Effects of Anthocyanin Supplementation on Reduction of Obesity Criteria: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Bioavailability of Anthocyanins: Whole Foods versus Extracts

Anthocyanins have gained significant popularity in recent years for their diverse health benefits, yet their limited bioavailability poses a challenge. To address this concern, technologies have emerged to enhance anthocyanin concentration, often isolating these compounds from other food constituents. However, the extent to which isolated anthocyanins confer health benefits compared to their whole-food counterparts remains unclear. This review explores the current literature on anthocyanin bioavailability and metabolism in the body, with a focus on comparing bioavailability when consumed as extracts versus whole foods rich in anthocyanins, drawing from in vitro, in vivo, and human clinical studies. While direct comparisons between anthocyanin bioavailability in whole foods versus isolates are scarce, prevailing evidence favours whole-food consumption over anthocyanin extracts. Further clinical investigations, preferably with direct comparisons, are needed to validate these findings and elucidate the nuanced interplay between anthocyanins and food matrices, informing future research directions and practical recommendations.

Effects of Anthocyanins on Components of Metabolic Syndrome-A Review

Metabolic syndrome (MetS) is a significant health problem. The co-occurrence of obesity, carbohydrate metabolism disorders, hypertension and atherogenic dyslipidaemia is estimated to affect 20-30% of adults worldwide. Researchers are seeking solutions to prevent and treat the conditions related to MetS. Preventive medicine, which focuses on modifiable cardiovascular risk factors, including diet, plays a special role. A diet rich in fruits and vegetables has documented health benefits, mainly due to the polyphenolic compounds it contains. Anthocyanins represent a major group of polyphenols; they exhibit anti-atherosclerotic, antihypertensive, antithrombotic, anti-inflammatory and anticancer activities, as well as beneficial effects on endothelial function and oxidative stress. This review presents recent reports on the mechanisms involved in the protective effects of anthocyanins on the body, especially among people with MetS. It includes epidemiological data, in vivo and in vitro preclinical studies and clinical observational studies. Anthocyanins are effective, widely available compounds that can be used in both the prevention and treatment of MetS and its complications. Increased consumption of anthocyanin-rich foods may contribute to the maintenance of normal body weight and modulation of the lipid profile in adults. However, further investigation is needed to confirm the beneficial effects of anthocyanins on serum glucose levels, improvement in insulin sensitivity and reduction in systolic and diastolic blood pressure.

Clinically Effective Molecules of Natural Origin for Obesity Prevention or Treatment

The prevalence and incidence of obesity and the comorbidities linked to it are increasing worldwide. Current therapies for obesity and associated pathologies have proven to cause a broad number of adverse effects, and often, they are overpriced or not affordable for all patients. Among the alternatives currently available, natural bioactive compounds stand out. These are frequently contained in pharmaceutical presentations, nutraceutical products, supplements, or functional foods. The clinical evidence for these molecules is increasingly solid, among which epigallocatechin-3-gallate, ellagic acid, resveratrol, berberine, anthocyanins, probiotics, carotenoids, curcumin, silymarin, hydroxy citric acid, and α-lipoic acid stand out. The molecular mechanisms and signaling pathways of these molecules have been shown to interact with the endocrine, nervous, and gastroenteric systems. They can regulate the expression of multiple genes and proteins involved in starvation-satiety processes, activate the brown adipose tissue, decrease lipogenesis and inflammation, increase lipolysis, and improve insulin sensitivity. This review provides a comprehensive view of nature-based therapeutic options to address the increasing prevalence of obesity. It offers a valuable perspective for future research and subsequent clinical practice, addressing everything from the molecular, genetic, and physiological bases to the clinical study of bioactive compounds.

