Stroke folates

Stroke Folate/folic acid Cobalamin (vitamin B12) Pyridoxine (vitamin Be) Homocysteine reduction MA of RCTs supplementation in patients does not affect risk of a recurrent event Clarke et al. (2010)... 

Homocysteine arises from dietary methionine. High levels of homocysteiae (hyperhomocysteinemia) are a risk factor for occlusive vascular diseases including atherosclerosis and thrombosis (81—84). In a controlled study, semm folate concentrations of <9.2 nmol/L were linked with elevated levels of plasma homocysteiae. Elevated homocysteine levels have beea associated also with ischemic stroke (9). The mechanism by which high levels of homocysteine produce vascular damage are, as of yet, aot completely uaderstood. lateractioa of homocysteiae with platelets or eadothehal cells has beea proposed as a possible mechanism. Clinically, homocysteine levels can be lowered by administration of vitamin B, vitamin B 2> foHc acid. 

Homocysteine, an amino acid associated with eoronary heart disease as a risk factor is elevated in folate deficiency (discussed earlier and also see Chapter 17). If the elevation of plasma homoeysteine is due to folate deficency, supplementation of folate corrects the plasma homocysteine level and may deerease the morbidity and mortality from atherosclerotie disease which can lead to heart attack and stroke. Vitamin Be and Vitamin B12 defieencies can also cause elevated plasma homocysteine levels. 

Bazzano, L.A., He, J., Ogden, L.G., Loria, C., Vupputuri, S., Myers, L., and Whelton, P.K., 2002. Dietary intake of folate and risk of stroke in US men and women NHANES I Epidemiologic Follow-up Study. National Health and Nutrition Examination Survey. Stroke. 33 1183-1188. 

Larsson, S.C., Mannisto, S., Virtanen, M.J., Kontto, J., Albanes, D., and Virtamo, J., 2008. Folate, vitamin B6, vitamin B12, and methionine intakes and risk of stroke subtypes in male smokers. American Journal of Epidemiology. 167 954-961. 

Van Guelpen, B., Hultdin, J., Johansson, I., Stegmayr, B., Hallmans, G., Nilsson, T.K., Weinehall, L., Witthoft, C., Palmqvist, R., and Winkvist, A., 2005. Folate, vitamin B12, and risk of ischemic and hemorrhagic stroke a prospective, nested case-referent study of plasma concentrations and dietary intake. Stroke. 36 1426-1431. 

However large RCTs, such as VISP (Toole et al. 2004) or VITATOPS (Anonymous 2010) have failed to document any significant effects of B vitamins on stroke prevention. Post hoc analyses, such as that of HOPE-2 (Saposnik et al. 2009) have suggested that folate, Bg and B12 could reduce stroke risk in patients with known CVD, mainly if patients were younger than 70 years, recruited from regions without folic acid food fortification, with higher baseline cholesterol and Hey levels, and not under antiplatelet or lipid-lowering... 

Epidemiological data indicate a benefit with folate fortification on stroke prevention. 

B Vitamins (Folate, and B22) in Relation to Stroke and its Cognitive Decline... 

Intake of vitamin B12, but not Be, was inversely associated with risk of ischemic stroke. Increased folate intake was associated with decreased risk of ischemic stroke in men. 

Various studies have suggested that a generous intake of folate and B vitamins may be beneficial in stroke prevention by reducing the level of plasma Hey (Robinson et al. 1998). The association between dietary intake of folate and the subsequent risk of stroke and cardiovascular disease (CVD) is well documented. 

Participants in the National Health and Nutrition Examination Survey I Epidemiologic Follow-up Study included 9764 US men and women aged 25-74 years who were free of CVD at baseline. The results showed that relative risk of incidence of stroke events was lower among subjects with dietary folate intake in the highest quartile (405.0 pg/day) compared with those in the lowest quartile (99.0 pg/day), after adjustment for established cardiovascular risk factors and dietary factors (Bazzano et al. 2002). 

This chapter focuses on the role of B vitamins—folate, Bg and B —on stroke. 

Poor dietary intake of folate, vitamin Bg and vitamin B12 are assoeiated with inereased risk of stroke. 

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