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Homocysteine is a biomarker of cardiovascular disease, and it is thought that higher circulating levels of homocysteine are indicative of a higher risk for cardiovascular incidents.

Research analysis led by Kamal Patel.
All content reviewed by the Examine.com Team. Published: Jul 5, 2013
Last Updated:

Human Effect Matrix

The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what supplements affect homocysteine
Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
grade-b Strong Very High See all 9 studies
Betaine (3g or more) appears to potently and reliable reduce homocysteine concentrations following a single dose and maintaining this reduction for as long as supplementation is continued. The magnitude is around 10% in persons with normal homocysteine levels, and greater (20-40%) in those with high homocysteine, and (unlike folate) works in instances of methionine loading tests. 500mg betaine can reduce homocysteine after a methionine load, but it too low to influence fasting homocysteine.
grade-b Notable Moderate See all 5 studies
Homocysteine appears to be reduced to a large degree at 1.6mg, but this effect is exclusive to subjects with a specific genetic mutation known as MTHFR 677TT (two copies of MTHFR 677C->T).
grade-c Minor - See study
Somewhat high acute spike of homocysteine, which is normally a negative thing. Practical significance of this unknown
grade-c Minor - See study
Decrease in homocysteine (biomarker of inflammatory cardiovascular disease) was present, but not to a remarkable magnitude
grade-c Minor Very High See 2 studies
May decrease homocysteine content
grade-c Minor - See study
Decrease in homocysteine noted, thought to be indicative of cardioprotection
grade-c - - See study
Homocysteine has been found to be unaltered in response to cocoa ingestion compared to control.
grade-c - Very High See 2 studies
No significant alterations in homocysteine concentrations are seen with garlic supplementation.
grade-c - - See study
There was no influence on homocysteine seen with supplementation of hesperidin relative to placebo, despite subjects being in an inflammatory state.
grade-c - - See study
There do not appear to be changes to circulating homocysteine in premenopausal women given supplementation of red clover extract.
grade-c - Very High See all 3 studies
No significant alterations in plasma homocysteine occur following supplemental SAMe ingestion
grade-c - - See study
grade-c - Very High See 2 studies
There does not appear to be a significant influence of vitamin E supplementation on homocysteine concentrations.
grade-d Notable - See study
A notable effect was found in one study in obese people with a high risk of cardiovascular disease, but much more research is needed.