Effects of Ginger on Serum Lipids and Lipoproteins in Peritoneal Dialysis Patients: A Randomized Controlled Trial

Clinical dermatologic applications of ginger: a focused review

Ginger is a traditional herb with medicinal properties. Although most commonly utilized as a spice, it has been used for various medicinal ailments for thousands of years. Over the past century, the anti-inflammatory, antioxidative, and antimicrobial properties of ginger have been increasingly studied. Ginger has been demonstrated to be beneficial for many conditions including dermatologic, gastrointestinal, neoplastic, and respiratory diseases. Herein, we examine the existing literature regarding the clinical uses of ginger with a focus on its dermatologic applications.

Ginger intervention on body weight and body composition in adults: a GRADE-assessed systematic review and dose-response meta-analysis of 27 randomized controlled trials

CONTEXT

Ginger consumption may have an inverse relationship with obesity and metabolic syndrome parameters; however, clinical trials have reported contradictory results.

OBJECTIVE

To systematically review and analyze randomized controlled trials (RCTs) assessing the effects of ginger on body weight and body composition parameters.

METHODS

Databases were searched for appropriate articles up to August 20, 2022. All selected RCTs investigated the impact of ginger on glycemic indices in adults. A random effects model was used to conduct a meta-analysis, and heterogeneity was assessed using the I2 statistic. Net changes in body weight, body mass index (BMI), waist circumference (WC), and percent body fat were used to calculate the effect size, which was reported as a weighted mean difference (WMD) and 95% confidence intervals (CIs). The risk of bias was assessed.

RESULTS

A total of 27 RCTs involving 1309 participants were included. The certainty in the evidence was very low for WC and BMI, and low for body weight and percent body fat as assessed by the GRADE evidence profiles. The meta-analysis showed a significant association between ginger supplementation and a reduction in body weight (WMD, -1.52 kg; 95%CI, -2.37, -0.66; P < 0.001), BMI (WMD, -0.58 kg/m2; 95%CI, -0.87, -0.30; P < 0.001), WC (WMD, -1.04 cm; 95%CI: -1.93, -0.15; P = 0.021), and percent body fat consumption (WMD, -0.87%; 95%CI, -1.71, -0.03; P = 0.042). The results of the nonlinear dose-response analysis showed a significant association between the ginger dose with body weight (Pnonlinearity = 0.019) and WC (Pnonlinearity = 0.042). The effective dose of ginger intervention for body mass reduction was determined to be 2 g/d in dose-response analysis. The duration of ginger intervention had a significant nonlinear relationship with body weight (Pnonlinearity = 0.028) with an effective duration of longer than 8 weeks.

CONCLUSIONS

Our findings provide evidence that ginger consumption may significantly affect body composition parameters nonlinearly. More, well-constructed RCTs are needed.

Effect of ginger (Zingiber officinale) intake on human serum lipid profile: Systematic review and meta-analysis

Dyslipidemia is associated with an increased risk of cardiovascular events. Effect of ginger supplementation on lipid profile in humans remains controversial particularly in diabetic patients. A systematic search was performed covering PubMed, Medline, and Scopus, Web of Science (ISI), and Google scholar from January 2010 to January 2022. Inclusion criteria were randomized controlled clinical trials (RCT) study design, at least one of lipid profile components triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL-C), and high-density lipoprotein (HDL-C) measured before and after ginger consumption. For quantitative data synthesis, a random-effects model was applied. Pooled data showed that ginger intake reduced TC (SMD -0.44; 95% CI: -0.86, -0.02; p = 0.025) and TG (SMD -0.61; 95% CI: -1.14, -0.08; p = 0.024) levels significantly, but it has no significant effect on improving HDL-C (SMD 0.40; 95% CI: -0.01, 0.80; p = 0.057) and LDL-C (SMD -0.34; 95% CI: -0.81, 0.13; p = 0.153). Ginger supplementation decreased TG in obese and diabetic subjects more efficiently. In terms of ginger dose, the result of meta-regression found to be significant only for TC, so that increasing daily doses of ginger reduces TC levels by (β: -0.67; 95% CI: -1.28, -0.07; p = 0.028). Therefore, ginger could be considered as an effective lipid lowering nutraceuticals.

