-
1.
Dietary Strawberries Improve Serum Metabolites of Cardiometabolic Risks in Adults with Features of the Metabolic Syndrome in a Randomized Controlled Crossover Trial.
Basu, A, Izuora, K, Hooyman, A, Scofield, HR, Ebersole, JL
International journal of molecular sciences. 2023;24(3)
-
-
-
Free full text
Plain language summary
Metabolic syndrome has been identified as a major risk factor for type 2 diabetes and its cardiovascular complications. Several dietary strategies, especially the use of different forms of dietary supplements, continue to be investigated for the prevention and management of this condition. The aim of this study was to examine the serum metabolites (targeted and untargeted) that may be affected by strawberry supplementation. This study was a randomised, double-blind, controlled crossover trial which enrolled adult participants with one or more features of metabolic syndrome. Participants were assigned to one of the three arms for four weeks separated by a one-week washout period. Results show that several targeted and untargeted serum metabolites were modulated with strawberry supplementation. In fact, strawberry supplementation improved the serum metabolic profiles which are associated with decreased risks of insulin resistance and diabetes, as well as endothelial dysfunction in adults with features of metabolic syndrome. Authors conclude that adding whole strawberries to the habitual diet may be a beneficial and feasible strategy to improve the cardiometabolic health in adults.
Abstract
Dietary strawberries have been shown to improve cardiometabolic risks in multiple clinical trials. However, no studies have reported effects on serum metabolomic profiles that may identify the target pathways affected by strawberries as underlying mechanisms. We conducted a 14-week randomized, controlled crossover study in which participants with features of metabolic syndrome were assigned to one of the three arms for four weeks separated by a one-week washout period: control powder, 1 serving (low dose: 13 g strawberry powder/day), or 2.5 servings (high dose: 32 g strawberry powder/day). Blood samples, anthropometric measures, blood pressure, and dietary and physical activity data were collected at baseline and at the end of each four-week phase of intervention. Serum samples were analyzed for primary metabolites and complex lipids using different mass spectrometry methods. Mixed-model ANOVA was used to examine differences in the targeted metabolites between treatment phases, and LASSO logistic regression was used to examine differences in the untargeted metabolites at end of the strawberry intervention vs. the baseline. The findings revealed significant differences in the serum branched-chain amino acids valine and leucine following strawberry intervention (high dose) compared with the low-dose and control phases. Untargeted metabolomic profiles revealed several metabolites, including serum phosphate, benzoic acid, and hydroxyphenyl propionic acid, that represented improved energy-metabolism pathways, compliance measures, and microbial metabolism of strawberry polyphenols, respectively. Thus, dietary supplementation of strawberries significantly improves the serum metabolic profiles of cardiometabolic risks in adults.
-
2.
Dietary polyphenols, metabolic syndrome and cardiometabolic risk factors: An observational study based on the DCH-NG subcohort.
Lanuza, F, Zamora-Ros, R, Bondonno, NP, Meroño, T, Rostgaard-Hansen, AL, Riccardi, G, Tjønneland, A, Landberg, R, Halkjær, J, Andres-Lacueva, C
Nutrition, metabolism, and cardiovascular diseases : NMCD. 2023;33(6):1167-1178
-
-
-
Free full text
Plain language summary
Metabolic syndrome (MetS) is a cluster of metabolic disorders that increases the risk of developing chronic diseases. Cardiometabolic risk factors include high waist circumference (WC), insulin resistance, hypertension, dysglycaemia, dyslipidaemia, and altered inflammatory markers. The aim of this study was to investigate the associations between intakes of polyphenols (total polyphenols and their main classes) and the prevalence of MetS and cardiometabolic risk factors. This study is an observational sub-cohort study of 676 Danish participants of the MAX study from the Danish Diet, Cancer and Health - Next Generations (DCH-NG) cohort. Results showed that individuals with higher total polyphenol and phenolic acid intakes, were less likely to have MetS. Furthermore, for cardiovascular risk factors, intakes of total polyphenols, flavonoids and phenolic acids were associated with a lower risk of higher systolic blood pressure and lower high-density lipoprotein cholesterol. Authors conclude by suggesting that intervention studies should be undertaken to establish whether a polyphenol-rich diet can improve some cardiometabolic risk factors and can reduce or delay the onset of cardiometabolic diseases in free-living populations.
