknown differences in subcellular IMTG localisation based on metabolic health status and indicate the influence of sarcolemmal and nuclear IMTG on insulin sensitivity. Additionally, these studies suggest saturated IMTG may be uniquely deleterious for muscle insulin sensitivity. Graphical abstract.

Inverse association of improved adherence to dietary guidelines with metabolic syndrome: the Seoul Metabolic Syndrome Management program

BACKGROUND/OBJECTIVES

The Seoul Metabolic Syndrome Management (SMESY) program is a 1-yr lifestyle modification program targeting metabolic syndrome (MetS) in Seoul residents. This study investigated the associations between adherence to dietary guidelines and MetS among the SMESY program participants.

SUBJECTS/METHODS

Data of 54,385 participants aged 20–64 yrs who completed the SMESY program in 2015, had information on adherence to dietary guidelines, and were not medicated for diabetes, hypertension, or dyslipidemia were analyzed. Participants underwent MetS screening and completed a lifestyle questionnaire including adherence to 10 dietary guidelines before and after participation. Participants were classified according to the number of MetS risk factors at baseline (MetS group, ≥ 3; risk group, 1–2; healthy group, none). Adherence to dietary guidelines was determined from the number of “yes” responses regarding the fulfillment of each guideline on ≥ 5 days/week. Multiple logistic regression was used to evaluate associations between newly diagnosed MetS and changes in adherence to dietary guidelines.

RESULTS

In the MetS group, MetS prevalence decreased after the SMESY program (men, −41.9%p; women, −48.7%p), and all risk factors were significantly improved (P < 0.0001). All groups exhibited improved adherence to all dietary guidelines after participation (P < 0.0001). In the MetS group with positively changed adherence scores, the MetS prevalence decreased by −44.1%p for men and −49.5%p for women, whereas the prevalence in those with negative changes decreased by −38.1%p for men and −48.6%p for women. In the risk group, those with positively changed adherence scores had significantly decreased odds ratios (ORs) for newly diagnosed MetS compared with those with negative changes (OR, 0.70; 95% confidence interval [CI], 0.61–0.80 for men; OR, 0.88; 95% CI, 0.79–0.99 for women).

CONCLUSIONS

The SMESY program may effectively reduce the risk of MetS among adults with risk factors by improving adherence to dietary guidelines.

Prevalence of Type 2 Diabetes and Its Association with Added Sugar Intake in Citizens and Refugees Aged 40 or Older in the Gaza Strip, Palestine

BACKGROUND

Little is known about the prevalence and risk factors of diabetes among Gaza Palestinians, 64% of whom are refugees with exceeded sugar intake. We aimed to estimate the prevalence of type 2 diabetes (T2D) and its association with added sugar intake among residents, with regular visits to primary healthcare centers (PHCs) across Gaza.

METHODS

From October to December of 2019, a cross-sectional survey was conducted among 1000 citizens and refugees in nine PHCs selected from the five governorates of the Gaza Strip. Information on dietary intake, medical history, and other risk factors was collected by trained health workers, using structured questionnaires. Anthropometry and biochemical data were extracted from the PHC medical record system.

RESULTS

Overall, the prevalence of diagnosed T2D and undiagnosed T2D were 45.2% and 16.8%, respectively, in adults aged 42 to 74 years, with the differences among citizens and refugees (diagnosed: 46.2% vs. 43.8%; undiagnosed: 15.7% vs. 18.2%). The uncontrolled glycaemic rate was 41.9% and 36.8% for diagnosed patients in citizens and refugees, respectively. Among those without a clinical diagnosis of T2D, after multivariable adjustment, daily added sugar intake was positively associated with fasting glucose and the risk of undiagnosed T2D (odds ratio, 95% CI, highest vs. lowest intake, was 2.71 (1.12-6.54) (pfor trend < 0.001). In stratified analysis, the associations between added sugar intake and the risk of undiagnosed T2D tend to be stronger among refugees or those with higher body mass index.

CONCLUSIONS

Among Palestinian adults, both citizens and refugees are affected by T2D. Added sugar intake is associated with the risk of undiagnosed T2D.

Palmitate but Not Oleate Exerts a Negative Effect on Oxygen Utilization in Myoblasts of Patients with the m.3243A>G Mutation: A Pilot Study

It is known that exposure to excess saturated fatty acids, especially palmitate, can trigger cellular stress responses interpreted as lipotoxicity. The effect of excessive free fatty acids on oxidative phosphorylation capacity in myoblasts of patients with the m.3243A>G mutation was evaluated with the mitochondrial (Mito) stress test using a Seahorse XF96 analyzer. ß-oxidation, measured with the Seahorse XF96 analyzer, was similar in patients and controls, and reduced in both patients and controls at 40 °C compared to 37 °C. Mito stress test in the absence of fatty acids showed lower values in patients compared to controls. The mitochondrial activity and ATP production rates were significantly reduced in presence of palmitate, but not of oleate in patients, showing a negative effect of excessive palmitate on mitochondrial function in patients. Diabetes mellitus is a frequent symptom in patients with m.3243A>G mutation. It can be speculated that the negative effect of palmitate on mitochondrial function might be related to diacylglycerols (DAG) and ceramides (CER) mediated insulin resistance. This might contribute to the elevated risk for diabetes mellitus in m.3243A>G patients.

