Effect of Omega-3 and vitamin E co-supplementation on serum lipids concentrations in overweight patients with metabolic disorders: A systematic review and meta-analysis of randomized controlled trials

Potential Role of Natural Antioxidants in Countering Reperfusion Injury in Acute Myocardial Infarction and Ischemic Stroke

Stroke and acute myocardial infarction are leading causes of mortality worldwide. The latter accounts for approximately 9 million deaths annually. In turn, ischemic stroke is a significant contributor to adult physical disability globally. While reperfusion is crucial for tissue recovery, it can paradoxically exacerbate damage through oxidative stress (OS), inflammation, and cell death. Therefore, it is imperative to explore diverse approaches aimed at minimizing ischemia/reperfusion injury to enhance clinical outcomes. OS primarily arises from an excessive generation of reactive oxygen species (ROS) and/or decreased endogenous antioxidant potential. Natural antioxidant compounds can counteract the injury mechanisms linked to ROS. While promising preclinical results, based on monotherapies, account for protective effects against tissue injury by ROS, translating these models into human applications has yielded controversial evidence. However, since the wide spectrum of antioxidants having diverse chemical characteristics offers varied biological actions on cell signaling pathways, multitherapy has emerged as a valuable therapeutic resource. Moreover, the combination of antioxidants in multitherapy holds significant potential for synergistic effects. This study was designed with the aim of providing an updated overview of natural antioxidants suitable for preventing myocardial and cerebral ischemia/reperfusion injuries.

The effects of vitamin C supplementation on glycemic control in patients with type 2 diabetes: A systematic review and meta-analysis

BACKGROUND AND AIM

It has been suggested that taking vitamin C supplements may improve glycemic control in patients with type 2 diabetes mellitus (T2DM). However, there has not been a thorough evaluation of the actual impact or certainty of the findings. This systematic review and meta-analysis was conducted to determine the effect of vitamin C supplementation on glycemic profile in T2DM patients.

METHODS

A systematic search was performed across online databases including Scopus, Web of Science, and PubMed/Medline to identify relevant randomized controlled trials (RCTs) published until July 2022. A random-effects model was applied for the meta-analysis.

RESULTS

The present meta-analysis included a total of 22 RCTs with 1447 patients diagnosed with T2DM.A pooled analysis revealed a significant decrease in levels of serum hemoglobin A1c (HbA1c), fasting insulin, and fasting blood glucose (FBG) in vitamin C-treated T2DM patients compared with their untreated counterparts. The dose-response evaluation displayed a substantial linear association between the intervention duration and changes in serum HbA1c levels. However, the analysis did not demonstrate any significant effect of vitamin C on serum values of homeostasis model assessment of insulin resistance(HOMA-IR) in diabetic patients. Subgroup analyses indicated that high-dose vitamin C administration (≥1000 mg/d) considerably decreased serum HOMA-IR levels.

CONCLUSION

These findings suggest that long-term (≥12 weeks) and high-dose vitamin C supplementation (≥1000 mg/d) may ameliorate glycemic profile in T2DM patients. However, additional high-quality RCTs are necessary to validate these results.

The impact of Emblica Officinalis (Amla) on lipid profile, glucose, and C-reactive protein: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

Emblica Officinalis (Amla) is a plant often utilized in traditional medicine due to its purported anti-inflammatory, antioxidant, hypoglycemic, and hypolipidemic properties. However, current evidence regarding its potential for preventing and treating metabolic abnormalities associated with chronic diseases remains unclear.

METHODS

This systematic review and meta-analysis aimed to examine the effects of Amla supplementation on lipid profile, glucose, and C-reactive protein (CRP) concentrations in adults. We completed a systematic search (current as of December 2022) of all available randomized controlled trials (RCTs) in the database including ISI Web of Science, PubMed, Scopus, and Embase. Any effect's mean difference (MD) was calculated using a random-effects model. Weighted mean difference (WMD) and 95% confidence intervals (CIs) were calculated also calculated using a random-effects model.

RESULTS

Five RTCs were included in the meta-analysis. Following Amla supplementation, pooled results showed a significant reduction in CRP (p = 0.002), fasting blood glucose (FBG) (p < 0.001), low-density lipoprotein cholesterol (LDL-c) (p < 0.001), total cholesterol (TC) (p < 0.001), and serum triglyceride (TG) (p < 0.001) concentrations as well as an increase in high-density lipoprotein cholesterol (HDL-c) (p < 0.001). The baseline concentration of biochemical indicators was used for subgroup analysis.