Abstract
BACKGROUND AND AIMS Polyphenol-rich foods have beneficial properties that may lower cardiometabolic risk. We aimed to prospectively investigate the relationship between intakes of dietary polyphenols, and metabolic syndrome (MetS) and its components, in 676 Danish residents from the MAX study, a subcohort of the Danish Diet, Cancer and Health-Next Generations (DCH-NG) cohort. METHODS AND RESULTS Dietary data were collected using web-based 24-h dietary recalls over one year (at baseline, and at 6 and 12 months). The Phenol-Explorer database was used to estimate dietary polyphenol intake. Clinical variables were also collected at the same time point. Generalized linear mixed models were used to investigate relationships between polyphenol intake and MetS. Participants had a mean age of 43.9y, a mean total polyphenol intake of 1368 mg/day, and 75 (11.6%) had MetS at baseline. Compared to individuals with MetS in Q1 and after adjusting for age, sex, lifestyle and dietary confounders, those in Q4 - for total polyphenols, flavonoids and phenolic acids-had a 50% [OR (95% CI): 0.50 (0.27, 0.91)], 51% [0.49 (0.26, 0.91)] and 45% [0.55 (0.30, 1.00)] lower odds of MetS, respectively. Higher total polyphenols, flavonoids and phenolic acids intakes as continuous variable were associated with lower risk for elevated systolic blood pressure (SBP) and low high-density lipoprotein cholesterol (HDL-c) (p < 0.05). CONCLUSIONS Total polyphenol, flavonoid and phenolic acid intakes were associated with lower odds of MetS. These intakes were also consistently and significantly associated with a lower risk for higher SBP and lower HDL-c concentrations.
-
3.
A Randomised Placebo-Controlled Study of Purified Anthocyanins on Cognition in Individuals at Increased Risk for Dementia.
Aarsland, D, Khalifa, K, Bergland, AK, Soennesyn, H, Oppedal, K, Holteng, LBA, Oesterhus, R, Nakling, A, Jarholm, JA, de Lucia, C, et al
The American journal of geriatric psychiatry : official journal of the American Association for Geriatric Psychiatry. 2023;31(2):141-151
-
-
-
Free full text
Plain language summary
A growing body of evidence suggests that some modifiable factors, including cardiometabolic disorders such as hypertension, diabetes and hypercholesterolemia, as well as lifestyle factors such as physical exercise and diet, are associated with an increased risk of developing dementia. Anthocyanins, a flavonoid subclass found in dark berries and fruits, are among the dietary factors that may have positive effects on the pathogenesis of Alzheimer’s disease. The aim of this study was to assess whether anthocyanins can improve cognition and reduce the risk of dementia. This study is a 24-week randomised, double-blind, placebo-controlled Phase II study. Two-hundred and six participants were randomly assigned to one of the two groups: anthocyanins (n=106) or placebo (n=100). Results show that there wasn’t any significant group difference at the end of the study (24 weeks) in episodic memory (primary analysis) or for the secondary cognitive outcomes. However, there was a significant difference in slopes during weeks 8−24 where the anthocyanin group improved while the placebo group worsened. Furthermore, anthocyanin capsules were well-tolerated and safe to use. Authors conclude that future studies need to explore the potential mechanisms leading to cognitive improvement, how they relate to bioavailability of anthocyanins and metabolites, the optimal dosage, and the duration of treatment.
