Serum Vitamin C Concentration Was Inversely Associated With Subsequent 20-Year Incidence of Stroke in a Japanese Rural Community

Abstract

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 and older who were initially free of stroke was examined in 1977 and followed until 1997. The baseline examination included a measurement of serum vitamin C concentration. The incidence of stroke was determined by annual follow-up examinations and registry. Results-During the 20-year observation period, 196 incident cases of all stroke, including 109 cerebral infarctions and 54 hemorrhagic strokes, were documented. Strong inverse associations were observed between serum vitamin C concentration and all stroke (sex-and age-adjusted hazard ratios were 0.93, 0.72, and 0.59, respectively, for the second, third, and fourth quartiles compared with the first quartile; P for trendϭ0.002), cerebral infarction (0.71, 0.59, and 0.51; P for trendϭ0.015), and hemorrhagic stroke (0.89, 0.75, and 0.45; P for trendϭ0.013). Additional adjustments for blood pressure, serum total cholesterol, body mass index, physical activity, smoking, alcohol drinking, antihypertensive medication, atrial fibrillation, and history of ischemic heart disease did not attenuate these associations markedly. Conclusions-Serum vitamin C concentration was inversely related to the subsequent incidence of stroke. This relationship was significant for both cerebral infarction and hemorrhagic stroke. Additional mechanistic hypotheses may be required to explain our findings.

Is vitamin C supplementation beneficial? Lessons learned from randomised controlled trials

“…The authors concluded that vitamin C status was as strong a predictor of death from stroke as diastolic blood pressure (9) . An inverse correlation between vitamin C status and stroke was also reported from a study (2121 subjects) in a rural Japanese population aged 40 years or older (42) . In the 12-year follow up on the Basel Prospective Study, a significantly increased risk of IHD and stroke was found in individuals with plasma ascorbate , 22·7 mmol/l, corresponding to severe or marginal vitamin C deficiency (43 -45) .…”

Ascorbic Acid Reduces the Adverse Effects of Delayed Administration of Tissue Plasminogen Activator in a Rat Stroke Model

“…It has been shown that delayed use of r-tPA leads to hyperperfusion which results in the accumulation of free radicals and the up-regulation of matrix metalloproteinases (MMPs) including MMP-9 [6,7] and these events lead to more injuries to the brain parenchyma. Under normal conditions, the endogenous and exogenous antioxidants scavenge free radicals and inhibit the harmful effects of oxidative stress [8]. Previous investigations revealed that after IBI, the concentrations of glutathione and ascorbic acid (AA) are decreased, while free radicals are increased [9,10], suggesting that increasing the concentration of AA, which may act as an antioxidant under these conditions, could be considered as new therapeutic strategy for treatment of IBI [11].…”

Approaches to prevention of a first stroke

“…A protective effect of fruits, vegetables, and whole grain on stroke development has been reported [89][90][91][92]. Mechanisms proposed include the lowering of blood pressure associated with dietary fibre, reduction of serum cholesterol by dietary soluble fibre, increased potassium intake, antioxidant vitamin effects, and decreased homocysteine levels by provision of dietary folate [89,92].…”

“…The Basel Prospective Study [98] and the recent Shibata Study [90] suggested that low vitamin levels are associated with stroke, but clinical trials…”