Garlic supplements and heart disease risk factors
What it found
Garlic supplements lowered blood pressure and total cholesterol in people, and some small studies found less plaque buildup in heart arteries.
The authors say larger studies are needed.
What they found
Studies in people
Blood pressure
Garlic supplements lowered systolic blood pressure by 7 to 16 mm Hg and diastolic blood pressure by 5 to 9 mm Hg compared with placebo. This effect was seen only in people who already had high blood pressure at the start.
Total cholesterol
Garlic supplements lowered total cholesterol by 7.4 to 29.8 mg/dL across 8 meta-analyses. The authors note this reduction is smaller than what statin drugs achieve but similar to diet changes alone.
Artery calcium
Three small randomized trials in people with heart disease or at high risk found that aged garlic extract slowed the buildup of calcium in heart arteries over 1 year compared with placebo. Two of these studies also gave other supplements along with the garlic.
Arterial stiffness
In one randomized trial of 65 men at intermediate risk, aged garlic extract plus coenzyme Q10 reduced pulse wave velocity, a measure of artery stiffness, after 1 year compared with placebo.
Inflammation marker
One quality trial found that aged garlic extract plus coenzyme Q10 lowered C-reactive protein in 65 intermediate-risk patients over 1 year. Five other studies either had poor design or found no effect.
Side effects
The most common side effects reported were body odor and bad breath, especially with raw garlic. Rare case reports include allergic reactions and bleeding problems, but the authors say cause and effect has not been proven.
What the authors conclude
- They advise that larger studies are warranted to evaluate these effects further.
How it was done
The authors wanted to pull together what is known about garlic's effects on heart disease risk factors, because garlic is one of the most researched herbal medicines and many studies are small or use different preparations.
They searched PubMed for human studies on garlic and heart disease risk factors up to 2013. They included only double-blind, randomized, controlled trials and meta-analyses of such trials, and two authors reviewed the studies independently.
What it can’t tell you
- No studies have looked at whether garlic prevents heart attacks, strokes, or death.
- The small studies on artery calcium and artery stiffness cannot prove that garlic lowers the risk of heart disease events.
- Many of the studies used different garlic preparations, making it hard to compare results.
Who paid
- Authors work at
- University of Saskatchewan, Canada; Harbor-UCLA Research and Education Institute, CA
The paper
- Title
- Garlic and Heart Disease
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Varshney R, Budoff MJ (2016). Garlic and Heart Disease. The Journal of nutrition. doi:10.3945/jn.114.202333Free full textPubMed 26764327DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error