Abstract
IMPORTANCE Identifying nutritional compounds which can reduce cognitive decline in older people is a hugely important topic. OBJECTIVE To study the safety and effect of anthocyanins in maintaining cognitive functioning in people at increased risk for dementia. DESIGN, SETTING, AND PARTICIPANTS Participants (206 individuals, aged 60-80 years) diagnosed with either mild cognitive impairment (MCI) or two or more cardiometabolic disorders (i.e., diabetes, hypertension, obesity) were enrolled at three different centres in Norway. INTERVENTION Participants were randomly assigned to four capsules with a total of 320 mg/d of naturally purified anthocyanins or placebo 1:1 for 24 weeks. MAIN OUTCOMES AND MEASURES The primary outcome was the Quality of Episodic Memory composite measure (0-100) from an online cognitive test battery CogTrack, which was administered at baseline and monthly for the next 24 weeks. Secondary outcomes included other cognitive scores from the CogTrack battery. We applied mixed effects models with a baseline test score, group, time and their interaction as fixed effects, as well as other predefined baseline covariates. The primary comparison was the group difference at week 24 based on a modified intention-to-treat principle. RESULTS The primary analysis did not show a significant group difference at 24 weeks (78.2 versus 76.8; adjusted mean difference 1.4 (95% confidence interval -0.9-3.7); effect size 0.15; p = 0.23). However, there was a significant difference in slopes during weeks 8-24 (p = 0.007); the anthocyanin group improved while the placebo group worsened. No differences were found for the secondary cognitive outcomes. Anthocyanin capsules were well-tolerated and safe to use. CONCLUSION Anthocyanin supplementation for 24 weeks was safe and well tolerated in people with MCI or cardiometabolic disorders. We found no significant group difference in episodic memory at the end of the study but statistically significant differences in slopes. Further studies are warranted to explore whether anthocyanins supplementation can reduce cognitive decline in people at increased risk of dementia. TRIAL REGISTRATION ClinicalTrials.gov, (Identifier NCT03419039). http://www. CLINICALTRIALS gov/, NCT03419039.
-
4.
Effects of tart cherry juice consumption on cardio-metabolic risk factors: A systematic review and meta-analysis of randomized-controlled trials.
Moosavian, SP, Maharat, M, Chambari, M, Moradi, F, Rahimlou, M
Complementary therapies in medicine. 2022;71:102883
-
-
-
Free full text
Plain language summary
Cardiovascular disease (CVD) is a general term for disorders affecting the heart and blood vessels and is the number one cause of death world-wide. CVD risk factors include high blood pressure, high cholesterol, obesity, being overweight and diabetes. Tart cherry juice is a rich source of strong antioxidants such as proanthocyanidins, anthocyanins, and flavonols. These compounds have anti-inflammatory properties and are therefore potentially beneficial in CVD. The antioxidant potential of tart cherry juice has been extensively studied, but studies have shown contradictory results relating to the efficacy of tart cherry juice on cardio-metabolic risk factors. To date there is no meta-analysis looking at these effects. 10 RCTs were included and the results showed that cherry juice consumption led to a significant reduction in fasting blood sugar. However, there wasn’t any significant effect of cherry juice consumption on blood pressure, insulin, lipid profile levels, fat mass, and BMI. Further clinical trials using higher sample sizes are needed. The clinical importance of this study was that clinicians and nutritionists can recommend the consumption of tart cherry for the prevention and management of CVD related symptoms.
Abstract
BACKGROUND Tart cherries are rich in bioactive compounds, such as anthocyanins and other phytochemicals known to have antioxidant properties and exert cardiovascular protective effects. However, there is no definitive consensus on this context. The present systematic review and meta-analysis aimed to investigate the effect of tart cherry juice consumption on cardio-metabolic risk factors. METHODS A systematic search was conducted on electronic databases, including PubMed, Web of Science, Scopus, and Google Scholar from inception up to December 2021 to identify eligible RCT studies. A random-effect model was utilized to estimate the weighted mean difference (WMD) and 95% confidence (95% CI). RESULTS Ten RCTs were included in the present meta-analysis. The pooled analysis revealed that tart cherry juice consumption led to a significant reduction in the fasting blood sugar (FBS) levels (WMD = -0.51 mg/dl [95% CI: -0.98, -0.06]). This lowering effect of FBS was robust in subgroups with cross-over studies, participants with age range ≥ 40, duration of follow-up ≤ 4 weeks, and baseline BMI ≥ 30. In contrast, tart cherry juice had no effect on total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), insulin, body mass index (BMI), fat mass, systolic and diastolic blood pressure. However, in the subgroup analysis, some significant effects were observed for insulin, TG, TC, LDL-C, and HDL-C. CONCLUSION In summary, this meta-analysis showed that tart cherry juice mostly had a favorable effect on FBG levels. However, further RCTs with long-term intervention with different doses of administration are needed.
-
5.
The Effect of Walnut (Juglans regia) Leaf Extract on Glycemic Control and Lipid Profile in Patients With Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.