Oleic Acid Protects Against Insulin Resistance by Regulating the Genes Related to the PI3K Signaling Pathway

BACKGROUND

The effects of different types of fatty acids on the gene expression of key players in the IRS1/PI3K signaling pathway have been poorly studied.

MATERIAL AND METHODS

We analyzed IRS1, p85α, and p110β mRNA expression and the fatty acid composition of phospholipids in visceral adipose tissue from patients with morbid obesity and from non-obese patients. Moreover, we analyzed the expression of those genes in visceral adipocytes incubated with oleic, linoleic, palmitic and dosahexaenoic acids.

RESULTS

We found a reduced IRS1 expression in patients with morbid obesity, independent of insulin resistance, and a reduced p110β expression in those with lower insulin resistance. A positive correlation was found between p85α and stearic acid, and between IRS1 and p110β with palmitic and dosahexaenoic acid. In contrast, a negative correlation was found between p85α and oleic acid, and between IRS1 and p110β with linoleic, arachidonic and adrenic acid. Incubation with palmitic acid decreased IRS1 expression. p85α was down-regulated after incubation with oleic and dosahexaenoic acid and up-regulated with palmitic acid. p110β expression was increased and decreased after incubation with oleic and palmitic acid, respectively. The ratio p85α/p110β was decreased by oleic and dosahexaenoic acid and increased by palmitic acid.

CONCLUSIONS

Our in vitro results suggest a detrimental role of palmitic acid on the expression of gene related to insulin signaling pathway, with oleic acid being the one with the higher and more beneficial effects. DHA had a slight beneficial effect. Fatty acid-induced regulation of genes related to the IRS1/PI3K pathway may be a novel mechanism by which fatty acids regulate insulin sensitivity in visceral adipocytes.

Seaweed's Bioactive Candidate Compounds to Food Industry and Global Food Security

The world population is continuously growing, so it is important to keep producing food in a sustainable way, especially in a way that is nutritious and in a sufficient quantity to overcome global needs. Seaweed grows, and can be cultivated, in seawater and generally does not compete for arable land and freshwater. Thus, the coastal areas of the planet are the most suitable for seaweed production, which can be an alternative to traditional agriculture and can thus contribute to a reduced carbon footprint. There are evolving studies that characterize seaweed's nutritional value and policies that recognize them as food, and identify the potential benefits and negative factors that may be produced or accumulated by seaweed, which are, or can be, dangerous for human health. Seaweeds have a high nutritional value along with a low caloric input and with the presence of fibers, proteins, omega 3 and 6 unsaturated fatty acids, vitamins, and minerals. Moreover, several seaweed sub-products have interesting features to the food industry. Therefore, the focus of this review is in the performance of seaweed as a potential alternative and as a safe food source. Here described is the nutritional value and concerns relating to seaweed consumption, and also how seaweed-derived compounds are already commercially explored and available in the food industry and the usage restrictions to safeguard them as safe food additives for human consumption.

The combined effects of cholesteryl ester transfer protein (CETP) TaqIB gene polymorphism and canola, sesame and sesame-canola oils consumption on metabolic response in patients with diabetes and healthy people

Introduction: Cholesteryl ester transfer protein (CETP) is a key regulating enzyme in the lipid metabolism pathway, and its gene polymorphism may be a candidate for modulating the metabolic responses to dietary intervention. We thus examined whether the effects of the CETP TaqIB polymorphism on metabolic profiles were modified by dietary plant oils.

Methods: This is a retrospective analysis of data collected during a randomized triple-blind cross over trial. A total of 95 patients with type 2 diabetes and 73 non-diabetes individuals completed a 9-weekof the intake of sesame, canola and sesame-canola oils. Blood samples were collected at the beginning and at the end of each intervention period for biochemical analysis. Genotyping was done using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

Results: In diabetes patients, B1B1 homozygotes of the CETP TaqIB polymorphism compared with B2 carriers (B1B2 + B2B2) had significantly lower diastolic blood pressure, apoB and apoB: apoA-1,and higher Lp(a) after the intake of sesame-canola oil, as well as lower insulin and HOMA-IR after the intake of sesame oil. There was also a significant effect of genotype on adjusted changes of apoB, apoB: apoA-1, insulin, HOMA-IR and QUICKI. A significant genotype-dietary oils combined effects were observed for diastolic blood pressure, and LDL: HDL, TC: HDL and TG: HDL ratios in diabetes patients. No independent or combined effects of dietary oils and genotypes on outcomes were found in healthy people.

Conclusion: There was a modulatory effect of the CETP TaqIB polymorphism on some metabolic traits in response to plant oils in patients with diabetes. Taken together, the intake of sesame-canola and canola oils showed more favorable effects in diabetes patients with B1B1 genotype. Future investigations are needed to confirm these results.

