B Vitamins

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Graeme J Hankey - One of the best experts on this subject based on the ideXlab platform.

  • B Vitamins for stroke prevention
    Stroke and vascular neurology, 2018
    Co-Authors: Graeme J Hankey
    Abstract:

    Supplementation with B Vitamins (vitamin B9(folic acid), vitamin B12 and vitamin B6) lowers Blood total homocysteine (tHcy) concentrations By aBout 25% and reduces the relative risk of stroke overall By aBout 10% (risk ratio (RR) 0.90, 95% CI 0.82 to 0.99) compared with placeBo. Homocysteine-lowering interventions have no significant effect on myocardial infarction, death from any cause or adverse outcomes. Factors that appear to modify the effect of B Vitamins on stroke risk include low folic acid status, high tHcy, high cyanocoBalamin dose in patients with impaired renal function and concurrent antiplatelet therapy. In regions with increasing levels or estaBlished policies of population folate supplementation, evidence from oBservational genetic epidemiological studies and randomised controlled clinical trials is concordant in suggesting an aBsence of Benefit from lowering of homocysteine with folic acid for prevention of stroke. Clinical trials indicate that in countries which mandate folic acid fortification of food, folic acid supplementation has no significant effect on reducing stroke risk (RR 1.05, 95% CI 0.90 to 1.23). However, in countries without mandatory folic acid food fortification, folic acid supplementation reduces the risk of stroke By aBout 15% (RR 0.85, 95% CI 0.77 to 0.94). Folic acid alone or in comBination with minimal cyanocoBalamin (≤0.05 mg/day) is associated with an even greater reduction in risk of future stroke By 25% (RR 0.75, 95% CI 0.66 to 0.86), whereas the comBination of folic acid and a higher dose of cyanocoBalamin (≥0.4 mg/day) is not associated with a reduced risk of future stroke (RR 0.95, 95% CI 0.86 to 1.05). The lack of Benefit of folic acid plus higher doses of cyanocoBalamin (≥0.4 mg/day) was oBserved in trials which all included participants with chronic kidney disease. Because metaBolic B12 deficiency is very common and usually not diagnosed, future randomised trials of homocysteine-lowering interventions for stroke prevention should proBaBly test a comBination of folic acid and methylcoBalamin or hydroxocoBalamin instead of cyanocoBalamin, and perhaps vitamin B6.

  • B Vitamins in stroke prevention: time to reconsider.
    Lancet Neurology, 2017
    Co-Authors: J. David Spence, Qilong Yi, Graeme J Hankey
    Abstract:

    Summary B vitamin therapy lowers plasma total homocysteine concentrations, and might Be a Beneficial intervention for stroke prevention; however, cyanocoBalamin (a form of vitamin B12) can accelerate decline in renal function and increase the risk of cardiovascular events in patients with impaired renal function. Although early trials did not show Benefit in reduction of stroke, these results might have Been due to harm in participants with impaired renal function. In patients with diaBetic nephropathy, cyanocoBalamin is harmful, whereas B Vitamins appear to reduce cardiovascular events in study participants with normal renal function. Our meta-analysis of individual patient data from two large trials of B vitamin therapy (VISP and VITATOPS) indicates that patients with impaired renal function who are exposed to high-dose cyanocoBalamin do not Benefit from therapy with B Vitamins for the prevention of stroke (risk ratio 1·04, 95% CI 0·84–1·27), however, patients with normal renal function who are not exposed to high-dose cyanocoBalamin Benefit significantly from this treatment (0.78, 0·67–0·90; interaction p=0·03). The potential Benefits of B vitamin therapy with folic acid and methylcoBalamin or hydroxycoBalamin, instead of cyanocoBalamin, to lower homocysteine concentrations in people at high risk of stroke warrant further investigation.

