The effects of onion consumption on treatment of metabolic, histologic, and inflammatory features of nonalcoholic fatty liver disease

Onion supplementation and health metabolic parameters: A systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Functional foods, such as onions, have been the center of many recent investigations. In this systematic-review and meta-analysis, we aimed to gather up the existing information with regard to the impact of onion supplementation on anthropometric measurements/indices, lipid profile, indices of glycemic control and hepatic health, systolic and diastolic blood pressures (SBP and DBP), and adiponectin and leptin.

METHODS

All major online datasets (PubMed, Web of Science, Cochrane, and Scopus) were thoroughly searched from inception up to October 2022. Relevant randomized controlled trials (RCTs) were obtained using the eligibility criteria. Weighted mean differences (WMDs) were calculated and reported. Statistical significance was set as p-values <0.05.

RESULTS

Among all the retrieved data, 14 RCTs were eligible to be included. The results of the crude analysis showed that onion supplementation significantly improved body fat percentage (BFP), low-density lipoprotein-cholesterol (LDL-c), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-c), systolic blood pressure, adiponectin, and aspartate aminotransferase (AST). Subgroup analysis revealed that interventions lasting more than 12 weeks can significantly alter weight, waist circumference (WC), body mass index (BMI), BFP, LDL-c, TC, SBP, and DBP. Moreover, the intake of dosages of >300 mg/day of onion supplementation could significantly improve weight, WC, BMI, BFP, LDL-c, HDL-C, TC, AST, ALT, SBP and DBP.

CONCLUSION

It seems that the intake of onion supplementation can improve health metabolic parameters. We observed that with either longer follow-up periods or higher dosages of onion supplementation, improvements in cardio-metabolic parameters could be expected.

Antiobesity effects of onion (Allium cepa) in subjects with obesity: Systematic review and meta-analysis

Onions are rich in bioactive compounds and have been found to prevent various chronic diseases, including obesity. We performed a systematic review and meta-analysis to investigate the antiobesity effect of onions. Studies were identified in PubMed/MEDLINE, Embase, Web of Science, and CENTRAL focusing on clinical trials evaluating the antiobesity effects of onion in obese subjects. The risk of bias in the studies was evaluated using Cochrane's Risk of Bias tool. The effect of onions was analyzed using data from the selected studies, and the results were indicated by weighted mean difference with 95% CI. The I 2 static test was used to examine heterogeneity between the studies. A total of 38 studies were reviewed, of which five clinical trials meeting the criteria were selected. As investigational products, onion peels were used in four studies and onions were used in one study. Following systematic review, it was determined that the risk of bias was generally low, and body weight, BMI, waist circumference, and triglyceride levels were significantly reduced in the onion groups compared to the placebo. In conclusion, onion intake had an antiobesity effect by reducing body weight and body fat, and this effect was particularly pronounced with onion peel.

Protective role of Siberian onions against toxin-induced liver dysfunction: an insight into health-promoting effects

Siberian onions (SOs) are delicious wild vegetables. Their taste is most unique, not only like scallions but also like leeks or garlic. They also have a traditional medicinal value for anti-inflammation, anti-oxidation, and anti-pyretic analgesia, particularly facilitating hepatoprotective effects. The current study investigates the potential mechanism of SOs against toxin-induced liver dysfunction. BALB/c mice were administrated with SO or silymarin by oral gavage for one week, followed by injecting carbon tetrachloride (CCl₄) to induce hepatic fibrosis. The effect of SO against hepatic fibrosis was evaluated by examining the liver tissue for serum transaminase, oxidative stress, extracellular matrix, histological alterations, cytokine levels, and apoptosis. In vitro, HSC-T6 cells were cultured with the supernatant from Raw 264.7 cells stimulated with lipopolysaccharides, followed by SO extracts or Niclosamide (Signal Transducer and Activator of Transcription 3 (STAT3) inhibitor) at indicated time periods and doses. SO decreased serum transaminase levels and oxidative stress, and regulated the balance of ECM in CCl₄-induced mice, including α-SMA, collagen-I and TIMP-1. SO reduced the release of inflammatory factors and regulated apoptosis-associated proteins, which is related to the inhibition of STAT3 phosphorylation. Moreover, SO reduced the positive expressions of α-SMA and NLRP3 by inhibiting STAT3 phosphorylation in activated HSCs. SO could show health-promoting effects for liver dysfunction by alleviating hepatic fibrogenesis, apoptosis and inflammation in the development of hepatic fibrosis potential depending on the STAT3 signaling pathway.

