Effects of garlic supplementation on serum inflammatory markers: A systematic review and meta-analysis of randomized controlled trials

Effect of Encapsulated Purple Garlic Oil on Microvascular Function and the Components of Metabolic Syndrome: A Randomized Placebo-Controlled Study-The ENDOTALLIUM Study

Endothelial dysfunction (ED) is associated with progressive changes contributing to clinical complications related to macro- and microvascular diseases. Garlic (Allium sativum L.) and its organosulfur components have been related to beneficial cardiovascular effects and could improve endothelial function. The ENDOTALLIUM Study aimed to evaluate the effect of the regular consumption of encapsulated purple garlic oil on microvascular function, endothelial-related biomarkers, and the components of metabolic syndrome (MetS) in untreated subjects with cardiometabolic alterations. Fifty-two individuals with at least one MetS component were randomized (1:1) in a single-center, single-blind, placebo-controlled, parallel-group study. The participants received encapsulated purple garlic oil (n = 27) or placebo (n = 25) for five weeks. Skin microvascular peak flow during post-occlusive reactive hyperemia significantly increased in the purple garlic oil group compared to the placebo group (between-group difference [95%CI]: 15.4 [1.5 to 29.4] PU; p = 0.031). Likewise, hs-CRP levels decreased in the purple garlic group compared to the control group (-1.3 [-2.5 to -0.0] mg/L; p = 0.049). Furthermore, we observed a significant reduction in the mean number of MetS components in the purple garlic group after five weeks (1.7 ± 0.9 vs. 1.3 ± 1.1, p = 0.021). In summary, regular consumption of encapsulated purple garlic oil significantly improved microvascular function, subclinical inflammatory status, and the overall MetS profile in a population with cardiometabolic alterations.

A historical, evidence-based, and narrative review on commonly used dietary supplements in lipid-lowering

Dietary supplements augment the nutritional value of everyday food intake and originate from the historical practices of ancient Egyptian (Ebers papyrus), Chinese (Pen Ts'ao by Shen Nung), Indian (Ayurveda), Greek (Hippocrates), and Arabic herbalists. In modern-day medicine, the use of dietary supplements continues to increase in popularity with greater than 50% of the US population reporting taking supplements. To further compound this trend, many patients believe that dietary supplements are equally or more effective than evidence-based therapies for lipoprotein and lipid-lowering. Supplements such as red yeast rice, omega-3 fatty acids, garlic, cinnamon, plant sterols, and turmeric are marketed to and believed by consumers to promote "cholesterol health." However, these supplements are not subjected to the same manufacturing scrutiny by the Food and Drug Administration as pharmaceutical drugs and as such, the exact contents and level of ingredients in each of these may vary. Furthermore, supplements do not have to demonstrate efficacy or safety before being marketed. The holistic approach to lowering atherosclerotic cardiovascular disease risk makes dietary supplements an attractive option to many patients; however, their use should not come at the expense of established therapies with proven benefits. In this narrative review, we provide a historical and evidence-based approach to the use of some dietary supplements in lipoprotein and lipid-lowering and provide a framework for managing patient expectations.

The Effect of Nonthermal Pretreatment on the Drying Kinetics and Quality of Black Garlic