Mirzababaei, A, Daneshvar, M, Abaj, F, Daneshzad, E, Hosseininasab, D, Clark, CCT, Mirzaei, K
Clinical nutrition research. 2022;11(2):120-132
-
-
-
Free full text
Plain language summary
The main characteristics of type 2 diabetes mellitus (T2DM) are hyperinsulinemia, insulin resistance, and β-cells decline, concomitant to dyslipidaemia. The latter includes abnormalities in concentrations of triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), or total cholesterol (TC), which are major risk factors for cardiovascular diseases. The aim of this study was to evaluate the effect of Juglans regia leaf extract (JRLE) on glycaemic control and lipid profile in T2DM patients. This study is a systematic review and meta-analysis of four randomised controlled studies. All studies were conducted in Iran, on T2DM patients, and both genders. Results show that JRLE supplementation did not have any significant effect on TC, LDL-C, and HDL-C; however, it significantly reduced fasting blood glucose and significantly increased alanine transaminase [enzyme]. Authors conclude that their findings strengthen the available evidence of JRLE as an alternative adjunctive therapy to better control glycaemic targets and lipid parameters.
Abstract
Numerous clinical trials have examined the beneficial effects of Juglans regia leaf extract (JRLE) in patients with type 2 diabetes mellitus (T2DM); however, the results of these studies are inconsistent. Therefore, we conducted the current systematic review and meta-analysis to evaluate the effect of JRLE on glycemic control and lipid profile in T2DM patients. We searched online databases including PubMed, Scopus, EMBASE, and Web of Science for randomized controlled clinical trials that examined the effect of JRLE on glycemic and lipid indices in T2DM patients. Data were pooled using both fixed and random-effect models and weighted mean difference (WMD) was considered as the overall effect size. Of the total records, 4 eligible studies, with a total sample size of 195 subjects, were included. The meta-analysis revealed that JRLE supplementation significantly reduces fasting blood glucose (WMD, -18.04; 95% confidence interval [CI], -32.88 mg/dL, -3.21 mg/dL; p = 0.017) and significantly increases fasting insulin level (WMD, 1.93; 95% CI, 0.40 U/L, 3.45 U/L; p = 0.014). Although the overall effect of JRLE supplementation on hemoglobin A1c was not significant, a significant reduction was seen in studies with an intervention duration of > 8 weeks (WMD, -0.64; 95% CI, -1.16%, -0.11%; p = 0.018). Moreover, we also found no significant change in lipid parameters. Our findings revealed a beneficial effect of JRLE supplementation on glycemic indices in T2DM patients, but no significant improvement was found for lipid profile parameters.
-
6.
Effects of the Treatment with Flavonoids on Metabolic Syndrome Components in Humans: A Systematic Review Focusing on Mechanisms of Action.
Gouveia, HJCB, Urquiza-Martínez, MV, Manhães-de-Castro, R, Costa-de-Santana, BJR, Villarreal, JP, Mercado-Camargo, R, Torner, L, de Souza Aquino, J, Toscano, AE, Guzmán-Quevedo, O
International journal of molecular sciences. 2022;23(15)
-
-
-
Free full text
Plain language summary
Metabolic syndrome is a condition characterised by at least three of the five risk factors, such as abdominal obesity, elevated fasting glucose, blood pressure and triglycerides and reduced high-density lipoprotein cholesterol (HDL-c). There is a strong link between metabolic syndrome and the development of cardiovascular disease and Type 2 diabetes. Research suggests that increasing consumption of flavonoid-rich foods can be beneficial in reducing cardiovascular morbidity and mortality. Flavonoids are bioactive compounds that possess antioxidative, anti-inflammatory, anti-cancerous, anti-mutagenic, and enzymatic properties. This systematic review of 29 randomised controlled trials evaluated the beneficial effects of long-term flavonoid supplementation in reducing the risk factors of metabolic syndrome. This review included a variety of flavonoid supplements, such as anthocyanin, hesperidin, quercetin, epigallocatechin gallate (egcg), genistein, theaflavin, catechin, and eriocitrin. Additionally, this research investigated the mechanisms behind the beneficial effects of flavonoid supplementation. Results showed that flavonoid supplementation for at least three weeks improved metabolic parameters and inflammatory markers, with hesperidin showing the greatest improvements in metabolic parameters. Healthcare professionals can use these findings to understand the potential benefits of long-term flavonoid supplementation in improving metabolic parameters. However, more robust studies are needed to determine the therapeutic dosages of different flavonoids.
