The role of oxidative stress, antioxidants and vascular inflammation in cardiovascular disease (a review).

High blood pressure (hypertension)

Summary The concept of mild chronic vascular inflammation as part of the pathophysiology of cardiovascular disease, most importantly hypertension and atherosclerosis, has been well accepted. Indeed there are links between vascular inflammation, endothelial dysfunction and oxidative stress. However, there are still gaps in our understanding regarding this matter that might be the cause behind disappointing…

Ascorbic acid decreases the binding affinity of the AT1 receptor for angiotensin II

High blood pressure (hypertension)

Summary Background: Ascorbic acid is an essential vitamin and a powerful antioxidant. Many studies have highlighted the benefits of ascorbic acid for chronic cardiovascular diseases such as hypertension in which angiotensin II (Ang II) plays an significant role. We therefore hypothesized that ascorbic acid could modify the pharmacological properties of the AT(1) receptor for Ang…

Vitamin C Lowers Blood Pressure in Spontaneously Hypertensive Rats by Targeting Angiotensin-Converting Enzyme I Production in a Frequency-Dependent Manner

High blood pressure (hypertension)

Summary The lowering blood pressure effect of vitamin C (VC) has been evaluated in various models. As VC has a fast degradation rate in the body after consumption, a study of the frequency-dependent manner of VC is essential for the sustained antihypertension effect of VC. In this study, we investigated the frequency and dose dependency…

Decrease in oxidative stress through supplementation of vitamins C and E is associated with a reduction in blood pressure in patients with essential hypertension

High blood pressure (hypertension)

Summary Plant-derived bioflavonoids have been recognized to support arterial wall structural integrity and interfere with a variety of pro-atherosclerotic stimuli. This study examined the effect of various bioflavonoids on angiotensin II-stimulated contraction by human aortic smooth muscle cells (SMC) embedded in a three-dimensional collagen matrix. Bioflavonoid inhibition of SMC contraction was found to be dependent…

Ascorbic acid supplementation improves postprandial glycaemic control and blood pressure in individuals with type 2 diabetes: Findings of a randomized cross-over trial

High blood pressure (hypertension)

Summary Aim: The primary aim of this study was to investigate whether ascorbic acid (AA) supplementation improves postprandial glucose responses under free-living conditions in individuals with type 2 diabetes. A secondary aim was to investigate the effect of AA supplementation on blood pressure. Materials and methods: A total of 31 individuals with type 2 diabetes…

Ascorbate Attenuates Oxidative Stress and Increased Blood Pressure Induced by 2-(4-Hydroxyphenyl) Amino-1,4-naphthoquinone in Rats

High blood pressure (hypertension)

Summary Quinone derivatives like 2-(4-hydroxyphenyl) amino-1,4-naphthoquinone (Q7) are used as antitumor agents usually associated with adverse effects on the cardiovascular system. The objective of this study was to evaluate the cardioprotective effect of ascorbate on Q7-induced cardiovascular response in Wistar rats. In this study, blood pressure, vascular reactivity, and intracellular calcium fluxes were evaluated in…

High-Dose Vitamin C Prevents Secondary Brain Damage After Stroke via Epigenetic Reprogramming of Neuroprotective Genes

High blood pressure (hypertension)

Summary Vitamin C has recently been identified as an epigenetic regulator by activating ten-eleven translocases (TETs), enzymes involved in generating DNA hydroxymethylcytosine (5hmC). Currently, we investigated whether high-dose vitamin C promotes neuroprotection through epigenetic modulation of 5hmC, if there are sex-specific differences in outcome, and the therapeutic potential of vitamin C in stroke-related comorbidities in…

Serum vitamin C concentration was inversely associated with subsequent 20-year incidence of stroke in a Japanese rural community. The Shibata study

High blood pressure (hypertension)

Summary Background and purpose: Epidemiological evidence suggests that vitamin C may decrease the risk of stroke. The purpose of the present study was to examine the association of serum vitamin C concentration with the subsequent incidence of stroke. Methods: In a Japanese rural community, a cohort of 880 men and 1241 women aged 40 years…

Vitamin C improves endothelial function of epicardial coronary arteries in patients with hypercholesterolaemia or essential hypertension–assessed by cold pressor testing

High blood pressure (hypertension)

Summary Aims: There is evidence that formation of free radicals increases in patients with hypertension or hypercholesterolaemia, which may contribute to endothelial dysfunction of epicardial coronary arteries due to inactivation of the vasodilator NO. The present study was designed to test whether the abnormal constriction of epicardial coronary arteries due to sympathetic stimulation by the…

Effects of vitamin C supplementation on essential hypertension: A systematic review and meta-analysis

High blood pressure (hypertension)

Summary Background: Vitamin C as a supplement to treat hypertension has been proposed. However, it remains controversial whether vitamin C can improve blood pressure in patients with primary hypertension. Objectives: To analyze the effect of vitamin C (VitC) supplementation on systolic (SBP) and diastolic (DBP) blood pressure in patients with essential hypertension. Methods: We searched…