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.

Hepatoprotective effects of moderate-intensity interval training along with ginger juice in an old male rat model

Aging is a natural process coupled with oxidative stress and chronic inflammation, gradually associated with losing organ function over time. Therefore, the objective of the current work was to peruse the protective effects of 8-week moderate-intensity interval training (MIIT) and ginger extract supplementation on some biomarkers of oxidative stress, inflammation, and lipid metabolism in the liver of elderly males Wistar rats (animal study with ethical code IR.BMSU.REC.1401.015). A total of thirty-two 22-month-aged male Wistar rats were randomly assigned to four groups: (1) control, (2) MIIT, (3) ginger, and (4) MIIT + ginger. After 8 weeks of treadmill training and ginger extract supplementation, the biochemical parameters (liver enzyme and lipid profile), inflammatory mediators (leucine-rich α-2 glycoprotein 1 (LRG1), tumor necrosis factor-alpha, and interleukin-6), pro-oxidant (malondialdehyde), antioxidant biomarkers (catalase, superoxide dismutase, total antioxidant capacity), some lipid metabolism regulators (carnitine palmitoyltransferase 1, adipose triglyceride lipase, acetyl-CoA carboxylase, CD36, and AMP-activated protein kinase), and liver histopathological changes were appraised. The acquired findings pointed out that MIIT combined with ginger extract appreciably diminished the serum levels of LRG1, liver enzymes, and lipid profile relative to the other groups after 8 weeks of intervention. Furthermore, ginger + MIIT caused a great improvement in the liver levels of antioxidant biomarkers, pro-oxidant, pro-inflammatory biomarkers, lipid metabolism regulators, and liver tissue impairment compared to the other groups. The findings suggested that MIIT + ginger was more effective in improving examined indices relative to the other groups.

A comparison of the effects of cinnamon, ginger, and metformin consumption on metabolic health, anthropometric indices, and sexual hormone levels in women with poly cystic ovary syndrome: A randomized double-blinded placebo-controlled clinical trial

BACKGROUND/OBJECTIVES

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder in women that can alter blood glucose, lipid profile and sexual hormonal level. Therefore, the evaluation of potential therapeutic agents in this population is important. The aim of the study was to determine the effects of cinnamon, ginger, and metformin intake on improvement of sex hormones level, metabolic health (lipid profiles, insulin level and fasting blood glucose) and anthropometric indices (weight, body mass index (BMI), etc.) in women with PCOS.

METHODS

A total of 100 women with PCOS were randomly assigned to one of the following four groups: cinnamon (500 mg of cinnamon, 3 × day), ginger (500 mg of ginger, 3 × day), metformin (500 mg of metformin 3 × day) or placebo. However, 17 participants were excluded for various reasons and consequently, 83 participants were considered for analysis. Sexual hormones, anthropometrics, glycemic and lipid markers were evaluated before and after the 8-week intervention.

RESULTS

Weight and BMI decreased significantly in all intervention groups. The consumption of metformin and cinnamon significantly decreased insulin resistance (HOMA-IR) in comparison to the placebo and ginger groups (P < 0.05). Moreover, a significant decrease in FSH (follicle-stimulating hormone) and LH (Luteinizing hormone) levels were observed in the ginger compared to the placebo group. While metformin and cinnamon significantly lowered testosterone levels (P < 0.05), none of the groups experienced a significant change in DHEA (dehydroepiandrosterone).

CONCLUSION

Our findings suggest that in women with PCOS, cinnamon supplementation causes similar reductions in insulin resistance and testosterone level to that of metformin. Ginger supplementation decreased FSH and LH, hormonal effects not seen following metformin consumption. Overall, cinnamon and ginger supplementations may potentially be used as alternative treatment in women with PCOS.

CLINICAL TRIAL REGISTRATION

[https://www.irct.ir/trial/28548], identifier [IRCT20171227038105N1].