Interplay between hormones and exercise on hippocampal plasticity across the lifespan

The hippocampus is a brain structure known to play a central role in cognitive function (namely learning and memory) as well as mood regulation and affective behaviors due in part to its ability to undergo structural and functional changes in response to intrinsic and extrinsic stimuli. While structural changes are achieved through modulation of hippocampal neurogenesis as well as alterations in dendritic morphology and spine remodeling, functional (i.e., synaptic) changes can be noted through the strengthening (i.e., long-term potentiation) or weakening (i.e., long-term depression) of the synapses. While age, hormone homeostasis, and levels of physical activity are some of the factors known to module these forms of hippocampal plasticity, the exact mechanisms through which these factors interact with each other at a given moment in time are not completely understood. It is well known that hormonal levels vary throughout the lifespan of an individual and it is also known that physical exercise can impact hormonal homeostasis. Thus, it is reasonable to speculate that hormone modulation might be one of the various mechanisms through which physical exercise differently impacts hippocampal plasticity throughout distinct periods of an individual's life. The present review summarizes the potential relationship between physical exercise and different types of hormones (namely sex, metabolic, and stress hormones) and how this relationship may mediate the effects of physical activity during three distinct life periods, adolescence, adulthood, and senescence. Overall, the vast majority of studies support a beneficial role of exercise in maintaining hippocampal hormonal levels and consequently, hippocampal plasticity, cognition, and mood regulation.

A high fat diet with a high C18:0/C16:0 ratio induced worse metabolic and transcriptomic profiles in C57BL/6 mice

BACKGROUND

Differential effects of individual saturated fatty acids (SFAs), particularly stearic acid (C18:0), relative to the shorter-chain SFAs have drawn interest for more accurate nutritional guidelines. However, specific biologic and pathologic functions that can be assigned to particular SFAs are very limited. The present study was designed to compare changes in metabolic and transcriptomic profiles in mice caused by a high C18:0 diet and high palmitic acid (C16:0) diet.

METHODS

Male C57BL/6 mice were assigned to a normal fat diet (NFD), a high fat diet with high C18:0/C16:0 ratio (HSF) or an isocaloric high fat diet with a low C18:0/C16:0 ratio (LSF) for 10 weeks. An oral glucose tolerance test, 72-h energy expenditure measurement and CT scan of body fat were done before sacrifice. Fasting glucose and lipids were determined by an autobiochemical analyzer. Blood insulin, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels were measured by enzyme-linked immunosorbent assay methods. Free fatty acids (FFAs) profiles in blood and liver were determined by using gas chromatography-mass spectrometry. Microarray analysis was applied to investigate changes in transcriptomic profiles in the liver. Pathway analysis and gene ontology analysis were applied to describe the roles of differentially expressed mRNAs.

RESULTS

Compared with the NFD group, body weight, body fat ratio, fasting blood glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), triglyceride, IL-6, serum and liver FFAs including total FFAs, C16:0 and C18:0 were increased in both high fat diet groups and were much higher in the HSF group than those in the LSF group. Both HSF and LSF mice exhibited distinguishable long non-coding RNA (lncRNA), microRNA and mRNA expression profiles when compared with those of NFD mice. Additionally, more differentially expressed lncRNAs and mRNAs were observed in the HSF group than in the LSF group. Some biological functions and pathways, other than energy metabolism regulation, were identified as differentially expressed mRNAs between the HSF group and the LSF group.

CONCLUSION

The high fat diet with a high C18:0/C16:0 ratio induced more severe glucose and lipid metabolic disorders and inflammation and affected expression of more lncRNAs and mRNAs than an isocaloric low C18:0/C16:0 ratio diet in mice. These results provide new insights into the differences in biological functions and related mechanisms, other than glucose and lipid metabolism, between C16:0 and C18:0.

Palmitate-induced toxicity is associated with impaired mitochondrial respiration and accelerated oxidative stress in cultured cardiomyocytes: The critical role of coenzyme Q9/10

Impaired mitochondrial function concomitant to enhanced oxidative stress-induced damage are well established mechanisms involved in hyperlipidemia-induced cardiotoxicity. Currently, limited information is available on the direct effect of myocardial lipid overload on endogenous coenzyme Q_9/10 (CoQ_9/10) levels in association with mitochondrial respiration and oxidative stress status. Here, such effects were explored by exposing H9c2 cardiomyocytes to various doses (0.15 to 1 mM) of palmitate for 24 h. The results demonstrated that palmitate doses ≥0.25 mM are enough to impair mitochondrial respiration and cause oxidative stress. Although endogenous CoQ_9/10 levels are enhanced by palmitate doses ≤0.5 mM, this is not enough to counteract oxidative stress, but is sufficient to maintain cell viability of cardiomyocytes. Palmitate doses >0.5 mM caused severe mitochondrial toxicity, including reduction of cell viability. Interestingly, enhancement of CoQ_9/10 levels with the lowest dose of palmitate (0.15 mM) was accompanied by a significantly reduction of CoQ₉ oxidation status, as well as low cytosolic production of reactive oxygen species. From the overall findings, it appears that CoQ_9/10 response may be crucial to improve mitochondrial function in conditions linked to hyperlipidemia-induced insult. Confirmation of such findings in relevant in vivo models remains essential to better understand the cardioprotective effects in association with improving endogenous CoQ_9/10 content.