Anthocyanins of Hierbamora (Solanum nigrescens): Revealing their Nutraceutical Potential for Controlling Hypertriglyceridemia and Helicobacter pylori Viability

We present the inhibitory properties of the Solanum nigrescens anthocyanin fraction (SNAF) and its major constituents on alpha-glucosidase (AG), pancreatic lipase (PL), HMG-CoA reductase, and ornithine decarboxylase (ODC). The effect of SNAF was simultaneously evaluated in ICR male mice exposed to triglyceride charge test (TCT). HPLC-MS profiling revealed the presence cyanidin-3-O-rutinoside-5-glucoside (CRG), delphinidin-3-(p-coumaroyl)-rutinoside-5-glucoside (DCRG), and petunidin-3-(cis-p-coumaroyl)-rutinoside-5-glucoside (PCRG) as major constituents of the fraction. SNAF, CRG, and specially PCRG, induced strong non-competitive inhibition on PL (IC50 , 33-86 μg mL-1 ). The results of TCT confirmed their capacity to ameliorate (p <0.001) hypertriglyceridemia during postprandial and interdigestive stages. SNAF, CRG, DCRG, and PCRG caused negligible growth inhibition (MIC>600 μg mL-1 ) on beneficial bacteria whereas SNAF and DCRG exerted inhibitory activity on Helicobacter pylori ATCC 53504 (MIC,187-64 μg mL-1 ). Additional exploration revealed that SNAF and DCRG produced non-competitive activity on H. pylori urease, which facilitates bacterial growth under acidic conditions.

The Role of Cyanidin-3-O-glucoside in Modulating Oxaliplatin Resistance by Reversing Mesenchymal Phenotype in Colorectal Cancer

BACKGROUND

Epithelial-mesenchymal transition (EMT) plays an important role in the biological and biochemical processes of cells, and it is a critical process in the malignant transformation, and mobility of cancer. Additionally, EMT is one of the main mechanisms contributing to chemoresistance. Resistance to oxaliplatin (OXA) poses a momentous challenge in the chemotherapy of advanced colorectal cancer (CRC) patients, highlighting the need to reverse drug resistance and improve patient survival. In this study, we explored the response of cyanidin-3-O-glucoside (C3G), the most abundant anthocyanin in plants, on the mechanisms of drug resistance in cancer, with the purpose of overcoming acquired OXA resistance in CRC cell lines.

METHODS

We generated an acquired OXA-resistant cell line, named HCT-116-ROx, by gradually exposing parental HCT-116 cells to increasing concentrations of OXA. To characterize the resistance, we performed cytotoxicity assays and shape factor analyses. The apoptotic rate of both resistant and parental cells was determined using Hoechst 33342/Propidium Iodide (PI) fluorescence staining. Migration capacity was evaluated using a wound-healing assay. The mesenchymal phenotype was assessed through qRT-PCR and immunofluorescence staining, employing E-cadherin, N-cadherin, and Vimentin markers.

RESULTS

Resistance characterization announced decreased OXA sensitivity in resistant cells compared to parental cells. Moreover, the resistant cells exhibited a spindle cell morphology, indicative of the mesenchymal phenotype. Combined treatment of C3G and OXA resulted in an augmented apoptotic rate in the resistant cells. The migration capacity of resistant cells was higher than parental cells, while treatment with C3G decreased the migration rate of HCT-116-ROx cells. Analysis of EMT markers showed that HCT-116-ROx cells exhibited loss of the epithelial phenotype (E-cadherin) and gain of the mesenchymal phenotype (N-cadherin and Vimentin) compared to HCT-116 cells. However, treatment of resistant cells with C3G reversed the mesenchymal phenotype.

CONCLUSION

The morphological observations of cells acquiring oxaliplatin resistance indicated the loss of the epithelial phenotype and the acquisition of the mesenchymal phenotype. These findings suggest that EMT may contribute to acquired OXA resistance in CRC. Furthermore, C3G decreased the mobility of resistant cells, and reversed the EMT process, indicating its potential to overcome acquired OXA resistance.

