Does pomegranate consumption affect weight and body composition? A systematic review and meta-analysis of randomized controlled clinical trials

Polyphenols in obesity and weight management: Are they worth further research? An umbrella review

Polyphenols are widely known for their putative antioxidant and anti-inflammatory effects and their potential protective role in several diseases such as type 2 diabetes, cardiovascular disease and cancer. They have also attracted significant interest as 'anti-obesity' agents, although with mechanisms of action that have been exclusively demonstrated in animal and in vitro studies. This umbrella review aims to evaluate current evidence surrounding the role of polyphenols in obesity and weight management and to establish the usefulness of these agents in combatting obesity. A search of systematic reviews and meta-analyses of randomised controlled trials was carried out. Nine systematic reviews (of which eight included a meta-analysis) were included. Evidence of polyphenols' effects on reducing bodyweight is mixed, and where the effects are significant, they are numerically small and unlikely to be of help in reducing bodyweight or preventing weight gain. Future research should focus on establishing the anti-inflammatory and antioxidant effects of polyphenols through well-designed randomised controlled trials. Such research could be more valuable and cost-effective since it has shown potential to improve human health.

A polyphenol fraction from Rosa multiflora var. platyphylala reduces body fat in overweight humans through appetite suppression - a randomized, double-blind, placebo-controlled trial

BACKGROUND

Rosa species are rich sources of polyphenols with physiological functions. In this study a polyphenol-rich Rosa multiflora (var. platyphylala) petal extract (RoseFit™) was investigated for weight loss in humans.

METHODS

In a randomized, placebo-controlled, parallel-group, double-blind clinical trial seventy overweight male and female subjects (20-50 years) with body mass index (BMI) 25-30 kg/m2 were randomly allocated to the active treatment group (RoseFit) and placebo group in a 1:1 ratio. The subjects received 300 mg capsules twice daily for 12 weeks. The primary efficacy outcome measures included body weight, BMI, and body composition, as determined using Dual-energy X-ray absorptiometry (DEXA). Secondary measures consisted of serum lipid profile and appetite marker (leptin and ghrelin) analyses. Safety analyses included biochemical and hematological assessments.

RESULTS

At the end of the study, a marked reduction in body weight (-1.20 ± 2.62 kg, p < 0.05) and BMI from baseline was observed in the RoseFit group. In addition, the body fat % (RoseFit = -1.69 ± 2.59%, placebo = 0.96 ± 3.21%; p < 0.001) and fat mass (RoseFit = -1.75 ± 1.80 kg, placebo = 1.61 ± 3.82 kg; p < 0.001) were significantly abated in RoseFit group. Importantly, the lean mass was maintained during the intervention. RoseFit ingestion significantly increased the serum leptin levels compared to the placebo (4.85%; p < 0.05). Further, RoseFit group showed reduction in the hunger hormone ghrelin level (2.27%; p < 0.001) from baseline to the end of study, compared to the placebo. The subjective evaluation of appetite using visual analog scale (VAS) questionnaires further confirmed the appetite-suppression effects of RoseFit. The lipid profile significantly improved in RoseFit-treated subjects. No serious adverse events were observed during the study, indicating the tolerability of RoseFit.

CONCLUSIONS

Supplementation with RoseFit significantly impacts body weight management and can thus be a potential nutraceutical ingredient for sustainable weight loss.

TRIAL REGISTRATION

CTRI/2019/10/021584 dated 09/10/2019.

Unlocking the Therapeutic Potential of Ellagic Acid for Non-Alcoholic Fatty Liver Disease and Non-Alcoholic Steatohepatitis

Obesity is in epidemic proportions in many parts of the world, contributing to increasing rates of non-alcoholic fatty liver disease (NAFLD). NAFLD represents a range of conditions from the initial stage of fatty liver to non-alcoholic steatohepatitis (NASH), which can progress to severe fibrosis, through to hepatocellular carcinoma. There currently exists no treatment for the long-term management of NAFLD/NASH, however, dietary interventions have been investigated for the treatment of NASH, including several polyphenolic compounds. Ellagic acid is one such polyphenolic compound. Nutraceutical food abundant in ellagic acid undergoes initial hydrolysis to free ellagic acid within the stomach and small intestine. The proposed mechanism of action of ellagic acid extends beyond its initial therapeutic potential, as it is further broken down by the gut microbiome into urolithin. Both ellagic acid and urolithin have been found to alleviate oxidative stress, inflammation, and fibrosis, which are associated with NAFLD/NASH. While progress has been made in understanding the pharmacological and biological activity of ellagic acid and its involvement in NAFLD/NASH, it has yet to be fully elucidated. Thus, the aim of this review is to summarise the currently available literature elucidating the therapeutic potential of ellagic acid and its microbial-derived metabolite urolithin in NAFLD/NASH.