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.

Preparation, pungency and bioactivity of gingerols from ginger (Zingiber officinale Roscoe): a review

Ginger has been widely used for different purposes, such as condiment, functional food, drugs, and cosmetics. Gingerols, the main pungent component in ginger, possess a variety of bioactivities. To fully understand the significance of gingerols in the food and pharmaceutical industry, this paper first recaps the composition and physiochemical properties of gingerols, and the major extraction and synthesis methods. Furthermore, the pungency and bioactivity of gingerols are reviewed. In addition, the food application of gingerols and future perspectives are discussed. Gingerols, characterized by a 3-methoxy-4-hydroxyphenyl moiety, are divided into gingerols, shogaols, paradols, zingerone, gingerdiones and gingerdiols. At present, gingerols are extracted by conventional, innovative, and integrated extraction methods, and synthesized by chemical, biological and in vitro cell synthesis methods. Gingerols can activate transient receptor potential vanilloid type 1 (TRPV1) and induce signal transduction, thereby exhibiting its pungent properties and bioactivity. By targeted mediation of various cell signaling pathways, gingerols display potential anticancer, antibacterial, blood glucose regulatory, hepato- and renal-protective, gastrointestinal regulatory, nerve regulatory, and cardiovascular protective effects. This review contributes to the application of gingerols as functional ingredients in the food and pharmaceutical industry.

[Not Available]

OBJECTIVE

We sought to evaluate ginger's cardiovascular and metabolic effects (Zingiberofficinale) add-on therapy in type 2 diabetes patients over six weeks.

METHODS

We performed a single-arm clinical trial. In well-to-moderately controlled Type 2 diabetic patients with unchanged treatment for at least three months, the intervention consisted of 6-week add-on oral supplementation of powdered ginger extracts in capsules at a dose of 399 mg three times per day. Transthoracic Doppler echocardiography, ambulatory blood pressure monitoring (ABPM), glycatedhaemoglobin (HbA1c), lipid profile, kidney and liver function analysis were performed at initial and final visits, with a follow-up visit on day 21. Adherence to treatment, palatability and safety were also assessed.

RESULTS

Overall, 21 participants (16 females) were included in the analysis. We found a non-significant decrease of E' wave from 0.05[0.04-0.09] to 0.06[0.05-0.7]cm/s, A-wave from 0.8[0.6-0.8] to 0.7[0.6-0.8] cm/s, and E-wave from 0.6[0.5-0.7] to 0.5[0.425-0.6]cm/s. There was a significant reduction of HbA1c from 49.7[47.0-57.4] to 44.3[38.8-53.0] mmol/mol and triglycerides from 1.6[1.4-1.9] to 1.2[0.9-1.8] mmol/l. A 5% decrease or more was observed for diurnal DBP, diurnal MAP and 24-hour DBP.

CONCLUSION

Zingiberofficinale used as add-on therapy tend to improve diastolic function, blood pressure and lipid profile of type 2 diabetes patients. Further studies are needed to define the dosage and duration of this supplementary treatment accurately.

TRIAL REGISTRATION NUMBER

NCT04222738.

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.

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.

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.

Chondroprotection and Molecular Mechanism of Action of Phytonutraceuticals on Osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease and an important cause of incapacitation. There is a lack of drugs and effective treatments that stop or slow the OA progression. Modern pharmacological treatments, such as analgesics, have analgesic effects but do not affect the course of OA. Long-term use of these drugs can lead to serious side effects. Given the OA nature, it is likely that lifelong treatment will be required to stop or slow its progression. Therefore, there is an urgent need for disease-modifying OA treatments that are also safe for clinical use over long periods. Phytonutraceuticals are herbal products that provide a therapeutic effect, including disease prevention, which not only have favorable safety characteristics but may have an alleviating effect on the OA and its symptoms. An estimated 47% of OA patients use alternative drugs, including phytonutraceuticals. The review studies the efficacy and action mechanism of widely used phytonutraceuticals, analyzes the available experimental and clinical data on the effect of some phytonutraceuticals (phytoflavonoids, polyphenols, and bioflavonoids) on OA, and examines the known molecular effect and the possibility of their use for chondroprotection.

