The association between dietary polyphenol intake and cardiometabolic factors in overweight and obese women: a cross-sectional study

The interaction between polyphenol intake and genes (MC4R, Cav-1, and Cry1) related to body homeostasis and cardiometabolic risk factors in overweight and obese women: a cross-sectional study

Background

Cardiovascular disease (CVD), which is an important global health challenge, is expanding. One of the main factors in the occurrence of CVD is a high genetic risk. The interaction between genetic risk in CVD and nutrition is debatable. Polyphenols are one of the important dietary components that may have a protective role in people who have a high genetic risk score (GRS) for cardiometabolic risk factors. This study, conducted in overweight and obese women, examines the interaction between polyphenol intake and specific genes (MC4r, Cav-1, and Cry1) related to maintaining body balance and their interaction with cardiometabolic risk factors.

Methods

This cross-sectional study included 391 women who were overweight or obese, aged 18 to 48 years, with a body mass index (BMI) between 25 and 40 kg/m2. Body composition was measured using the InBody 770 scanner. Total dietary polyphenol intake (TDPI) was assessed with a validated 147-item food frequency questionnaire (FFQ), and polyphenol intakes were determined using the Phenol-Explorer database. Serum samples underwent biochemical tests. The Genetic Risk Score (GRS) was calculated based on the risk alleles of three genes: MC4r, Cav-1, and Cry1.

Results

The mean ± standard deviation (SD) age and BMI of women were 36.67 (9.1) years and 30.98 (3.9) kg/m2, respectively. The high GRS and high TDPI group had a significant negative interaction with fasting blood glucose (FBS) (p = 0.01). Individuals who had a high GRS and a high phenolic acid intake were found to have a significant negative interaction with Triglyceride (p = 0.04). Similarly, individuals with high GRS and a high intake of flavonoids had a significant negative interaction with TG (p < 0.01) and a significant positive interaction with High-density lipoprotein (HDL) (p = 0.01) in the adjusted model.

Conclusion

According to our findings, those with a high GRS may have a protective effect on cardiometabolic risk factors by consuming high amounts of polyphenols. Further studies will be necessary in the future to validate this association.

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.

Dietary Antioxidant Quality Score (DAQS), serum lipids, markers of glucose homeostasis, blood pressure and anthropometric features among apparently metabolically healthy obese adults in two metropolises of Iran (Tabriz and Tehran): a cross-sectional study

BACKGROUND

Oxidative stress (OS) is associated with a variety of non-communicable diseases, including MetS, diabetes mellitus, metabolic syndrome, and cardiovascular disease through increased production of reactive oxygen species (ROS) and impairment of antioxidant defense mechanisms. Antioxidants can protect cells against free radical damage, so it seems important to determine the relationship between the quality of dietary antioxidants intake and chronic diseases. The Dietary Antioxidant Quality Score (DAQS) is obtained by adding the daily intake of known dietary vitamins and minerals, including selenium, zinc, vitamin A, vitamin C, and vitamin E, compared to the recommended daily intake (RDI). Therefore, this study aims to determine the relationship between DAQS, serum lipids, markers of glucose homeostasis, blood pressure and anthropometric features among obese adults.

METHODS

In the present cross-sectional study, 338 individuals who were obese (BMI ≥ 30 kg/m²) aged 20-50 years were recruited from Tabriz and Tehran, Iran. A validated semi-quantitative Food Frequency Questionnaire (FFQ) with 168 food items was used to quantify dietary consumption; accordingly, DAQS was computed. Blood biomarkers were measured using enzyme-linked immunosorbent assay (ELISA) kits. A standard mercury sphygmomanometer was used to assess blood pressure, and bioelectrical impedance analysis (BIA) was performed to determine body composition. The association between the DAQS tertiles and biochemical variables was investigated using multinomial logistic regression.

RESULTS

Participants in the highest tertile of DAQS have a lower diastolic blood pressure (DBP) values in all of the adjusted models [odds ratio (OR) = 0.920; confidence interval (CI)= 0.852-0.993, P-value = 0.03] in the analysis of co-variance (ANCOVA) model. Similarly, subjects at the second tertile of DAQS had lower DBP compared with the first tertile in age and sex-adjusted model [OR= 0.937; CI= 0.882-0.997]. There was no statistically significant difference for other metabolic parameters in different DAQS tertiles.

CONCLUSION

According to our findings, higher DAQS was associated with lower DBP among obese adults with obesity in two major cities of Iran (Tehran and Tabriz). Other studies with interventional design are needed to better elucidate these associations and underlying mechanisms.