Allium cepa: A Treasure of Bioactive Phytochemicals with Prospective Health Benefits

As Allium cepa is one of the most important condiment plants grown and consumed all over the world, various therapeutic and pharmacological effects of A. cepa were reviewed. Onion (Allium cepa) is a high dietary fiber-rich perennial herb that is placed under the family Amaryllidaceae. It contains high concentration of folic acid, vitamin B6, magnesium, calcium, potassium, and phosphorus as well as vitamins and minerals. It is widely used as an antimicrobial agent, but it showed anticancer, antidiabetic, antioxidant, antiplatelet, antihypertensive, and antidepressant effects and neuroprotective, anti-inflammatory, and antiparasitic effects and so on. It is said to have beneficial effects on the digestive, circulatory, and respiratory systems, as well as on the immune system. This review article was devoted to discussing many health benefits and traditional uses of onions in pharmacological perspectives, as well as the safety/toxicological profile. If more detailed research on this perennial herb is conducted, it will open the door to an infinite number of possibilities.

Red and Processed Meat Intake in Relation to Non-Alcoholic Fatty Liver Disease Risk: Results from a Case-Control Study

Data on the association between dietary red meat intake and non-alcoholic fatty liver disease (NAFLD) are limited. We designed this case-control study to determine the association between red and processed meat consumption and risk of NAFLD in Iranian adults. A total of 999 eligible subjects, including 196 NAFLD patients and 803 non-NAFLD controls were recruited from hepatology clinics in Tehran, Iran. A reliable and validated food frequency questionnaire was used to evaluate the red and processed meat intakes. The analyzes performed showed that in an age- and gender-adjusted model, patients with the highest quartile of red meat intake had an approximately three-fold higher risk of NAFLD than those with the lowest quartile of intake (odds ratio [OR], 3.42; 95% confidence interval [CI], 2.16–5.43; p value < 0.001). Moreover, patients in the highest quartile of processed meat intake had a 3.28 times higher risk of NAFLD, compared to the lowest quartile(OR, 3.28; 95% CI, 1.97–5.46; p value < 0.001).Both these associations remained significant by implementing additional adjustments for body mass index, energy intake, dietary factors, diabetes, smoking, and physical activity (OR, 3.65; 95% CI, 1.85–7.18; p value < 0.001 and OR, 3.25; 95% CI, 1.57–6.73; p value = 0.002, respectively).Our findings indicate that both red and processed meat intakes are related to the increased odds of NAFLD; however, prospective studies are needed to confirm these results.

Plant-Based Foods and Their Bioactive Compounds on Fatty Liver Disease: Effects, Mechanisms, and Clinical Application

Fatty liver disease (FLD), including nonalcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (AFLD), is a serious chronic metabolic disease that affects a wide range of people. Lipid accumulation accompanied by oxidative stress and inflammation in the liver is the most important pathogenesis of FLD. The plant-based, high-fiber, and low-fat diet has been recommended to manage FLD for a long time. This review discusses the current state of the art into the effects, mechanisms, and clinical application of plant-based foods in NAFLD and AFLD, with highlighting related molecular mechanisms. Epidemiological evidence revealed that the consumption of several plant-based foods was beneficial to alleviating FLD. Further experimental studies found out that fruits, spices, teas, coffee, and other plants, as well as their bioactive compounds, such as resveratrol, anthocyanin, curcumin, and tea polyphenols, could alleviate FLD by ameliorating hepatic steatosis, oxidative stress, inflammation, gut dysbiosis, and apoptosis, as well as regulating autophagy and ethanol metabolism. More importantly, clinical trials confirmed the beneficial effects of plant-based foods on patients with fatty liver. However, several issues need to be further studied especially the safety and effective doses of plant-based foods and their bioactive compounds. Overall, certain plant-based foods are promising natural sources of bioactive compounds to prevent and alleviate fatty liver disease.

