Effect of ginger ( Zingiber officinale ) on blood glucose and lipid concentrations in diabetic and hyperlipidemic subjects: A meta-analysis of randomized controlled trials

Phytonutrients in the promotion of healthspan: a new perspective

Considering a growing, aging population, the need for interventions to improve the healthspan in aging are tantamount. Diet and nutrition are important determinants of the aging trajectory. Plant-based diets that provide bioactive phytonutrients may contribute to offsetting hallmarks of aging and reducing the risk of chronic disease. Researchers now advocate moving toward a positive model of aging which focuses on the preservation of functional abilities, rather than an emphasis on the absence of disease. This narrative review discusses the modulatory effect of nutrition on aging, with an emphasis on promising phytonutrients, and their potential to influence cellular, organ and functional parameters in aging. The literature is discussed against the backdrop of a recent conceptual framework which describes vitality, intrinsic capacity and expressed capacities in aging. This aims to better elucidate the role of phytonutrients on vitality and intrinsic capacity in aging adults. Such a review contributes to this new scientific perspective-namely-how nutrition might help to preserve functional abilities in aging, rather than purely offsetting the risk of chronic disease.

Potential Benefit of Spices for Glycemic Control

The prevalence of hyperglycemia is increasing worldwide in large part due to the escalating prevalence of obesity. It can occur along with other disorders and diseases, contributing to escalating health costs and accumulating disabilities. Besides dietary approaches and availability of antidiabetic medications, other complementary approaches and adjunct therapies using biologically active botanical phytochemicals have received growing attention for managing type 2 diabetes mellitus. Spices are one source of these bioactive plant constituents, and considerable preclinical studies have investigated their possible health benefits. There also are an increasing number of human clinical trials assessing the ability of spices and their individual plant constituents to improve glucose homeostasis in those with type 2 diabetes mellitus and other dysglycemic conditions. This narrative review provides a summary of the human studies evaluating the effects of select spices on glucose homeostasis and highlights areas for future research.

The Effect of Therapeutic Doses of Culinary Spices in Metabolic Syndrome: A Randomized Controlled Trial

Non-communicable diseases (NCDs) place a significant burden on global health and the healthcare systems which support it. Metabolic syndrome is a major risk factor for a large number of NCDs; however, treatments remain limited. Previous research has shown the protective benefits of edible dietary spices on key components of metabolic syndrome. Therefore we performed a 12-week double-blind, placebo-controlled, randomized, clinical trial to evaluate the effect of ginger (Zingiber officinale), cinnamon (Cinnamomum), and black seed (Nigella sativa) consumption on blood glucose, lipid profiles, and body composition in 120 participants with, or at risk of, metabolic syndrome. Each participant consumed 3 g/day of powder (spice or placebo). Data related to different parameters were collected from participants at the baseline, midpoint, and endpoint of the intervention. Over the 12-week interventions, there was an improvement in a number of biochemical indices of metabolic syndrome, including fasting blood glucose, HbA1c, LCL, and total cholesterol associated with supplementation with the spices when compared to a placebo. This study provides evidence to support the adjunct use of supplementation for those at risk of metabolic syndrome and its sequelae.

Can Polyherbal Medicine be used for the Treatment of Diabetes? - A Review of Historical Classics, Research Evidence and Current Prevention Programs

Diabetes mellitus (DM), a chronic medical condition, has attained a global pandemic status over the last few decades affecting millions of people. Despite a variety of synthetic drugs available in the market, the use of herbal medicines for managing diabetes is gaining importance because of being comparatively safer. This article reviews the result of a substantial literature search on polyherbal formulations (PHFs) developed and evaluated with potential for DM. The accumulated data in the literature allowed us to enlist 76PHFs consisting of different parts of 147 plant species belonging to 58 botanical families. The documented plant species are laden with bioactive components with anti-diabetic properties and thus draw attention. The most favoured ingredient for PHFs was leaves of Gymnema sylvestre and seeds of Trigonella foenum-graecum used in 27 and 22 formulations, respectively. Apart from herbs, shilajit (exudates from high mountain rocks) formed an important component of 9 PHFs, whereas calcined Mytilus margaritiferus and goat pancreas were used in Dolabi, the most commonly used tablet form of PHF in Indian markets. The healing properties of PHFs against diabetes have been examined in both pre-clinical studies and clinical trials. However, the mechanism(s) of action of PHFs are still unclear and considered the pitfalls inherent in understanding the benefits of PHFs. From the information available based on experimental systems, it could be concluded that plant-derived medicines will have a considerable role to play in the control of diabetes provided the challenges related to their bioavailability, bioefficacy, optimal dose, lack of characterization, ambiguous mechanism of action, and clinical efficiency are addressed.

Phenolics Extracted from Jasminum sambac Mitigates Diabetic Cardiomyopathy by Modulating Oxidative Stress, Apoptotic Mediators and the Nfr-2/HO-1 Pathway in Alloxan-Induced Diabetic Rats

Diabetes mellitus is a chronic metabolic disorder defined as hyperglycemia and pancreatic β-cell deterioration, leading to other complications such as cardiomyopathy. The current study assessed the therapeutic effects of phenolic acids extracted from Jasminum sambac phenols of leaves (JSP) against diabetes-induced cardiomyopathy in rats. The rats were divided into four groups, with each group consisting of 20 rats. The rats were given intraperitoneal injections of alloxan monohydrate (150 mg/kg) to induce diabetes. The diabetes-induced groups (III and IV) received treatment for six weeks that included 250 and 500 mg/kg of JSP extract, respectively. In the treated rats, the results demonstrated that JSP extract restored fasting glucose, serum glucose, and hyperlipidemia. Alloxan induced cardiomyopathy, promoted oxidative stress, and altered cardiac function biomarkers, including cardiac troponin I, proBNP, CK-MB, LDH, and IMA. The JSP extract-treated rats showed improved cardiac function indicators, apoptosis, and oxidative stress. In diabetic rats, the mRNA expression of caspase-3, BAX, and Bcl-2 was significantly higher, while Bcl-2, Nrf-2, and HO-,1 was significantly lower. In the treated groups, the expression levels of the BAX, Nrf-2, HO-1, Caspase-3, and Bcl-2 genes were dramatically returned to normal level. According to our findings, the JSP extract prevented cardiomyopathy and heart failure in the hyperglycemic rats by improving cardiac biomarkers and lowering the levels of hyperlipidemia, oxidative stress, apoptosis, hyperglycemia, and hyperlipidemia.