CONCLUSION

Amla supplementation shows promise for improving metabolic parameters in adults. In general, the populations included in the analysis were generally 40-58 years with an average BMI of 25.5 and a length of intervention ranging from 3 to 12 weeks. Thus additional investigations are warranted to confirm and expand the findings presented herein.

A meta-analysis of effects of vitamin E supplementation alone and in combination with omega-3 or magnesium on polycystic ovary syndrome

Vitamin E supplementation might have favorable effects on risk factors of polycystic ovary syndrome (PCOS). This systematic review and meta-analysis aimed to summarize the effects of vitamin E supplementation or vitamin E in combination with omega-3 or magnesium on PCOS. PubMed, Scopus, ISI Web of Science, Cochrane, Embase electronic databases, and Google scholar were searched for all available articles up to September 2022. Randomized controlled trials (RCTs) that examined the effect of vitamin E supplementation or vitamin E in combination with omega-3 or magnesium on lipid and glycemic profiles, anthropometric measurements, biomarkers of inflammation and oxidative stress, hormonal profile, and hirsutism score in patients with PCOS were included. Ten RCTs (with 504 participants) fulfilled the eligible criteria. Vitamin E supplementation or vitamin E in combination with omega-3 or magnesium in comparison to placebo could significantly reduce serum levels of TG (weighted mean difference: - 18.27 mg/dL, 95% CI - 34.68 to - 1.87), VLDL (- 5.88 mg/dL, 95% CI - 8.08 to - 3.68), LDL-c (- 12.84 mg/dL, 95% CI - 22.15 to - 3.52), TC (- 16.30 mg/dL, 95% CI - 29.74 to - 2.86), TC/HDL-c ratio (- 0.52, 95% CI - 0.87 to - 0.18), hs-CRP (- 0.60 ng/mL, 95% CI - 0.77 to - 0.44), hirsutism score (- 0.33, 95% CI - 0.65 to - 0.02) and significantly increase nitric oxide levels (2.79 µmol/L, 95% CI 0.79-4.79). No significant effect was found on HDL-c, glycemic indices, hormonal profile, anthropometric measurements, and other biomarkers of inflammation or oxidative stress. This meta-analysis highlights the potential anti-hyperlipidemic, anti-oxidant, and anti-inflammatory properties of vitamin E supplementation alone or in combination with omega-3 or magnesium on PCOS patients.

Dependence of Seasonal Dynamics in Healthy People's Circulating Lipids and Carbohydrates on Regional Climate: Meta-Analysis

We analyzed the seasonal dynamics of lipid profile, glucose, and insulin in healthy subjects from 29 studies conducted in 23 regions, located in different climate zones ranging from subarctic to tropical. Our meta-analysis showed that people have higher the level of TC (total cholesterol), LDL (low-density lipoprotein), HDL (high-density lipoprotein), FBG (fasting blood glucose) in winter than in summer regardless of gender. Regional climate had a significant impact on the seasonal dynamics of lipid profile and glucose. TC, HDL, FBG seasonal fluctuations were more prominent in a climate that had a marked increase in average monthly atmospheric pressure in winter compared with summer as opposed to a climate where atmospheric pressure did not vary significantly in winter and summer. In a climate with humid winters, TC seasonal changes were significantly greater than in the regions with humid summers, most likely due to LDL seasonal changes, since HDL seasonal dynamics with peaks in winter were more prominent in the regions with humid summers. The level of triglycerides had prominent seasonal dynamics with peak values in winter only in the regions with a large difference in winter and summer air temperatures. The results of our current and prior meta-analysis allow for the conclusion that the seasonal dynamics of circulating lipids and glucose are frequently linked to the seasonal dynamics of thyroid-stimulating hormone and hematocrit. Dependence of the seasonal changes in the biochemical parameters on annual fluctuations in air temperature, atmospheric pressure and relative humidity is more obvious than on photoperiod changes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12291-022-01064-6.

Effect of vitamin E supplementation on cardiometabolic risk factors, inflammatory and oxidative markers and hormonal functions in PCOS (polycystic ovary syndrome): a systematic review and meta-analysis