Associations between dietary total antioxidant capacity and odds of non-alcoholic fatty liver disease (NAFLD) in adults: a case-control study

The relationships between the total antioxidant capacity (TAC) of the diet and the risk of non-alcoholic fatty liver disease (NAFLD) have not previously been assessed. The aim of this study was to assess relationships between DTAC and odds of NAFLD in a case–control study. This case–control study was carried out in 158 patients with NAFLD and 357 healthy individuals aged 18–55 years. Dietary data were collected using validated 168-item quantitative food frequency questionnaires. Triacylglycerols (TAGs), total cholesterol (TC), high-density lipoprotein (HDL-C), low-density lipoprotein (LDL-C) and fasting blood glucose (FBS) concentrations were assessed using enzymatic methods and commercial kits. The DTAC was calculated based on the oxygen radical absorbance capacity of each food reported by the U.S. Department of Agriculture. The mean ± sd (standard deviation) for age and body mass index (BMI) of the study participants were 43⋅9 years ±5⋅9 and had 30⋅5 kg/m² ±2⋅6. The NAFLD patients included higher BMI and female proportion, compared with the control group. The NAFLD patients included higher smoking rates, biochemical parameters (TG, TC, LDL-C and FBS) and DTAC scores, compared with control groups (P-value < 0⋅05). However, patients with NAFLD had lower HDL levels and physical activities, compared with the control group. The highest tertile of DTAC showed lower odds of NAFLD, compared with the lowest tertile. This association was significant after adjustment for potential confounders (OR, 0⋅19; 95 % CI, 0⋅9–0⋅34; P for trend 0⋅001). Findings suggest that the promotion of naturally increased antioxidant capacities may help prevent odds of NAFLD.

The efficacy of flaxseed and hesperidin on non-alcoholic fatty liver disease: an open-labeled randomized controlled trial

BACKGROUND/OBJECTIVES

Non-alcoholic fatty liver disease (NAFLD) is growing in prevalence globally and no definitive evidence for any approved pharmacological approaches for patients with NAFLD has been found yet. This study was aimed to assess the clinical effects of flaxseed and hesperidin in patients with NAFLD.

SUBJECTS/METHODS

In this randomized, controlled, clinical trial, one hundred eligible patients with NAFLD were enrolled and randomly assigned to four dietary intervention groups including lifestyle modification program (control), lifestyle modification program with 30 g whole flaxseed powder, lifestyle modification program with 1 g hesperidin supplementation, and lifestyle modification program with combination of 30 g flaxseed and 1 g hesperidin (flax-hes) for 12 weeks. The changes in anthropometric parameters, metabolic profiles of glucose and lipids, inflammatory biomarkers and hepatic steatosis and fibrosis were evaluated.

RESULTS

After the 12-week dietary interventions, significant reductions in body mass index, glucose hemostasis parameters and hepatic steatosis were observed in all groups. Repeated measures analysis of variance revealed a significant effect for time relative to almost all paraclinical parameters. Post hoc analysis with Bonferroni correction revealed that the three intervention groups experienced significant decreases in plasma levels of alanine aminotransferase, indices of insulin resistance and insulin sensitivity, fasting glucose and fatty liver index compared to control (p < 0.008).

CONCLUSIONS

In conclusion, our study confirmed that hesperidin and flaxseed supplementation improved glucose and lipid metabolism, while reduced inflammation and hepatic steatosis (controlled attenuation parameter) in NAFLD patients. The synergistic effects of their combination were observed on plasma glucose concentration and HOMA-IR.

Curcumin and inflammation in non-alcoholic fatty liver disease: a randomized, placebo controlled clinical trial

Background

The aim of the present study was to evaluate the effects of curcumin supplementation on inflammatory indices, and hepatic features in patients with non-alcoholic fatty liver disease (NAFLD).

Methods

Fifty patients with NAFLD were randomized to receive lifestyle modification advice plus either 1500 mg curcumin or the same amount of placebo for 12 weeks.

