Stroke: roles of B vitamins, homocysteine and antioxidants

Abstract

In the present review concerning stroke, we evaluate the roles of B vitamins, homocysteine and antioxidant vitamins. Stroke is a leading cause of death in developed countries. However, current therapeutic strategies for stroke have been largely unsuccessful. Several studies have reported important benefits on reducing the risk of stroke and improving the post-stroke-associated functional declines in patients who ate foods rich in micronutrients, including B vitamins and antioxidant vitamins E and C. Folic acid, vitamin B6and vitamin B12are all cofactors in homocysteine metabolism. Growing interest has been paid to hyperhomocysteinaemia as a risk factor for CVD. Hyperhomocysteinaemia has been linked to inadequate intake of vitamins, particularly to B-group vitamins and therefore may be amenable to nutritional intervention. Hence, poor dietary intake of folate, vitamin B6and vitamin B12are associated with increased risk of stroke. Elevated consumption of fruits and vegetables appears to protect against stroke. Antioxidant nutrients have important roles in cell function and have been implicated in processes associated with ageing, including vascular, inflammatory and neurological damage. Plasma vitamin E and C concentrations may serve as a biological marker of lifestyle or other factors associated with reduced stroke risk and may be useful in identifying those at high risk of stroke. After reviewing the observational and intervention studies, there is an incomplete understanding of mechanisms and some conflicting findings; therefore the available evidence is insufficient to recommend the routine use of B vitamins, vitamin E and vitamin C for the prevention of stroke. A better understanding of mechanisms, along with well-designed controlled clinical trials will allow further progress in this area.

Editorial

“…Small but useful, they conclude, and worthy of further investigation as adjunctive therapy alongside fibrinates or statins. Vitamins have also been implicated as being protective against CVD, in particular folate and the B vitamins, via their plasma homocysteine-lowering effect, as reported here by Sánchez-Moreno et al (4) in the context of stroke. Whether this effect will track through to an actual reduction of stroke risk among patients with hyperhomocysteinaemia will not be clear until the conclusion of several ongoing intervention studies.…”

Dietary patterns of men in ALSPAC: associations with socio-demographic and lifestyle characteristics, nutrient intake and comparison with women's dietary patterns

“…This includes 50% of total fat intake and 48% of fibre intake; increased intake of both total fat and fibre has been implicated as a risk factor for the development of cancer (WCRF, 2007). Important micronutrient intakes (Chakraborti et al, 2002;Voutilainen et al, 2006;WCRF, 2007;Sanchez-Moureno et al, 2009). The associations with nutrient intake are similar to the results we reported in the women's study .…”

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

“…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].One vitamer form of AA, vitamin C, is a potential antioxidant factor that can neutralize free radicals (especially hydroxyl radicals) via electron transfer, especially in brain parenchyma [12,13]. It has been shown that antioxidant treatment with AA significantly reduces lipid peroxidation and increases superoxide dismutase and catalase activities after seizures induced by pilocarpine [14].…”

“…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].…”