Abstract
Diets high in bioactive compounds, such as polyphenols, have been used to mitigate metabolic syndrome (MetS). Polyphenols are a large group of naturally occurring bioactive compounds, classified into two main classes: non-flavonoids and flavonoids. Flavonoids are distributed in foods, such as fruits, vegetables, tea, red wine, and cocoa. Studies have already demonstrated the benefits of flavonoids on the cardiovascular and nervous systems, as well as cancer cells. The present review summarizes the results of clinical studies that evaluated the effects of flavonoids on the components of the MetS and associated complications when offered as supplements over the long term. The results show that flavonoids can significantly modulate several metabolic parameters, such as lipid profile, blood pressure, and blood glucose. Only theaflavin and catechin were unable to affect metabolic parameters. Moreover, only body weight and body mass index were unaltered. Thus, the evidence presented in this systematic review offers bases in support of a flavonoid supplementation, held for at least 3 weeks, as a strategy to improve several metabolic parameters and, consequently, reduce the risk of diseases associated with MetS. This fact becomes stronger due to the rare side effects reported with flavonoids.
-
7.
Consumption of flavonoids and risk of hormone-related cancers: a systematic review and meta-analysis of observational studies.
Liu, F, Peng, Y, Qiao, Y, Huang, Y, Song, F, Zhang, M, Song, F
Nutrition journal. 2022;21(1):27
-
-
-
-
Free full text
Plain language summary
Hormone-related cancers (HRCs) are greatly influenced by hormone levels and generally respond to hormone regulation, which plays an indispensable role in tumour growth. Encouragingly, diets rich in vegetables, fruits and tea are found to reduce the cancer risk, having the potential to exert chemo-preventive effects with the presence of anticarcinogenic phytochemicals. The aim of this study was to elucidate the association between flavonoids intake and HRCs risk. This study is a meta-analysis of fifty-one studies. It consisted of 22 prospective cohort studies, 1 nested case–control study, 18 population-based case–control studies and 10 hospital-based case–control studies. Results show that higher consumption of total flavonoids was only associated with an increased risk of men-specific cancers, mainly prostate cancer. Furthermore, the subclasses, flavanols, flavones, and isoflavones, and the three main individual compounds of isoflavones (daidzein, genistein and glycitein) may have protective effects on women-specific cancers, whereas flavones and flavanones have been found to cause potentially dangerous effects in thyroid cancer. Additionally, there was no evidence in support of any role for anthocyanidins in HRCs. Authors conclude that there is a small amount of evidence that total flavonoids, flavanols, flavones, flavanones, flavan-3-ols and isoflavones may be associated with a lower or higher risk of certain HRCs, which may provide guidance for dietary guidelines to a certain extent in the future.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Dietary flavonoids are widely available in plant-based foods such as vegetables, citrus fruits, green tea and berries
- Menopausal status may be an important consideration for flavonoid intake when considering breast cancer risk
- Differences in results for Asians and non-Asians need to be considered for the use of flavonoids in women-specific hormonal cancers and prostate cancer in men
- Caution should be exercised when considering flavones and flavanones and thyroid cancer risk until further research is available
Evidence Category:
-
X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
-
B: Systematic reviews including RCTs of limited number
-
C: Non-randomized trials, observational studies, narrative reviews
-
D: Case-reports, evidence-based clinical findings
-
E: Opinion piece, other
Summary Review:
Background
Hormone-related cancers (HRCs) are the most frequently diagnosed cancers globally , accounting for more than a quarter of new cancer cases worldwide in 2018. They include breast, ovarian, endometrial, prostate, testicular and thyroid cancer which share a similar carcinogenic mechanism. Diets rich in vegetables, fruit, legumes and tea may reduce cancer risk due to anticarcinogenic phytochemicals, such as flavonoids. Flavonoids are claimed to have many different physiological and pathological functions in the cancer process, including tumour cell proliferation, inflammation, angiogenesis, invasion and metastasis.. This study aimed to summarise the relationships between consumption of flavonoids with the risk of HRC.
Methods:
The meta-analysis was carried out following PRISMA guidelines and registered on PROSPERO. A literature search in PubMed and Embase was conducted using the keywords flavonoids, flavanols and isoflavones and breast, ovarian, endometrial, prostate, testicular and thyroid cancer. 51 studies published between 1999 and 2022 consisted of 22 prospective cohort, 18 population-based and 10 hospital-based case-control studies. On the Newcastle-Ottawa Scale assessment all studies were of medium or high methodological quality.
