Folic acid supplementation and blood pressure: a GRADE-assessed systematic review and dose-response meta-analysis of 41,633 participants.

Hypertension is a predisposing factor for cardiovascular disease (CVD). The extant literature regarding the effects of folic acid supplementation on blood pressure (BP) is inconsistent. Therefore, this systematic review and meta-analysis of randomized controlled trials was conducted to summarize the effects of folic acid supplementation on BP. A systematic search was carried out in PubMed, Scopus, ISI Web of Science, and Cochrane library, from database inception to August 2021. Data were pooled using the random-effects method and were expressed as weighted mean difference (WMD) and 95% confidence intervals (CI). The pooled results of 22 studies, including 41,633 participants, showed that folic acid supplementation significantly decreased systolic BP (SBP) (WMD: -1.10 mmHg; 95% CI: -1.93 to -0.28; p = 0.008). Subgroup analysis showed that the results remained significant when baseline SBP was ≥120 mmHg, intervention duration was ≤6 weeks, intervention dose was ≥5 mg/d, in patients with CVD, males and females, and overweight participants, respectively. Furthermore, the changes observed in diastolic BP (DBP) (WMD: -0.24 mmHg; 95% CI: -0.37 to -0.10; p < 0.001) were also statistically significant. However, subgroup analysis showed that the results remained significant in subject with elevated DBP, long term duration of intervention (>6 weeks), low dose of folic acid (<5 mg/day), CVD patients, both sexes and male, and participants with normal BMI. Dose-response analysis showed that folic acid supplementation changed SBP and DBP significantly based on dose and duration. However, meta-regression analysis did not reveal any significant association between dose and duration of intervention with changes in SBP. The present study demonstrates the beneficial effects of folic acid supplementation on BP by decreasing both SBP and DBP.

Effects of betaine supplementation on cardiovascular markers: A systematic review and Meta-analysis.

Controversy regarding the effects of betaine supplementation on cardiovascular markers has persisted for decades. This systematic review and meta-analysis compared the effects of betaine supplementation on cardiovascular disease (CVD) markers. Studies examining betaine supplementation on CVD markers published up to February 2021 were identified through PubMed, the Cochrane Library, Web of Science, Embase, and SCOPUS. Betaine supplementation had a significant effect on concentrations of betaine (MD: 82.14 µmol/L, 95% CI: 67.09 to 97.20), total cholesterol (TC) (MD: 14.12 mg/dl, 95% CI%: 9.23 to 19.02), low-density lipoprotein (LDL) (MD: 10.26 mg/dl, 95% CI: 6.14 to 14.38)], homocysteine (WMD: -1.30 micromol/L, 95% CI: -1.61 to -0.98), dimethylglycine (DMG) (MD: 21.33 micromol/L, 95% CI: 13.87 to 28.80), and methionine (MD: 2.06 micromol/L, 95% CI: 0.23 to 3.88). Moreover, our analysis indicated that betaine supplementation did not affect serum concentrations of triglyceride (TG), high-density lipoprotein (HDL), fasting blood glucose (FBG), C-reactive protein (CRP), liver enzymes [alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT)], and blood pressure. Our subgroup analysis suggested that a maximum dose of 4 g/d might have homocysteine-lowering effects without any adverse effect on lipid profiles reported with doses of ≥4 g/d. In conclusion, the present systematic review and meta-analysis supports the advantage of a lower dose of betaine supplementation (<4 g/d) on homocysteine concentrations without the lipid-augmenting effect observed with a higher dosage.

Effects of epigallocatechin-3-gallate of Camellia sinensis leaves on blood pressure, lipid profile, atherogenic index of plasma and some inflammatory and antioxidant markers in type 2 diabetes mellitus patients: a clinical trial.

BACKGROUND: In patients with type 2 diabetes mellitus (T2DM) the inflammatory and metabolic responses to epigallocatechin-3-gallate (EGCG) are unknown. OBJECTIVES: Evaluate the impacts of EGCG on metabolic factors and some biomarkers of stress oxidative in patients with T2DM. METHODS: In this randomized, double-blind, placebo-controlled trial, 50 patients with T2DM consumed either 2 tablets (300 mg) EGCG (n=25) or wheat flour as placebo (n=25) for 2 months. The total antioxidant capacity (TAC), interleukin-6 (IL-6), lipid profile, mean arterial pressure (MAP), atherogenic index of plasma (AIP) were evaluated before and after the intervention. RESULTS: The finding of present study exhibited a significant increase in the serum levels of TAC after the EGCG supplementation (p=0.001). Also, in compare with control group, the mean changes of TAC were significantly higher in supplement group (p=0.01). In intervention group, a significant decrease was observed in the mean levels of triglyceride, total cholesterol, diastolic blood pressure (DBP), AIP, and MAP (p<0.05). Taking EGCG resulted in the mean changes of total cholesterol, MAP and DBP were significantly lower in compare with control group (p<0.05). CONCLUSIONS: This study recommended that EGCG supplementation may be improved blood pressure, lipid profile, AIP, and oxidative status in patients with T2DM.