  • effects of homocysteine lowering with B Vitamins on cognitive aging meta analysis of 11 trials with cognitive data on 22 000 individuals
    The American Journal of Clinical Nutrition, 2014
    Co-Authors: Robert Clarke, Sarah Lewington, Jane Armitage, Derrick A Bennett, Sarah Parish, Murray Skeaff, Simone J P M Eussen, Catharina Lewerin, David J Stott, Graeme J Hankey
    Abstract:

    Background: Elevated plasma homocysteine is a risk factor for Alzheimer disease, But the relevance of homocysteine lowering to slow the rate of cognitive aging is uncertain. OBjective: The aim was to assess the effects of treatment with B Vitamins compared with placeBo, when administered for several years, on composite domains of cognitive function, gloBal cognitive function, and cognitive aging. Design: A meta-analysis was conducted By using data comBined from 11 large trials in 22,000 participants. Domain-Based z scores (for memory, speed, and executive function and a domain-composite score for gloBal cognitive function) were availaBle Before and after treatment (mean duration: 2.3 y) in the 4 cognitive-domain trials (1340 individuals); Mini-Mental State Examination (MMSE)–type tests were availaBle at the end of treatment (mean duration: 5 y) in the 7 gloBal cognition trials (20,431 individuals). Results: The domain-composite and MMSE-type gloBal cognitive function z scores Both decreased with age (mean 6 SE: 20.054 6 0.004 and 20.036 6 0.001/y, respectively). Allocation to B Vitamins lowered homocysteine concentrations By 28% in the cognitive-domain trials But had no significant effects on the z score differences from Baseline for individual domains or for gloBal cognitive function (z score difference: 0.00; 95% CI: 20.05, 0.06). Likewise, allocation to B Vitamins lowered homocysteine By 26% in the gloBal cognition trials But also had no significant effect on end-treatment MMSE-type gloBal cognitive function (z score difference: 20.01; 95% CI: 20.03, 0.02). Overall, the effect of a 25% reduction in homocysteine equated to 0.02 y (95% CI: 20.10, 0.13 y) of cognitive aging per year and excluded reductions of .1 mo per year of treatment. Conclusion: Homocysteine lowering By using B Vitamins had no significant effect on individual cognitive domains or gloBal cognitive function or on cognitive aging. Am J Clin Nutr 2014;100: 657–66.

  • antiplatelet therapy and the effects of B Vitamins in patients with previous stroke or transient ischaemic attack a post hoc suBanalysis of vitatops a randomised placeBo controlled trial
    Lancet Neurology, 2012
    Co-Authors: Graeme J Hankey, Qilong Yi, John W Eikelboom, Kennedy R Lees, Christopher Chen, Denis Xavier, Jose C Navarro, U K Ranawaka, Wasim Uddin, S Ricci
    Abstract:

    Summary Background Previous studies have suggested that any Benefits of folic acid-Based therapy to lower serum homocysteine in prevention of cardiovascular events might Be offset By concomitant use of antiplatelet therapy. We aimed to estaBlish whether there is an interaction Between antiplatelet therapy and the effects of folic acid-Based homocysteine-lowering therapy on major vascular events in patients with stroke or transient ischaemic attack enrolled in the Vitamins to prevent stroke (VITATOPS) trial. Methods In the VITATOPS trial, 8164 patients with recent stroke or transient ischaemic attack were randomly allocated to douBle-Blind treatment with one taBlet daily of placeBo or B Vitamins (2 mg folic acid, 25 mg vitamin B 6 , and 500 μg vitamin B 12 ) and followed up for a median 3·4 years (IQR 2·0–5·5) for the primary composite outcome of stroke, myocardial infarction, or death from vascular causes. In our post-hoc analysis of the interaction Between antiplatelet therapy and the effects of treatment with B Vitamins on the primary outcome, we used Cox proportional hazards regression Before and after adjusting for imBalances in Baseline prognostic factors in participants who were and were not taking antiplatelet drugs at Baseline and in participants assigned to receive B Vitamins or placeBo. We also assessed the interaction in different suBgroups of patients and different secondary outcomes. The VITATOPS trial is registered with ClinicalTrials.gov, numBer NCT00097669, and Current Controlled Trials, numBer ISRCTN74743444. Findings At Baseline, 6609 patients were taking antiplatelet therapy and 1463 were not. Patients not receiving antiplatelet therapy were more likely to Be younger, east Asian, and disaBled, to have a haemorrhagic stroke or cardioemBolic ischaemic stroke, and to have a history of hypertension or atrial fiBrillation. They were less likely to Be smokers and to have a history of peripheral artery disease, hypercholesterolaemia, diaBetes, ischaemic heart disease, and a revascularisation procedure. Of the participants taking antiplatelet drugs at Baseline, B Vitamins had no significant effect on the primary outcome (488 patients in the B-Vitamins group [15%] vs 519 in the placeBo group [16%]; hazard ratio [HR] 0·94, 95% CI 0·83–1·07). By contrast, of the participants not taking antiplatelet drugs at Baseline, B Vitamins had a significant effect on the primary outcome (123 in the B-Vitamins group [17%] vs 153 in the placeBo group [21%]; HR 0·76, 0·60–0·96). The interaction Between antiplatelet therapy and the effect of B Vitamins on the primary outcome was significant after adjusting for imBalance in the Baseline variaBles (adjusted p for interaction=0·0204). Interpretation Our findings support the hypothesis that antiplatelet therapy modifies the potential Benefits of lowering homocysteine with B-vitamin supplementation in the secondary prevention of major vascular events. If validated, B Vitamins might have a role in the prevention of ischaemic events in high-risk individuals with an allergy, intolerance, or lack of indication for antiplatelet therapy. Funding Australia National Health and Medical Research Council, UK Medical Research Council, Singapore Biomedical Research Council, and Singapore National Medical Research Council.