Effect of Zingiber officinale on Lipid Profile and Some Inflammatory Markers in Diabetic Hemodialysis Patients: A Randomized Double-Blind Placebo-Controlled Clinical Trial

Background

Diabetes, inflammation, and abnormal lipid levels are the main risk factors for mortality in end-stage renal disease (ESRD). The present study aimed to investigate the effects of ginger supplementation on inflammatory markers and lipid profile in diabetic patients with ESRD undergoing hemodialysis.

Methods

In this study, 44 patients were randomly assigned to either the ginger or the placebo group. The patients in the ginger group received 2000 mg/d ginger for eight weeks, while the control group received the placebo with the same protocol. The serum concentrations of triglyceride (TG), total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-c), high-density lipoprotein-cholesterol (HDL-c), albumin, and high-sensitivity C-reactive protein (hs-CRP) were measured after a 12- to 14-hours fast at the baseline and the end of the study, as along with the platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), and Glasgow prognostic score (GPS).

Results

Forty-one subjects were analyzed based on the intention-to-treat method of all included patients. Serum levels of TG (p=0.003), hs-CRP (p=0.022), and NLR (p=0.001) decreased significantly in the ginger group compared to the placebo group, while albumin concentration in serum was elevated (p=0.022). However, there were no significant differences in GPS, levels of TC, LDL-C, HDL-C, and PLR within and between the groups (p > 0.05).

Conclusion

Ginger administration reduced NLR, hs-CRP, and TG serum levels and increased serum albumin levels in included patients. Thus, ginger can be considered an effective complementary treatment for these patients. This trail is registered with IRCT20191109045382N3.

Renoprotective effects of the ginger (Zingiber officinale) on Diabetic kidney disease, current knowledge and future direction: a systematic review of animal studies

OBJECTIVE

Diabetic kidney disease affects approximately 40% of diabetic patients and is the leading cause of chronic kidney disease (CKD) worldwide. As a result, preventing renal complications in diabetic patients is critical. Ginger (Zingiber Officinale Rosco) is a popular spice and natral medicine. The present study was a systematic review focused on the existing evidence of the renoprotective effect of ginger extract on some features of diabetic kidney disease.

METHODS

The literature was searched in online databases such as PubMed, Scopus, EMBASE, ProQuest databases, and Google Scholar from inception to July 2022.

RESULTS

This review included 41 articles that met the eligibility criteria. Ginger supplementation was found to be associated with a significant decrease in blood glucose in 28 studies. Nine studies showed a significant reduction in malondialdehyde (MDA) after supplementation. Also, seventeen studies showed decreased serum levels of creatinine. Fifteen studies reported a decrease in total cholesterol (TC) and fourteen studies showed a lowered triglycerides (TG) concentrations. In twenty-six studies, ginger reduced renal injuries due to diabetes.

CONCLUSION

Ginger may improve blood sugar indices, lipid profile, some inflammatory markers, oxidative stress, and pathologic injuries in diabetic kidney disease. However, future well-designed clinical trials and meta-analyses are required for a solid consensus.

Antibacterial activity and mechanism of ginger extract against Ralstonia solanacearum

AIMS

The current study aimed to determine the chemical compositions of ginger extract (GE) and to assess the antibacterial activities of GE against the ginger bacterial wilt pathogen Ralstonia solanacearum and to screen their mechanisms of action.

METHODS AND RESULTS

A total of 393 compounds were identified by using ultra-performance liquid chromatography and tandem-mass spectrometry. The antibacterial test indicated that GE had strong antibacterial activity against R. solanacearum and that the bactericidal effect exhibited a dose-dependent manner. The minimum inhibitory concentration and minimum bactericidal concentration of R. solanacearum were 3.91 and 125 mg/ml, respectively. The cell membrane permeability and integrity of R. solanacearum were destroyed by GE, resulting in cell content leakage, such as electrolytes, nucleic acids, proteins, extracellular adenosine triphosphate and exopoly saccharides. In addition, the activity of cellular succinate dehydrogenase and alkaline phosphatase of R. solanacearum decreased gradually with an increase in the GE concentration. Scanning electron microscopy analysis revealed that GE treatment changed the morphology of the R. solanacearum cells. Further experiments demonstrated that GE delayed or slowed the occurrence of bacterial wilt on ginger.

CONCLUSIONS

GE has a significant antibacterial effect on R. solanacearum, and the antibacterial effect is concentration dependent. The GE treatments changed the morphology, destroyed membrane permeability and integrity, reduced key enzyme activity and inhibit the synthesis of the virulence factor EPS of R. solanacearum. GE significantly controlled the bacterial wilt of ginger during infection.

SIGNIFICANCE AND IMPACT OF THE STUDY

This research provides insight into the antimicrobial mechanism of GE against R. solanacearum, which will open a new application field for GE.

The efficacy of Zingiber officinale on dyslipidaemia, blood pressure, and inflammation as cardiovascular risk factors: A systematic review

BACKGROUND & AIMS

Hypertension, dyslipidaemia, and chronic inflammation contribute to the development of cardiovascular disease (CVD). Zingiber officinale has been suggested to reduce these CVD risk factors; however, the clinical evidence remains unclear. This systematic review aims to analyse the effect of Z. officinale as a sole intervention on these risk factors.

METHODS

In this PRISMA-based systematic review, we included randomised clinical trials from PubMed, Scopus and Cochrane Database of Systematic Reviews (July 2020) analysing triglycerides, low- and high-density lipoprotein (LDL, HDL), total cholesterol, C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), interleukin 1, 6, 10, systolic and/or diastolic blood pressure as outcomes. Quality of studies was evaluated by JADAD and the Cochrane risk-of-bias tools.

RESULTS

A total of 24 studies were included, mostly (79.2%) showing low risk of bias. These were based on obesity and cardio-metabolic derangements (33.3%), type 2 diabetes mellitus (37.5%), and miscellaneous conditions (29.2%). While total cholesterol and triglycerides levels mostly improved after Z. officinale, results were inconsistent for other blood lipids markers. Inflammatory markers (CRP, TNF-α) were more consistently reduced by Z. officinale, while only 3 studies reported a non-significant reduction of blood pressure.

CONCLUSIONS

Although there remains a paucity of studies, Z. officinale may be beneficial for improving dyslipidaemia and inflammation.