Vasculoprotective effects of ginger (Zingiber officinale Roscoe) and underlying molecular mechanisms

Ginger (Zingiber officinale Roscoe) is a common and widely used spice. It is rich in various chemical constituents, including phenolic compounds, terpenes, polysaccharides, lipids, organic acids, and raw fibers. Herein, we reviewed its effects on the vascular system. Studies utilizing cell cultures or animal models showed that ginger constituents alleviate oxidative stress and inflammation, increase nitric oxide synthesis, suppress vascular smooth muscle cell proliferation, promote cholesterol efflux from macrophages, inhibit angiogenesis, block voltage-dependent Ca2+ channels, and induce autophagy. In clinical trials, ginger was shown to have a favorable effect on serum lipids, inflammatory cytokines, blood pressure, and platelet aggregation. Taken together, these studies point to the potential benefits of ginger and its constituents in the treatment of hypertension, coronary artery disease, peripheral arterial diseases, and other vascular diseases.

Effect of ginger (Zingiber officinale) on inflammatory markers: A systematic review and meta-analysis of randomized controlled trials

The aim of this systematic review and meta-analysis was to investigate the efficacy of ginger supplementation on circulating levels of C-reactive protein (CRP), high sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-α), soluble intercellular adhesion molecule (sICAM), and interleukin-6 (IL-6) concentrations in randomized controlled trials (RCTs). The search included PubMed-Medline, EMBASE, Scopus, Web of Science and Cochrane Library databases to identify randomized clinical trials on the effect of ginger supplementation on circulation levels of CRP, hs-CRP, IL-6, sICAM, and TNF-α published up until February 1st, 2020. We did not restrict articles based on language of publication. Standard mean differences and 95% confidence intervals were calculated for net changes in inflammatory mediators using a random-effects model. Sixteen RCTs comprising 1010 participants were found to be eligible for this meta-analysis. There was a significant reduction of circulating CRP (SMD: -5.11, 95% CI: -7.91, -2.30, I2 = 98.1%), hs-CRP (SMD: -0.88, 95% CI: -1.63, -0.12, I2 = 90.8%) and TNF-α levels (SMD: -0.85, 95% CI: -1.48, -0.21, I2 = 89.4%) following ginger supplementation. However, meta-analysis results did not show any significant impact of ginger supplementation on IL-6 (SMD: -0.45, 95% CI: -1.29, 0.38, I2 = 89.2%), and sICAM levels (SMD: -0.05, 95% CI: -0.36, 0.26, I2 = 00.0%). This systematic review and meta-analysis of RCTs demonstrates a significant impact of ginger in lowering circulating CRP, hs-CRP and TNF-α levels. Large-scale RCTs are still needed to draw concrete conclusions about the effect of ginger on other inflammatory mediators.

Ginger on Human Health: A Comprehensive Systematic Review of 109 Randomized Controlled Trials

Clinical applications of ginger with an expectation of clinical benefits are receiving significant attention. This systematic review aims to provide a comprehensive discussion in terms of the clinical effects of ginger in all reported areas. Following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guideline, randomized controlled trials on the effects of ginger were investigated. Accordingly, 109 eligible papers were fully extracted in terms of study design, population characteristics, evaluation systems, adverse effects, and main outcomes. The reporting quality of the included studies was assessed based on the Cochrane Collaboration's tool for assessing the risk of bias in randomized trials and integrated together with studies that investigated the same subjects. The included studies that examined the improvement of nausea and vomiting in pregnancy, inflammation, metabolic syndromes, digestive function, and colorectal cancer's markers were consistently supported, whereas other expected functions were relatively controversial. Nevertheless, only 43 clinical trials (39.4%) met the criterion of having a 'high quality of evidence.' In addition to the quality assessment result, small populations and unstandardized evaluation systems were the observed shortcomings in ginger clinical trials. Further studies with adequate designs are warranted to validate the reported clinical functions of ginger.