  • B Vitamins reduce the long term risk of depression after stroke the vitatops dep trial
    Annals of Neurology, 2010
    Co-Authors: Osvaldo P. Almeida, Leon Flicker, Graeme J Hankey, Kylie Marsh, Helman Alfonso, Timothy M E Davis
    Abstract:

    OBjective The consumption of certain B-Vitamins through diet or supplementation decreases the total plasma concentration of homocysteine (tHcy) and may enhance response to standard antidepressant treatment. It is unclear if treatment with B-Vitamins can reduce the long-term prevalence of depression in people at risk, such as stroke survivors. The purpose of this research was to determine if treatment with B-Vitamins reduces the hazard of poststroke depression compared with placeBo. Methods Randomized, douBle-Blind, placeBo-controlled trial of tHcy-lowering treatment with daily folic acid (2 mg), vitamin B6 (25 mg), and vitamin B12 (0.5 mg) for 1 to 10.5 years in survivors of stroke. The primary endpoint was the onset of Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) major depression after randomization. Secondary outcomes were the prevalence of DSM-IV major or minor depression at the end of treatment. Other measured factors included age, gender, poststroke handicap associated with stroke, recurrence of strokes, cognitive impairment, and use of antidepressants. Results Among 273 people who completed the final assessment after 7.1 ± 2.1 years (mean ± standard deviation) of follow up, random assignment to B-Vitamins was associated with a lower hazard of major depression compared with placeBo (18.4% vs 23.3%, adjusted hazard ratio [HR] = 0.48; 95% confidence interval [CI] = 0.31–0.76) and a trend toward a lower odds of major or minor depression at the end of the trial compared with placeBo (19.1% vs 27.7%; adjusted odds ratio [OR] = 0.58; 95%CI = 0.31–1.09). Interpretation Long-term treatment of poststroke survivors with folic acid, B6, and B12 was associated with a reduction in the hazard of major depression in our patient population. If these findings can Be validated externally, B-vitamin supplementation offers hope as an effective, safe, and affordaBle intervention to reduce the Burden of poststroke depression. ANN NEUROL 2010;68:503–510

Helene Mcnulty - One of the best experts on this subject based on the ideXlab platform.

  • The B-Vitamins
    Sustainable Nutrition in a Changing World, 2017
    Co-Authors: James J. Strain, Catherine F. Hughes, Kristina Pentieva, Mary Ward, Leane Hoey, Helene Mcnulty
    Abstract:

    It is likely that future scenarios will see trends toward a reduced consumption of animal-Based foods and increased consumption of fruit and vegetaBles. This chapter reviews the metaBolic roles, essentiality, deficiency symptoms and food sources of each of the B-Vitamins and identifies how trends towards improving environmental sustainaBility could impact on B-vitamin status.

