Garlic supplements and heart risk factors across 108 trials in adults
What it found
In adults, taking garlic lowered blood fats, blood sugar, blood pressure and signs of inflammation.
It did not change body weight or several other measured markers.
What they found
Studies in people
Blood fats improved
Taking garlic lowered triglycerides by about 5.82 mg/dL and total cholesterol by about 10.21 mg/dL. LDL cholesterol fell by 5.90 mg/dL while HDL cholesterol rose slightly by 2.18 mg/dL.
Blood sugar and insulin
Fasting blood sugar dropped by 2.77 mg/dL and insulin levels fell by 1.74 mU/L. A measure of insulin resistance also improved slightly.
Blood pressure lowered
The top blood pressure number fell by 3.71 mmHg and the bottom number by 1.97 mmHg in people taking garlic.
Inflammation and oxidative stress
C-reactive protein, a marker of inflammation, fell by 1.6 mg/L. Another inflammatory marker called tumor necrosis factor-alpha dropped by 3.94 Pg/mL. Total antioxidant capacity rose slightly while malondialdehyde, a sign of cell damage, fell by 1.03 nmol/mL.
No change in weight
Garlic did not change body mass index, body weight or a hormone called adiponectin. It also did not affect certain liver enzymes or another inflammatory marker called interleukin-6.
What the authors conclude
- They conclude that garlic intake improves key heart risk markers like blood fats, blood sugar, blood pressure and inflammation in adults.
- They note these benefits were strongest in people who already had poor baseline risk factors.
- They advise that larger trials with longer follow-up are needed before firm conclusions can be drawn.
How it was done
Garlic is widely used in cooking and traditional Asian medicine, and interest has grown in whether it protects against heart disease. Earlier studies gave mixed results, so the authors wanted to update the evidence with newer trials.
They gathered 108 randomised trials involving 7137 adults who took garlic supplements. They combined the results to see how garlic affected various heart risk factors. They also looked at differences by dose, duration, supplement type and starting health status.
What it can’t tell you
- We summarised it from the abstract only.
- These trials tested garlic supplements rather than garlic used as a food ingredient.
- The results may not apply to eating garlic in normal meals.
- Because the trials varied in length and dose, scientists do not yet know the ideal amount or how long someone must take it to see lasting effects.
Who paid
- Funding
- Funded by Kerman University of Medical Sciences (from the PubMed record).
- Authors work at
- Kerman University of Medical Sciences, Iran; Shahid Beheshti University of Medical Sciences, Iran; Birmingham City University, United Kingdom
The paper
- Title
- Effects of Garlic Supplementation on Cardiovascular Risk Factors in Adults: A Comprehensive Updated Systematic Review and Meta-Analysis of Randomized Controlled Trials
- Type
- Systematic review and meta-analysisThe authors follow a set, published method to find every relevant study, then combine the numbers from them into one result.
- Evidence
- Studies in people
- Summarised from
- Abstract only
- Cite
- Behrouz V, Zahroodi M, Clark CCT, Mir E, Atashi N, Rivaz R (2026). Effects of Garlic Supplementation on Cardiovascular Risk Factors in Adults: A Comprehensive Updated Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrition reviews. doi:10.1093/nutrit/nuaf090PubMed 40580481DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error