Effect of acute administration of vitamin C on muscle sympathetic activity, cardiac sympathovagal balance, and baroreflex sensitivity in hypertensive patients

High blood pressure (hypertension)

Summary Background: Essential hypertension is characterized by both increased oxidative stress and sympathetic traffic. Experimental studies have shown that reactive oxygen species can modulate autonomic activity. Objective: The aim of this study was to determine whether acute administration of the antioxidant vitamin C modifies sympathetic nerve activity in essential hypertension. Design: Thirty-two untreated patients with…

Effects of ascorbic acid on ambulatory blood pressure in elderly patients with refractory hypertension

High blood pressure (hypertension)

Summary The increased production of reactive oxygen species plays a role in the etiology of hypertension, but the effects of antioxidants on blood pressure are controversial. However, antioxidants possibly lower blood pressure in elderly patients with hypertension, because vascular aging is also closely related to oxidative stress. Effects of chronic treatment with ascorbic acid (CAS…

Supplementation with vitamins C and E improves arterial stiffness and endothelial function in essential hypertensive patients.

High blood pressure (hypertension)

Summary Background: Essential hypertension is characterized by endothelial dysfunction, arterial stiffness, and increased oxidative stress. We evaluated the effect of short-term combined treatment with the antioxidants vitamins C and E on endothelial function, arterial stiffness, and oxidative stress in untreated essential hypertensive patients. Methods: A randomized, double-blind, placebo-controlled, crossover study design was used to assign…

Effect of ascorbic acid on endothelial dysfunction of epicardial coronary arteries in chronic smokers assessed by cold pressor testing

High blood pressure (hypertension)

Summary Background: In chronic smokers there is evidence for increased formation of oxygen-derived free radicals within the vessel wall impairing endothelial function. It has been suggested that the inactivation of endothelium-derived nitric oxide by oxygen free radicals contributes to endothelial dysfunction. Hence, we tested the hypothesis that in chronic smokers the antioxidant ascorbic acid could…

Vitamin C Deficiency-Induced Pulmonary Arterial Hypertension

High blood pressure (hypertension)

Summary We report a case of a man in his 60s who developed pulmonary arterial hypertension (PAH) in association with profound vitamin C deficiency. Decreased availability of endothelial nitric oxide and activation of the hypoxia-inducible family of transcription factors, both consequences of vitamin C deficiency, are believed to be mechanisms contributing to the pathogenesis of…

Vitamin C supplementation improves blood pressure and oxidative stress after acute exercise in patients with poorly controlled type 2 diabetes mellitus: A randomized, placebo-controlled, cross-over study

High blood pressure (hypertension)

Summary This study aimed to assess the effect of Vitamin C on blood pressure (BP), and subsequently on oxidative stress and nitric oxide (NO) release, following the low-intensity exercise in the patients. This study included 24 patients with type 2 diabetes mellitus (T2D) (age, 53 ± 7 years; hemoglobin A1c, 10.1% ± 0.9%) randomized into…

Effects of vitamin C supplementation on blood pressure: a meta-analysis of randomized controlled trials

High blood pressure (hypertension)

Summary Background: In observational studies, increased vitamin C intake, vitamin C supplementation, and higher blood concentrations of vitamin C are associated with lower blood pressure (BP). However, evidence for blood pressure-lowering effects of vitamin C in clinical trials is inconsistent. Objective: The objective was to conduct a systematic review and meta-analysis of clinical trials that…

Vitamin C supplementation improves inflammation in obese adults

High blood pressure (hypertension)

Summary Obesity is associated with chronic inflammation. Thus, this study investigated the anti-inflammatory capacity of vitamin C in obese patients. 64 obese participants with high blood pressure and/or diabetes and high levels of inflammatory markers were enrolled into either the experimental group (31 patients) or the control group (33 patients). The experimental group was treated…

Low vitamin C levels can increase risk of stroke in hypertensive patients

High blood pressure (hypertension)

Summary A clinical epidemiological study involving more than 2,400 participants in Finland investigated the association between blood levels of vitamin C and the occurrence of stroke. The study participants were patients with hypertension – a condition associated with an increased risk of stroke – who were observed over a period of 10.4 years. The results…

Vitamin C supplementation leads to significant reduction in blood pressure

High blood pressure (hypertension)

Summary An analysis of 8 clinical trials investigating the association between vitamin C supplementation and essential hypertension showed that vitamin C supplementation led to a significant reduction in blood pressure. For daily supplementation above 500 mg of vitamin C, these results were even statistically significant (P = 0.005). What is particularly remarkable about this research…

Inadequate micronutrient intake increases risk of high blood pressure

High blood pressure (hypertension)

Summary This study analyzed the relationship between the intakes of micronutrients (vitamins and minerals) and developing high blood pressure. Vitamin and mineral intakes were estimated from a three-day food record in 120 children. The researchers found that intakes of vitamin D, calcium and potassium were inadequate, whereas sodium intake was considered to be too high.…