Polycystic ovary syndrome (PCOS) is a common endocrinopathy among reproductive-age women. Various therapeutical approaches are currently used to manage or control symptoms associated with PCOS. This systematic review intended to assess the effects of Vit E supplementation on cardiometabolic risk factors, inflammatory and oxidative markers, and hormonal functions in PCOS women based on the clinical trial's results. The databases including PubMed, Scopus, Cochrane, Web of Science, and Embase were used to find all relevant studies. The authors reviewed all relevant clinical trials via systematic evaluation of abstracts and titles. Searches were conducted on August 1, 2020. After the initial search and reading of the article's title and abstract, 353 articles were reviewed; finally, 12 articles met the inclusion criteria. Vitamin E supplementation improves lipid profile, decreases insulin and HOMA-IR levels. Furthermore, while Vitamin E supplementation decreases LH and testosterone concentrations, it increases FSH and progestrone concentrations. The following meta-analysis showed that vitamin E supplementation made statistically significant improvements in triglyceride (TG) and low-density lipoproteins (LDL) levels, meanwhile, pooled mean difference for waist circumference (WC) and HOMA-IR were also statistically significant. Supplementary regimens containing vitamin E can positively affect metabolic and hormonal parameters in women with PCOS.

Reactive Oxygen Species-Mediated Diabetic Heart Disease: Mechanisms and Therapies

Significance: Diabetic heart disease (DHD) is the primary cause of mortality in people with diabetes. A significant contributor to the development of DHD is the disruption of redox balance due to reactive oxygen species (ROS) overproduction resulting from sustained high glucose levels. Therapies specifically focusing on the suppression of ROS will hugely benefit patients with DHD. Recent Advances: In addition to the gold standard pharmacological therapies, the recent development of gene therapy provides an exciting avenue for developing new therapeutics to treat ROS-mediated DHD. In particular, microRNAs (miRNAs) are gaining interest due to their crucial role in several physiological and pathological processes, including DHD. Critical Issues: miRNAs have many targets and differential function depending on the environment. Therefore, a proper understanding of the function of miRNAs in specific cell types and cell states is required for the successful application of this technology. In the present review, we first provide an overview of the role of ROS in contributing to DHD and the currently available treatments. We then discuss the newer gene therapies with a specific focus on the role of miRNAs as the causative factors and therapeutic targets to combat ROS-mediated DHD. Future Directions: The future of miRNA therapeutics in tackling ROS-mediated DHD is dependent on a complete understanding of how miRNAs behave in different cells and environments. Future research should also aim to develop conditional miRNA therapeutic platforms capable of switching on and off in response to disruptions in the redox state. Antioxid. Redox Signal. 36, 608-630.

Targeting dyslipidemia with antioxidative vitamins C, D, and E; a systematic review of meta-analysis studies: Dyslipidemia and antioxidative vitamins

BACKGROUND

There is controversial evidence for the beneficial effects of antioxidative vitamins (vits) on dyslipidemia. In this regard, we aimed to systematically review all meta-analyses of trials on this topic.

METHODS

We comprehensively searched PubMed, Web of Science, Scopus, and Cochrane Library databases until January 2021 to explore the published English meta-analyses of trials conducted to assess the effects of single or combined vits C, D and E consumption on lipid profile. The meta-analyses of observational, in vivo/in vitro, or case-report studies were excluded. Search results were reported based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) flowchart.

RESULTS

Overall, 25 meta-analyses including 32,177 individuals with different underlying disorders met our inclusion criteria. Numerous studies had assessed supplementation with Vit-D or its combination with other agents on lipid profile. Consumption of 400 IU/day (d) to 50,000 IU/week (w) Vit-D for at least eight weeks improved the levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) in type 2 diabetes mellitus or polycystic ovary syndrome (PCOS) patients. This treatment reduced the levels of TC and TG in patients with chronic kidney disease. A significant increase in high-density lipoprotein cholesterol (HDL-C) levels was only observed in coronary artery disease patients. Sole intake of 500-2000 mg/d Vit-C for at least 3 weeks improved LDL-C and TG values in hypercholesterolemic patients. Nevertheless, sole intake of Vit-E had controversial effects on lipid profile. The combination of 400-1800 IU/d omega-3 free fatty acid (FFA) and 400 IU/d Vit-E significantly reduced the levels of LDL-C and TG in overweight individuals, without any significant effect on other components. A significant improvement of TG values was observed after consumption of 1000-2000 mg/d omega-3 FFA plus 400 IU/d Vit-E along with 50,000 IU/each 2w Vit-D for at least 6 weeks in diabetic patients.

CONCLUSION

The beneficial effects of antioxidative vitamins (C, D, E) or their combination with other agents on lipid profile varied based on their dosage, intake duration, and the health status of the individuals.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40200-021-00919-8.