The effects of pomegranate consumption on obesity indices in adults: A systematic review and meta-analysis

Evidence supports the potential application of polyphenols as agents against obesity. Pomegranate is one of the fruits that possess a high content of polyphenols. This systematic review and meta-analysis of randomized controlled trials (RCTs) sought to evaluate the effects of pomegranate consumption on obesity indices, including body mass index (BMI), body weight, waist circumference (WC), fat mass (FM), body fat percentage (BFP), and fat-free mass (FFM) in adults. Relevant RCTs were obtained by searching databases, including PubMed, SCOPUS, and Web of Science, up to May 2023. Heterogeneity tests of the included trials were performed using the I 2 statistic. Random effects models were assessed based on the heterogeneity tests, and pooled data were determined as the weighted mean difference with a 95% confidence interval. Pooled analysis of 28 trials revealed that pomegranate consumption led to a significant reduction in body weight (WMD: -1.97, 95% CI: -2.91, -1.03, p < .05), and a significant decrease in BMI (WMD: -0.48, 95% CI: -0.76, -0.20, p < .05) in comparison with the control group. However, there were no significant effects on WC, FM, FFM, and BFP in comparison with the control group. Pomegranate consumption may yield a beneficial effect on body weight and BMI in adults. However, there were no significant effects on WC, FM, FFM, and BFP, by pomegranate consumption. Also, pomegranate consumption can reduce body weight, BMI, WC, and BFP in obese adults. Long-term trials with different doses of pomegranate are needed.

Anthropometric and cardiometabolic effects of polyphenols in people with overweight and obesity: an umbrella review

CONTEXT

Polyphenols are plant-based compounds with potential anti-inflammatory, antioxidant, and anti-obesogenic properties. However, their effects on health outcomes remain unclear.

OBJECTIVE

To evaluate the effects of polyphenols on anthropometric and cardiometabolic markers.

DATA SOURCES

Six electronic databases-namely, EMBASE, CINAHL, PubMed, Scopus, The Cochrane Library (reviews only), and Web of Science-were searched for relevant systematic reviews with meta-analyses (SRMAs).

DATA EXTRACTION

Three reviewers performed the data extraction via a data-extraction Microsoft Excel spreadsheet.

DATA ANALYSIS

An umbrella review and meta-analysis of existing SRMAs was conducted. Eighteen SRMAs published from 2015 to 2023, representing 445 primary studies and 838 unique effect sizes, were identified. Meta-analyses were conducted using random-effects models with general inverse variance. Polyphenol-containing foods were found to significantly improve weight (-0.36 kg; 95% confidence interval [CI]: -0.62, 0.77 kg; P < 0.01, I2 = 64.9%), body mass index (-0.25 kg/m2; 95% CI: -0.34, -0.17 kg/m2; P < 0.001, I2 = 82.4%), waist circumference (-0.74 cm; 95% CI: -1.34, -0.15 cm; P < 0.01, I2 = 99.3%), low-density-lipoprotein cholesterol (-1.75 mg/dL; 95% CI: -2.56, -0.94; P < 0.001, I2 = 98.6%), total cholesterol (-1.23 mg/dL; 95% CI: -2.00, -0.46; P = 0.002, I2 = 94.6%), systolic blood pressure (-1.77 mmHg; 95% CI: -1.77, -0.93 mmHg; P < 0.001, I2 = 72.4%), diastolic blood pressure (-1.45 mmHg; 95% CI: -2.09, -0.80 mmHg; P < 0.001, I2 = 61.0%), fat percentage (-0.70%; 95% CI: -1.03, -0.36%; P < 0.001, I2 = 52.6%), fasting blood glucose (-0.18 mg/dL; 95% CI: -0.35, -0.01 mg/dL; P = 0.04, I2 = 62.0%), and C-reactive protein (CRP; including high-sensitivity-CRP [hs-CRP]) (-0.2972 mg/dL; 95% CI: -0.52, -0.08 mg/dL; P = 0.01, I2 = 87.9%). No significant changes were found for high-density-lipoprotein cholesterol (-0.12 mg/dL; 95% CI: -1.44, 0.69; P = 0.67, I2 = 89.4%) and triglycerides (-1.29 mg/dL; 95% CI: -2.74, 0.16; P = 0.08, I2 = 85.4%). Between-study heterogeneity could be explained by polyphenol subclass differences.

CONCLUSION

The findings of this umbrella review support the beneficial effects of polyphenols on anthropometric and metabolic markers, but discretion is warranted to determine the clinical significance of the magnitude of the biomarker improvements.

SYSTEMATIC REVIEW REGISTRATION

International Prospective Register of Systematic Reviews no. CRD42023420206.

