Several epidemiological studies have linked flavonols with decreased risk of cardiovascular disease (CVD). However, some heterogeneity in the individual physiological responses to the consumption of these compounds has been identified. This meta-analysis aimed to study the effect of flavonol supplementation on biomarkers of CVD risk such as, blood lipids, blood pressure and plasma glucose, as well as factors affecting their inter-individual variability. Data from 18 human randomized controlled trials were pooled and the effect was estimated using fixed or random effects meta-analysis model and reported as difference in means (DM). Variability in the response of blood lipids to supplementation with flavonols was assessed by stratifying various population subgroups: age, sex, country, and health status. Results showed significant reductions in total cholesterol Subgroup analysis showed a more pronounced effect of flavonol intake in participants from Asian countries and in participants with diagnosed disease or dyslipidemia, compared to healthy and normal baseline values. In conclusion, flavonol consumption improved biomarkers of CVD risk, however, country of origin and health status may influence the effect of flavonol intake on blood lipid levels.

These findings strengthen the involvement of AGEs-RAGE axis in liver injury and the pathogenesis of NAFLD.

Polyphenols have been extensively studied for their antioxidant and anti-inflammatory properties.Recently, their antiglycative actions by oxidative stress modulation have been linked to prevention of diabetes and associated complications. This paper assesses the evidence for polyphenol interventions on glycohaemoglobin (HbA1c) in non-diabetic, pre-diabetic and type 2 diabetes mellitus (T2DM) subjects. A systematic review of polyphenols clinical trials on HbA1c in humans was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis. Thirty-six controlled randomized trials with HbA1c values were included.Polyphenols (extracts, supplements, foods), were supplemented (28 mg to 1.5g) for 0.7 to 12 months. Combining all subjects (n=1954, mean baseline HbA1c=7.03%, 53 mmol/mol), polyphenol supplementation significantly (p<0.001) lowered HbA1c% by -0.53±0.12 units (-5.79±0.13 mmol/mol). This reduction was significant (p<0.001) in T2DM subjects, specifically (n=1426, mean baseline HbA1c=7.44%, 58 mmol/mol), with HbA1c% lowered by -0.21±0.04 units (-2.29±0.4 mmol/mol). Polyphenol supplementation had no significant effect (p>0.21) in the non-diabetic (n=258, mean baseline HbA1c=5.47%, 36 mmol/mol) and the pre-diabetic subjects (n=270, mean baseline HbA1c=6.06%, 43 mmol/mol) strata: -0.39±0.27 HbA1c% units (-4.3±0.3 mmol/mol), and -0.38±0.31 units (-4.2±0.31 mmol/mol), respectively. In conclusion, polyphenols can successfully reduce HbA1c in T2DM, without any intervention at glycaemia, and could contribute to the prevention of diabetes complications. [Escriba texto]

Human urine, which is rich in metabolites, provides valuable approaches for biomarker measurement. Maintaining the stability of metabolites in urine is critical for accurate and reliable research results and subsequent interpretation. In this study, the effect of storage temperature (4, 22, and 40 °C), storage time (24 and 48 h), and use of preservatives (boric acid (BA), thymol) and para-aminobenzoic acid (PABA) on urinary metabolites in the pooled urine samples from 20 participants was systematically investigated using large-scale targeted liquid chromatography tandem mass spectrometry (LC-MS/MS)-based metabolomics. Statistical analysis of 158 reliably detected metabolites showed that metabolites in urine with no preservative remained stable at 4 °C for 24 and 48 h as well as at 22 °C for 24 h, but significant metabolite differences were observed in urine stored at 22 °C for 48 h and at 40 °C. The mere addition of BA caused metabolite changes. Thymol was observed to be effective in maintaining metabolite stability in urine in all the conditions designed, most likely due to the inhibitory effect of thymol on urine microbiota. Our results provide valuable urine preservation guidance during sample storage, which is essential for obtaining reliable, accurate, and reproducible analytical results from urine samples.

Plant-based diets rich in bioactive compounds such as polyphenols have been shown to positively modulate the risk of cardiometabolic (CM) diseases. The inter-individual variability in the response to these bioactives may affect the findings. This systematic review aimed to summarize findings from existing randomized clinical trials (RCTs) evaluating the effect of hydroxycinnamic acids (HCAs) on markers of CM health in humans. Literature searches were performed in PubMed and the Web of Science. RCTs on acute and chronic supplementation of HCA-rich foods/extracts on CM biomarkers were included. Forty-four RCTs (21 acute and 23 chronic) met inclusion criteria. Comparisons were made between RCTs, including assessments based on population health status. Of the 44 RCTs, only seven performed analyses on a factor exploring inter-individual response to HCA consumption. Results demonstrated that health status is a potentially important effect modifier as RCTs with higher baseline cholesterol, blood pressure and glycaemia demonstrated greater overall effectiveness, which was also found in studies where specific subgroup analyses were performed. Thus, the effect of HCAs on CM risk factors may be greater in individuals at higher CM risk, although future studies in these populations are needed, including those on other potential determinants of inter-individual variability. PROSPERO, registration number CRD42016050790.