Zingiberaceae plants/curcumin consumption and multiple health outcomes: An umbrella review of systematic reviews and meta-analyses of randomized controlled trials in humans

This umbrella review is to recapitulate and grade the available evidence of associations between consumption of Zingiberaceae plants/curcumin (Cur) and multiple health-related outcomes. This study included 161 meta-analyses of randomized controlled trials in 76 articles with 67 unique health outcomes. Data on heterogeneity and publication bias are considered to assess the quality of evidence. Based on the different impact of Zingiberaceae plants/Cur on human health, the advantages outweigh the disadvantages. Zingiberaceae plants/Cur can mainly improve metabolic syndrome, non-alcoholic fatty liver disease, cardiovascular disease, and some chronic inflammatory diseases, likewise, obviously relief the pain of osteoarthritis and related diseases. Ginger supplements have been shown to improve vomiting during pregnancy and to relieve nausea and vomiting caused by chemotherapy and surgery. The surgery is any type of surgery, including laparoscopic surgery, gynecological surgery and mixed surgery. Beneficial associations were found with Cur intervention in gastrointestinal, neurological and oral diseases. Zingiberaceae plants/Cur are generally safe and favorable for multiple health outcomes in humans. High-quality research is further needed to prove the observed associations.

Orally consumed ginger and human health: an umbrella review

BACKGROUND

Emerging evidence supports the health benefits of ginger for a range of conditions and symptoms; however, there is a lack of synthesis of literature to determine which health indications are supported by quality evidence.

OBJECTIVES

In this umbrella review of systematic reviews we aimed to determine the therapeutic effects and safety of any type of ginger from the Zingiber family administered in oral form compared with any comparator or baseline measures on any health and well-being outcome in humans.

METHODS

Five databases were searched from inception to April 2021. Review selection and quality were assessed in duplicate using the Assessment of Multiple Systematic Reviews-2 (AMSTAR-2) checklist and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) method, with results presented in narrative form.

RESULTS

Twenty-four systematic reviews were included with 3% overlap of primary studies. The strongest evidence was found for the antiemetic effects of ginger in pregnant women (effect size: large; GRADE: high), analgesic effects for osteoarthritis (effect size: small; GRADE: high), and glycemic control (effect size: none to very large; GRADE: very low to moderate). Ginger also had a statistically significant positive effect on blood pressure, weight management, dysmenorrhea, postoperative nausea, and chemotherapy-induced vomiting (effect size: moderate to large; GRADE: low to moderate) as well as blood lipid profile (effect size: small; GRADE: very low) and anti-inflammatory and antioxidant biomarkers (effect size: unclear; GRADE: very low to moderate). There was substantial heterogeneity and poor reporting of interventions; however, dosage of 0.5-3 g/d in capsule form administered for up to 3 mo was consistently reported as effective.

CONCLUSIONS

Dietary consumption of ginger appears safe and may exert beneficial effects on human health and well-being, with greatest confidence in antiemetic effects in pregnant women, analgesic effects in osteoarthritis, and glycemic control. Future randomized controlled and dose-dependent trials with adequate sample sizes and standardized ginger products are warranted to better inform and standardize routine clinical prescription.

Nutritional benefits of ginger for patients with non-communicable diseases

Ginger (Zingiber officinale) is a famous dietary spice rich in bioactive components like gingerols, and it has been used for a long time as food and medicine. Indeed, clinical studies have confirmed the anti-inflammatory and antioxidant properties of ginger. Thus, ginger seems to be an excellent complementary nutritional strategy for non-communicable diseases (NCD) such as obesity, diabetes, cardiovascular disease and chronic kidney disease. This narrative review aims to discuss the possible effects of ginger on the mitigation of common complications such as inflammation, oxidative stress, and gut dysbiosis in NCD.

The effect of ginger supplementation on metabolic profiles in patients with type 2 diabetes mellitus: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

There is some evidence regarding the positive effects of ginger supplementation on metabolic profile in patients with type 2 diabetes (T2DM). However, they are conflicting. The present systematic review and meta-analysis aimed to summarize earlier findings for the effect of ginger supplementation on metabolic profile in patients with T2DM.

METHODS

Scopus, PubMed and Google Scholar databases were systematically searched up until September 2021 to collect all randomized clinical trials that evaluated the effect of ginger supplementation on FBS, HbA1c, TC, TG, LDL, HDL, SBP and DBP in patients with T2DM. We conducted our study according to the 2020 PRISMA guidelines. We included only English language publications. Pooled effect sizes were measured using a random-effects model and were reported as the weighted mean difference (WMD) and 95% CI. In addition, the Cochrane Collaboration's risk of bias tool was used to evaluate quality of the trials.

RESULTS

In overall, 10 articles were included in this systematic review and meta-analysis. Our pooled meta-analysis indicated a significant reduction in FBS following ginger supplementation by polling 8 effect sizes [weighted mean difference (WMD): - 18.81; 95% CI: - 28.70, - 8.92), I2 = 77.4%] and in HbA1C through 7 effect sizes (WMD: -0.57; 95% CI: -0.93, -0.20, I2 =88.6%). Pooling 5 effect sizes, we found a significant reduction in SBP (WMD: -4.20; 95% CI: -7.64, -0.77, I2 =97%) and DBP [WMD: - 1.61; 95% CI: - 3.04, - 0.18), I2 = 93.2%] after supplementation with ginger. However, our pooled meta-analysis indicated that ginger supplementation had no significant influence on lipid profile involving TG, TC, LDL and HDL.

CONCLUSIONS

We found significant reductions in FBS, HbA1C, SBP and DBP after supplementation with ginger in patients with T2DM compared to control group, with no significant changes in serum lipids. Further large RCTs are required to shed light on this issue.