Pomegranate effects on the health aspects of women during peri- and postmenopause: A systematic review and meta-analysis

Pomegranate is widely used to preserve human health and help prevent many kinds of diseases. This study aims to review and assess the effects of pomegranate on women's health during and after menopause. PubMed, Web of science, Cochrane, Scopus, and Google Scholar were searched up to the end of 2022 with no language or study type restriction. All types of clinical research studies (randomized clinical trial [RCT], pre-post, case report, and case series) were included. The Cochrane RoB 2.0 tool was used for quality assessment of RCTs. A summary of intervention's effects for each study was provided by calculating standardized mean differences and accompanying 95% confidence interval using random effect model. Weighted mean differences and heterogeneity between studies were assessed using Hedges's method and Cochran's Q test, respectively. Pomegranate can significantly improve hot flashes severity and menopause symptoms and decrease FSH. It significantly improves high-density lipoprotein but not low-density lipoprotein, body mass index, and weight. Most of our results are inconclusive, and the small sample sizes and the lack of blinding and randomization have led to an increased risk of bias. Pomegranate can decrease menopause symptoms, but more well-designed studies, with bigger sample sizes are needed to establish its other clinical benefits for menopausal women.

An insight into the neuroprotective effects and molecular targets of pomegranate (Punica granatum) against Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease that still has no permanent cure. The drugs prescribed in the present days are only for symptomatic relief for the patients. Many studies correlating the reduction in the incidence of AD with the diet consumed have been published. These studies showed that a diet rich in polyphenols is associated with a decrease in the incidence of AD. The present review is focused on the ability of pomegranate and its bioactive components to ameliorate the progression of AD and their ability to exert a neuroprotective effect. Various studies showing the ability of pomegranate in inhibiting enzymes, reducing reactive oxygen species, inhibition of microglial activation, inhibition of tau protein hyperphosphorylation, maintenance of synaptic plasticity, anti-inflammatory activity and its ability to inhibit Beta secretase-1 (BACE-1) has been reviewed in this article. In spite of the lack of studies on humans, there are compelling evidence indicating that pomegranate can reduce various risk factors involved in the causation of AD and thus can be used as a persistent nutraceutical to slow ageing and for providing neuroprotection for the treatment of AD.Highlights An overview of traditional and pharmacological uses of pomegranate (POM).Potential of POM in the treatment of neurodegenerative diseases especially in AD.Insight into the molecular mechanisms of neuroprotective effects of POM in AD.Clinical evaluation studies involving POM and its bioactive components.

The effect of concentrated pomegranate juice on biomarkers of inflammation, oxidative stress, and sex hormones in overweight and obese women with polycystic ovary syndrome: A randomized controlled trial

Polycystic ovary syndrome (PCOS) is a common gynecological endocrine disorder. Pomegranate juice (PJ) has been known to play anti-inflammatory and antioxidant roles. However, the effects of PJ on inflammation, oxidative stress, and sex hormones in PCOS patients are very little studied, and thus more studies are needed. This randomized controlled trial enrolled 44 women diagnosed with PCOS according to the Rotterdam criteria, body mass index (BMI) ≥ 25 kg/m² , and aged 18-40 years old. Participants were randomly assigned to take 45 ml/day of concentrated PJ or a control group without intervention. Some biomarkers of sex hormones, inflammation, and oxidative stress were quantified at baseline and after the 8-week intervention. Compared with the controls, serum testosterone levels were significantly decreased in overweight and obese women with PCOS who supplemented with concentrated PJ (-0.004 ± 0.013 vs. 0.039 ± 0.013, p = .039). However, we did not observe significant differences in luteinizing hormone (LH) and sex hormone-binding globulin (SHBG) levels and inflammation and oxidative stress factors between the two groups after adjustment for confounding variables. An 8-week supplementation with concentrated PJ could effectively improve testosterone levels in overweight and obese women with PCOS. This study was registered at www.irct.ir (IRCT20191109045383N1).

Pharmacotherapeutic potential of pomegranate in age-related neurological disorders

Age-related neurological disorders [AND] include neurodegenerative diseases [NDDs] such as Alzheimer's disease [AD] and Parkinson's disease [PD], which are the most prevalent types of dementia in the elderly. It also includes other illnesses such as migraine and epilepsy. ANDs are multifactorial, but aging is their major risk factor. The most frequent and vital pathological features of AND are oxidative stress, inflammation, and accumulation of misfolded proteins. As AND brain damage is a significant public health burden and its incidence is increasing, much has been done to overcome it. Pomegranate (Punica granatum L.) is one of the polyphenol-rich fruits that is widely mentioned in medical folklore. Pomegranate is commonly used to treat common disorders such as diarrhea, abdominal pain, wound healing, bleeding, dysentery, acidosis, microbial infections, infectious and noninfectious respiratory diseases, and neurological disorders. In the current review article, we aimed to summarize the data on the pharmacotherapeutic potentials of pomegranate in ANDs.