Anthocyanins: Molecular Aspects on Their Neuroprotective Activity

Anthocyanins are a type of flavonoids that give plants and fruits their vibrant colors. They are known for their potent antioxidant properties and have been linked to various health benefits. Upon consumption, anthocyanins are quickly absorbed and can penetrate the blood-brain barrier (BBB). Research based on population studies suggests that including anthocyanin-rich sources in the diet lower the risk of neurodegenerative diseases. Anthocyanins exhibit neuroprotective effects that could potentially alleviate symptoms associated with such diseases. In this review, we compiled and discussed a large body of evidence supporting the neuroprotective role of anthocyanins. Our examination encompasses human studies, animal models, and cell cultures. We delve into the connection between anthocyanin bioactivities and the mechanisms underlying neurodegeneration. Our findings highlight how anthocyanins' antioxidant, anti-inflammatory, and anti-apoptotic properties contribute to their neuroprotective effects. These effects are particularly relevant to key signaling pathways implicated in the development of Alzheimer's and Parkinson's diseases. In conclusion, the outcome of this review suggests that integrating anthocyanin-rich foods into human diets could potentially serve as a therapeutic approach for neurological conditions, and we identify promising avenues for further exploration in this area.

Nutraceutical Activity of Anthocyanins from the Edible Berries of Rhamnus pompana

We present the inhibitory properties of the R. pompana anthocyanin fraction (RPAF) and its major constituents on alpha-glucosidase (AG), pancreatic lipase (PL), HMG-CoA reductase, and ornithine decarboxylase (ODC). The effect of RPAF was also evaluated in ICR male mice subjected to oral glucose tolerance test (OGTT) and hypercaloric/atherogenic diet for 30 days. RP-HPLC/MS profiling revealed that RPAF contained five major anthocyanins and induced slight inhibition on PL and HMG-CoA reductase (IC50 , 245-338 μg mL-1 ) whereas strong activity on AG and ODC (IC50 , 130-133 μg mL-1 ) was observed. Kinetic studies and molecular docking with pelargonidin-3-O-rutinoside (P3R) on ODC, revealed changes in Km (0.9514-0.9746 mM) and Vmax (1.96-2.32 μmol mg-1  min-1 ) suggesting mixed inhibition and molecular interaction with two active sites of ODC. P3R showed antiproliferative activity (IC50, 46.5 μM) and decreased polyamine accumulation in DLD-1 cells. The results of OGTT confirmed that RPAF regulates postprandial glucose levels in diabetic animals which experienced a significant glucose depletion (30 %; p<0.001) from 30 to 120 min post-treatment. Prolonged supplementation of RPAF caused significant decrease (p<0.001) in plasma glucose, total cholesterol, LDL-c and triglycerides as well as significant increase (p<0.001) of HDL-c compared with normoglycemic untreated animals.

A Comprehensive Review of Phytonutrients as a Dietary Therapy for Obesity

Obesity is a complex medical condition mainly caused by eating habits, genetics, lifestyle, and medicine. The present study deals with traditional diets like the Mediterranean diet, Nordic diet, African Heritage diet, Asian diet, and DASH, as these are considered to be sustainable diets for curing obesity. However, the bioavailability of phytonutrients consumed in the diet may vary, depending on several factors such as digestion and absorption of phytonutrients, interaction with other substances, cooking processes, and individual differences. Hence, several phytochemicals, like polyphenols, alkaloids, saponins, terpenoids, etc., have been investigated to assess their efficiencies and safety in the prevention and treatment of obesity. These phytochemicals have anti-obesity effects, mediated via modulation of many pathways, such as decreased lipogenesis, lipid absorption, accelerated lipolysis, energy intake, expenditure, and preadipocyte differentiation and proliferation. Owing to these anti-obesity effects, new food formulations incorporating these phytonutrients were introduced that can be beneficial in reducing the prevalence of obesity and promoting public health.