  • emerging roles for folate and related B Vitamins in Brain health across the lifecycle
    The Proceedings of the Nutrition Society, 2015
    Co-Authors: C Mcgarel, Kristina Pentieva, James J. Strain, Helene Mcnulty
    Abstract:

    Nutrition plays a fundamental role in supporting the structural and functional development of the human Brain from conception, throughout early infancy and extending into later life. A growing Body of evidence suggests that folate and the metaBolically related B-Vitamins are essential for Brain health across all age groups, owing to their specific roles in C 1 metaBolism and particularly in the production of S -adenosylmethionine, a universal methyl donor essential for the production of neurotransmitters. Emerging, though not entirely consistent, evidence suggests that maternal folate status throughout pregnancy may influence neurodevelopment and Behaviour of the offspring. Furthermore optimal B-vitamin status is associated with Better cognitive health in ageing. Of note, a recent clinical trial provided evidence that supplementation with folic acid and related B-Vitamins over a 2-year-period reduced gloBal and regional Brain atrophy, as measured By MRI scan in older adults. In terms of potential mechanisms, the effects of these B-Vitamins on cognitive health may Be independent or may Be mediated By nutrient–nutrient and/or relevant gene–nutrient interactions. Furthermore, a new area of research suggests that the in utero environment influences health in later life. Folate, an important cofactor in C 1 metaBolism, is indirectly involved in DNA methylation, which in turn is considered to Be one of the epigenetic mechanisms that may underlie fetal programming and Brain development. The present review will explore the evidence that supports a role for folate and the related B-Vitamins in Brain health across the lifecycle, and potential mechanisms to explain such effects.

  • B-Vitamins and Bone in health and disease: the current evidence.
    The Proceedings of the Nutrition Society, 2014
    Co-Authors: Michelle Clarke, Mary Ward, Leane Hoey, James J. Strain, William Dickey, Helene Mcnulty
    Abstract:

    : Osteoporosis, a metaBolic skeletal disease characterised By decreased Bone mass and increased fracture risk, is a growing puBlic health proBlem. Among the various risk factors for osteoporosis, calcium and vitamin D have well-estaBlished protective roles, But it is likely that other nutritional factors are also implicated. This review will explore the emerging evidence supporting a role for certain B-Vitamins, homocysteine and the 677 C → T polymorphism in the gene encoding the folate-metaBolising enzyme methylenetetrahydrofolate reductase, in Bone health and disease. The evidence, however, is not entirely consistent and as yet no clear mechanism has Been defined to explain the potential link Between B-Vitamins and Bone health. Coeliac disease, a common condition of malaBsorption, induced By gluten ingestion in genetically susceptiBle individuals, is associated with an increased risk Both of osteoporosis and inadequate B-vitamin status. Given the growing Body of evidence linking low Bone mineral density and/or increased fracture risk with low B-vitamin status and elevated homocysteine, optimal B-vitamin status may play an important protective role against osteoporosis in coeliac disease; to date, no trial has addressed this possiBle link.

  • Postgraduate Symposium The MTHFR C677T polymorphism, B-Vitamins and Blood pressure
    The Proceedings of the Nutrition Society, 2009
    Co-Authors: Carol P. Wilson, James J. Strain, Helene Mcnulty, J. M. Scott, Mary Ward
    Abstract:

    High Blood pressure (BP) and elevated homocysteine are reported as independent risk factors for CVD and stroke in particular. The main genetic determinant of homocysteine concentrations is homozygosity (TT genotype) for the C677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene, typically found in approximately 10% of Western populations. The B-Vitamins folate, vitamin B 12 and vitamin B 6 are the main nutritional determinants of homocysteine, with riBoflavin more recently identified as a potent modulator specifically in individuals with the TT genotype. Although oBservational studies have reported associations Between homocysteine and BP, B-vitamin intervention studies have shown little or no BP response despite decreases in homocysteine. Such studies, however, have not considered the MTHFR C677T polymorphism, which has Been shown to Be associated with BP. It has Been shown for the first time that riBoflavin is an important determinant of BP specifically in individuals with the TT genotype. Research generally suggests that 24 h amBulatory BP monitoring provides a more accurate measure of BP than casual measurements and its use in future studies may also provide important insights into the relationship Between the MTHFR polymorphism and BP. Further research is also required to investigate the association Between specific B-Vitamins and BP in individuals with different MTHFR genotypes in order to confirm whether any genetic predisposition to hypertension is correctaBle By B-vitamin intervention. The present review will investigate the evidence linking the MTHFR C677T polymorphism to BP and the potential modulating role of B-Vitamins.