Effects of Fish Oil Supplementation on Cardiometabolic Risk Factors in Overweight or Obese Children and Adolescents: A Meta-Analysis of Randomized Controlled Trials

Background: Influences of fish oil supplementation on body weight and other cardiometabolic factors in overweight or obese children and adolescents remain not fully understood. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the role of fish oil for these children. Methods: Relevant studies were obtained by search of PubMed, Embase, and Cochrane's Library databases. A random-effect model, which incorporates the potential heterogeneity of the included studies, was used to pool the results. Results: Twelve RCTs including 1,028 overweight or obese children and adolescents were included. Compared to control, fish oil supplementation significantly reduced body mass index [BMI, mean difference (MD): -0.96 kg/m2, 95% confidence interval (CI): -1.69 to -0.23, P = 0.01] but did not significantly reduce body weight or waist circumference (P = 0.68 and 0.76). Moreover, fish oil supplementation significantly reduced serum triglyceride (MD: -0.24 mmol/L, 95% CI: -0.40 to -0.08, P = 0.004) but did not significantly affect serum total cholesterol and high-density or low-density lipoprotein cholesterol (P = 0.83, 0.42, and 0.31, respectively). Additionally, fish oil supplementation significantly lowered systolic blood pressure (SBP, MD: -2.46 mmHg, 95% CI: -4.93 to -0.01, P = 0.04) but did not significantly change diastolic blood pressure (P = 0.22). Supplementation with fish oil did not significantly affect fasting plasma glucose (P = 0.33). Conclusions: In overweight or obese children and adolescents, supplementation with fish oil could reduce BMI, decrease serum triglyceride, and lower SBP, while serum cholesterol and fasting glucose may not be significantly affected.

Omega-3 fatty acids reduce cardiometabolic risk in first-episode schizophrenia patients treated with antipsychotics: Findings from the OFFER randomized controlled study

Metabolic syndrome (MetS) increases the risk of premature mortality observed in schizophrenia (SCZ). N-3 polyunsaturated fatty acid (PUFA) deficiency has been reported in different stages of schizophrenia. N-3 PUFA supplementation was found to be beneficial in both chronic SCZ and MetS. No intervention studies based on n-3 PUFA as add-on therapy to antipsychotics have examined the changes in MetS risk in first-episode schizophrenia.

AIM

This randomized placebo-controlled trial assesses the effect of a 26-week intervention composed of either 2.2 g/day of n-3 PUFA or olive oil placebo on the frequency of MetS and the changes in its constituents as a secondary outcome measure.

METHODS

Seventy-one adult inpatients diagnosed with first-episode schizophrenia were randomly assigned to study groups. The active intervention used a 3:2 mixture of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Metabolic syndrome components were monitored throughout the study.

RESULTS

A significant reduction in the frequency of MetS was observed in the EPA + DHA group (p = 0.0408); as well as some specific MetS components: e.g., a decrease in fasting blood glucose (p = 0.045). The beneficial effects of EPA + DHA were even more pronounced in patients treated mainly with olanzapine, e.g. significant reductions of total cholesterol (p = 0.037) and blood glucose levels (p = 0.034). Significant positive correlations were found between the general psychopathology subscale of PANSS (primary outcome) and triglyceride level changes.

CONCLUSION

N-3 PUFA supplementation in early SCZ may constitute a safe and affordable intervention that can reduce the risk of MetS and its lethal complications.

Omega-3 polyunsaturated fatty acids prevent obesity by improving tricarboxylic acid cycle homeostasis

The beneficial effects of omega-3 polyunsaturated fatty acids (n-3 PUFAs) on preventing obesity are well known; however, the underlying mechanism by which n-3 PUFAs influence tricarboxylic acid (TCA) cycle under obesity remains unclear. We randomly divided male C57BL/6 mice into 5 groups (n=10) and fed for 12 weeks as follows: mice fed a normal diet (Con, 10% kcal); mice fed a high-fat diet (HFD, lard, 60% kcal); and mice fed a high-fat diet (60% kcal) substituting half the lard with safflower oil (SO), safflower oil and fish oil (SF) and fish oil (FO), respectively. Then we treated HepG2 cells with palmitic acid and DHA for 24 h. We found that body weight in FO group was significantly lower than it in HFD and SO groups. N-3 PUFAs reduced the transcription and translation of TCA cycle enzymes, including IDH1, IDH2, SDHA, FH and MDH2, to enhance mitochondrial function in vivo and vitro. DHA significantly inhibited protein expression of the mTORC1 signaling pathway, increased p-AKT protein expression to alleviate insulin resistance and improved mitochondrial oxygen consumption rate and glycolysis ability in HepG2 cells. In addition, the expressions of IDH2 and SDHB were reduced by rapamycin. N-3 PUFAs could prevent obesity by improving TCA cycle homeostasis and mTORC1 signaling pathway may be upstream.

