Oral ascorbic acid increases plasma oestradiol during postmenopausal hormone replacement therapy

Vihtamäki, Tarja; Parantainen, J.; Koivisto, Anna‐Maija; Metsä‐Ketelä, T.; Tuimala, Risto

doi:10.1016/s0378-5122(02)00005-1

Cited by 20 publications

(15 citation statements)

References 27 publications

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“…Additive effect of AsA in anti-oxidation may be responsible for increased levels of tissue estrogen. As a result of the study, ascorbic acid has been interacted with estrogen therapy, this effect may be found possible interaction of AsA with E2 at the level of antioxidation [16]. As a conclusion, the finding of this study showed that AsA in comparison to control group, while did not have an effect on serum estrogen/progesterone ratio, induced the increased tissue estrogen/progesterone ratio.…”

Section: Discussionsupporting

confidence: 54%

The Effects of Ascorbic Acid on the Estrogen/Progesteron Levels in the Isolated Rabbit Uterine Muscle

Bostancı¹

2012

J Clin Gynecol Obstet

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Section: Discussionsupporting

confidence: 54%

The Effects of Ascorbic Acid on the Estrogen/Progesteron Levels in the Isolated Rabbit Uterine Muscle

Bostancı¹

2012

J Clin Gynecol Obstet

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“…Our hypothesis was that several nutrients that may result in increased 2‐hydroxylated oestrogen metabolites (low energy intake, high protein intake, low carbohydrate intake, high cruciferous vegetable intake and high fibre intake) would be associated with reduced risk of hypospadias among offspring 10–14 . In contrast, high vitamin C intake was hypothesised to result in increased oestrogen levels; vitamin C competes with oestrogens for sulphate conjugation during first‐pass metabolism, thus resulting in reduced clearance of oestrogen via the hepatic drug‐oxidising system 27–29 . Our results did not support these hypotheses, with the exception of our finding that protein intake in the highest vs. lowest quartile was associated with lower risk (OR 0.6 [95% CI 0.5, 0.9]).…”

Section: Commentsmentioning

confidence: 63%

Nutritional Factors and Hypospadias Risks

Carmichael

Feldkamp

et al. 2012

Paediatric Perinatal Epid

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SUMMARY We examined whether hypospadias was associated with several aspects of the diet, including intake of animal products, intake of several nutrients and food groups related to a vegetarian diet and estrogen metabolism, and diet quality. The study included deliveries from 1997 to 2005 that were part of the National Birth Defects Prevention Study. Diet was assessed by food frequency questionnaire during maternal telephone interviews, and two diet quality indices were developed based on existing indices. Analyses included 1,250 cases with second or third degree hypospadias (urethra opened at the penile shaft, scrotum or perineum) and 3,118 male, liveborn, non-malformed controls. All odds ratios (ORs) and 95% confidence intervals (CI) were estimated from logistic regression models that included several potential confounders, including energy intake. Intake of animal products was not associated with hypospadias; e.g., the adjusted OR for any versus no intake of meat was 1.0 (95% CI 0.6, 1.6). Frequency of intake of meat or other animal products was also not associated with hypospadias, nor was intake of iron or several nutrients that are potentially related to estrogen metabolism. Diet quality was also not associated with hypospadias; the ORs for diet quality in the highest versus lowest quartile for the two diet quality indices were 1.0 (95% CI 0.6, 1.6) and 0.9 (95% CI 0.7, 1.1). In conclusion, this large study does not support an association of a vegetarian diet or worse diet quality with hypospadias.

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“…Therefore, a continuously regenerated source of an antioxidant may be available. Ascorbic acid has been shown to influence estrogen levels in postmenopausal women receiving hormone therapy [Vihtamaki et al, 2002]. On the other hand, estrogens have been shown to interact synergistically with the water-soluble antioxidant glutathione Gridley et al, 1998].…”

Section: Lh-looh 1lmentioning

confidence: 99%

Mechanistic insights into the direct antioxidant effects of estrogens

Prókai

Prókai-Tátrai

Perjési

et al. 2005

Drug Development Research

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Free-radical scavenging by estrogens has been implicated as one of their non-genomic (estrogen-receptor independent) mechanisms of cytoprotection. This activity is associated with the presence of the phenolic A-ring in the structure of these molecules, thus rendering them members of the class of compounds called phenolic antioxidants. Direct oxyradical-scavenging by estrogens has been thought to cause interruption of free-radical chain reactions such as lipid peroxidation, and to prevent freeradical induced oxidative damage to biological macromolecules such as DNA and proteins. These antioxidant effects are determined not only by chemical reactivities toward reactive oxygen or reactive nitrogen species, but also by the mobility and/or distribution of estrogens in the biological microenvironment and by the fate of the estrogen-derived radicals. Recent results have highlighted the importance of investigations aimed at understanding mechanistic details of the underlying chemistry, especially with a focus on estrogen neuroprotection. Such fundamental studies have facilitated the discovery of a previously unrecognized antioxidant cycle for estrogens in which estrogen-derived quinols are key intermediates. Additionally, the use of these quinols as prodrugs in animal models has revealed a significant reduction of side effects compared to treatment directly with the feminizing hormones. Drug Dev.

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Oral ascorbic acid increases plasma oestradiol during postmenopausal hormone replacement therapy

Cited by 20 publications

References 27 publications

The Effects of Ascorbic Acid on the Estrogen/Progesteron Levels in the Isolated Rabbit Uterine Muscle

The Effects of Ascorbic Acid on the Estrogen/Progesteron Levels in the Isolated Rabbit Uterine Muscle

Nutritional Factors and Hypospadias Risks

Mechanistic insights into the direct antioxidant effects of estrogens

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