Efficacy of Ginger Supplementation in Relieving Persistent Hypothyroid Symptoms in Patients with Controlled Primary Hypothyroidism: A Pilot Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Primary hypothyroidism is a common disease. Some patients have persistent symptoms despite normal serum thyroid-stimulating hormone (TSH) levels. Ginger is reported to be beneficial in relieving similar symptoms. Our aim was to evaluate the efficacy of ginger supplementation in relieving persistent symptoms in these patients. In this randomized, double-blind, placebo-controlled clinical trial, 60 hypothyroid patients aged 20-60 years with normal serum TSH concentrations were randomly allocated to two equal parallel study groups of ginger (500 mg twice a day) or placebo for 30 days. Hypothyroid symptoms were evaluated as the primary outcome using the Thyroid Symptom Rating Questionnaire (ThySRQ) before and after the intervention. Anthropometric measures and laboratory indices including TSH, triglyceride (TG), total cholesterol (TChol), and fasting blood sugar (FBS) were considered as secondary outcomes. A significant lower mean total ThySRQ score (8.63 ± 5.47 vs. 15.76 ± 6.09, P < 0.001) was observed in the ginger group compared to the control group. Ginger led to significant improvements in the mean scores of the weight gain, cold intolerance, constipation, dry skin, appetite, memory loss, concentration disturbance, and feeling giddy or dizzy domains (P < 0.001). However, no significant improvements were observed in hair loss, nail fragility, hearing, hoarseness, speech, and depression or feeling down (P > 0.05). Ginger supplementation also led to a significant decrease in body weight, body mass index, waist circumference, serum TSH, FBS, TG, and TChol levels compared to the placebo. In summary according to preliminary results of this study, ginger supplementation can help relieve persistent hypothyroid symptoms. Also, it may have beneficial effects in terms of weight reduction and regulation of the FBS and lipid profile in hypothyroid patients.

Antidiabetic Phytochemicals From Medicinal Plants: Prospective Candidates for New Drug Discovery and Development

Diabetes, a chronic physiological dysfunction affecting people of different age groups and severely impairs the harmony of peoples' normal life worldwide. Despite the availability of insulin preparations and several synthetic oral antidiabetic drugs, there is a crucial need for the discovery and development of novel antidiabetic drugs because of the development of resistance and side effects of those drugs in long-term use. On the contrary, plants or herbal sources are getting popular day by day to the scientists, researchers, and pharmaceutical companies all over the world to search for potential bioactive compound(s) for the discovery and development of targeted novel antidiabetic drugs that may control diabetes with the least unwanted effects of conventional antidiabetic drugs. In this review, we have presented the prospective candidates comprised of either isolated phytochemical(s) and/or extract(s) containing bioactive phytoconstituents which have been reported in several in vitro, in vivo, and clinical studies possessing noteworthy antidiabetic potential. The mode of actions, attributed to antidiabetic activities of the reported phytochemicals and/or plant extracts have also been described to focus on the prospective phytochemicals and phytosources for further studies in the discovery and development of novel antidiabetic therapeutics.

The Effect of Saffron (Crocus sativus L.) Supplementation on Renal Function: A Systematic Review and Meta-Analysis of Randomized Controlled Clinical Trials

BACKGROUND

The present systematic review and meta-analysis of randomized controlled trials (RCTs) aimed at determining the effect of saffron supplementation on renal function.

METHODS

Electronic databases were searched up to February 2021. The risk of bias in individual studies was assessed using the Cochrane Collaboration tool. The overall weighted mean difference (WMD) and their 95% confidence intervals (CIs) were calculated using random-effect models. P < 0.05 was considered statistically significant.

RESULTS

A total of 11 trials were included in this study. Saffron had beneficial effect on BUN (WMD = -0.69 mg/dl; 95% CI, -1.36 to -0.01; P=0.046) compared to placebo, with significant heterogeneity (I ² = 49.6%, P=0.037). However, it had no significant effect on serum Cr (WMD = 0.04 mg/dl; 95% CI: -0.01 to 0.09; P=0.127).

CONCLUSION

It seems that saffron supplementation had no significant effect on Cr as a renal function factor. However, BUN reduction was significant in the saffron group compared to placebo.

The Effect of Ginger (Zingiber officinale) on Improving Blood Lipids and Body Weight; A Systematic Review and Multivariate Meta-analysis of Clinical Trials

BACKGROUND

Beneficial effects of ginger consumption on metabolic biomarkers has been reported previously. The current research aimed to investigate the effects of ginger supplementation on lipid profile and body weight using a meta-analysis of randomized, controlled trials.

METHODS

Online databases PubMed, Embase, Web of Science, and Science Direct were searched until December 2021 to identify eligible articles. Twenty-six trials were included.

RESULTS

The results showed that ginger consumption could significantly improve lipid profile including total triglyceride (-12.54 (-20.01 to -5.08)), cholesterol (-6.53 (-10.76 to -2.31)), LDL (-5.14 (-8.79 to -1.50)), and HDL (1.13 (0.35 to 1.91)). Moreover, ginger supplementation could significantly decrease body mass index (BMI) (-0.49 (-0.79 to -0.18)). However, the small number of sample studies that investigated reductions in body weight (-0.52 (-1.48 to 0.43)) were not statistically significant. Sub-group analysis of treatment dose and duration showed that in most of the analyzed lipid profiles, both ≤1500 and >1500 mg/d for both of ≤8 and >8 weeks could be effective; however, in the case of weight control dose of >1500 mg/d for more than 8 weeks was more effective. Besides, the results of multivariate meta-analysis revealed the effect of the intervention on all lipid profiles simultaneously.

CONCLUSION

The present meta-analysis and review revealed that ginger supplementation can improve lipid profile and body weight if used at the appropriate dose and duration. More studies are needed to fully evaluate the effect of ginger supplements' different doses and duration on lipid profile and BMI.

The Role of Bioactive Compounds from Dietary Spices in the Management of Metabolic Syndrome: An Overview

Metabolic syndrome (MetS) is a combination of physiologically dysregulated parameters that can include elevated fasting blood glucose, high blood pressure, central obesity, increased triglyceride levels, insulin resistance, diabetes, elevated low density lipoprotein levels, and reduced high density lipoprotein levels in the blood. Effective clinical management of MetS is critical as it is strongly associated with long lasting and fatal complications in patients. Alongside standard care of lifestyle changes and medication, dietary supplements derived from herbal resources could be an alternative therapeutic strategy that is safe, efficient, culturally acceptable, and has few side effects. Of the dietary supplements, spicy foods have always been considered a great source of functional bioactive compounds. Herbal therapy is broadly used in many countries as a treatment or as a preventive measure in the management of MetS risk factors, including blood glucose, blood pressure, and blood lipid levels. Herein, an attempt is made to evaluate the recent studies in the management of MetS with herbal alternatives, and to explore the possibility of their use as therapeutic treatments or supplements.