Results

Curcumin supplementation was associated with significant decrease in hepatic fibrosis (p < 0.001), and nuclear factor-kappa B activity (p < 0.05) as compared with the baseline. Hepatic steatosis and serum level of liver enzymes, and tumor necrosis-α (TNF-α) significantly reduced in both groups (p < 0.05). None of the changes were significantly different between two groups.

Conclusion

Our results indicated that curcumin supplementation plus lifestyle modification is not superior to lifestyle modification alone in amelioration of inflammation.

Trial registration

IRCT20100524004010N24, this trial was retrospectively registered on May 14, 2018.

The effects of black seed supplementation on cardiovascular risk factors in patients with nonalcoholic fatty liver disease: A randomized, double-blind, placebo-controlled clinical trial

Nonalcoholic fatty liver disease (NAFLD) is highly related to cardiovascular disorders risk factors. This study aimed to evaluate the effects of black seed (Nigella sativa) supplementation on cardiovascular disorders risk factors in patients with NAFLD. This randomized, double-blind, placebo-controlled clinical trial was conducted on 50 patients with NAFLD. Participants were assigned to receive a lifestyle modification plus 2 g/day of either N. sativa or placebo for 12 weeks. Compared with the placebo, N. sativa supplementation led to significant reductions in serum glucose (-7.95 vs. -1.22; p = .041), serum insulin (-3.87 vs. -1.07; p = .027), homeostatic model of assessment for insulin resistance (-1.02 vs. -0.28; p = .021), and a significant increase in quantitative insulin sensitivity check index (0.03 vs. 0.006; p = .002). All of these changes were remained significant after adjusting for known confounding variables; however, there was no significant difference in lipid profile changes between the two groups (p = .05). N. sativa supplementation significantly decreased hepatic steatosis percentage compared with the placebo after adjustment for confounding variables (p = .005). In conclusion, our results indicate that daily intake of 2-g N. sativa plus lifestyle modification is superior to lifestyle modification alone in amelioration of insulin resistance and hepatic steatosis in patients with NAFLD.

Inflammatory markers response to citrulline supplementation in patients with non-alcoholic fatty liver disease: a randomized, double blind, placebo-controlled, clinical trial

Objectives

The aim of this study was to investigate the effects of citrulline (Cit) supplementation on inflammatory markers and liver histopathology in patients with non-alcoholic fatty liver disease (NAFLD). In this clinical trial, fifty NAFLD patients were assigned to receive 2 g/day Cit or placebo for 3 months.

Results

At the end of study, serum high sensitive C-reactive protein (hs-CRP) and activity of nuclear factor kappa B (NF-κB) were reduced in Cit group significantly more than placebo group (P-value = 0.02 and < 0.01 respectively). Serum concentrations of tumor necrosis factor-α (TNF-α) was reduced in Cit group significantly more than placebo after adjusting for levels of baseline (P-value < 0.001). Moreover, Cit supplementation decreased serum alanine aminotransferase (ALT) and hepatic steatosis significantly (P = 0.04). Anthropometric measurements and hepatic enzymes did not change significantly in any group (P ≥ 0.05). In conclusion, our results showed that 12 weeks supplementation with 2 g/day Cit improved inflammatory markers in patients with NAFLD. Further studies with longer period of supplementation and different dosages of Cit are needed to be able to conclude.

Trial registration IRCT201703194010N18 on 2017-10-13

Legume intake and risk of nonalcoholic fatty liver disease

BACKGROUND

It is known that diet plays a pivotal role in the pathogenesis and management of nonalcoholic fatty liver disease (NAFLD); however, the knowledge on the role of different food groups such as legumes is not enough.

METHODS

We designed this study to assess the relationship between legume intake and risk of NAFLD in framework of a case-control study among Tehrani adults. One hundred and ninety-six newly diagnosed patients with NAFLD and 803 controls were studied, and their dietary intake was assessed using a valid and reliable food frequency questionnaire. Conditional logistic regression was used to determine the odds ratio (OR) of NAFLD per increase of one serving/week dietary legumes, lentil, and beans adjusting for potential confounders.