The Accumulation of Visceral Fat and Preventive Measures among the Elderly

Visceral fat is a specific fat that is produced in the body, transformed into cholesterol, and circulated in the blood to other parts of the body. The circulated cholesterol usually in the form of low-density lipoproteins forms plaque on the walls of the arteries, thereby constricting and blocking them and preventing the free flow of nutrients to various vital organs in the body. Visceral fat is deleterious to the health of elderly people because it is mostly found in the region of the abdomen that houses vital organs such as the pancreas, liver, and digestive tract, and it further affects the normal functioning of hormones in the body. Globally, 15 million people die of a noncommunicable disease (NCD) annually between the age of 30 years and the age of 69 years, and there is an increase in NCD morbidity among people older than 70 years. Accumulated visceral fat in elderly people could have deleterious health consequences, as it is a predisposing factor for many other NCDs and chronic health conditions. Sedentary lifestyle, unhealthy eating, stress, and inactivity are the major causes of excessive visceral fat. However, measures to prevent the accumulation of visceral fat are straightforward, and impressive results are achieved with regular physical exercise, healthy diet choices, and proper stress management.

Mitochondrial dynamic modulation exerts cardiometabolic protection in obese insulin-resistant rats

Obese insulin resistance impairs cardiac mitochondrial dynamics by increasing mitochondrial fission and decreasing mitochondrial fusion, leading to mitochondrial damage, myocardial cell death and cardiac dysfunction. Therefore, inhibiting fission and promoting fusion could provide cardioprotection in this pre-diabetic condition. We investigated the combined effects of the mitochondrial fission inhibitor (Mdivi1) and fusion promoter (M1) on cardiac function in obese insulin-resistant rats. We hypothesized that Mdivi1 and M1 protect heart against obese insulin-resistant condition, but also there will be greater improvement using Mdivi1 and M1 as a combined treatment. Wistar rats (n=56, male) were randomly assigned to a high-fat diet (HFD) and normal diet (ND) fed groups. After feeding with either ND or HFD for 12 weeks, rats in each dietary group were divided into groups to receive either the vehicle, Mdivi1 (1.2 mg/kg, i.p.), M1 (2 mg/kg, i.p.) or combined treatment for 14 days. The cardiac function, cardiac mitochondrial function, metabolic and biochemical parameters were monitored before and after the treatment. HFD rats developed obese insulin resistance which led to impaired dynamics balance and function of mitochondria, increased cardiac cell apoptosis and dysfunction. Although Mdivi1, M1 and combined treatment exerted similar cardiometabolic benefits in HFD rats, the combined therapy showed a greater reduction in mitochondrial reactive oxygen species (ROS). Mitochondrial fission inhibitor and fusion promoter exerted similar levels of cardioprotection in a pre-diabetic condition.

Association of dietary energy density with cardiometabolic risk factors and metabolic syndrome in Tehranian older adults

Introduction: The objective of this study was to evaluate the association between the consumption of an energy-dense diet and cardiometabolic risk factors in Iranian older adults. Methods: This cross-sectional study was conducted on 226 older adults who were living in Tehran, Iran. Dietary energy density (DED) was calculated as energy per weight of food, kcal/g. The usual intake of participants was measured using a validated semi-quantitative food frequency questionnaire. Anthropometric measurements, fasting blood sugar, serum lipid profile and blood pressure and were assessed. The metabolic syndrome was defined according to National Cholesterol Education Program Adult Treatment Panel-III (NCEP ATP III). Results: Those who were in the third tertile of DED compared to the first tertile had 19% lower odds of having the cardiometabolic risk factors and metabolic syndrome (MetS) 0.81 (0.39,1.68) but the association was no significant (P =0.58). There was a significant inverse association between DED and systolic blood pressure (SBP) (β=-0.14, P =0.03) and diastolic blood pressure (DBP) (β=-0.17, P =0.01). We did not find any significant association between intake of energy-dense foods and serum levels of triglyceride (TG) (P =0.62), fasting blood sugar (FBS) (P =0.06), high-density lipoprotein (HDL) (P =0.72) and waist circumference (WC) (P=0.28). Conclusion: DED is negatively associated with SBP and DBP in Iranian older adults. Prospective studies are needed to establish a causal link between DED and MetS and risk factors of cardiovascular disease (CVD).

Novel Insights into the Pathogenesis and Management of the Metabolic Syndrome

The metabolic syndrome, by definition, is not a disease but is a clustering of individual metabolic risk factors including abdominal obesity, hyperglycemia, hypertriglyceridemia, hypertension, and low high-density lipoprotein cholesterol levels. These risk factors could dramatically increase the prevalence of type 2 diabetes and cardiovascular disease. The reported prevalence of the metabolic syndrome varies, greatly depending on the definition used, gender, age, socioeconomic status, and the ethnic background of study cohorts. Clinical and epidemiological studies have clearly demonstrated that the metabolic syndrome starts with central obesity. Because the prevalence of obesity has doubly increased worldwide over the past 30 years, the prevalence of the metabolic syndrome has markedly boosted in parallel. Therefore, obesity has been recognized as the leading cause for the metabolic syndrome since it is strongly associated with all metabolic risk factors. High prevalence of the metabolic syndrome is not unique to the USA and Europe and it is also increasing in most Asian countries. Insulin resistance has elucidated most, if not all, of the pathophysiology of the metabolic syndrome because it contributes to hyperglycemia. Furthermore, a major contributor to the development of insulin resistance is an overabundance of circulating fatty acids. Plasma fatty acids are derived mainly from the triglycerides stored in adipose tissues, which are released through the action of the cyclic AMP-dependent enzyme, hormone sensitive lipase. This review summarizes the latest concepts in the definition, pathogenesis, pathophysiology, and diagnosis of the metabolic syndrome, as well as its preventive measures and therapeutic strategies in children and adolescents.