Black garlic is obtained from regular garlic (Allium sativum L.) through the aging process and consequently gains many health-promoting properties, including antidiabetic and antioxidant. However, the material is still prone to microbiological deterioration and requires a long time to dry due to its properties. Therefore, this study aimed to investigate the effect of various drying methods on the quality of black garlic as well as determine the influence of selected nonthermal pretreatments on the drying kinetics and quality of black garlic, which is especially important in the case of the materials that are difficult to dry. The Weibull model was chosen to describe drying kinetics. Additionally, color, water activity together with antioxidant activity, phenolic compounds, and antidiabetic potential were determined. This study found that the application of a pulsed electric field (PEF), a constant electric field (CEF) as well as a magnetic field (MF) significantly reduced the time of drying (by 32, 40, and 24 min for a PEF, a CEF, and a MF, respectively, compared to combined drying without the pretreatment), and resulted in high antidiabetic potential. However, the highest content of phenolic compounds (1123.54 and 1125.36 mg/100 g dm for VMD125 and CD3h-VMD, respectively) and antioxidant capacity (ABTS = 6.05 and 5.06 mmol Trolox/100 g dm for VMD500 and CD6h-VMD, respectively) were reported for black garlic treated by vacuum-microwave drying and combined convective pre-drying followed by vacuum-microwave drying. Overall, the nonthermal pretreatment decreased the time of drying and showed very good efficiency in maintaining the antidiabetic potential of black garlic, especially in the case of the materials pretreated by a constant electric field (IC₅₀ = 99 and 56 mg/mL, for α-amylase and α-glucosidase, respectively).

Evaluating the effects of dark chocolate formulated with micro-encapsulated fermented garlic extract on cardio-metabolic indices in hypertensive patients: A crossover, triple-blind placebo-controlled randomized clinical trial

This study aimed to investigate the health-related effects of microencapsulated fermented garlic extract (FGE) containing dark chocolate in hypertensive adults. For this purpose, 36 hypertensive adults (15 males vs. 21 females) were randomized to receive the FGE (5 g/day) dark chocolate containing 650 mg of FGE powder or the placebo. Intervention periods lasted for 6 weeks and were separated by a 3-week wash-out period. The response variables included blood pressure, anthropometric indices, lipid profile, and inflammatory and oxidative stress indices. Statistical analyses were performed using the Pkcross procedure, and Cohen's d was estimated for all response variables. There was no significant inter-period difference between the mean changes of body weight, waist circumference, and body mass index (BMI). Furthermore, no significant change was confirmed in participants' blood pressure, triglycerides, total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), very low-density lipoprotein (VLDL), serum homocysteine, high-sensitive c-reactive protein (hs-CRP), malondialdehyde (MDA), and total antioxidant capacity (TAC). It seems that the dose of FGE used in this study was not sufficient to cause any significant changes in the outcomes. Therefore, further studies with dose-response designs and longer durations are recommended.

The antinociceptive effect of garlic, garlic preparations, and derivative compounds

The antinociceptive effects of garlic have shown promise in treating different chronic diseases in humans, such as knee osteoarthritis, rheumatoid arthritis, and peripheral arterial occlusive disease stage II. The most common garlic products are garlic powder (dried garlic), steam distilled garlic oils, garlic oil macerate, and aged garlic extract. These commercial products contain organosulfur compounds (OSC) that have been extensively evaluated in preclinical models and some clinical assays to treat different diseases against pain. In this review, we describe the importance of some bioactive compounds found in garlic and its role in treating pain. A systematic search of the literature in Dimensions, PubMed, Scopus, Web of Science was performed. Terms and preselected keywords relating to garlic, its derivates and organusulfur compunds in pain, were used to perform a systematic literature search. Two independent reviewers screened papers for inclusion and assessed the methodological quality. The antinociceptive activity of garlic and its OSC is related to its antioxidant and anti-inflammatory properties, which may be explained by the ability to block the synthesis of PGs, pro-inflammatory cytokines and interferon-γ, by the reduction COX- 2 activity and by increases the levels of anti-inflammatory cytokines. Besides, garlic extract is an activator of TRPA1 and TRPV1, where the principal responsible for this activation are OSC. The relationship between these pathways allows a better understanding how garlic and its derivates could be carrying out its pharmacological action over the management of acute and chronic pain and provide a base by further investigations.

Did Iranians change their eating behavior following COVID-19 outbreak?

BACKGROUND

Significant lifestyle changes have been reported after COVID-19 outbreak. The present study aimed at investigating changes in dietary habits in response to the COVID-19 outbreak in an Iranian population sample.