Extracts of Dunkelfelder Grape Seeds and Peel Increase the Metabolic Rate and Reduce Fat Deposition in Mice Maintained on a High-Fat Diet

Chronic high-fat diet intake may induce obesity and increase the risk of metabolic syndrome. The pomace of grape (Vitis vinifera L.) is rich in polyphenols, which are candidates for anti-obesity therapy. The present study aimed to investigate the effects of Dunkelfelder grape seed extract (GSE) and grape peel extract (GPE) on lipid and energy metabolism disorders in mice maintained on a high-fat diet (HFD). Male nine-week C57BL/6J mice were randomly assigned to one of four groups, namely, the normal chow diet (ND), HFD, HFD plus GSE (400 mg/kg BW) administered by oral gavage, or HFD plus GPE (400 mg/kg BW) administered by oral gavage. There were eight mice per group, and the experiment was 14 weeks in duration. The results showed that GSE and GPE treatments did not affect energy intake in mice on a high-fat diet, but body weight gain was 24.5% and 17.3% lower in the GSE- and GPE-treated mice than in the HFD group, respectively. They also decreased blood triglyceride (TG), total cholesterol (TC), and fasting blood glucose levels and increased high-density lipoprotein cholesterol (HDL-C). In addition, GSE and GPE reduced adipose tissue weight and excessive lipid droplet accumulation in the adipocytes. The metabolic chamber test showed that the GSE and GPE treatments enhanced oxygen consumption, carbon dioxide production, and heat release while decreasing the respiratory exchange rate (RER). This suggests that GSE and GPE augmented fuel oxidation and energy generation and increased the proportion of lipids being utilized in energy metabolism. GSE and GPE also upregulated the genes controlling lipolysis and downregulated those controlling lipogenesis in adipose tissues. Moreover, they significantly increased the expression levels of the genes regulating thermogenesis in BAT, eWAT, and iWAT, and mitochondrial biogenesis in all three types of adipose tissue. In conclusion, the present study empirically demonstrated that GSE and GPE enhance body fat utilization by augmenting lipid and energy metabolism and could, therefore, ameliorate high-fat diet-induced obesity.

How effective are anthocyanins on healthy modification of cardiometabolic risk factors: a systematic review and meta-analysis

BACKGROUND

In this meta-analysis, findings from recent studies on the preventive properties of anthocyanins (ACN) against cardiovascular disease are summarized.

METHODS

MEDLINE, PubMed, Embase, Cochrane Library, and Google Scholar were searched and 2512 studies were found in a preliminary search. After screening of titles and abstracts, 47 studies met the inclusion criteria (randomized clinical trial design and sufficient data of outcomes). Studies were excluded based on the following criteria: incomplete data; obscurely reported outcomes, or lack of control groups; and animal studies.

RESULTS

The results showed that intervention with ACNs resulted in a significant decrease in body mass index ((MD),- 0.21; 95% CI, - 0.38, - 0.04; P < 0.001) and body fat mass (MD: - 0.3%, 95% CI - 0.42 to - 0.18%, p < 0.001). Pooled data comparing ACN with control showed statistically significant effect on fasting blood sugar and HbA1c. However, the reductions were significantly more in the subjects with type 2 diabetes and in those who used ACN as supplement/extract. The subgroup analysis test showed that there was a significant effect of ACN on triglyceride concentrations, total cholesterol, LDL-C and HDL-C concentrations in all subgroups of participants (with vs. without dyslipidemia at baseline) and intervention type (supplement/extract vs. food). However, we did not observe any significant effect on apo A and apo B concentrations.

CONCLUSIONS

ACN intake in the forms of natural foods and supplements can induce healthy changes in body fat mass, glycemic and lipidemic status and these effects are more prominent in the subjects with above-normal values. This meta-analysis was registered at http://www.crd.york.ac.uk/Prospero (Registration no. CRD42021286466).

Dietary intake of anthocyanins improves arterial stiffness, but not endothelial function, in volunteers with excess weight: A randomized clinical trial