Dietary Patterns and Cognitive Health in Older Adults: A Systematic Review

While the role of diet and nutrition in cognitive health and prevention of dementia in older adults has attracted much attention, the efficacy of different dietary patterns remains uncertain. Previous reviews have mainly focused on the Mediterranean diet, but either omitted other dietary patterns, lacked more recent studies, were based on cross-sectional studies, or combined older and younger populations. We followed PRISMA guidelines, and examined the efficacy of current research from randomized controlled trials and cohort studies on the effects of different dietary patterns. We reviewed the Mediterranean diet, Dietary Approach to Stop Hypertension (DASH) diet, the Mediterranean-DASH diet Intervention for Neurodegenerative Delay (MIND) diet, Anti-inflammatory diet, Healthy diet recommended by guidelines via dietary index, or Prudent healthy diets generated via statistical approaches, and their impact on cognitive health among older adults. Of 38 studies, the Mediterranean diet was the most investigated with evidence supporting protection against cognitive decline among older adults. Evidence from other dietary patterns such as the MIND, DASH, Anti-inflammatory, and Prudent healthy diets was more limited but showed promising results, especially for those at risk of cardiovascular disease. Overall, this review found positive effects of dietary patterns including the Mediterranean, DASH, MIND, and Anti-inflammatory diets on cognitive health outcomes in older adults. These dietary patterns are plant-based, rich in poly- and mono-unsaturated fatty acids with lower consumption of processed foods. Better understanding of the underlying mechanisms and effectiveness is needed to develop comprehensive and practical dietary recommendations against age-related cognitive decline among older adult.

Short-Term Responses to Fatty Acids on Lipid Metabolism and Adipogenesis in Rainbow Trout (Oncorhynchus mykiss)

Fish are rich in n-3 long-chain polyunsaturated fatty acids (LC-PUFA) such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Due to the increasing use of vegetable oils (VO), their proportion in diets has lowered, affecting lipid metabolism and fillet composition. Rainbow trout cultured preadipocytes were treated with representative FA found in fish oils (EPA and DHA) or VO (linoleic, LA and alpha-linolenic, ALA acids), while EPA and LA were also orally administered, to evaluate their effects on adipogenesis and lipid metabolism. In vitro, all FA increased lipid internalization, with ALA producing the highest effect, together with upregulating the FA transporter fatp1. In vivo, EPA or LA increased peroxisome proliferator-activated receptors ppara and pparb transcripts abundance in adipose tissue, suggesting elevated β-oxidation, contrary to the results obtained in liver. Furthermore, the increased expression of FA synthase (fas) and the FA translocase/cluster of differentiation (cd36) in adipose tissue indicated an enhanced uptake of lipids and lipogenesis de novo, whereas stable or low hepatic expression of genes involved in lipid transport and turnover was found. Thus, fish showed a similar tissue metabolic response to the short-term availability of EPA or LA in vivo, while in vitro VO-derived FA demonstrated greater potential inducing fat accumulation.

Relationship Between the Consumption of Milk-Based Oils Including Butter and Kermanshah Ghee with Metabolic Syndrome: Ravansar Non-Communicable Disease Cohort Study

BACKGROUND

The prevalence of metabolic syndrome (MetS) in recent years has been growing in different societies, which may be due to lifestyle changes including changes in diet, in particular the consumption pattern of edible oils. The purpose of this study was to investigate the relationship between the consumption of animal oils including butter and Kermanshah ghee with MetS and its components in the adult population of Ravansar Non-Communicable Disease (RaNCD) cohort study.

METHODS

This cross-sectional study was carried out on 5550 adults aged 35-65 years using baseline data of Ravansar's prospective study center in Iran. MetS was defined according to the criteria of modified NCEP ATP III for Iranian adults. Relationship between the consumption of butter and Kermanshah ghee and MetS was analyzed by logistic regression model using STATA software.

RESULTS

In our study, the frequency of MetS was 31.40%. The mean body mass index and mean age were 27.1±4.6 kg/m² and 47.6±8.2 years. The mean values of consumed butter and Kermanshah ghee were 3.3±1.8 and 5.1±2.3 g/day, respectively. After adjusting the confounding variables, the highest to the lowest quintile of butter and Kermanshah ghee consumption showed a reverse correlation with the MetS (OR = 0.7, 95% CI = 0.5-0.9) and (OR= 0.7, 95% CI=0.6-0.9), respectively.