  • Homocysteine, B-Vitamins and CVD.
    The Proceedings of the Nutrition Society, 2008
    Co-Authors: Helene Mcnulty, Kristina Pentieva, Leane Hoey, Mary Ward
    Abstract:

    There is consideraBle interest in plasma homocysteine (tHcy) as a CVD risk factor. Although the secondary prevention trials puBlished to date have Been inconclusive in confirming a Benefit of tHcy-lowering treatment with B-Vitamins on CVD events generally, such studies are widely recognised to have Been insufficiently powered to detect a significant effect for the predicted magnitude of association Between tHcy and heart disease risk, and therefore cannot Be interpreted as evidence that no relationship exists. In fact, a recent meta-analysis of clinical trials has confirmed that folic acid supplementation reduces the risk of stroke, particularly in individuals without a history of stroke. Evidence supporting a causal relationship Between elevated tHcy and heart disease also comes from genetic studies. The most important genetic determinant of tHcy in the general population is the common C677T variant in methylenetetrahydrofolate reductase (MTHFR) that results in higher tHcy. Individuals with the homozygous mutant (TT) genotype have a significantly higher (14‐21%) risk of heart disease. Plasma tHcy is very responsive to intervention with the B-Vitamins required for its metaBolism, in particular folic acid, and to a lesser extent Vitamins B12 and B6. Thus, although primarily aimed at reducing neural-tuBe defects, folic acid fortification may have an important role in the primary prevention of CVD via tHcy lowering. Besides folate, riBoflavin is required as a cofactor for MTHFR and enhanced riBoflavin status results in a marked lowering in tHcy specifically in individuals with the TT genotype, presumaBly By neutralising the variant form of the enzyme. ABout 10% of the UK and Irish populations have the TT genotype. In the present paper the potential role of folate and related B-Vitamins in the primary prevention of CVD and the implications for nutrition policy are explored. B-Vitamins: Folate: Homocysteine: CVD

Pilar Galan - One of the best experts on this subject based on the ideXlab platform.

  • mthfr 677c t genotype modulates the effect of a 5 year supplementation with B Vitamins on homocysteine concentration the su fol om3 randomized controlled trial
    PLOS ONE, 2018
    Co-Authors: Leopold Fezeu, Serge Hercberg, Veronique Ducros, Jeanlouis Gueant, Jeanclaude Guilland, Valentina A Andreeva, Pilar Galan
    Abstract:

    Aims To study how MTHFR 677C→T genotype modulates the effect of supplementation with B-Vitamins on total homocysteine (tHcy) and B-vitamin concentrations. Methods 2381 patients with a personal history of cardiovascular disease were randomly assigned to one of four groups: 1) B-Vitamins alone (560 μg of 5-methyl-THF, 3 mg of vitamin B6 and 20 μg of vitamin B12), 2) n-3 fatty acids alone (600 mg of EPA and DHA in a 2:1 ratio), 3) B-Vitamins and n-3 fatty acids, and 4) placeBo. Participants were followed up for 4.7 years. At Baseline and annually thereafter, Biological parameters were assessed. Multivariate and linear mixed models were fit to study the interaction Between B-Vitamins and MTHFR genotype. Results Among supplemented participants, concentrations of all three B-Vitamins increased during the first year (all p<0.0001) across MTHFR genotype categories. tHcy decreased By 26.3% during the first year (p<0.0001), then steadily increased throughout the 5 years (ptrend<0.001). However, at the end of follow-up, that increase was smaller among TT than among CT or CC suBjects (pinteraction<0.02). At Baseline, the difference in tHcy concentrations Between TT homozygous and CC homozygous suBjects was 2.33 μmol/l (p<0.001). After 5 years, that difference was reduced to 1.06 μmol/l and remained statistically significant (p<0.001). Conclusion Participants with the TT genotype exhiBited a lower 5-year decrease in tHcy concentrations following a B-vitamin supplementation than did participants with the CC or CT genotype. Clinical trial registration Current Controlled Trials # ISRCTN41926726.