Targeting dyslipidemia by herbal medicines: A systematic review of meta-analyses

ETHNOPHARMACOLOGICAL RELEVANCE

The worldwide increasing prevalence of dyslipidemia has become a global health concern. Various herbal remedies have been claimed to be effective for the treatment of dyslipidemia in traditional and folkloric medicine of different regions clinical trials have been conducted to investigate their efficacy. The aim of the current systematic review is to critically assess the meta-analyses of controlled trials (CT) evaluated herb medicines for dyslipidemia.

MATERIALS AND METHODS

Relevant studies from Web of Science, PubMed, Scopus, and Cochrane Library databases based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist until January 2021 have been searched. All meta-analyses which pooled studies on the effect of herbal medicines on lipid profile including total cholesterol (TC), triglyceride (TG), and low- or high-density lipoprotein cholesterol (LDL-C, HDL-C) were also included. Meta-analyses of in vitro, animal or observational studies were excluded.

RESULTS

The overall of 141 meta-analyses were revealed. Vegetable oils, phytosterols, tea, soy protein, nuts, and curcumin have been studied frequently among the herbal medicines. Among 13 meta-analyses on vegetable oils, the greater reduce of TC (18.95 mg/dl), LDL-C (16.24 mg/dl) and TG (13.69 mg/dl) were exhibited from sunflower oil. Furthermore, rice bran oil (6.65 mg/dl) increased HDL-C significantly. Phytosterols in 12 meta-analyses demonstrated significant improvements in reducing TC, LDL-C and TG as 16.4, 23.7, and 8.85 mg/dl, respectively, and rise in HDL-C as 10.6 mg/dl. The highest reduction in serum level of TC, LDL-C and TG was reported while intake Green tea; 27.57, 24.75, and 31.87 mg/dl, accordingly within 9 meta-analyses. Average improvement of lipid profiles by 6 meta-analyses on plant proteins were 23.2, 21.7, 15.06, and 1.55 mg/dl for TC, LDL-C, TG, and HDL-C, respectively. Among 11 meta-analyses on nuts, almond showed better and significant alleviations in TC (10.69 mg/dl), walnut in LDL-C (9.23 mg/dl), pistachio in TG (22.14 mg/dl), and peanut in HDL-C (2.72 mg/dl). Overall, Curcumin, Curcuminoid, and Turmeric have resulted in the reduction of TC (25.13 mg/dl), LDL-C (39.83 mg/dl), TG (33.65 mg/dl), and an increase in the HDL-C (4.31 mg/dl).

CONCLUSION

The current systematic review shed light on the use of herbal medicines for the management of dyslipidemia. However, more well-conducted CTs are required to determine effective doses of herbal medicines.

Ginger extract and its compound, 6-shogaol, attenuates painful diabetic neuropathy in mice via reducing TRPV1 and NMDAR2B expressions in the spinal cord

ETHNOPHARMACOLOGICAL RELEVANCE

In silico data revealed that the active compound of ginger (Zingiber officinale Roscoe), 6-shogaol, has strong affinity toward transient receptor potential vanilloid-1 (TRPV-1). TRPV-1 is expressed in nervous tissue and pancreatic β-cells. Prolonged induction of TRPV-1 is related to the expression of N-methyl-D-aspartate receptor subunit 2B (NMDAR2B). However, there are no data on TRPV-1 and NMDAR2B expressions in nervous tissue after 6-shogaol or ginger extract treatment nor pancreatic islet morphology and insulin expression in mice model of painful diabetic neuropathy (PDN).

AIM OF THE STUDY

This study aimed to investigate the mechanism of action of ginger extract and its compound, 6-shogaol, on pancreatic islets as well as on expressions of TRPV-1 and NMDAR2B in the spinal cord of streptozotocin (STZ)-induced mice model of PDN.

MATERIALS AND METHODS

Sixty-four 5-6 weeks old male-Balb/C mice were induced with 110 mg/kgBW STZ i.p., while eight mice were used as control group. Mice with blood glucose level ≥200 mg/d, that suffered hyperalgesia and allodynia were classified as PDN mice. Hot plate and von Frey filament tests were performed once a week until termination. At day 28 after considered as PDN, ginger extracts, 6-shogaol or gabapentin as control treatment were given once daily for 21 days until day 49, except for the diabetic control group. Upon termination, mice' pancreas were fixed, processed as paraffin sections and stained with hematoxylin eosin. Total volume of pancreatic islets was estimated using Cavalieri methods. Immunohistochemistry on pancreatic sections were performed to observe insulin expression. mRNA was extracted from lumbar segments of the spinal cord, followed by cDNA preparation and quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) to measure the expressions of TRPV1 and NMDAR2B. The mean differences between groups were analyzed using one-way analysis of variance (ANOVA) with p < 0.05 considered statistically significant.

RESULTS

Ginger extracts and 6-shogaol alleviated hyperalgesia and allodynia. The groups that received ginger extract 400 mg/kgBW or 6-shogaol 15 mg/kgBW had significantly lower TRPV1 and NMDAR2B expressions in the spinal cord compared to the diabetic control group (p < 0.001; p < 0.05). However, no differences in volume of pancreatic islets (p > 0.05) nor insulin expression were observed in all PDN groups.

CONCLUSION

Ginger extracts and its compound, 6-shogaol, reduced pain symptoms in PDN via its effect on decreasing TRPV1 and NMDAR2B expressions in the spinal cord, with very limited effect on pancreatic islets.

Hesperidin supplementation has no effect on blood glucose control: A systematic review and meta-analysis of randomized controlled clinical trials

AIMS

To the best of our knowledge, no study has tried to quantitatively summarize the published evidence regarding the effect of hesperidin supplementation on blood glucose control. The present systematic review and meta-analysis of randomized controlled trials aimed to determine the effectiveness of hesperidin supplementation in improving blood glucose control in adults.

METHODS

Electronic databases including PubMed, ISI Web of Science, Scopus, and Google Scholar were searched up to February 2019. The risk of bias in individual studies was assessed using the Cochrane collaboration's tool. The overall estimates and their 95% confidence intervals (CIs) were calculated using a random-effects model.