CONCLUSION

This study revealed a reverse relationship between milk and Kermanshah ghee consumption with MetS and its components. Therefore, consumption of milk-based oils may be associated with lower cardiovascular risk factors.

The Dose-Response Associations of Sedentary Time with Chronic Diseases and the Risk for All-Cause Mortality Affected by Different Health Status: A Systematic Review and Meta-Analysis

PURPOSE

To determine the dose-response associations of sedentary behaviour with cardiovascular diseases (CVD), cancer, and all-cause mortality, and to examine whether the sedentary-associated all-cause mortality risk was affected by appearance of diabetes and hypertension, physical activity, and body mass index (BMI).

DESIGN

We carried out a systematic review and meta-analysis to search Medline, SportDiscus, and Web of Science for eligible studies.

SETTINGS

Prospective cohort studies that reported sedentary time and CVD, cancer, and mortality incidents.

MEASUREMENTS

Two authors independently extracted data based on predefined criteria. The effect estimates were evaluated by hazard ratios (HRs) with 95% confidences (CIs).

RESULTS

Twenty-four studies met the inclusion criteria. Sitting time showed dose-response associations with CVD, cancer, and all-cause mortality, with each 1-hour increment of sitting time daily accounting for HRs 1.04 (95% CIs 1.02-1.07), 1.01 (1.00-1.02), and 1.03 (1.02-1.03), respectively. The link between sitting time and CVD and all-cause mortality was non-linear (pnon-linear < 0.0001). The relationship between TV viewing and CVD and all-cause mortality was dose-dependent, with HRs 1.07 (1.06-1.09) and 1.04 (1.01-1.06) for per 1-hour increment of TV time every day, respectively. The regression was curved (pnon-linear < 0.0001). When the analysis was stratified by the percentage of diabetes and hypertension, BMI values, and physical activity levels, we found that higher BMI and a greater percentage of diabetes and hypertension further increased all-cause mortality risk in the most sedentary populations, whereas higher physical activity levels decreased it.

CONCLUSION

Sitting time and TV viewing significantly increased cardiovascular, cancer, and mortality risk; the associations were dose-dependent. More importantly, sedentary behaviour in combination with chronic diseases or high BMI increased all-cause mortality risk whereas physical activity was likely to alleviate the adverse associations.

Antiobesity Effect of Biochanin-A: Effect on Trace Element Metabolism in High Fat Diet-Induced Obesity in Rats

BACKGROUND

Imbalanced diets have contributed to the increased prevalence of obesity and other metabolic disorders in the modern world including trace element metabolism. However, the underlying mechanisms are not fully understood.

AIM AND OBJECTIVES

The present study investigated the effects of Biochanin A (BCA) on the changes in element metabolism induced by HFD-induced obese rats.

METHODS

BCA was administered orally for 30 days to experimental obese rats. Changes in body weight, glucose, insulin resistance and lipid profiles of plasma, as well as the level of trace elements (Fe, Zn, Mg and Cu) in various tissues (liver, kidney, heart and pancreas) and hepsidine and heme oxygenase, were observed in experimental rats.

RESULTS

The administration of BCA elicited a significant (p<0.05) reduction in, glucose, insulin, ferritin, total cholesterol, phospholipids, free fatty acids, VLDL-C, LDL-C, triglycerides and hepsidin. Significant alterations were observed in trace elements level, HDL-C, transferrin, bilirubin and HO - 1 level.

CONCLUSION

These findings suggested that HFD results in derangement of trace elements in the tissues of rats fed with HFD. BCA may alleviate the derangement of HFD induced trace elements metabolism by modulating hyperglycemic and insulin resistance status and altering hepcidin and HO-1.

Aging induced by D-galactose aggravates cardiac dysfunction via exacerbating mitochondrial dysfunction in obese insulin-resistant rats

The prevalence of obesity and an aging population are increasing worldwide. Both obesity and aging are independently known to be associated with cardiac dysfunction. However, in obese insulin-resistant subjects, the effects of aging on metabolic status and cardiac and mitochondrial functions are not completely understood. We hypothesized that in the obese insulin-resistant condition, aging induced by D-galactose increases cardiac senescence markers and aggravates the impairment of metabolic parameters, cardiac and mitochondrial function, and increases oxidative stress, inflammation, apoptosis, and autophagy. Sixty-four male Wistar rats were fed with either normal diet (ND) or high-fat diet (HFD) for 12 weeks. Then, rats were divided into vehicle groups (0.9% NSS, subcutaneous injection (SC)) or D-galactose groups (150 mg/kg/day, SC). After 0.9%NSS or D-galactose treatment for 4 weeks and 8 weeks, metabolic and cardiac functions were determined. The heart was then removed to determine mitochondrial functions and enable biochemical studies. After 4 weeks of D-galactose injection, ND rats treated with D-galactose (NDD4), HFD rats treated with vehicle (HFV4), and HFD rats treated with D-galactose (HFD4) had reduced cardiac function, impaired cardiac mitochondrial function and autophagy, and increased oxidative stress, inflammation, and apoptosis. Interestingly, after 8 weeks, HFD rats treated with D-galactose (HFD8) had the worst impairment of cardiac and mitochondrial function, autophagy, and apoptosis in comparison to the other groups. Aging induced by D-galactose aggravated cardiac dysfunction in obese insulin-resistant rats through the worsening of cardiac mitochondrial function, autophagy, and increased apoptosis in a time-dependent manner.