Excess body weight has been associated with endothelial dysfunction and increased arterial stiffness. Foods rich in polyphenols and anthocyanins such as açaí-juçara (Euterpe edulis Martius) fruit may have protective vascular effects. Thus, we examined the effect of dietary intake of anthocyanins (açaí-juçara fruit) on endothelial function (flow-mediated dilation [FMD]) and arterial stiffness (pulse wave velocity [PWV]) in individuals with excess body weight. Fifty-five individuals with BMI ≥25 kg/m² were randomized into non-anthocyanin (N-ATH, n = 25) or anthocyanin (ATH, n = 30) intake groups. A 12-week individualized diet plan (20% reduction in total energy intake) was prescribed and included daily intake of açaí-juçara 200 g (anthocyanins 293.6 mg) in the ATH diet plan. We evaluated anthropometric and biochemical parameters, FMD, PWV, and peripheral vascular resistance (PVR). A GEE (Bonferroni post-hoc) was used (p ≤ 0.05). No change in FMD was observed. However, PWV showed a reduction from baseline in the ATH (p = 0.002) and vs. N-ATH (p = 0.036). Both groups showed reduced peripheral vascular resistance (N-ATH, p = 0.005; ATH, p = 0.040) with no significant differences between them. In conclusion, dietary intake of anthocyanins proved effective in protecting against arterial stiffness (by PWV) in individuals with excess weight. PVR was reduced in both diet groups regardless of dietary intake of anthocyanins.

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

Background and Aims

Anthocyanins (ACNs) are water-soluble plant pigments belong to flavonoids with beneficial effects on health and disease prevention. Some studies have examined the effect of ACNs on anthropometric and body composition indices, but the findings were inconsistent. This systematic review and meta-analysis aimed to investigate the effect of ACNs and sources rich in anthocyanins on body mass index (BMI), body weight (BW), waist circumference (WC), hip circumference (HC), waist-hip ratio (WHR), percentage of fat mass (PFM) and fat free mass (FFM).

Methods

PubMed, Web of Science, Scopus, and Google Scholar were searched with no limitation until May 2021 to find relevant randomized controlled clinical trials (RCT). The risk of bias was assessed utilizing Cochrane collaboration's tool. Weighted mean differences (WMD) and 95% confidence intervals (CIs) were obtained using a random effects model.

Results

A total of 31 RCTs (with 0.77-640 mg/day of ACNs supplementation for 28-90 days) with 1438 participants were included. No significant effect was found in BMI, WC, HC, WHR, PFM and FFM after ACNs consumption.

Conclusions

The results showed that ACNs did not significantly affect anthropometric and body composition parameters. Further high-quality RCTs are required to validate these findings.

Ageing, Metabolic Dysfunction, and the Therapeutic Role of Antioxidants

The gradual ageing of the world population has been accompanied by a dramatic increase in the prevalence of obesity and metabolic diseases, especially type 2 diabetes. The adipose tissue dysfunction associated with ageing and obesity shares many common physiological features, including increased oxidative stress and inflammation. Understanding the mechanisms responsible for adipose tissue dysfunction in obesity may help elucidate the processes that contribute to the metabolic disturbances that occur with ageing. This, in turn, may help identify therapeutic targets for the treatment of obesity and age-related metabolic disorders. Because oxidative stress plays a critical role in these pathological processes, antioxidant dietary interventions could be of therapeutic value for the prevention and/or treatment of age-related diseases and obesity and their complications. In this chapter, we review the molecular and cellular mechanisms by which obesity predisposes individuals to accelerated ageing. Additionally, we critically review the potential of antioxidant dietary interventions to counteract obesity and ageing.

Comparative Study on Grape Berry Anthocyanins of Various Teinturier Varieties

The red-fleshed grape cultivars, called teinturier or dyer grapes, contain anthocyanins in both the skin and flesh. These phenolic compounds exhibit excellent coloring ability, and as antioxidants, they are important bioactive compounds in food crops. In this work, anthocyanin patterns of grape berries of fifteen teinturier varieties collected from the gene bank located at Pécs in the southwest of Hungary were compared. Anthocyanin profiles of numerous varieties originating from Hungary such as 'Bíborkadarka', 'Kármin', 'Kurucvér', and 'Turán' are reported for the first time. Anthocyanins extracted separately from the skin and juice were analyzed using high-performance liquid chromatography coupled with a photodiode array detector. For the identification of compounds, high-resolution orbitrap mass spectrometry was used. All in all, twenty-one anthocyanins were identified and quantified. We found that anthocyanin patterns differed significantly in the skin and juice for all investigated cultivars. For Vitis vinifera varieties, the predominant anthocyanin in the skin was malvidin-3-O-glucoside, while the main pigment in the juice was peonidin-3-O-glucoside. For the first time, a significant amount of diglucosides was detected in two Vitis Vinifera cultivars with a direct relationship. In general, the pigment composition of the skin was much more complex than that of the juice. The comparative study with presented patterns gives valuable and beneficial information from a chemotaxonomical point of view. Our results also help to choose the appropriate teinturier varieties with the desired anthocyanins for food coloring or winemaking purposes.