An Open Pilot Study of the Effect and Tolerability of Add-On Multivitamin Therapy in Patients with Intractable Focal Epilepsy

Observational studies have investigated the potential modulatory effect of neuronal excitability by vitamins in epilepsy. We aimed to investigate whether the addition of multivitamin therapy (B6/B9, D, E and Q) to regular antiepileptic drug therapy could ameliorate seizures in patients with refractory focal epilepsy. We conducted a prospective cohort open study to investigate the effect and tolerability of add-on multivitamin therapy (daily dose: B6 100 mg, B9 5 mg, D 1000 IU, E 400 IU and coenzyme Q10 100 mg) in patients with intractable focal epilepsy. All patients had effect and safety assessments at baseline and after one, three and six months of the supplementation. Thirty patients (11 men and 19 women) with a mean age of 42.37 ± 9.40 years were recruited and four patients discontinued. The seizure frequency significantly decreased after the six-month supplementation (9.04 ± 18.16/month and 2.06 ± 3.89/month, p = 0.045). At the final visit, 62.5% of the patients showed a ≥50% reduction in seizure frequency, and 12.5% were seizure-free. As to safety and tolerability, most patients did not experience significant adverse events, although three patients reported seizure worsening. In conclusion, this pilot study demonstrated the therapeutic potential and essentially good tolerability of add-on multivitamin therapy in patients with refractory focal epilepsy.

The Relationship between Serum Vitamin E Level and Risk Factors for Arteriosclerosis in Japanese Postmenopausal Women

Since vitamin E is one of the most potent antioxidant and anti-inflammatory agents, vitamin E can play a role against arteriosclerosis through various actions. Then, we have studied the relationship between serum vitamin E status and risk factors for arteriosclerosis in Japanese postmenopausal women. One hundred and seven subjects (70.0±7.7 y) were evaluated for vitamin E status by measuring serum α- and γ-tocopherol (αT and γT) levels. The number of arteriosclerosis risk factors was defined by the existence of high blood pressure, hyperglycemia, and dyslipidemia. Median serum αT and γT concentrations were 24.32 and 2.79 μmol/L, respectively. In none of the subjects, serum αT level was below the cutoff value (<12 μmol/L) for vitamin E deficiency which causes fragile erythrocyte and hemolysis. While no significant differences were found in serum levels of αT and γT between the groups categorized by the number of arteriosclerosis risks, serum levels of αT adjusted by serum total cholesterol (TC) and triglyceride (TG) decreased with an increasing number of arteriosclerotic risk factors (p=0.074). Serum αT level adjusted by serum TC and TG was also a negative significant predictor for the number of arteriosclerosis risk factors controlled by covariates associated with arteriosclerosis. The present study described that serum vitamin E level was positively associated with a lower number of arteriosclerotic risks, and its role for preventing noncommunicable diseases was suggested.

The benefits of omega-3 fatty acid nanocapsulation for the enrichment of food products: a review

ABSTRACT Polyunsaturated fatty acids oxidize easily due to their chemical structure, causing a reduction of their nutritional properties. Nanostructured systems may be an alternative to protect fatty acids against oxidation, improving solubility and stability. Consequently, nutritional value of food is maintained as well as the sensory characteristics (color, flavor, texture, and aroma) when fatty acids are added to food products. The present study is a narrative review to introduce the potential benefits of omega-3 unsaturated fatty acids nanoparticles incorporated in food products. The literature review includes publications in English and Portuguese issued between March 1985 and March 2019, in PubMed, ScienceDirect and Web of Science databases. Manual searches were conducted in the articles references lists of the articles included to identify other relevant studies. There were studies that evaluated the stability of fatty acids in food products such as bread, fruit juice, milk, yogurt, and meat. In this study, the most used nanostructured systems for the incorporation of fatty acids were the nanocapsules and the nanoliposomes. Currently, the nanostructured system demonstrates a potential to improve protection of polyunsaturated fatty acids against oxidization and thermal degradation. In this way, they maintain their functional properties and their bioavailability increases and therapeutic efficacy and sensory properties are improved. There are several methodologies being tested, which makes it difficult to identify the most efficient formulation to protect fatty acids. Nanostructured systems seem to be the best alternative to protect polyunsatured fatty acids from oxidization. The encapsulation efficiency, particle’s size and type are relevant factors to be considered to evaluate oxidization. In conclusion, the review showed that currently it is impossible to determine the most efficient methodology. Besides, nanoformulations should follow international guidelines to present more standardized and therefore more efficient particles.