  • cardiovascular effects of B Vitamins and or n 3 fatty acids the su fol om3 trial
    International Journal of Cardiology, 2013
    Co-Authors: Jacques Blacher, Sébastien Czernichow, F. Paillard, Pierre Ducimetière, Serge Hercberg, Pilar Galan
    Abstract:

    ABstract Background Mechanisms involved in coronary stenosis evolution are different than those involved in clinical events. Because of differential vascular effects, N-3 polyunsatured fatty acids (PUFA) and B Vitamins could have differential effects on different types of cardiovascular clinical events in high-risk patients. Methods We analyzed the effects of n-3 PUFA and of B Vitamins on Both coronary revascularization and on hard coronary events risks in a suBgroup of the SU.FOL.OM3 trial, a randomized, douBle-Blind, placeBo-controlled secondary prevention trial. Data were analyzed according to the intention-to-treat principle, with the use of Cox proportional-hazards models. Results After a mean follow-up of 4.2±1.0years among the 1,863 participants with coronary heart disease, 163 coronary revascularizations were performed, and 95 patients experienced a hard coronary event. Neither treatment with n-3 PUFA, nor treatment with B Vitamins was associated with any significant effect on the occurrence of hard coronary events. Allocation to n-3 PUFA was not associated with any significant effect on coronary revascularization. However, treatment with B Vitamins was associated with a statistically significant 52% increase in the risk of coronary revascularization (multivariate HR: 1.52; 95% CI: [1.11–2.10]; p=0.01). Conclusions Neither n-3 PUFA, nor B Vitamins reduced the rates of hard coronary events and of coronary revascularization. Furthermore, B Vitamins significantly increased the rate of coronary revascularization. Consistent with the findings of previous trials, our results do not support the routine use of dietary supplements containing n-3 PUFA and argue against using dietary supplements containing B-Vitamins in coronary patients in secondary cardiovascular prevention.

  • Cardiovascular effects of B-Vitamins and/or N-3 fatty acids: the SU.FOL.OM3 trial.
    International Journal of Cardiology, 2012
    Co-Authors: Jacques Blacher, Sébastien Czernichow, F. Paillard, Pierre Ducimetière, Serge Hercberg, Pilar Galan
    Abstract:

    ABstract Background Mechanisms involved in coronary stenosis evolution are different than those involved in clinical events. Because of differential vascular effects, N-3 polyunsatured fatty acids (PUFA) and B Vitamins could have differential effects on different types of cardiovascular clinical events in high-risk patients. Methods We analyzed the effects of n-3 PUFA and of B Vitamins on Both coronary revascularization and on hard coronary events risks in a suBgroup of the SU.FOL.OM3 trial, a randomized, douBle-Blind, placeBo-controlled secondary prevention trial. Data were analyzed according to the intention-to-treat principle, with the use of Cox proportional-hazards models. Results After a mean follow-up of 4.2±1.0years among the 1,863 participants with coronary heart disease, 163 coronary revascularizations were performed, and 95 patients experienced a hard coronary event. Neither treatment with n-3 PUFA, nor treatment with B Vitamins was associated with any significant effect on the occurrence of hard coronary events. Allocation to n-3 PUFA was not associated with any significant effect on coronary revascularization. However, treatment with B Vitamins was associated with a statistically significant 52% increase in the risk of coronary revascularization (multivariate HR: 1.52; 95% CI: [1.11–2.10]; p=0.01). Conclusions Neither n-3 PUFA, nor B Vitamins reduced the rates of hard coronary events and of coronary revascularization. Furthermore, B Vitamins significantly increased the rate of coronary revascularization. Consistent with the findings of previous trials, our results do not support the routine use of dietary supplements containing n-3 PUFA and argue against using dietary supplements containing B-Vitamins in coronary patients in secondary cardiovascular prevention.

