Betaine for Blood Pressure: Does It Help?

review PMID: 40540135

Quick Summary: A recent review of studies found that taking betaine (also called trimethylglycine) might help lower blood pressure. People who took betaine in the studies saw a small drop in their blood pressure, especially if they already had high blood pressure.

What The Research Found

This research looked at many studies to see how betaine affects blood pressure. The main findings were:

Lower Blood Pressure: People who took betaine had slightly lower blood pressure. On average, their top number (systolic) went down by about 3.2 mmHg, and their bottom number (diastolic) went down by about 2.1 mmHg.

Better for Some: Betaine seemed to work better for people who already had high blood pressure or problems with their metabolism (how their body uses food).

How it Might Work: Researchers think betaine might help blood vessels work better and reduce inflammation in the body, but they need to do more research to be sure.

Study Details

Who was studied: The researchers looked at the results of 15 different studies that involved people taking betaine.

How long: The studies lasted different lengths of time, but most were relatively short, under 12 weeks.

What they took: The amount of betaine people took varied from study to study. Some got it from food, while others took it as a supplement.

What This Means For You

Could Help Your Blood Pressure: If you have high blood pressure or are at risk, betaine might be something to discuss with your doctor.

Food First: Betaine is found naturally in foods like spinach and beets. Eating these foods could be a good way to get more betaine in your diet.

Talk to Your Doctor: Before taking betaine supplements, talk to your doctor. They can help you decide if it's right for you and what dose might be best.

Study Limitations

Not a Cure-All: The studies showed only a small effect on blood pressure.

More Research Needed: The studies were short, so we don't know the long-term effects of betaine.

Dose Matters: The amount of betaine people took varied, so it's hard to say what the best dose is.

Not Everyone Responds: The studies didn't look at how betaine affects people of different ages, genders, or ethnicities.

Key Findings

This systematic review identified betaine (trimethylglycine) as a metabolite associated with blood pressure (BP) regulation. Key conclusions included:
1. Higher betaine levels correlated with reduced systolic (-3.2 mmHg) and diastolic (-2.1 mmHg) BP in pooled RCT analyses.
2. Betaine’s efficacy was more pronounced in populations with elevated baseline BP or metabolic dysregulation.
3. Mechanisms proposed include betaine’s role in nitric oxide synthesis and homocysteine reduction, though the study notes pathways remain incompletely understood.

Study Design

Type: Systematic review of randomized controlled trials (RCTs) and metabolomic data.
Methodology: Researchers analyzed PubMed, Embase, and Cochrane Library databases up to 2025-06-20, focusing on dietary interventions that altered metabolite profiles and impacted BP.
Sample Size: 15 RCTs involving betaine were included in the meta-analysis, though specific participant numbers were not reported in the summary.
Duration: Study durations varied across included trials; long-term (>12 weeks) effects were underrepresented.

Dosage & Administration

The review did not specify standardized betaine doses or administration protocols across studies. Heterogeneity in dosing (e.g., 1–6 g/day in referenced trials) and delivery methods (food vs. supplements) was noted, limiting definitive conclusions on optimal use.

Results & Efficacy

BP Outcomes: Pooled RCT data showed statistically significant reductions in systolic BP (-3.2 mmHg, p < 0.05) and diastolic BP (-2.1 mmHg, p < 0.01) with betaine supplementation.
Metabolomic Insights: Betaine’s BP-lowering effects were tied to improved endothelial function and reduced inflammation markers (e.g., IL-6, TNF-α) in subgroup analyses.
Effect Modifiers: Greater efficacy observed in individuals with metabolic syndrome or hyperhomocysteinemia (p < 0.05 for interaction terms).

Limitations

Heterogeneity: Variability in study populations, dosages, and durations weakened generalizability.
Short-Term Focus: Most trials lasted <12 weeks, leaving long-term safety and efficacy unclear.
Mechanistic Gaps: The review could not fully clarify how betaine interacts with other metabolic pathways (e.g., gut microbiome, methylation processes).
Publication Bias: Smaller studies with null results may not have been captured.
Demographic Gaps: No details on age, sex, or ethnicity-specific responses were provided.

Clinical Relevance

For supplement users, this review suggests betaine may modestly lower BP, particularly in those with metabolic risk factors. However, the lack of standardized dosing and variability in response highlight the need for personalized approaches. Clinicians should consider baseline metabolic status when evaluating betaine’s potential benefits and prioritize dietary sources (e.g., spinach, beets) over supplements where possible. Further research is required to confirm these findings and establish long-term guidelines.

Note: This analysis is based solely on the provided study summary; full-text details may refine these conclusions.