Garlic supplements and heart risk factors in adults
What it found
In 108 trials in adults, garlic supplements improved several blood markers linked to heart risk, including cholesterol, blood sugar, blood pressure and inflammation.
The authors say more research is needed before firm conclusions.
What they found
Studies in people
Cholesterol changes
Garlic lowered total cholesterol, LDL (bad) cholesterol and triglycerides, and raised HDL (good) cholesterol. The authors report these as significant improvements.
Blood sugar and insulin
Garlic lowered fasting blood glucose, insulin and a measure of insulin resistance. These were significant changes.
Blood pressure
Garlic lowered both systolic and diastolic blood pressure. The authors report these as significant improvements.
Inflammation and oxidative stress
Garlic lowered C-reactive protein, TNF-alpha and malondialdehyde, and raised total antioxidant capacity. It also lowered a liver enzyme called aspartate aminotransferase.
Markers with no change
Garlic did not affect apolipoprotein A-1, apolipoprotein B, alanine aminotransferase, interleukin-6, body mass index, weight or adiponectin.
Who benefited most
The authors say the improvements were particularly seen in adults who started with unfavourable risk factors.
What the authors conclude
“This meta-analysis demonstrates that garlic intake significantly improves key cardiovascular risk markers, including lipid profiles, glycemic indices, blood pressure, oxidative stress, and inflammatory biomarkers, particularly in adults with unfavorable baseline risk factors.”
Also in their conclusions
- They conclude that garlic intake significantly improves key cardiovascular risk markers, including lipid profiles, glycemic indices, blood pressure, oxidative stress, and inflammatory biomarkers, particularly in adults with unfavorable baseline risk factors.
- They suggest that garlic may enhance cardiovascular health in high-risk populations.
- They advise that further research involving larger sample sizes, extended follow-up periods, and enhanced methodological rigor is essential to draw definitive conclusions.
How it was done
Garlic has a long history in traditional Asian medicine, and there is growing interest in whether it protects against heart disease. Earlier studies gave mixed results, so the authors pooled them to get a clearer picture.
They combined 108 randomised controlled trials with 7,137 adults that tested garlic intake against heart and metabolic risk factors. They also looked at whether results differed by dose, duration, type of garlic, health status and starting risk.
What it can’t tell you
- We summarised it from the abstract only.
- The trials varied in dose, duration and type of garlic, so the results cannot show the best way to take it.
- The authors say larger and longer trials with stronger methods are needed before firm conclusions can be drawn.
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 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error