The effect of an oral ginger supplementation on NF-κB concentration in peripheral blood mononuclear cells and anthropomorphic data of patients with type 2 diabetes: A randomized double-blind, placebo-controlled clinical trial

INTRODUCTION

The complications of diabetes are extensive which can be caused by excessive oxidative stress, inflammation and impaired insulin system. Plant-sourced bioactive compounds can reduce inflammation and oxidative stress. The aim of present study was to determine the effect of ginger supplementation on diabetic complications.

METHODS

The present study is a randomized double blind clinical trial which is conducted with 48 diabetic patients. The participants were randomly divided into two intervention and placebo groups which were received 2 g ginger powder and 2 g wheat flour respectively for 10 weeks. Nuclear factor kappa B (NF-κB) concentration and anthropometric measurements were evaluated at the baseline and at the end of study.

RESULTS

The effect of ginger supplementation on hip circumference was marginal and there was no significant effect on BMI and waist circumference. Mean NF-κB p65 concentrations were reduced in ginger supplementation group, however, the amount was not statistically significant.

CONCLUSION

Ginger supplementation had significant effects on anthropometric evaluations. Ginger supplementation decreased mean NF-κB concentration in comparison with placebo, however the significance level was marginal. In order to achieve reliable information, more researches should be complemented with uptake of other diagnostic tools.

Dietary natural products as emerging lipoprotein(a)-lowering agents

Elevated plasma lipoprotein(a) (Lp(a)) levels are associated with an increased risk of cardiovascular disease (CVD). Hitherto, niacin has been the drug of choice to reduce elevated Lp(a) levels in hyperlipidemic patients but its efficacy in reducing CVD outcomes has been seriously questioned by recent clinical trials. Additional drugs may reduce to some extent plasma Lp(a) levels but the lack of a specific therapeutic indication for Lp(a)-lowering limits profoundly reduce their use. An attractive therapeutic option is natural products. In several preclinical and clinical studies as well as meta-analyses, natural products, including l-carnitine, coenzyme Q ₁₀ , and xuezhikang were shown to significantly decrease Lp(a) levels in patients with Lp(a) hyperlipoproteinemia. Other natural products, such as pectin, Ginkgo biloba, flaxseed, red wine, resveratrol and curcuminoids can also reduce elevated Lp(a) concentrations but to a lesser degree. In conclusion, aforementioned natural products may represent promising therapeutic agents for Lp(a) lowering.

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.

Roles of Spicy Foods and Their Bioactive Compounds in Management of Hypercholesterolemia

Hypercholesterolemia, as one of the major risk factors in development of cardiovascular diseases, is of mounting prevalence worldwide in recent years. Many nutraceuticals and phytochemical supplements serve as a promising complementary therapy in the management of hypercholesterolemia. Among them, spicy foods have attracted special attention. Plasma lipid-lowering activity of garlic, ginger, and turmeric have been well-studied in both humans and animals. Consumption of either 3 g/day of ginger or 2 g/day of curcumin for over 4 weeks effectively reduced blood cholesterol in hypercholesterolemia subjects. However, effects of chili and black peppers on blood cholesterol are studied little clinically. The present review is to summarize the findings of recent studies on the efficacy and mechanism of spicy foods and their primary bioactive components in management of hypercholesterolemia from preclinical studies to clinical trials.

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.

Effects of Ginger (Zingiber officinale Roscoe) on Type 2 Diabetes Mellitus and Components of the Metabolic Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective

This article aims to assess the effects of ginger (Zingiber officinale Roscoe) on type 2 diabetes mellitus (T2DM) and/or components of the metabolic syndrome (MetS).

Methods

Electronic literature was searched in PubMed, Embase, the Cochrane Library, Chinese Biomedical Database, China National Knowledge Infrastructure, and Wanfang Database from inception of the database to May 19, 2017, and supplemented by browsing reference lists of potentially eligible articles. Randomized controlled trials on research subjects were included. Data were extracted as a mean difference (MD) and 95% confidence interval (CI). Subgroup analysis of fasting blood glucose (FBG) was performed.