RESULTS

Six trials with 318 participants were reviewed in the present systematic review. The results showed that hesperidin had no significant effect on serum fasting blood glucose (weighted mean difference [WMD] = -1.10 mg/dL, 95% CI: -3.79, 1.57), plasma insulin (WMD = -0.01 μU/mL, 95% CI: -1.20, 1.19), glycated haemoglobin A1c (WMD = -0.04%, 95% CI: -0.14, 0.04), homeostasis model assessment for insulin resistance (WMD = 0.117, 95% CI: -0.06, 0.29) and quantitative insulin sensitivity check index (WMD = 0.135; 95% CI: -0.13, 0.39), with no significant between-study heterogeneity. Subgroup analyses also indicated that the effects were not different based on the studies' design and duration, or the health status of the participants.

CONCLUSION

Although several animal studies have proposed that hesperidin supplementation might improve blood glucose control, the present study could not confirm this benefit in humans.

Promotion of Mitochondrial Biogenesis via Activation of AMPK-PGC1ɑ Signaling Pathway by Ginger (Zingiber officinale Roscoe) Extract, and Its Major Active Component 6-Gingerol

Several studies indicated that ginger (Zingiber officinale Roscoe) enhances thermogenesis and/or energy expenditure with which to interpret the beneficial effects of ginger on metabolic disorders. It is well known that mitochondrial activity plays an essential role in these processes. Thus, this study aimed to investigate the effect of ginger extract (GE) and its major components, 6-gingerol and 6-shogaol, on mitochondrial biogenesis and the underlying molecular mechanisms. Our results showed that GE at dose of 2 g/kg promoted oxygen consumption and intrascapular temperature in mice. The mitochondrial DNA (mtDNA) copy number in muscle and liver increased. Expression levels of oxidative phosphorylation (OXPHOS) related proteins and AMP-activated protein kinase ɑ/proliferator-activated receptor gamma coactivator 1 ɑ (AMPK/PGC1ɑ) signaling related proteins in the muscle, liver, and brown adipose tissue (BAT) increased as well. In HepG2 cells, GE at concentration of 2.5 and 5 mg/mL increased mitochondrial mass and mtDNA copy number. GE promoted ATP production, the activities of mitochondrial respiratory chain complex I and IV, and expression levels of OXPHOS complex related proteins and AMPK/PGC1ɑ signaling related proteins. The antagonist of AMPK eliminated partly the effect of GE on mitochondrial biogenesis. 6-Gingerol increased mitochondrial mass, mtDNA copy number and ATP production, and the activities of mitochondrial respiratory chain complexes in HepG2 cells as well. However, both 6-gingerol at high concentration of 200 µM and 6-shogaol at 10 to 200 µM inhibited cell viability. In conclusion, GE promoted mitochondrial biogenesis and improved mitochondrial functions via activation of AMPK-PGC1ɑ signaling pathway, and 6-gingerol other than 6-shogaol, may be the main active component. PRACTICAL APPLICATION: Ginger (Zingiber officinale Roscoe) is a food seasoning and also used as a medical plant in alternative medicine throughout the world. Here, we demonstrated that ginger extract (GE) promoted mitochondrial biogenesis and mitochondrial function via activation of AMPK-PGC1ɑ signaling pathway both in mice and in HepG2 cells, and 6-gingerol may be its main active component. Ginger, with anticipated safety, is expected to be a long-term used dietary supplement and be developed into a new remedy for mitochondrial dysfunctional disorders.

Ginger for health care: An overview of systematic reviews

OBJECTIVES

To summarize the evidence from systematic reviews (SRs) and meta-analyses that evaluated the efficacy of ginger in treating any conditions and critically assess the quality of these evidence.

METHODS

A systematic search of the literature was conducted from inception until February 28, 2019 using the PubMed, EMBASE, Web of science, Cochrane library, and four Chinese databases. Literature selection and data extraction were conducted by two independent reviewers. The quality of SRs was evaluated using the AMSTAR-2 tool. The GRADE system was used to assess the quality of evidence.

RESULTS

Twenty-seven SRs were included. The number of included studies were various, range from 3 to 27. The condition with the most included SRs was nausea and vomiting (n = 12, 44.4%). Many SRs showed a promising efficacy of ginger, including nausea and vomiting, metabolic syndrome and pain, while the effect of ginger for platelet aggregation failed to draw a certain conclusion. The quality of SRs was heterogeneous. All of included SRs well complied with the Item 1 ("research questions included the components of PICO") and Item 3 ("explained selection of the study designs for inclusion"). Twenty review failed to provide registration information. Only one SR reported the sources of funding for studies included.

CONCLUSIONS

In our overview, most of SRs suggest ginger is a promising herbal medicine for health care, which is beneficial for nausea and vomiting, metabolic syndrome and pain. However, considering the limited quality of included evidence and heterogeneity of different clinical trials, more well-design studies are required to confirm the conclusion further.

Comparative study of aflatoxin contamination of winter and summer ginger from the North West Province of South Africa

The presence of mycotoxins in staple food can have adverse effect that result in ill health and associated socio-economic losses. Mycotoxins are naturally occurring toxins produced by certain fungi and can be found in staple food plants such as ginger. Ginger is a renowned medicinal plant that is extensively used for cooking and healing. However, this medicinal plant is with little information about its possible mycotoxins contamination. This study determined the occurrence and prevalence of Aflatoxin B1, B2, G1 and G2 and Ochratoxin A contamination in raw ginger sold around Mahikeng, North West Province, South Africa. Samples were collected purposively from various retailers over winter and summer. The analytical procedure optimized was based on immunoaffinity column cleanup (IAC), followed by High performance liquid chromatography with fluorescence (HPLC-FLC) detection. ELISA was also used for mycotoxin screening. On HPLC, the limits of detection and quantification for the four Aflatoxins were 3.9 × 10-7-1.4 × 10 -3 and 1.3 × 10-6 - 4.7 × 10-3 for samples collected in winter, and 3.7 × 10-7- 1.4 × 10-3, LOQ 1.2 × 10-6 - 4.6 × 10-3 for the summer samples. The average recoveries at three spiking levels ranged from 62 to 91% for the summer samples and 70-93% for those collected in winter. A linearity was observed for the analytes whose correlation coefficients were within the range of 0.9995 and 1.000 for the winter samples and 0.9995 and 1.000 for those collected in summer. The results showed that the contamination levels, especially for samples collected in summer were greater than the legally permissible limits. The t-test analysis shows that the mean and standard deviation of the four types of Aflatoxins considered were higher in summer than in winter. The findings of the study indicated that ginger, as for all agricultural commodities, are prone to mycotoxin contamination.