MATERIALS AND METHODS

In this cross-sectional study, the dietary habits of Iranian adults were assessed before and during the COVID-19 outbreak. Consumption of different food groups such as meats, dairy, fruits, vegetables, seeds, and nuts was assessed using a digital questionnaire which was shared on social media platforms. For the statistical analysis, the Wilcoxon signed-rank test was used.

RESULTS

In this online survey, 1553 questionnaires were completed. The results showed that the reported consumption of protein-rich foods increased (P < 0.05), but fish and dairy consumption showed a significant reduction (P = 0.006 and <0.001, respectively). There was a significant reduction in reported fast-food consumption (P < 0.001). Fruits and vegetables (P < 0.001), natural fruit juices (P < 0.001), and water (P < 0.001) were consumed more frequently. Individuals also consumed more vitamin and mineral supplements (P < 0.001) including those containing Vitamin D.

CONCLUSION

During the COVID-19 pandemic, participants reported a significant change in their dietary habits and intake of supplements. Higher intakes of meats, protein-rich foods, fruits, vegetables, and nutritional supplements and lower intakes of fish, dairy, and fast foods were reported.

Systematic review and meta-analysis of randomised, controlled trials on the effects of garlic supplementation on serum adiponectin and leptin levels

BACKGROUND

Our aim in this meta-analysis was to determine the effect of garlic supplementation on adiponectin and leptin serum levels.

METHOD

A systematic search was conducted using PubMed, Scopus, ISI Web of Science and Cochrane Library for eligible trials up to November 2020. A fixed-effects model was used to pool calculated effect sizes.

RESULTS

Five trials were included in the overall analysis. Our analysis showed that garlic supplementation did not significantly affect adiponectin (Hedges's: 0.20; 95% CI: -0.06, 0.47; P-values = .12) and leptin (Hedges's: 0.08; 95% CI: -0.26, 0.41; P-values = .65) concentrations in comparison with placebo. However, in the subgroup analysis, significantly increased serum adiponectin level was seen following garlic supplementation in trials with a mean age of participants ˂30 years (Hedges's: 0.44; 95% CI: 0.01, 0.87; P-values = .04), the doses ˂1.5 g/d (Hedges's: 0.38; 95% CI: 0.02, 0.71; P-values = .04) and trials with duration ≥8 weeks (Hedges's: 0.48; 95% CI: 0.08, 0.89; P-values = .02).

CONCLUSION

Overall, garlic supplementation could not change the circulatory adiponectin and leptin levels. Subgroup analyses showed a significant reduction in adiponectin levels in younger participants, longer duration and lower intervention dose. However, further studies are needed to confirm the present results.

The Effect of Garlic (Allium sativum L) Supplementation on Circulating Adiponectin: a Systematic Review and Meta-Analysis of Randomized Controlled Trials

Our aim was to conduct a systematic review and meta-analysis on randomized controlled trials (RCTs) evaluating the effect of garlic on serum adiponectin levels. We searched Scopus, Web of Science, PubMed, and Cochrane Library to databases up to January 2021. RCTs investigating the effects of garlic on serum adiponectin levels in adult participants were included. The change in serum adiponectin levels was estimated using weighted mean differences (WMD) and standard deviations (SD). The random effects model was used to provide a summary of mean estimates and their SDs. Out of 386 records, 6 trials with 8 arms treatment which enrolled 266 subjects were included. Garlic supplementation resulted in a non-significant increase in adiponectin concentrations when compared to placebo, according to the pooled data (WMD, 0.27 Hedges' g; 95% confidence interval [CI], -0.07, 0.62; p = 0.124). Greater effects on adiponectin were observed in trials with supplementation dose less than 1.5 gram per day (WMD, 0.71 Hedges' g; 95% CI, -0.01, 1.43; p = 0.600) and in trials with female subset (WMD, 0.62 Hedges' g; 95% CI, -0.96, 2.21; p = 0.441). Garlic boosts adiponectin levels in general. However, due to different target population, various units for reporting adiponectin level and few eligible studies in final analysis, more research is needed to get a firm conclusion about the influence of garlic on adiponectin levels.