Results

10 studies met the inclusion criteria with a total of 490 individuals. Ginger showed a significant beneficial effect in glucose control and insulin sensitivity. The pooled weighted MD of glycosylated hemoglobin (HbA1c) was −1.00, (95% CI: −1.56, −0.44; P < 0.001). Subgroup analysis revealed that ginger obviously reduced FBG in T2DM patients (−21.24; 95% CI: −33.21, −9.26; P < 0.001). Meanwhile, the significant effects of improvement of lipid profile were observed. Most analyses were not statistically heterogeneous.

Conclusion

Based on the negligible side effects and obvious ameliorative effects on glucose control, insulin sensitivity, and lipid profile, ginger may be a promising adjuvant therapy for T2DM and MetS.

Plants of the Genus Zingiber as a Source of Bioactive Phytochemicals: From Tradition to Pharmacy

Plants of the genus Zingiber (Family Zingiberaceae) are widely used throughout the world as food and medicinal plants. They represent very popular herbal remedies in various traditional healing systems; in particular, rhizome of Zingiber spp. plants has a long history of ethnobotanical uses because of a plethora of curative properties. Antimicrobial activity of rhizome essential oil has been extensively confirmed in vitro and attributed to its chemical components, mainly consisting of monoterpene and sesquiterpene hydrocarbons such as α-zingiberene, ar-curcumene, β-bisabolene and β-sesquiphellandrene. In addition, gingerols have been identified as the major active components in the fresh rhizome, whereas shogaols, dehydrated gingerol derivatives, are the predominant pungent constituents in dried rhizome. Zingiber spp. may thus represent a promising and innovative source of natural alternatives to chemical food preservatives. This approach would meet the increasing concern of consumers aware of the potential health risks associated with the conventional antimicrobial agents in food. This narrative review aims at providing a literature overview on Zingiber spp. plants, their cultivation, traditional uses, phytochemical constituents and biological activities.

The effect of ginger supplementation on serum C-reactive protein, lipid profile and glycaemia: a systematic review and meta-analysis

Aim

To undertake a systematic review and meta-analysis of prospective studies to determine the effect of ginger supplementation on serum C-reactive protein (CRP), lipid profile, and glycaemia.

Method

PubMed-MEDLINE, Web of Science, Cochrane Database, and Google Scholar databases were searched (up until July 2016) to identify prospective studies evaluating the impact of ginger supplementation on serum CRP. Random-effects model meta-analysis was used for quantitative data synthesis. Sensitivity analysis was conducted using the leave-one-out method. Heterogeneity was quantitatively assessed using the I² index. Systematic review registration: CRD42016035973.

Results

From a total of 265 entries identified via searches, 9 studies were included in the final selection. The meta-analysis indicated a significant reduction in serum CRP concentrations following ginger supplementation [weighted mean difference (WMD)−0.84 mg/L (95% CI −1.38 to −0.31, I² 56.3%)]. The WMD for fasting blood glucose and HbA1c was −1.35 mg/dl (95% CI −2.04 to −0.58, I² 12.1%) and −1.01 (95% CI −1.28 to −0.72, I² 9.4%), respectively. Moreover, high-density lipoprotein and triglyceride significantly improved after ginger administration [1.16 mg/dl (95% CI 0.52 to 1.08, I² 12.3%) and −1.63 mg/dl (95% CI −3.10 to −0.17, I² 8.1%), respectively]. These findings were robust in sensitivity analyses. Random-effects meta-regression revealed that changes in serum CRP levels were independent of the dosage of ginger supplementation (slope −0.20; 95% CI −0.95 to 0.55; p=0.60).

Conclusions

This meta-analysis suggests that ginger supplementation significantly reduces serum CRP and improves glycaemia indexes and lipid profile. Randomized control trials with larger sample size and with a longer-term follow-up period should be considered for future investigations.