Results:
Results were analysed using Stata 15.1 software and ORs with 95% CIs used to measure the association between flavonoid intake and HRCs risk. Statistical I2 evaluated heterogeneity among the studies.
Funnel plots were inspected for publication bias and calculated by Begg’s/Egger’s regression tests. Sensitivity analyses were performed to explore the source of heterogeneity. Subgroup analysis was performed on study design and region, as well as menopausal status.
Higher consumption of flavonoids was associated with a decreased risk of women-specific cancers but a significant elevated risk of prostate cancer as seen below.
Women specific cancers:
For flavonoid sub-classes, higher consumption of flavanols (OR=0.85; 95% CI, 0.76–0.94; I2=75.5%; p<0.001), flavones (OR=0.85; 95% CI, 0.77–0.95; I2=76.3%; p<0.001) and isoflavones (OR=0.87; 95% CI, 0.82–0.92; I2=73.8%; p<0.001) was associated with a decreased risk of women-specific cancers (breast, ovarian and endometrial), especially among the case–control studies. Similar results were seen in the main compounds of isoflavones: daidzen, genistein and glycitein. There were differences in the association between isoflavones in Asian and non-Asian regions.
Men-specific cancers:
The higher consumption of total flavonoids (OR=1.11; 95% CI, 1.02–1.21; I2 = 0%; p = 0.484) was associated with an increased risk of prostate cancer and this was only found in non-Asian populations.
Conclusion:
Despite limitations of the meta-analysis, such as the use of observational studies and small sample sizes of the included studies, this systematic review may provide some preliminary dietary evidence for the use of flavonoids in HRCs.
Clinical practice applications:
- The promotion of a plant-based diet, rich in vegetables, fruits, green tea and legumes may have protective effects on women-specific cancers due to the rich presence of flavanols, flavones and isoflavones, as well as the compounds genistein, glycitein and daidzein.
- Results show no associations between total flavonoids intake and women-specific cancer however, the sub-groups of flavanols, flavones and isoflavones were associated with a decreased risk in women-specific cancers. Similar results were seen in the individual compounds of isoflavones: genistein, glycitein and daidzein. These results may guide decision-making when recommending the inclusion of these compounds for protective benefits in women-specific cancers.
- The positive association between total flavonoids and prostate cancer risk was only seen in non-Asians, and between higher consumption of flavones and flavanones and thyroid cancer risk albeit in limited studies (n=3) may provide important guidelines when considering which foods to include from a plant-based diet.
Considerations for future research:
- Further meta-analysis of prospective studies with larger sample sizes
- The use of a validated and reliable questionnaire for measuring flavonoid intake
- Intervention studies evaluating flavonoid subclasses
- Comparisons between Asian and non-Asian populations
- Consideration of menopausal status as an effect modifier
Abstract
BACKGROUND Flavonoids seem to have hormone-like and anti-hormone properties so that the consumption of flavonoids may have potential effects on hormone-related cancers (HRCs), but the findings have been inconsistent so far. This meta-analysis was aimed to explore the association between flavonoids intake and HRCs risk among observational studies. METHODS Qualified articles, published on PubMed, EMBASE, and China National Knowledge Infrastructure (CNKI) from January 1999 to March 2022 and focused on relationships between flavonoids (total, subclass of and individual flavonoids) and HRCs (breast, ovarian, endometrial, thyroid, prostate and testicular cancer), were retrieved for pooled analysis. Random effects models were performed to calculate the pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs). Funnel plots and Begg's/Egger's test were used to evaluate the publication bias. Subgroup analyses and sensitivity analyses were conducted to explore the origins of heterogeneity. RESULTS All included studies were rated as medium or high quality. Higher consumption of flavonols (OR = 0.85, 95% CI: 0.76-0.94), flavones (OR = 0.85, 95% CI: 0.77-0.95) and isoflavones (OR = 0.87, 95% CI: 0.82-0.92) was associated with a decreased risk of women-specific cancers (breast, ovarian and endometrial cancer), while the higher intake of total flavonoids was linked to a significantly elevated risk of prostate cancer (OR = 1.11, 95% CI: 1.02-1.21). A little evidence implied that thyroid cancer risk was augmented with the higher intake of flavones (OR = 1.24, 95% CI: 1.03-1.50) and flavanones (OR = 1.31, 95% CI: 1.09-1.57). CONCLUSIONS The present study suggests evidence that intake of total flavonoids, flavonols, flavones, flavanones, flavan-3-ols and isoflavones would be associated with a lower or higher risk of HRCs, which perhaps provides guidance for diet guidelines to a certain extent. TRIAL REGISTRATION This protocol has been registered on PROSPERO with registration number CRD42020200720 .