Effect of natural polyphenols in Chinese herbal medicine on obesity and diabetes: Interactions among gut microbiota, metabolism, and immunity

With global prevalence, metabolic diseases, represented by obesity and type 2 diabetes mellitus (T2DM), have a huge burden on human health and medical expenses. It is estimated that obese population has doubled in recent 40 years, and population with diabetes will increase 1.5 times in next 25 years, which has inspired the pursuit of economical and effective prevention and treatment methods. Natural polyphenols are emerging as a class of natural bioactive compounds with potential beneficial effects on the alleviation of obesity and T2DM. In this review, we investigated the network interaction mechanism of "gut microbial disturbance, metabolic disorder, and immune imbalance" in both obesity and T2DM and systemically summarized their multiple targets in the treatment of obesity and T2DM, including enrichment of the beneficial gut microbiota (genera Bifidobacterium, Akkermansia, and Lactobacillus) and upregulation of the levels of gut microbiota-derived metabolites [short-chain fatty acids (SCFAs)] and bile acids (BAs). Moreover, we explored their effect on host glucolipid metabolism, the AMPK pathway, and immune modulation via the inhibition of pro-inflammatory immune cells (M1-like Mϕs, Th1, and Th17 cells); proliferation, recruitment, differentiation, and function; and related cytokines (TNF-α, IL-1β, IL-6, IL-17, and MCP-1). We hope to provide evidence to promote the clinical application of natural polyphenols in the management of obesity and T2DM.

The Antiaging Activities of Phytochemicals in Dark-Colored Plant Foods: Involvement of the Autophagy- and Apoptosis-Associated Pathways

In the last two decades, human life expectancy has increased by about 10 years, but this has not been accompanied by a corresponding increase in healthy lifespan. Aging is associated with a wide range of human disorders, including cancer, diabetes, and cardiovascular and neurodegenerative diseases. Delaying the aging of organs or tissues and improving the physiological functions of the elderly can reduce the risk of aging-related diseases. Autophagy and apoptosis are crucial mechanisms for cell survival and tissue homeostasis, and may also be primary aging-regulatory pathways. Recent epidemiological studies have shown that eating more colorful plant foods could increase life expectancy. Several representative phytochemicals in dark-colored plant foods such as quercetin, catechin, curcumin, anthocyanins, and lycopene have apparent antiaging potential. Nevertheless, the antiaging signaling pathways of the phytochemicals from dark-colored plant foods remain elusive. In the present review, we summarized autophagy- and apoptosis-associated targeting pathways of those phytochemicals and discussed the core targets involved in the antiaging effects. Further clinical evaluation and exploitation of phytochemicals as antiaging agents are needed to develop novel antiaging therapeutics for preventing age-related diseases and improving a healthy lifespan.

Effects of Antioxidant Supplementation on Metabolic Disorders in Obese Patients from Randomized Clinical Controls: A Meta-Analysis and Systematic Review

Purpose

This systematic review and meta-analysis aim at elucidating the heterogeneity in beneficial effects of antioxidant supplementation in obese adults by exploring the differential effects of antioxidant supplementation on basic indicators of obesity, lipid metabolism, systemic antioxidant capacity, inflammatory biomarkers, and liver function.

Methods

The inclusion criteria specified randomized controlled trials with antioxidant intervention for adults (mean body mass index (BMI) > 30), from inception to Aug. 8, 2021, in the PubMed, Embase, The Cochrane Library, Web of Science, and Scopus databases. Meta-analysis and publication bias were performed using RevMan 5.4 software. Stata16 software was used to detect publication bias with Egger's and Begg's methods being mainly used. The data of basic indicators of obesity, lipid metabolism index, oxidative stress index, inflammatory biomarkers, and liver function index were collected to analyze the beneficial effects of antioxidant supplementation in obese patients.