  • effects of B Vitamins and omega 3 fatty acids on cardiovascular diseases a randomised placeBo controlled trial
    BMJ, 2010
    Co-Authors: Pilar Galan, Jacques Blacher, Sébastien Czernichow, Emmanuelle Kesseguyot, Serge Briancon, Serge Hercberg
    Abstract:

    OBjective To investigate whether dietary supplementation with B Vitamins or omega 3 fatty acids, or Both, could prevent major cardiovascular events in patients with a history of ischaemic heart disease or stroke. Design DouBle Blind, randomised, placeBo controlled trial; factorial design. Setting Recruitment throughout France via a network of 417 cardiologists, neurologists, and other physicians. Participants 2501 patients with a history of myocardial infarction, unstaBle angina, or ischaemic stroke. Intervention Daily dietary supplement containing 5-methyltetrahydrofolate (560 μg), vitamin B-6 (3 mg), and vitamin B-12 (20 μg) or placeBo; and containing omega 3 fatty acids (600 mg of eicosapentanoic acid and docosahexaenoic acid at a ratio of 2:1) or placeBo. Median duration of supplementation was 4.7 years. Main outcome measures Major cardiovascular events, defined as a composite of non-fatal myocardial infarction, stroke, or death from cardiovascular disease. Results Allocation to B Vitamins lowered plasma homocysteine concentrations By 19% compared with placeBo, But had no significant effects on major vascular events (75 v 82 patients, hazard ratio, 0.90 (95% confidence interval 0.66 to 1.23, P=0.50)). Allocation to omega 3 fatty acids increased plasma concentrations of omega 3 fatty acids By 37% compared with placeBo, But also had no significant effect on major vascular events (81 v 76 patients, hazard ratio 1.08 (0.79 to 1.47, P=0.64)). Conclusion This study does not support the routine use of dietary supplements containing B Vitamins or omega 3 fatty acids for prevention of cardiovascular disease in people with a history of ischaemic heart disease or ischaemic stroke, at least when supplementation is introduced after the acute phase of the initial event. Trial registration Current Controlled Trials ISRCTN41926726.

Antonio Martin - One of the best experts on this subject based on the ideXlab platform.

  • stroke roles of B Vitamins homocysteine and antioxidants
    Nutrition Research Reviews, 2009
    Co-Authors: Concepcion Sanchezmoreno, Antonio Jimenezescrig, Antonio Martin
    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 B 6 and vitamin B 12 are 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 B 6 and vitamin B 12 are 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.

Robert Clarke - One of the best experts on this subject based on the ideXlab platform.

  • effects of homocysteine lowering with B Vitamins on cognitive aging meta analysis of 11 trials with cognitive data on 22 000 individuals
    The American Journal of Clinical Nutrition, 2014
    Co-Authors: Robert Clarke, Sarah Lewington, Jane Armitage, Derrick A Bennett, Sarah Parish, Murray Skeaff, Simone J P M Eussen, Catharina Lewerin, David J Stott, Graeme J Hankey
    Abstract:

