Vitamin C and blood pressure–an overview

Abstract

Background: Laboratory and some epidemiological reported an inverse association with vitamin C intake. studies suggest that antioxidants, such as vitamin C,The two non-randomised and four randomised conare protective for cardiovascular disease. This protectrolled trials were all small. Of the randomised trials one tive effect may be mediated through blood pressure reported a significant decrease in BP, one a non-(BP). This is the first systematic review of epidemiologsignificant decrease and two were uninterpretable. ical studies of vitamin C and BP.Conclusions: We found a consistent cross-sectional Method: Published cross-sectional studies, prospective association between higher vitamin C intake or status studies and trials in humans were identified that examand lower BP, though no study controlled adequately ined the association between vitamin C intake or plasma for confounding by other dietary factors. Further crossvitamin C levels and BP. Relevant references were sectional studies are required to establish whether an located by MEDLINE search 1966-1996, EMBASE search independent association exists. If this is shown to be 1980-1996, by searching personal bibliographies, books the case larger and longer term trials will be needed to and reviews and from citations in located articles.confirm the association is causal. Potentially the impact Results: Cross-sectional data were available from 18 on cardiovascular disease of a modest change in mean populations. Ten of 14 reported an inverse association population vitamin C intake is large. between plasma vitamin C and BP and three of four

Fostering venture research: A case study of the discovery that ascorbate enhances adrenergic drug activity

“…had extensive experience using these techniques, having done so in the discovery of the latch mechanism in the regulation of smooth muscle contraction [Dillon et al, 1981]. We were led to predict that if the ascorbate-adrenergic coupling did anything physiologically, it would produce a reduction in smooth muscle contraction, since a number of human studies had recently appeared showing that vitamin C supplementation lowers blood pressure [Bendich and Langseth, 1995;Ness et al, 1997;Nyyssonen et al, 1997;Bates et al, 1998]. Hindsight being, if not 20/20, at least a little better than foresight, we failed to note several phenomena.…”

The planetary biology of ascorbate and uric acid and their relationship with the epidemic of obesity and cardiovascular disease

“…Epidemiologic studies have confirmed a strong inverse relationship between serum ascorbate levels and blood pressure [61][62][63]. Plasma levels of ascorbate are lower in hypertensive subjects (mean 40 umol/L) compared to normotensive controls (mean 57 umol/L) [ 64 ].…”

“…Numerous animal models have shown a key role for oxidative stress (present in the circulation, blood vessels, and kidney) in mediating hypertension [ 56 ]. Ascorbate administration also lowers blood pressure in many hypertensive animal models [58][59][60].Epidemiologic studies have confirmed a strong inverse relationship between serum ascorbate levels and blood pressure [61][62][63]. Plasma levels of ascorbate are lower in hypertensive subjects (mean 40 umol/L) compared to normotensive controls (mean 57 umol/L) [ 64 ].…”

Is vitamin C an effective antihypertensive supplement? A review and analysis of the literature

“…[8][9][10][11][12][13][14][15][16][17][18][19][20] In 1997 Ness et al concluded that there were too few clinical trials, and those reported at that time were generally too small and too varied to provide confirmatory evidence for a casual relationship. 21 This study was undertaken in order to evaluate the current clinical evidence that vitamin C supplementation lowers both systolic and diastolic blood pressure in hypertensive individuals, and to also review the hypothesized mechanisms of action.…”