1.
The Effect of Resveratrol on Blood Lipid Profile: A Dose-Response Meta-Analysis of Randomized Controlled Trials.
Cao, X, Liao, W, Xia, H, Wang, S, Sun, G
Nutrients. 2022;14(18)
-
-
-
Free full text
Plain language summary
It is well known that cardiovascular disease is a leading cause of death. Imbalances in the blood lipid levels, such as elevation of total cholesterol, Triglycerides and LDL cholesterol, may increase the risk of cardiovascular disease. It has been shown that resveratrol, a polyphenol found in grapes, blueberries, mulberries, raspberries, peanuts, and knotweeds, has protective effects against cardiovascular disease. In this meta-analysis, 17 randomised controlled trials were included, with varying durations of 4 to 48 weeks and intervention dosages ranging from 10 to 3000 mg/day. According to the results of this meta-analysis, Resveratrol supplementation significantly reduced total cholesterol, triglycerides, and LDL cholesterol, but not HDL cholesterol. In addition, the reduction in LDL cholesterol was more significant in type 2 diabetic patients when resveratrol was supplemented for 12 weeks or more. A crucial factor in determining the effectiveness of resveratrol supplementation is its dosage. High doses over 500 mg/day were found to have the opposite effect of increasing body mass index and body weight and suppressing the cardioprotective effect. The effects of different dosages and durations of resveratrol supplementation on cardiometabolic health require further robust research. Healthcare professionals may use the results of this study to understand the importance of careful consideration when supplementing resveratrol as a nutraceutical.
Abstract
(1) Background: The effects of resveratrol on blood lipids are controversial. Whether there is a dose-response of the lipid profile upon resveratrol supplementation is unknown. (2) Methods: This dose-response meta-analysis of randomized controlled trials (RCTs) was performed to explore the effects of resveratrol supplementation on lipid profile. A systematical and comprehensive search of several databases was conducted by 30 June 2022. (3) Results: The results indicated that the intake of resveratrol could significantly decrease the total cholesterol (TC) (mean difference = -10.28; 95%CI: -13.79, -6.76, p < 0.001), triglyceride (TG) (Mean difference = -856; 95%CI: -12.37, -4.75, p < 0.001) and low-density lipoprotein cholesterol (LDL-C) (mean difference = -5.69; 95%CI: -11.07, -0.31, p = 0.038) level, but did not alter the level of high-density lipoprotein cholesterol (HDL-C). In the non-linear dose-response analysis, we observed a significant effect of the supplementation dosage on the level of LDL-C (p-nonlinearity = 0.002). Results from the sub-group analysis showed that the reduction of LDL-C was more significant in the trials with a duration of ≥12 weeks and in subjects with type 2 diabetes mellitus. (4) Conclusion: Findings from this study suggest that resveratrol may be beneficial to reduce TC, TG, and LDL-C levels in the blood. The dosage of the resveratrol intervention is an essential factor that affects the level of LDL-C.
2.
Nigella sativa supplementation improves cardiometabolic indicators in population with prediabetes and type 2 diabetes mellitus: A systematic review and meta-analysis of randomized controlled trials.
Saadati, S, Naseri, K, Asbaghi, O, Abhari, K, Zhang, P, Li, HB, Gan, RY
Frontiers in nutrition. 2022;9:977756
-
-
-
Free full text
Plain language summary
Chronic, non-infectious diseases contribute to nearly three-quarters of deaths worldwide. Type 2 diabetes mellitus (T2DM) together with cardiovascular disease, are the two most common conditions in this category. Insulin resistance, obesity, elevated blood fats, and high blood pressure are typical hallmarks of T2DM and its development and are also significant risk factors for diabetes-related cardiovascular events. The prolonged nature of T2DM and the complications that can go alongside make the condition one of the most costly diseases for healthcare systems hence finding cost-effective therapeutic strategies should be of high importance. Many functional plants and their bioactive components have shown to exert anti-diabetic effects, including Nigella sativa, commonly known as black cumin. Previous studies also reported promising benefits of Nigella on cardiometabolic health. How these effects manifest in individuals with T2DM and those who are prediabetic was analysed in this systematic review and meta-analysis. The review included 11 randomised controlled trials with a total of 666 subjects. The review focused on cardiometabolic measures such as body measurements, blood sugar control, insulin resistance and secretion, blood fats, and markers of inflammation and oxidative stress. Nigella supplementation appeared to have favourable effects on blood sugar control overall but with no changes in the outcomes of oral glucose tolerance tests. Furthermore, Nigella appeared to positively influence on various blood fats, and markers of inflammation and oxidative stress. There were no changes to fasting insulin, insulin resistance, triglyceride, high-density lipoprotein (HDL)-Cholesterol and body mass index (BMI) when compared to the control group. Yet, in a sub-analysis Nigella supplementation enhanced serum levels of 'good' HDL-Cholesterol in a particular group. An improvement in insulin resistance and a decrease in BMI were seen in supplementation trials lasting over 8-weeks with doses of over 1 g/day of Nigella. The authors concluded that Nigella has the potential to improve cardiometabolic parameters by favourably influencing blood sugar metabolism and blood fats, inflammation, and oxidative stress in individuals with prediabetes and T2DM. Hence Nigella supplementation has promsing potential as an adjunct therapeutic in the management of prediabetes and T2DM.
Abstract
OBJECTIVE Nigella sativa (N. sativa) from the family Ranunculaceae has medicinal properties. Previous studies have reported promising findings showing that N. sativa may benefit cardiometabolic health; however, current evidence on its cardiometabolic effects on those with prediabetes and type 2 diabetes mellitus (T2DM) is still unclear. Hence, we conducted a systematic review and meta-analysis to assess the efficacy of N. sativa on cardiometabolic parameters in population with prediabetes and T2DM. METHODS PubMed/Medline, ISI Web of Science, Scopus, and Cochrane library were systematically searched up to June 20, 2022. Meta-analyses using random-effects models were used. RESULTS Eleven randomized controlled trials (RCTs) were included in the meta-analysis. N. sativa intervention resulted in significant changes in fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), c-reactive protein (CRP), and malondialdehyde (MDA), without overall changes in glucose levels after oral glucose tolerance test (OGTT), fasting insulin, homeostatic model assessment of insulin resistance (HOMA-IR), triglyceride, high-density lipoprotein cholesterol (HDL-C), and body mass index (BMI) when compared with the control group. In subgroup analyses, N. sativa supplementation enhanced serum levels of HDL-C in subjects with baseline HDL-C lower than 40 mg/dL. Furthermore, HOMA-IR and BMI values decreased in the N. sativa-supplemented group compared with the control group, when the length of follow-up was more than 8 weeks and the dose was more than 1 g/day for N. sativa supplementation, respectively. CONCLUSION Our findings indicate that N. sativa supplementation may effectively improve cardiometabolic profiles in individuals with prediabetes and T2DM.
3.
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.