Promoting effect of pomegranate peel extract on second-degree burn wound-healing through VEGF-A and TGF-β1 regulation

Pomegranate peel extract (PPE), a polyphenolic compound derived from pomegranate, has been widely concerned for its anti-oxidant, anti-inflammatory, and bacteriostatic effects. The potential therapeutic effect of PPE on burn injury was investigated, and its possible mechanisms were explored. Minipigs with second-degree burn were treated with PPE, Jing Wan Hong, and silver sulfadiazine. Hematoxylin-eosin (HE) staining was performed to detect burn severity, and then biological tissues were biopsied on days 0, 7, 14, 21, and 28 after administration. Immunohistochemistry, western blot, and real-time polymerase chain reaction (RT-PCR) were used to detect the protein and mRNA expression levels of VEGF-A and TGF-β1 in skin tissues after treatment with PPE. Furthermore, the skin wound healing at different time points was monitored by macroscopic observation. HE showed that after 28-day PPE treatment, the morphology of the skin tissue showed a significant improvement. Macroscopic data monitoring indicated that the decrustation and fur growing time was shortened. Meanwhile, the rate of wound healing increased after PPE treatment. The combination of immunohistochemistry, western blotting, and RT-PCR showed that after PPE treatment, expression of VEGF-A and TGF-β1 increased sharply on day 7, maintaining a high level until day 14, showing a downward trend on day 21, and approaching normal levels on day 28. However, in the model group, the protein and mRNA expression levels of VEGF-A and TGF-β1 increased on day 28 after burn injury, which was a slow process. Results indicated that compared with the model group, the peak expression level of VEGF-A and TGF-β1 was earlier, which was consistent with decrustation, shortening of fur growing time, and improvement of wound healing rate in minipig second-degree burn model. PPE showed a significant promoting effect on minipig second-degree burn model, which might be associated with the upregulation of the protein and gene expression levels of VEGF-A and TGF-β1.

Ellagic Acid: A Review on Its Natural Sources, Chemical Stability, and Therapeutic Potential

Ellagic acid (EA) is a bioactive polyphenolic compound naturally occurring as secondary metabolite in many plant taxa. EA content is considerable in pomegranate (Punica granatum L.) and in wood and bark of some tree species. Structurally, EA is a dilactone of hexahydroxydiphenic acid (HHDP), a dimeric gallic acid derivative, produced mainly by hydrolysis of ellagitannins, a widely distributed group of secondary metabolites. EA is attracting attention due to its antioxidant, anti-inflammatory, antimutagenic, and antiproliferative properties. EA displayed pharmacological effects in various in vitro and in vivo model systems. Furthermore, EA has also been well documented for its antiallergic, antiatherosclerotic, cardioprotective, hepatoprotective, nephroprotective, and neuroprotective properties. This review reports on the health-promoting effects of EA, along with possible mechanisms of its action in maintaining the health status, by summarizing the literature related to the therapeutic potential of this polyphenolic in the treatment of several human diseases.

The Effects of Polyphenol Supplementation in Addition to Calorie Restricted Diets and/or Physical Activity on Body Composition Parameters: A Systematic Review of Randomized Trials

Background: Both, calorie restricted diets (CRD) and physical activity (PA) are conventional obesity therapies but their effectiveness is usually limited in the long-term. Polyphenols are bioactive compounds that have shown to possess some anti-obesity properties. The synergic effects between dietary polyphenols and CRD or PA on body weight and fat are supported by several animal studies, but evidence in human is still inconsistent. Thus, our aim was to review the combined effects of polyphenol supplementation with CRD and/or PA on body weight and fat, body mass index (BMI) and waist circumference (WC) in overweight or obese adults. Methods: Electronic databases (PubMed, Web of Science and Cochrane CENTRAL) were searched for randomized clinical trials (RCT) examining the combination of polyphenols with CRD and/or PA (up to December 31st, 2019). Articles were included if they had a duration of intervention ≥ 4 weeks. Both, quality and risk of bias of the included studies were assessed using the Cochrane RoB2 Tool. Results: The review included 4 and 11 RCTs investigating the anti-obesity effects of polyphenol supplementation combined with CRD and PA, respectively. Isoflavone supplementation may increase fat loss during exercise among post-menopausal women in non-Asian studies. In the rest of RCTs regarding polyphenol supplementation and CRD or PA, no additive changes were found. Conclusion: The results do not yet support polyphenol supplementation as a complementary strategy for enhancing the effectiveness of CRD and PA on weight and fat loss. However, this review suggests that isoflavone and soy products combined with lifestyle changes, especially exercise, provide additional anti-obesity effects in postmenopausal women. The potential role of polyphenols alone or, especially, in addition to conventional therapies (CRD and PA) mostly remains uncertain; and therefore, larger and longer RCTs examining these effects are needed. Protocol Registration: PROSPERO CRD42020159890.