Green cardamom supplementation improves serum irisin, glucose indices, and lipid profiles in overweight or obese non-alcoholic fatty liver disease patients: a double-blind randomized placebo-controlled clinical trial

Background

Despite the reported health effects of cardamom on dyslipidemia, hepatomegaly, and fasting hyperglycemia, no human research has studied its potency in non-alcoholic fatty liver disease (NAFLD) as the hepatic part of metabolic syndrome. Our aim was determining the effects of green cardamom (GC) on serum glucose indices, lipids, and irisin level among overweight or obese NAFLD patients.

Methods

The place of participant recruitment was the polyclinic of the National Iranian Oil Company (NIOC) central hospital in Tehran. Based on the ultrasonography and eligibility criteria, 87 participants were randomly divided into two groups as cardamom (n = 43) or placebo (n = 44). The supplementation was two 500 mg capsules 3 times/day with meals for 3 months. Serum irisin, fasting blood sugar (FBS), insulin (FBI), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-c), and high-density lipoprotein cholesterol (HDL-c) were measured. Quantitative insulin sensitivity check index (QUICKI) and homeostasis model assessment-insulin resistance (HOMA-IR) were also calculated.

Results

In comparison with placebo, GC significantly increased irisin, HDL-c, and QUICKI and decreased FBI, TG, LDL-c, HOMA-IR, and the grade of fatty liver (P < 0.05). After adjustment for confounders, the changes were similar (P < 0.05) with an exception for LDL-c which had a trend (P = 0.07). The differences in FBS, TC, and body mass index (BMI) were not significant (P > 0.05).

Conclusion

GC supplement improved the grade of fatty liver, serum glucose indices, lipids, and irisin level among overweight or obese NAFLD patients. The changes in these biomarkers may yield beneficial effects on NAFLD. Further trials on the efficacy of GC for clinical practice are suggested.

Trial registration

Iranian Registry of Clinical Trials, IRCT2015121317254N4. Registered 27/12/2015,

Electronic supplementary material

The online version of this article (10.1186/s12906-019-2465-0) contains supplementary material, which is available to authorized users.

Effects of Prebiotic and Synbiotic Supplementation on Glycaemia and Lipid Profile in Type 2 Diabetes: A Meta-Analysis of Randomized Controlled Trials

Purpose: Diabetes Mellitus (T2DM) as a chronic disease, is on rise in parallel with other non-communicable diseases. Several studies have shown that probiotics and prebiotics might exert beneficial effects in chronic diseases including diabetes. Because of controversial results from different trials, the present study aims to assess the effects of prebiotic/synbiotic consumption on metabolic parameters in patients with type2 diabetes. Methods: A systematic literature search was performed on randomized controlled trial published in PubMed/Medline, SciVerse Scopus, Google scholar, SID and Magiran up to March 2018. Of a total number of 255 studies found in initial literature search, ten randomized controlled trials were included in the meta-analysis. The pooled mean net change were calculated in fasting blood-glucose [FBG], Hemoglobin A1c [HbA1c] and lipid markers (total cholesterol [TC], triglyceride [TG], low-density lipoprotein cholesterol [LDL-C], high density lipoprotein cholesterol [HDL-C]). The meta-analyses was conducted using Revman Software (v5.3). Results: The pooled estimate indicated a significant difference for the mean change in FBG, HbA1c and HDL in treatment group in comparison with control group. Subgroup analysis by intervention showed a significant difference in TG, LDL and HDL (synbiotic group) and in TG, TC, FBG, HDL and HbA1c (prebiotic group) compared with placebo. In another subgroup analysis, high quality studies showed significant reductions in TG, TC, FBG and HbA1c in intervention group compared with placebo group. Conclusion: In summary, diets supplemented with either prebiotics or synbiotics can result in improvements in lipid metabolism and glucose homeostasis in type 2 diabetic patients.

Effect of N-acetyl cysteine (NAC) supplementation on positive and negative syndrome scale in schizophrenia: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To conduct a systematic review and meta-analysis of published randomised controlled trials on the efficacy of NAC supplementation on positive and negative syndrome scale in schizophrenia.

METHODS

A meta-analysis was conducted, and studies were identified by a search of electronic databases from inception to May 2018. Combined and stratified analyses were used.

RESULTS

Seven trials were identified, and data from n = 447 participants were included. Pooled analysis showed improvement of positive and negative syndrome scale following NAC treatment compared with placebo, for total (SMB = - 0.96) [95% CI - 1.69, - 0.24; P = 0.009], general (SMB = - 1.04) [95% CI - 1.80, - 0.27; P = 0.008] and negative (SMB = - 0.73) [95% CI - 1.29, - 0.17; P = 0.01] scores, respectively. Significant heterogeneity was found, and subgroup analysis showed significant reductions in studies with a treatment duration of ≤ 24 weeks, with a considerable effect size on total, general, and negative scores (Total SMD = - 0.83; General SMD = - 0.67; Negative SMD = - 1.09) following NAC.

CONCLUSIONS

NAC improved all aspects of positive and negative syndrome scale in schizophrenic populations and may be more efficacious with treatment durations up to 24 weeks.

Effect of garlic supplementation on serum C-reactive protein level: A systematic review and meta-analysis of randomized controlled trials

The present study was designed to systematically review randomized controlled trials (RCTs) that report on the effects of garlic supplementation on serum C-reactive protein (CRP) levels. We conducted a literature search of Scopus, PubMed, Cochrane Library, and Google Scholar up to January 2018. Weighted mean differences (WMD) were estimated for net change in serum CRP. Subgroup analyses were also performed by duration of study, dose of supplementation, baseline CRP level, and the quality of studies. From 438 articles found and screened in our initial search, nine RCTs with the sum of total sample size of 363 were included in the meta-analysis. Compared with the controls, garlic intake significantly reduced the concentrations of serum CRP by 0.8 mg/L (95% CI [-1.5, -0.1], p = 0.02) with the evidence of heterogeneity among studies. Subgroup analyses showed that garlic significantly lowered CRP by 0.82 mg/L (95% CI [-1.02, -0.62], p < 0.001) among studies with a daily garlic dose ≥1,200 mg/day and by 2.44 mg/L (95% CI [-4.02, -0.87], p = 0.002) among studies with baseline CRP ≥2 mg/L. Current data confirmed that garlic supplementation would reduce serum CRP levels. However, the changes were related to the supplemental doses and baseline levels of serum CRP.