Dietary linoleic acid and human health: Focus on cardiovascular and cardiometabolic effects

This narrative review aims to discuss the more relevant evidence on the role of linoleic acid (LA), a n-6 essential fatty acid that constitutes the predominant proportion of dietary polyunsaturated fatty acids (PUFA), in cardiovascular health. Although LA can be metabolized into Arachidonic Acid (AA), a 20 carbon PUFA which is the precursor of eicosanoids, including some with proinflammatory or prothrombotic-vasoconstrictor action, the large majority of experimental and clinical studies have assessed the potential benefit of increasing dietary intake of LA. Overall, data from clinical studies and meta-analyses suggest an association between high dietary intakes or tissue levels of n-6 PUFA, and specifically LA, and the improvement of cardiovascular risk (mainly of the plasma lipid profile), as well as long-term glycaemic control and insulin resistance. Most observational data show that elevated/increased dietary intake or tissue levels of LA is associated with a reduced incidence of cardiovascular diseases (mainly coronary artery diseases) and of new onset metabolic syndrome or type 2 diabetes. The effects of LA (or n-6 PUFA) in other physio-pathological areas are less clear. High quality clinical trials are needed to assess both the actual amplitude and the underlying mechanisms of the health effects related to dietary intake of this essential fatty acid.

High fat meals increases postprandial fat oxidation rate but not postprandial lipemia

BACKGROUND

This study investigated the effects of ingesting meals with the same calorie intake but distinct nutritional contents after exercise on postprandial lipemia the next day.

METHODS

Eight healthy male participants completed two 2-day trials in a random order. On day 1, the participants underwent five 12 min bouts of cycling exercise with a bout of higher intensity exercise (4 min) after each and then a bout of lower intensity cycling (2 min). The total exercise time was 90 min. After the exercise, the participants ingested three high-fat or low-fat meals. On Day 2, the participants were asked to rest in the laboratory and ingest a high-fat meal. Their postprandial reaction after a high-fat meal was observed.

RESULTS

Postprandial triglyceride concentrations in the high-fat diet trial and low-fat diet trial exhibited nonsignificant differences. Total TG AUC were no significantly different on HF trial and LF trial (HF: 6.63 ± 3.2; LF: 7.20 ± 3.4 mmol/L*4 h. p = 0.586). However, the postprandial fat oxidation rate total AUC (HF: 0.58 ± 0.1; LF: 0.39 ± 0.2 g/min*4 h. p = 0.045), plasma glucose, and insulin concentration of the high-fat trial were significantly higher than those of the low-fat trial.

CONCLUSIONS

This study revealed that meals with distinct nutritional contents after a 90-min exercise increased the postprandial fat oxidation rate but did not influence the postprandial lipemia after a high-fat meal the next day.

Obesity Status Affects the Relationship Between Protein Intake and Insulin Sensitivity in Late Pregnancy

The purpose of this study was to determine the associations between amount and type of dietary protein intake and insulin sensitivity in late pregnancy, in normal weight and overweight women (29.8 ± 0.2 weeks gestation, n = 173). A 100-g oral glucose tolerance test (OGTT) was administered following an overnight fast to estimate the metabolic clearance rate of glucose (MCR, mg·kg⁻¹·min⁻¹) using four different equations accounting for the availability of blood samples. Total (TP), animal (AP), and plant (PP) protein intakes were assessed using a 3-day food record. Two linear models with MCR as the response variable were fitted to the data to estimate the relationship of protein intake to insulin sensitivity either unadjusted or adjusted for early pregnancy body mass index (BMI) because of the potential of BMI to influence this relationship. There was a positive association between TP (β = 1.37, p = 0.002) and PP (β = 4.44, p < 0.001) intake in the last trimester of pregnancy and insulin sensitivity that weakened when accounting for early pregnancy BMI. However, there was no relationship between AP intake and insulin sensitivity (β = 0.95, p = 0.08). Therefore, early pregnancy BMI may be a better predictor of insulin sensitivity than dietary protein intake in late pregnancy.

Increased adiposity by feeding growing rats a high-fat diet results in iron decompartmentalisation

The present study reports the effects of a high-fat (HF) diet of over 8 weeks on the Fe status of growing rats. Tissue Fe levels were analysed by atomic absorption spectrophotometry, and whole-body adiposity was measured by dual-energy X-ray absorptiometry. Histopathology and morphometry of adipose tissue were performed. Liver homogenates were used for measuring ferroportin-1 protein levels by immunoblotting, and transcript levels were used for Fe genes measured by real-time PCR. Tissue Fe pools were fit to a compartmental biokinetic model in which Fe was assessed using fourteen compartments and twenty-seven transfer constants (kj,i from tissue 'i' to tissue 'j') adapted from the International Commission on Radiological Protection (ICRP) 69. Ten kj,i were calculated from the experimental data using non-linear regression, and seventeen were estimated by allometry according to the formula ${k_{i,j}} = a \times {M^b}$. Validation of the model was carried out by comparing predicted and analysed Fe pool sizes in erythrocytes, the liver and the spleen. Body adiposity was negatively associated with serum Fe levels and positively associated with liver Fe stores. An inferred increase in Fe transfer from bone marrow to the liver paralleled higher hepatic Fe concentrations and ferritin heavy-chain mRNA levels in the HF diet-fed animals, suggesting that liver Fe accumulation occurred at least in part due to a favoured liver erythrocyte uptake. If this feeding condition was to be prolonged, impaired Fe decompartmentalisation may occur, ultimately resulting in dysmetabolic Fe overload.

