Nutrition
Garlic reduces multiple cardiovascular risk factors
|
Ainhoa Pérez
Alumni
|
|
MPH, MSc.
|
A recent meta-analysis published in Nutrition Reviews has confirmed that garlic supplementation can significantly improve various cardiovascular risk factors such as blood pressure, glucose, insulin resistance, and lipids, along with antioxidant and anti-inflammatory effects. In this article, we analyze the findings, clinical significance, and limitations.
PATHOPHYSIOLOGY AND MECHANISMS
Risk factors associated with cardiovascular disease include impaired glucose and lipid metabolism, hypertension, inflammatory cytokines, endothelial dysfunction, and oxidative stress, among others. Garlic (Allium sativum) is high in organosulfur compounds, flavonoids, steroidal saponins, and other phytonutrients, and there is evidence of its ability to modulate metabolic pathways that regulate glucose, insulin, blood pressure, inflammation, and lipids. Fresh garlic, in addition to its allicin content (which is unstable and is lost during cooking), contains a variety of organosulfur compounds such as ajoene and disulfides, which are responsible for antimicrobial, antithrombotic, and vasodilator effects. It also provides flavonoids and phenolics with antioxidant and immunomodulatory action, with different preparations, such as aged garlic, which provides S-allyl cysteine, or black garlic, obtained by controlled fermentation, concentrating phenolic antioxidants. Therefore, it is possible that garlic in various forms and through various mechanisms of action plays a role in overall health and cardiovascular risk management.STUDY
A recent systematic review and meta-analysis (Behrouz et al., 2025) evaluated the effect of administering different garlic preparations from more than a hundred randomized clinical trials involving more than 7,000 participants. Some studies included people without pathologies, while others were conducted on people with type 2 diabetes, hypertension, heart failure, or metabolic syndrome, among others. The intervention groups received different garlic preparations (raw garlic, garlic oil, garlic powder, black garlic, aged extract) compared to placebo or no active intervention. Doses and durations varied widely, so subgroup analyses were performed. Subgroup analyses were performed to explore the impact of dose, duration, type of intervention, and baseline risk profile on outcomes.MAIN RESULTS
Garlic supplementation significantly reduced systolic and diastolic blood pressure, fasting blood glucose, insulin, insulin resistance (HOMA-IR), and lipids (triglycerides, total cholesterol, LDL-c, and increases in HDL-c). The results in the studies are generally consistent, although with more evident effects in high-risk individuals, at higher doses, and in longer interventions. Garlic powder and aged extract were the most frequently used forms, showing, together with raw garlic in general, greater efficacy than other common forms such as black garlic. Additionally, a decrease in aspartate aminotransferase levels (with a more modest effect), C-reactive protein, and tumor necrosis factor alpha was documented, along with an increase in total antioxidant capacity and a reduction in malondialdehyde, suggesting favorable modulation of inflammation and oxidative stress.CONCLUSION AND CLINICAL RELEVANCE
Overall, this meta-analysis shows that garlic supplementation produces a significant improvement in various cardiometabolic factors, especially in people with higher baseline risk, suggesting that it could be used as part of the comprehensive therapeutic management of individuals. The decreases in blood pressure are clinically relevant, while other effects can be classified as small or modest. However, establishing clinical relevance is complex. For example, by modulating different risk factors at the same time, the combined action may be clinically more relevant than the effect size of individual factors might suggest. However, as with drugs, improvement in markers does not necessarily imply a reduction in the incidence of major cardiovascular events, complications, and other important clinical outcomes, so prognostic studies documenting relevant clinical consequences are needed. The meta-analysis has other limitations. The heterogeneity in the formulations, doses, and duration of the interventions, as well as the small sample size of many trials, limit the robustness of the conclusions. However, most of the studies were assessed as having a low risk of bias, in addition to largely objective measures. The comparative analysis by risk of bias, however, shows an attenuation of the effect observed in multiple measures. Future research should focus on standardizing formulations, but above all, it should evaluate results on hard clinical events, particularly in populations with pathologies and risk factors.
#garlic #cardiovasculardisease #highbloodpressure #type2diabetes #metabolicsyndrome
References:
Behrouz et al, 2025. Effects of garlic supplementation on cardiovascular risk factors in adults: A comprehensive updated systematic review and meta-analysis of randomized controlled trials. Nutrition Reviews, 00(00), 1-35. https://doi.org/10.1093/nutrit/nuaf090
* The news published on studies do not represent an official position of ICNS, nor a clinical recommendation.
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