Results

A total of 30 studies were included in this study with a sample of 845 obese patients from the antioxidant supplementation group and 766 obese patients from the placebo control group. The meta-analysis showed that obese patients with antioxidant supplementation had lower BMI (mean difference (MD): − 0.44 [95%confidence interval (CI): − 0.84, −0.04], p = 0.03), waist circumference (MD : −0.78 [95%CI:−1.45, −0.11], p = 0.02), fasting blood glucose (FBG) level (standardized mean difference (SMD): − 4.92 [95%CI:−6.87, −2.98], p < 0.001) and homeostasis model assessment of insulin resistance (MD : −0.45 [95%CI:−0.61, −0.3], p < 0.001) when compared to the placebo group. Obese patients on antioxidant supplementation had lower levels of total cholesterol (SMD : −0.43 [95%CI:−0.84, −0.02], p = 0.04), triglycerides (SMD : −0.17 [95%CI:−0.31, −0.04], p = 0.01), low-density lipoprotein (SMD : −0.15 [95%CI:−0.29, −0.01], p = 0.03), malondialdehyde (SMD : −1.67 [95%CI:−2.69, −0.65], p = 0.001), and tumor necrosis factor-alpha (SMD : −0.29 [95%CI:−0.56, −0.02], p = 0.03), respectively, when compared to the placebo group. In addition, obese patients with antioxidant supplementation had higher levels of high-density lipoprotein (SMD : 0.25 [95%CI : 0.03, 0.46], p = 0.03) and superoxide dismutase (SMD : 1.09 [95%CI : 0.52, 1.65], p < 0.001) when compared to the placebo group. Antioxidant supplementation had no effects on other analyzed parameters including waist–hip ratio, leptin, fat mass, interleukin-6, C-reactive protein, alanine transaminase, and aspartate transaminase in obese patients.

Conclusion

The meta-analysis results indicated that antioxidant supplementation exerted potential beneficial effects in obese patients by regulating FBG, oxidative stress, and inflammation, whilst more high-quality studies are required to confirm these effects. The present study may provide important insights for the treatment of clinical obesity and obesity-associated complications.

An Exploratory Critical Review on TNF-α as a Potential Inflammatory Biomarker Responsive to Dietary Intervention with Bioactive Foods and Derived Products

This review collects and critically examines data on the levels of tumour necrosis factor-alpha (TNF-α) in lean, overweight and obese subjects, and the effects of intervention with different foods and food products containing bioactive constituents in overweight/obese individuals. We additionally explore the influence of different single nucleotide polymorphisms (SNPs) on TNF-α levels and compare the response to food products with that to some anti-obesity drugs. Our aim was to provide an overview of the variability, consistency, and magnitude of the reported effects of dietary factors on TNF-α, and to envisage the reliability of measuring changes in the levels of this cytokine as a biomarker responsive to food intervention in association with the reduction in body weight. Regarding the circulating levels of TNF-α, we report: (i) a large intra-group variability, with most coefficients of variation (CV%) values being ≥30% and, in many cases, >100%; (ii) a large between-studies variability, with baseline TNF-α values ranging from <1.0 up to several hundred pg/mL; (iii) highly variable effects of the different dietary approaches with both statistically significant and not significant decreases or increases of the protein, and the absolute effect size varying from <0.1 pg/mL up to ≈50 pg/mL. Within this scenario of variability, it was not possible to discern clear differentiating limits in TNF-α between lean, overweight, and obese individuals or a distinct downregulatory effect on this cytokine by any of the different dietary approaches reviewed, i.e., polyunsaturated fatty acids (PUFAs), Vitamin-D (VitD), mixed (micro)nutrients, (poly)phenols or other phytochemicals. Further, there was not a clear relationship between the TNF-α responses and body weight changes. We found similarities between dietary and pharmacological treatments in terms of variability and limited evidence of the TNF-α response. Different factors that contribute to this variability are discussed and some specific recommendations are proposed to reinforce the need to improve future studies looking at this cytokine as a potential biomarker of response to dietary approaches.