RESULTS

In energy-adjusted model, greater intake of legumes, lentils, and beans was associated with a lower risk of NAFLD. These risk associations remained significant after adjusting for all known risk factors of NAFLD. OR of NAFLD in adjusted models for higher dietary intake of legumes, lentils, and beans were 0.73 (0.64-0.84), 0.61 (0.46-0.78), and 0.35 (0.17-0.74), respectively.

CONCLUSION

Our findings suggest that higher intake of total legumes (beans, lentils, and peas) was associated with lower risk of NAFLD.

Egg consumption and risk of non-alcoholic fatty liver disease

AIM

To evaluate the association between egg consumption and risk of non-alcoholic fatty liver disease (NAFLD) development.

METHODS

This case-control study was conducted on individuals who were referred to two hepatology clinics in Tehran, Iran in 2015. The study included 169 patients with NAFLD and 782 controls. Egg consumption was estimated using a validated food frequency questionnaire. The participants were categorized according to the frequency of their egg consumption during the previous year: Less than two eggs per week, two to three eggs per week, and four or more eggs per week.

RESULTS

In the crude model, participants who consumed 2 to 3 eggs per week, were 3.56 times more likely to have NAFLD in comparison to those who consumed less than 2 eggs per week (OR: 3.56; 95%CI: 2.35-5.31). Adjustment for known risk factors of NAFLD strengthened this significant association so that individuals have consumed two to three eggs per week had 3.71 times higher risk of NAFLD than those who have eaten less than two eggs per week (OR: 3.71; 95%CI: 1.91, 7.75).

CONCLUSION

Our data indicate that higher egg consumption in common amount of usage is associated with higher risk of NAFLD.

Therapeutic Role of Functional Components in Alliums for Preventive Chronic Disease in Human Being

Objectives. Functional components in alliums have long been maintained to play a key role in modifying the major risk factors for chronic disease. To obtain a better understanding of alliums for chronic disease prevention, we conducted a systematic review for risk factors and prevention strategies for chronic disease of functional components in alliums, based on a comprehensive English literature search that was conducted using various electronic search databases, especially the PubMed, ISI Web of Science, and CNKI for the period 2007-2016. Allium genus especially garlic, onion, and Chinese chive is rich in organosulfur compounds, quercetin, flavonoids, saponins, and others, which have anticancer, preventive cardiovascular and heart diseases, anti-inflammation, antiobesity, antidiabetes, antioxidants, antimicrobial activity, neuroprotective and immunological effects, and so on. These results support Allium genus; garlic and onion especially may be the promising dietotherapeutic vegetables and organopolysulfides as well as quercetin mechanism in the treatment of chronic diseases. This review may be used as scientific basis for the development of functional food, nutraceuticals, and alternative drugs to improve the chronic diseases.

Metabolomic Fingerprinting in the Comprehensive Study of Liver Changes Associated with Onion Supplementation in Hypercholesterolemic Wistar Rats

The consumption of functional ingredients has been suggested to be a complementary tool for the prevention and management of liver disease. In this light, processed onion can be considered as a source of multiple bioactive compounds with hepatoprotective properties. The liver fingerprint of male Wistar rats (n = 24) fed with three experimental diets (control (C), high-cholesterol (HC), and high-cholesterol enriched with onion (HCO) diets) was obtained through a non-targeted, multiplatform metabolomics approach to produce broad metabolite coverage. LC-MS, CE-MS and GC-MS results were subjected to univariate and multivariate analyses, providing a list of significant metabolites. All data were merged in order to figure out the most relevant metabolites that were modified by the onion ingredient. Several relevant metabolic changes and related metabolic pathways were found to be impacted by both HC and HCO diet. The model highlighted several metabolites (such as hydroxybutyryl carnitine and palmitoyl carnitine) modified by the HCO diet. These findings could suggest potential impairments in the energy−lipid metabolism, perturbations in the tricarboxylic acid cycle (TCA) cycle and β-oxidation modulated by the onion supplementation in the core of hepatic dysfunction. Metabolomics shows to be a valuable tool to evaluate the effects of complementary dietetic approaches directed to hepatic damage amelioration or non-alcoholic fatty liver disease (NAFLD) prevention.