Plant bioactive compounds from Mediterranean diet improve risk factors for metabolic syndrome

Mediterranean (Med) dietary pattern consists of moderate or high consumption of foods that are linked to reduced risk factors for metabolic syndrome (MetS). This comprehensive review evaluates studies on Med diet-representative foods and beverages, such as red wine and olive oil, to understand the inverse associations of Med diet and MetS. The intake of dietary fibre, unsaturated fatty acids, vitamins, and polyphenols - including flavonoids and stilbenes - help to explain the benefits of Med diet on abdominal adiposity, glucose intolerance, hyperlipidaemia, and high blood pressure to some extent. Antioxidant and anti-inflammatory properties of polyphenols as well as the effects of unsaturated fatty acids on lipid metabolism are part of the underlying mechanisms. Overall, this review shows that dietary interventions using Med diet components improve MetS health markers in humans and/or rodents.

Influence of Polyphenols on Adipose Tissue: Sirtuins as Pivotal Players in the Browning Process

Adipose tissue (AT) can be classified into two different types: (i) white adipose tissue (WAT), which represents the largest amount of total AT, and has the main function of storing fatty acids for energy needs and (ii) brown adipose tissue (BAT), rich in mitochondria and specialized in thermogenesis. Many exogenous stimuli, e.g., cold, exercise or pharmacological/nutraceutical tools, promote the phenotypic change of WAT to a beige phenotype (BeAT), with intermediate characteristics between BAT and WAT; this process is called "browning". The modulation of AT differentiation towards WAT or BAT, and the phenotypic switch to BeAT, seem to be crucial steps to limit weight gain. Polyphenols are emerging as compounds able to induce browning and thermogenesis processes, potentially via activation of sirtuins. SIRT1 (the most investigated sirtuin) activates a factor involved in mitochondrial biogenesis, peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), which, through peroxisome proliferator-activated receptor γ (PPAR-γ) modulation, induces typical genes of BAT and inhibits genes of WAT during the transdifferentiation process in white adipocytes. This review article aims to summarize the current evidence, from pre-clinical studies to clinical trials, on the ability of polyphenols to promote the browning process, with a specific focus on the potential role of sirtuins in the pharmacological/nutraceutical effects of natural compounds.

Inflammatory biomarkers in overweight and obese Iranian women are associated with polyphenol intake

BACKGROUND

The evidence shows that obesity is associated with chronic inflammation in obese subjects. Polyphenols are a complex group of plant secondary metabolites that may play a role in reducing the risk of obesity and obesity-related diseases. Given the scarcity of evidence on the association between inflammatory markers and dietary polyphenols intake in overweight/obese Iranian women, the current study aims to investigate this link.

METHOD

The present cross-sectional study was conducted on 391 overweight and obese Iranian women aged 18-48 years (body mass index (BMI) ≥ 25 kg/m2). A 147-item food frequency questionnaire (FFQ) was used to assess dietary intake, as well as anthropometric indices including weight, height, waist circumference (WC), and hip circumference (HC) and biochemistry parameters including triglyceride (TG), total cholesterol (Chole), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), serum glutamic pyruvic transaminase (SGPT), serum glutamic-oxaloacetic transaminase (SGOT), galactin-3 (Gal-3), monocyte chemoattractant protein-1 (MCP-1), transforming growth factor beta (TGF-β), interleukin-1 beta (IL_1β), plasminogen activator inhibitor-1 (PA-I), serum leptin concentrations, and C-reactive protein of high sensitivity (hs-CRP) in all participants. The inflammatory markers were assessed using the enzyme-linked immunosorbent assay (ELISA).

RESULT

The findings revealed a significant negative association between flavonoids intake and MCP-1 (P = 0.024), lignans intake and MCP-1 (P = 0.017), and Gal-3 (P = 0.032). These significant associations were observed between other polyphenols intake and IL_1β (P = 0.014). There was also a significant positive association between other polyphenol intake and TGF-β (P = 0.008) and between phenolic acid intake and TGF-β (P = 0.014).

CONCLUSION

Our findings suggest that a high polyphenol intake may help individuals to reduce systemic inflammation. Further large studies involving participants of different ages and genders are highly warranted.

Association between Polyphenol Intake and Lipid Profile of Adults and Elders in a Northeastern Brazilian Capital

This research was aimed at evaluating the relationship between the estimated polyphenol intake and the atherogenic lipid profile in adult and elder residents in the city of Teresina, located in the Northeastern Region of Brazil. This study was a cross-sectional population-based survey with 501 adults and elders, conducted in Teresina, Brazil. Food intake was obtained by 24-h food recall. The estimated polyphenol intake was calculated by multiplying the food consumption data from the recall by the polyphenol content in the foods described in the Phenol-Explorer database. The mean intake of total polyphenols was 1006.53 mg/day. The phenolic acids was the class with the highest intake, followed by the flavonols. Coffee, beans and apples were the main foods contributing to the total polyphenol intake. In the individuals with elevated serum concentrations of total cholesterol and triglycerides, the intake of total polyphenols was significantly higher. The intake of total polyphenols, phenolic acids and lignans was higher in the subjects with dyslipidemia. This article provides, for the first time, data on the intake of the total polyphenol classes and subclasses in the evaluated population and the relationship with the lipid profile. The individuals with a higher intake of total polyphenols had a worse lipid profile, which may be a consequence of an improved diet in those individuals who present with dyslipidemia.