Should We ‘Eat a Rainbow’? An Umbrella Review of the Health Effects of Colorful Bioactive Pigments in Fruits and Vegetables

Health promotion campaigns have advocated for individuals to ‘eat a rainbow’ of fruits and vegetables (FV). However, the literature has only focused on individual color pigments or individual health outcomes. This umbrella review synthesized the evidence on the health effects of a variety of color-associated bioactive pigments found in FV (carotenoids, flavonoids, betalains and chlorophylls), compared to placebo or low intakes. A systematic search of PubMed, EMBASE, CINAHL and CENTRAL was conducted on 20 October 2021, without date limits. Meta-analyzed outcomes were evaluated for certainty via the GRADE system. Risk of bias was assessed using the Centre for Evidence-Based Medicine critical appraisal tools. A total of 86 studies were included, 449 meta-analyzed health outcomes, and data from over 37 million participants were identified. A total of 42% of health outcomes were improved by color-associated pigments (91% GRADE rating very low to low). Unique health effects were identified: n = 6 red, n = 10 orange, n = 3 yellow, n = 6 pale yellow, n = 3 white, n = 8 purple/blue and n = 1 green. Health outcomes associated with multiple color pigments were body weight, lipid profile, inflammation, cardiovascular disease, mortality, type 2 diabetes and cancer. Findings show that color-associated FV variety may confer additional benefits to population health beyond total FV intake.

Anthocyanins in Chronic Diseases: The Power of Purple

Anthocyanins are mainly purple-coloured phenolic compounds of plant origin that as secondary metabolites are important in plant survival. Understanding their health benefits in humans requires sourcing these unstable compounds in sufficient quantities at a reasonable cost, which has led to improved methods of extraction. Dark-coloured fruits, cereals and vegetables are current sources of these compounds. The range of potential sustainable sources is much larger and includes non-commercialised native plants from around the world and agri-waste containing anthocyanins. In the last 5 years, there have been significant advances in developing the therapeutic potential of anthocyanins in chronic human diseases. Anthocyanins exert their beneficial effects through improvements in gut microbiota, oxidative stress and inflammation, and modulation of neuropeptides such as insulin-like growth factor-1. Their health benefits in humans include reduced cognitive decline; protection of organs such as the liver, as well as the cardiovascular system, gastrointestinal tract and kidneys; improvements in bone health and obesity; and regulation of glucose and lipid metabolism. This review summarises some of the sources of anthocyanins and their mechanisms and benefits in the treatment of chronic human diseases.

Developing Germplasm and Promoting Consumption of Anthocyanin-Rich Grains for Health Benefits

Malnutrition, unhealthy diets, and lifestyle changes are the major risk factors for overweight and obesity-linked chronic diseases in humans adversely impact achieving sustainable development goals. Colored grains are a source of anthocyanins, a group of flavonoids, that contribute positively to human health. This review focuses on genetic variation harnessed through breeding and biotechnology tools for developing anthocyanin-rich grain crops. Agronomic practices, genotype × environment interactions, different stresses, seed development and seed maturity are factors that impact the content and composition of anthocyanins. Significant progress has been made in characterizing genes associated with anthocyanin biosynthesis in cereal and other crops. Breeding has led to the development and release of grain anthocyanin-rich crop cultivars in Europe, America and in some countries in Asia. Notably, genetic engineering utilizing specific transcription factors and gene editing has led to the development of anthocyanin-rich genetic variants without any significant yield penalty. A variety of food products derived from colored grains or flours are now available in grocery stores and supermarkets worldwide. The public perception about anthocyanin-rich food is positive, but availability, affordability, and willingness to pay a higher price than before limit consumption. Together with other seed nutrition traits in breeding programs the inclusion of anthocyanins can ensure the development of cultivars that meet nutrition needs of humans, especially in the developing world.