-
8.
Flavonoid-Rich Orange Juice Intake and Altered Gut Microbiome in Young Adults with Depressive Symptom: A Randomized Controlled Study.
Park, M, Choi, J, Lee, HJ
Nutrients. 2020;12(6)
-
-
-
Free full text
Plain language summary
Depression is a common brain disorder, which may be negatively affected by poor dietary intake. Naturally occurring compounds in fruits, vegetables, tea and cocoa called flavonoids, reportedly improve brain function and may help to lower risk of depression. Possible reasons for this are their influence on the gut microbiota, which can influence the brain. This randomised control trial of 40 individuals with depression aimed to determine the influence of flavonoid rich orange juice on the gut microbiome and symptoms of depression over 8 weeks. The results showed a marginal increase in a key blood indicator associated with symptoms of depression in the flavonoid supplemented group. Symptoms of depression were also decreased in the flavonoid treatment group. Interestingly gut microbiota diversity was higher before treatment, but the abundance of key gut microbiota species were influenced by flavonoid treatment. Biomarkers for depression were also associated with the abundance of gut microbiota. It was concluded that the consequences of high microbial diversity in individuals with depression is not fully understood. However, treatment with flavonoids may alter the gut microbiome and improve symptoms of depression. This study could be used by healthcare practitioners to understand the role of the gut microbiota in depression and recommend dietary changes to include high amounts of flavonoids.
Abstract
Depression is not just a general mental health problem but a serious medical illness that can worsen without treatment. The gut microbiome plays a major role in the two-way communication system between the intestines and brain. The current study examined the effects of flavonoids on depression by observing the changes in the gut microbiome and depressive symptoms of young participants consuming flavonoid-rich orange juice. The depressive symptom was assessed using the Center for Epidemiological Studies Depression Scale (CES-D), a psychiatric screening tool used to detect preexisting mental disorders. The study population was randomly divided into two groups: the flavonoid-rich orange juice (FR) and an equicaloric flavonoid-low orange cordial (FL) group. For 8 weeks, participants consumed FR (serving a daily 380 mL, 600 ± 5.4 mg flavonoids) or FL (serving a daily 380 mL, 108 ± 2.6 mg flavonoids). In total, 80 fecal samples from 40 participants (mean age, 21.83 years) were sequenced. Regarding depression, we observed positive correlations between brain-derived neurotrophic factor (BDNF) and the Lachnospiraceae family (Lachnospiraceae_uc and Murimonas) before flavonoid orange juice treatment. Most notably, the abundance of the Lachnospiraceae family (Lachnospiraceae_uc, Eubacterium_g4, Roseburia_uc, Coprococcus_g2_uc, Agathobacter_uc) increased after FR treatment compared to that after FL treatment. We also validated the presence of unclassified Lachnospiraceae through sensitive real-time quantitative polymerase chain reaction using stool samples from participants before and after flavonoid treatment. Our results provide novel interventional evidence that alteration in the microbiome due to flavonoid treatment is related to a potential improvement in depression in young adults.
-
9.
Could gestational diabetes mellitus be managed through dietary bioactive compounds? Current knowledge and future perspectives.
