Supplements

folic acid decreases cardiovascular disease

Strong support Supplements

RefutedContestedStrong support

consensus score 1.00

📅 Last reviewed: 2026-07-15 ⓘ

Evidence ladder

How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."

Top evidence so far: All trials, pooled (Meta-analysis)

MechanismIn-vitroAnimalObservationalRCTMeta-analysis

How the studies fall

7 support 0 contradict 0 tested null 0 mixed · 7 sources, 7 independent groups

What the evidence shows

Folate / B-vitamin homocysteine-lowering modestly reduces stroke risk (most in low-folate / high-homocysteine settings).

Cochrane has no ruling yet see how our grade compares ▾

Cochrane review 2009 · see review Not directly comparable

ENDPOINT MISMATCH: Cochrane's outcome is composite cardiovascular events; our claim is STROKE specifically, where later evidence diverges from the composite. 2009 search date.

“Homocysteine lowering interventions for preventing cardiovascular events (CD006612.pub2). 'Results from available published trials suggest that there is no evidence to support the use of HLI to prevent cardiovascular events.'”

Not directly comparable: their review asks a different question or reports an outcome we do not grade, so it neither corroborates nor contradicts this claim.

What is Cochrane, and why trust it?

Cochrane produces systematic reviews: instead of running a new study, they gather every trial ever done on a question, judge how well each was run, and pool the results. They take no commercial or industry funding, which is why the medical community treats their reviews as a gold standard — and why we check our own verdicts against theirs.

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The evidence (7)

Source	Grade	Stance	Quality	Finding
Xie K et al 2026 · study_type: RCT	RCT	supports	low	215 hemodialysis patients with cognitive impairment, RCT of thiamin+folic acid (30mg/day) vs placebo x96 weeks; combined cardiovascular/cerebrovascular events lower in treatment group (13.1% vs 25.9%, p=0.001), Hcy reduced.
Dai D et al 2026 · study_type: observational	observational	supports	moderate	Prospective cohort, 799 hemorrhagic-stroke + H-type hypertension patients on enalapril-folic acid; high vs low adherence: recurrent hemorrhagic stroke HR 0.21 (95% CI 0.07-0.67), CVD HR 0.16.
Zhang 2024 · Clin Nutr	meta-analysis	supports	high	MA of 21 RCTs: folic acid reduced stroke risk, strongest where baseline folate low / no fortification
Kagawa Y et al 2026 · study_type: observational	observational	supports	low	Sakado Folate Project (Japan), community-based gene-guided folate nutrition program since 2006, n=888 participants / 99,565 residents; standardized stroke prevalence ratio 52% vs regional average, cerebral infarction 86%.
folate-stroke-2016 2016	meta-analysis	supports	high	Folic acid reduced stroke RR 0.90 (0.84-0.96); no CHD effect.
Ghattas Hasbun 2025 · BMC Nutr	meta-analysis	supports	moderate	45 RCTs, 96962 participants: folic acid cut stroke risk (RR 0.85); null for mortality/CHD
Awashra A et al 2026 · study_type: observational	observational	supports	moderate	Narrative review (PubMed/Scopus/Google Scholar synthesis): folic acid supplementation 'significantly reduces stroke incidence in populations who lack mandatory folate fortification, whereas trials conducted in folate-sufficient cohorts gene

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