Effect of arabinoxylan on colonic bacterial metabolites and mucosal barrier in high-fat diet-induced rats

The aim of this study was to demonstrate the effect of arabinoxylan on colonic mucosal barrier and metabolomic profiles in high-fat diet-induced rats. A total of 20 six-week-old male rats were arranged randomly to two groups (n = 10/group), including a high-fat diet (HFD) group and a high-fat supplemented with arabinoxylan diet (AXD) group. Results showed that feeding AXD reduced serum lipopolysaccharide in rats after 5 weeks. In colonic digesta, Escherichia coli population was reduced, while Lactobacillus, Bifidobacterium, and Bacteroidetes populations were increased in AXD group. Metabolomics assay found that the different abundances of 84 metabolites were observed, involving lipid, carbohydrate, and nitrogenous metabolism in colonic digesta. In colonic mucosa, AXD up-regulated gene level of tight-junction-related proteins. Meanwhile, lower TNF-α and IL-1β levels were related to TLR4/NF-κB/MyD88 pathway in AXD group. In conclusion, arabinoxylan could change colonic microbial metabolism and improve the colonic mucosal barrier via modulating intestinal microflora and tight junction proteins.

Nutritional Challenges in Metabolic Syndrome

Metabolic Syndrome (MetS) is a combination of risk factors for the development of cardiovascular disease (CVD) and type 2 diabetes. Different diagnostic criteria were proposed, but a consensus was reached in 2009 based on values of waist circumference, blood pressure, fasting glycemia, triglycerides, and high-density lipoprotein (HDL)-cholesterol levels. The main underlying etiologic factor is insulin resistance. The quality and quantity of individual macronutrients have an influence on the development and resolution of this syndrome. However, the main treatment goal is weight loss and a decrease in insulin resistance. A controlled energy dietary recommendation, together with moderate levels of physical activity, may positively change the parameters of MetS. However, there is no single dietary or exercise prescription that works for all patients. Dietary patterns such as Mediterranean-style, dietary approaches to stop hypertension (DASH), low-carbohydrate, and low-fat diets can ameliorate insulin resistance and MetS. Long-term adherence to a healthy lifestyle is key in assuring that individuals significantly reduce the risk of CVD and diabetes mellitus.

Effects of palm oil consumption on biomarkers of glucose metabolism: A systematic review

Introduction

Vegetable oil is an important source of fatty acids, and as palm oil being the highest consumed vegetable oil in many countries, its high saturated fatty acid content has led many concerns on cardiometabolic health. Dietary fatty acids has also been linked to affect glucose metabolism and insulin sensitivity. This systematic review is aimed at critically evaluating the available evidence on the association of palm oil with the biomarkers of glucose metabolism as compared to other vegetable oils.

Methods

We systemically searched PubMed, CENTRAL and Scopus up to June 2018. We searched for published interventional studies on biomarkers of glucose metabolism (defined as fasting glucose, fasting insulin, HOMA, 2-hour post prandial glucose and HbA1C) that compared palm oil- or palm olein-rich diets with other edible vegetable oils (such as olive oil, canola oil and soybean oil). Two reviewers independently extracted data and assessed study risks of bias. Mean differences of outcomes were pooled for the meta-analysis.

Results

We identified 1921 potentially eligible articles with only eight included studies. Seven randomised cross-over trials and one parallel trial were included. Study population were among young to middle-aged, healthy, non-diabetic, and normal weight participants. Intervention duration ranged from three to seven weeks, and fat substitution ranged from 15% to 20% energy. There were insignificant differences in fasting glucose when compared to partially hydrogenated soybean oil [-0.15mmol/L (-0.46,0.16) P = 0.33, I² = 48%], soybean oil [0.05mmol/L (-0.09,0.18) P = 0.49, I² = 0%] and olive oil [0.04mmol/L (-0.09,0.17) P = 0.76, I² = 0%]. Insignificant effects were also seen on fasting insulin when compared to partially hydrogenated soybean oil [1.72pmol/L (-11.39,14.84) P = 0.80, I² = 12%] and olive oil diet [-0.14pmol/L (-4.87,4.59) P = 0.95, I² = 0%].

Conclusion

Current evidence on the effects of palm oil consumption on biomarkers of glucose metabolism is poor and limited to only healthy participants. We conclude that little or no additional benefit will be obtained by replacing palm oil with other oils rich in mono or polyunsaturated fatty acids for changes in glucose metabolism.