Santangelo, C, Zicari, A, Mandosi, E, Scazzocchio, B, Mari, E, Morano, S, Masella, R
The British journal of nutrition. 2016;115(7):1129-44
-
-
-
Free full text
-
Plain language summary
Gestational diabetes mellitus (GDM) is the most common metabolic disorder during pregnancy. Women with GDM are at a high risk of developing type 2 diabetes (T2D) later in life. Moreover, uncontrolled GDM is linked with a detrimental intra-uterine environment, which leads to foetal complications and an increased risk for the child of developing obesity and metabolic disorders. The aim of the review is to examine the current knowledge and issues about the impact of dietary polyphenols on the mechanisms and/or factors regulating glucose homeostasis, inflammation and adipose tissue function in metabolic alterations linked with GDM. Moreover, this study also reviews the role of Omega-3 fatty acids in pregnancy. The study is a descriptive review based on several studies. Literature data is mainly derived from in vitro and animal models. In vitro and animal studies show that almost all subclasses of flavonoids, stilbene RSV and some olive oil phenolic compounds, interact and modulate several molecular pathways regulating insulin. Obesity worsens GDM with increased risk of developing metabolic disorders in both mother and offspring later in life. The adoption of healthy lifestyle, with adherence to a healthy dietary pattern, has positive effects on the prevention and management of diabetes.
Abstract
Gestational diabetes mellitus (GDM) is a serious problem growing worldwide that needs to be addressed with urgency in consideration of the resulting severe complications for both mother and fetus. Growing evidence indicates that a healthy diet rich in fruit, vegetables, nuts, extra-virgin olive oil and fish has beneficial effects in both the prevention and management of several human diseases and metabolic disorders. In this review, we discuss the latest data concerning the effects of dietary bioactive compounds such as polyphenols and PUFA on the molecular mechanisms regulating glucose homoeostasis. Several studies, mostly based on in vitro and animal models, indicate that dietary polyphenols, mainly flavonoids, positively modulate the insulin signalling pathway by attenuating hyperglycaemia and insulin resistance, reducing inflammatory adipokines, and modifying microRNA (miRNA) profiles. Very few data about the influence of dietary exposure on GDM outcomes are available, although this approach deserves careful consideration. Further investigation, which includes exploring the 'omics' world, is needed to better understand the complex interaction between dietary compounds and GDM.
-
10.
Effect of Flavonoids on Upper Respiratory Tract Infections and Immune Function: A Systematic Review and Meta-Analysis.
Somerville, VS, Braakhuis, AJ, Hopkins, WG
Advances in nutrition (Bethesda, Md.). 2016;7(3):488-97
-
-
-
Free full text
-
Plain language summary
Upper respiratory tract infections (URTIs) are common and include sinusitis, tonsillitis, pharyngitis, otitis media, laryngitis, and the “common cold”. More than 90% of URTIs are cause by viruses. Flavonoids are found in many plant foods and have a range of physiologic effects in humans, including antiviral, anti-inflammatory, cytotoxic, antimicrobial, and antioxidant. The purpose of this systematic review and meta-analysis of 14 randomised controlled trials was to investigate the efficacy of flavonoids on URTIs and immune function. The authors found that flavonoids decrease URTI incidence by 33% compared with controls with no increase in adverse effects. There was also a non-significant decrease in URTI severity and duration with the flavonoid intervention. The meta-analysis demonstrated that differences between flavonoids and control for all immune biomarkers were clinically irrelevant. The authors therefore suggest that flavonoids do not attenuate URTI incidence by altering immune function but by an antiviral mechanism. They call for further research to establish the optimal dose and type of flavonoids.
Abstract
Previous research on animals indicates flavonoid compounds have immunomodulatory properties; however, human research remains inconclusive. The aim of this systematic review was to assess the efficacy of dietary flavonoids on upper respiratory tract infections (URTIs) and immune function in healthy adults. A created search strategy was run against Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and EMBASE classic, CINAHL, and AMED. The returned studies were initially screened, and 2 reviewers independently assessed the remaining studies for eligibility against prespecified criteria. Fourteen studies, of 387 initially identified, were included in this review, and the primary outcome measure was the effect of flavonoids on URTI incidence, duration, and severity. Of the included studies, flavonoid supplementation ranged from 0.2 to 1.2 g/d. Overall, flavonoid supplementation decreased URTI incidence by 33% (95% CI: 31%, 36%) compared with control, with no apparent adverse effects. Sick-day count was decreased by 40% with flavonoid supplementation, although unclear. Differences in bio-immune markers (e.g., interleukin-6, tumor necrosis factor-α, interferon-γ, neutrophils) were trivial between the intervention and control groups during the intervention and after exercise when a postintervention exercise bout was included. These findings suggest that flavonoids are a viable supplement to decrease URTI incidence in an otherwise healthy population.