Effects of superfoods on risk factors of metabolic syndrome: a systematic review of human intervention trials

Functional foods can be effective in the prevention of metabolic syndrome and subsequently the onset of cardiovascular diseases and type II diabetes mellitus. More recently, however, another term was introduced to describe foods with additional health benefits: "superfoods", for which, to date, no generally accepted definition exists. Nonetheless, their consumption might contribute to the prevention of metabolic syndrome, for example due to the presence of potentially bioactive compounds. This review provides an overview of controlled human intervention studies with foods described as "superfoods" and their effects on metabolic syndrome parameters. First, an Internet search was performed to identify foods described as superfoods. For these superfoods, controlled human intervention trials were identified until April 2017 investigating the effects of superfood consumption on metabolic syndrome parameters: waist circumference or BMI, blood pressure, or concentrations of HDL cholesterol, triacylglycerol or glucose. Seventeen superfoods were identified, including a total of 113 intervention trials: blueberries (8 studies), cranberries (8), goji berries (3), strawberries (7), chili peppers (3), garlic (21), ginger (10), chia seed (5), flaxseed (22), quinoa (1), cocoa (16), maca (1), spirulina (7), wheatgrass (1), acai berries (0), hemp seed (0) and bee pollen (0). Overall, only limited evidence was found for the effects of the foods described as superfoods on metabolic syndrome parameters, since results were not consistent or the number of controlled intervention trials was limited. The inconsistencies might have been related to intervention-related factors, such as duration or dose. Furthermore, conclusions may be different if other health benefits are considered.

Effect of L-citrulline supplementation on blood pressure: a systematic review and meta-analysis of randomized controlled trials

The objective of this study was to systematically investigate the efficacy of oral L-citrulline supplementation on systolic and diastolic blood pressure. Studies were identified by a search of electronic databases from inception to April 2018, and combined and stratified analyses were used. Fifteen trials were identified, and data from 424 participants were included. Pooled analysis showed significant reductions in systolic blood pressure by -7.54 mmHg (95% confidence interval (CI): -9.44, -5.63; P < 0.001, I² = 14%) and diastolic blood pressure by -3.77 mmHg (95% CI: -5.67, -1.86, P < 0.001, I² = 42%) following oral supplementation of L-citrulline or a watermelon extract. No changes were detected in controls. Significant heterogeneity (I² = 42%, P = 0.04) was found for diastolic blood pressure, and subgroup analysis showed significant improvements in systolic and diastolic blood pressure, particularly for study durations: ≥6 weeks, lower doses: ≤4 g/day, and in participants with higher baseline values: ≥130/85 mmHg. In conclusion, L-citrulline improves systolic and diastolic blood pressure and may be more efficacious in pre-hypertensive and hypertensive populations.

Cumin (Cuminum cyminum L.) is a safe approach for management of lipid parameters: A systematic review and meta-analysis of randomized controlled trials

We performed a meta-analysis to evaluate the efficacy of cumin supplementation on plasma lipid concentration in adult population. The search included PubMed, Scopus, ISI Web of Science, Google Scholar, and the Cochrane library (up to January 2018) to identify randomized controlled trials (RCTs) investigating the effects of cumin supplementation on serum lipid parameters. Mean difference (MD) was pooled using a random-effects model. Meta-analysis of data from six eligible RCTs with 376 participants showed a significant reduction in plasma concentration of total cholesterol (MD [95% CI] -10.90 [-21.39, -0.42] mg/dl, p = 0.042) and low-density lipoprotein cholesterol (MD [95% CI] -6.94 [-11.53, -2.35] mg/dl, p = 0.003) after supplementation with cumin compared with control treatment, and plasma concentration of high-density lipoprotein cholesterol (MD [95% CI] 3.35 [1.58, 5.12] mg/dl, p˂0.001) were found to be increased. Although our analysis indicated that cumin supplementation cannot change triglyceride (TG) concentration (MD [95% CI] -20.48 [-41.23, -0.26] mg/dl, p = 0.053), but after stratified the RCTs based on the primary level of TG (hypertriglyceridemia versus nonhypertriglyceridemia subjects), there was a significant decrease in nonhypertriglyceridemia subset. This systematic review and meta-analysis suggested the efficacy of cumin supplementation on lipid parameters.

The effect of ginger supplementation on lipid profile: A systematic review and meta-analysis of clinical trials

BACKGROUND

Elevated levels of blood lipids are a major cause of atherosclerosis and consequently cardiovascular disease. Several studies used ginger as a lipid lowering agent.

PURPOSE

The aim of the present systematic review and meta-analysis was to clarify the effect of ginger supplementation on lipid parameters.

METHODS

PubMed, Scopus, Science Direct, ISI Web of Science and Google Scholar were systematically searched until May 2017 to find clinical trials which examined effect of ginger supplementation on level of lipid parameters in adult participants. Means for blood lipids and potential sources of heterogeneity were extracted. A subgroup analysis was applied to find out potential sources of inter-study heterogeneity.

RESULTS

A total of 12 trials (586 participants) were included in the meta-analysis. Pooled analysis suggested that ginger supplementation reduced triacylglycerol (TAG) (-17.59 mg/dl; 95% CI: -29.32 to -5.87) and low density lipoprotein cholesterol (LDL-C) (-4.90 mg/dl; 95% CI: -22.30 to -6.17). Ginger had no significant effect on total cholesterol (TC) (-5.13 mg/dl, 95% CI: -11.05 to 0.78; P = 0.089) and high density lipoprotein cholesterol (HDL-C) (2.18 mg/dl, 95% CI: -0.08 to 4.45; P = 0.059). As inter-study heterogeneity was high, studies were classified by ginger dosage. Stratified analysis showed a significant reduction in TC (-12.26 mg/dl; 95% CI: -22.37 to -2.16) and TAG (-38.42 mg/dl; 95% CI: -57.01 to -19.82) in studies which used ≤2 g/day of ginger. However, a similar significant effect was not observed in trials with >2 g/day of ginger. Neither studies which used ≤2 g/day nor trials which used >2 g/day of ginger showed significant changes in LDL-C or HDL-C.

CONCLUSION

The present systematic review and meta-analysis suggests that ginger had a favorable effect on TAG and LDL-C. Also, the result revealed that low dose of ginger (≤2 g/day) had greater lowering impact on TAG and TC. Further studies with large-scale and better design are needed to confirm this result.