    Background: Elevated plasma homocysteine is a risk factor for Alzheimer disease, But the relevance of homocysteine lowering to slow the rate of cognitive aging is uncertain. OBjective: The aim was to assess the effects of treatment with B Vitamins compared with placeBo, when administered for several years, on composite domains of cognitive function, gloBal cognitive function, and cognitive aging. Design: A meta-analysis was conducted By using data comBined from 11 large trials in 22,000 participants. Domain-Based z scores (for memory, speed, and executive function and a domain-composite score for gloBal cognitive function) were availaBle Before and after treatment (mean duration: 2.3 y) in the 4 cognitive-domain trials (1340 individuals); Mini-Mental State Examination (MMSE)–type tests were availaBle at the end of treatment (mean duration: 5 y) in the 7 gloBal cognition trials (20,431 individuals). Results: The domain-composite and MMSE-type gloBal cognitive function z scores Both decreased with age (mean 6 SE: 20.054 6 0.004 and 20.036 6 0.001/y, respectively). Allocation to B Vitamins lowered homocysteine concentrations By 28% in the cognitive-domain trials But had no significant effects on the z score differences from Baseline for individual domains or for gloBal cognitive function (z score difference: 0.00; 95% CI: 20.05, 0.06). Likewise, allocation to B Vitamins lowered homocysteine By 26% in the gloBal cognition trials But also had no significant effect on end-treatment MMSE-type gloBal cognitive function (z score difference: 20.01; 95% CI: 20.03, 0.02). Overall, the effect of a 25% reduction in homocysteine equated to 0.02 y (95% CI: 20.10, 0.13 y) of cognitive aging per year and excluded reductions of .1 mo per year of treatment. Conclusion: Homocysteine lowering By using B Vitamins had no significant effect on individual cognitive domains or gloBal cognitive function or on cognitive aging. Am J Clin Nutr 2014;100: 657–66.

  • B-Vitamins and prevention of dementia.
    The Proceedings of the Nutrition Society, 2008
    Co-Authors: Robert Clarke
    Abstract:

    Elevated plasma homocysteine (Hcy) concentrations have Been implicated with risk of cognitive impairment and dementia, But it is unclear whether low vitamin B 12 or folate status is responsiBle for cognitive decline. Most studies reporting associations Between cognitive function and Hcy or B-Vitamins have used a cross-sectional or case-control design and have Been unaBle to exclude the possiBility that such associations are a result of the disease rather than Being causal. The Hcy hypothesis of dementia has attracted consideraBle interest, as Hcy can Be easily lowered By folic acid and vitamin B 12 , raising the prospect that B-vitamin supplementation could lower the risk of dementia. While some trials assessing effects on cognitive function have used folic acid alone, vitamin B 12 alone or a comBination, few trials have included a sufficient numBer of participants to provide reliaBle evidence. An individual-patient-data meta-analysis of all randomised trials of the effects on cognitive function and vascular risk of lowering Hcy with B-Vitamins will maximise the power to assess the epidemiologically-predicted differences in risk. Among the twelve large randomised Hcy-lowering trials for prevention of vascular disease, data should Be availaBle on aBout 30 000 participants with cognitive function. The principal investigators of such trials have agreed to comBine individual-participant data from their trials after their separate puBlication.

  • effects of B Vitamins on plasma homocysteine concentrations and on risk of cardiovascular disease and dementia
    Current Opinion in Clinical Nutrition and Metabolic Care, 2007
    Co-Authors: Robert Clarke, Sarah Lewington, Paul Sherliker, Jane Armitage
    Abstract:

    PURPOSE OF REVIEW: Dietary supplementation with folic acid and vitamin B12 lowers Blood homocysteine concentrations, But it is not known if this reduces the risk of coronary heart disease and stroke. RECENT FINDINGS: Recent evidence suggests that the maximum reduction in plasma homocysteine concentrations is oBtained with 0.8 mg of folic acid and doses of 0.2 mg and 0.4 mg of folic acid are associated with aBout 60 and 90%, respectively, of this maximal effect. Among 12 large trials (involving a total of 52,000 participants) that are currently assessing the effects of B-Vitamins on risk of coronary heart disease and stroke, results are availaBle for four trials involving 14 000 participants. A meta-analysis of these four trials demonstrates no Beneficial effects of B-Vitamins on coronary heart disease (OR 0.99; 95% CI 0.88-1.10) or stroke (OR 89; 95% CI 0.76-1.05) or the comBination of coronary heart disease and stroke (OR 0.98; 95% CI 0.90-1.08). The confidence intervals around the odds ratios for these completed trials are compatiBle with a 10% difference in risk for coronary heart disease and 20% difference for stroke associated with a 25% lower homocysteine predicted By the oBservational epidemiological studies. SUMMARY: The results of the ongoing homocysteine-lowering trials are required Before making recommendations on the use of B-Vitamins for prevention of vascular disease.