Does garlic lower blood pressure?

Aim of the study: There is no consensus in the existing literature on the effect of aged garlic extract (AGE) on blood pressure. This systematic review and meta-analysis was conducted to bring together existing data from randomized clinical trials (RCTs) on the impact of AGE supplements on blood pressure in people with hypertension.

Results: Overall, nine RCTs with 584 participants met the inclusion criteria. AGE supplementation reduced systolic blood pressure (SBP) (WMD: -4.03; 95% CI: -6.87, -1.20; I2: 57.1%) and diastolic blood pressure (DBP) (WMD: -1.44; 95% CI: -2.87, -0.02; P = 0.052; I2: 36.8%; P: 0.105). In addition, subgroup analysis showed that higher doses of AGE supplements significantly lowered DBP and SBP in people with hypertension. The results suggest that AGE supplements may help improve blood pressure in people with hypertension, but significant effects are seen only at doses above 1200 mg/day. Well-designed future trials are needed to confirm these results.

Aim of the study: To assess the effect, tolerability, and acceptability of aged garlic extract as an additional treatment to existing antihypertensive medication in patients with treated but uncontrolled hypertension.

Results: In patients with uncontrolled hypertension (SBP ≥ 140 mmHg at baseline), systolic blood pressure was on average 10.2 ± 4.3 mmHg (p=0.03) lower in the garlic group than in the control group over the 12-week treatment period. Blood pressure changes between the groups were not significant in patients with SBP<140 mmHg at baseline. Aged garlic extract was generally well tolerated, and acceptance of the trial treatment was high (92%). Our trial suggests that aged garlic extract is superior to placebo at lowering systolic blood pressure in patients with treated but uncontrolled hypertension, with an effect similar to current first-line medications.

Aim of the study: Hypertension affects 30% of adults worldwide. Garlic supplements have shown promise in treating uncontrolled hypertension, and their mechanism of action is biologically plausible. Our trial is the first to assess the effect of aged garlic extract on central blood pressure and arterial stiffness, which are considered important risk factors for cardiovascular disease.

Results: Mean blood pressure fell significantly by 5.0±2.1 mmHg systolic (P=0.016), and in responders by 11.5±1.9 mmHg systolic and 6.3±1.1 mmHg diastolic, compared with placebo (P<0.001). Central hemodynamic measures tended to improve more in the garlic group than in the placebo group, including central blood pressure, central pulse pressure, mean arterial pressure, augmentation pressure, pulse-wave velocity, and arterial stiffness. Although changes in other cardiovascular markers were not statistically significant because of small numbers in subgroups with elevated levels, garlic showed trends toward beneficial effects on the inflammatory marker TNFα, total cholesterol, low-density lipoprotein cholesterol, and apolipoproteins. Aged garlic extract was well tolerated and acceptable, and did not increase the risk of bleeding in patients taking blood-thinning medication.

Aim of the study: Background: Previous research suggests that Kyolic aged garlic extract can reduce blood pressure in a large proportion of patients with hypertension, with an effect similar to that of standard first-line antihypertensive medication. High blood pressure has been linked to gut dysbiosis, with significantly lower microbial richness and diversity in people with hypertension than in people with normal blood pressure.

Results: Furthermore, aged garlic extract improved gut microbiota, as shown by greater microbial richness and diversity and a marked increase in Lactobacillus and Clostridia species after 3 months of supplementation. Conclusions: Kyolic aged garlic extract is effective at reducing blood pressure in patients with uncontrolled hypertension and may improve arterial stiffness, inflammation, and gut microbial profile. Aged garlic extract is highly tolerable and has a strong safety profile as a standalone or additional antihypertensive treatment, with multiple benefits for cardiovascular health. Trial Registration: Australian New Zealand Clinical Trial Registry ACTRN12616000185460 (https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=370096).

Aim of the study: The use of garlic (Allium sativum) to treat arterial hypertension has been recognized as effective for several decades. However, tolerance to treatment is low, and several technological modifications have been developed to improve tolerability, such as aging at controlled temperature and humidity.

Results: A reduction in systolic and diastolic blood pressure of 1.8 mmHg (0.7 to 4.1 95% CI) and 1.5 mmHg (0.3 to 3.0 95% CI), respectively, was observed. There was also an increase in blood nitric oxide (10.3 µM, 1.1 to 19.5 95% CI) and antioxidant capacity (7 × 10-3 µM TE/min, (1.2 to 13 × 10-3 95% CI), and a reduction in uric acid levels (-0.3 mg/dL, -0.5 to -0.001 95% CI) and ACE activity (-9.3 U/L; -18.4 to -0.4 95% CI). No changes in endothelial function or inflammatory cytokines were observed. It was concluded that low-dose SAC supplementation in an optimized black garlic extract allows for an additional significant reduction in blood pressure in people with Grade I hypertension receiving drug treatment.

Aim of the study: Forty-seven non-hospitalized patients with mild hypertension took part in a randomized, placebo-controlled, double-blind trial conducted by 11 general practitioners. After a two-week acclimatization phase, the patients included in the study had diastolic blood pressures between 95 and 104 mmHg.

Results: Significant differences between the placebo and treatment groups were found during the course of therapy. For example, supine diastolic blood pressure in the garlic treatment group fell from 102 to 91 mmHg after eight weeks (p less than 0.05) and to 89 mmHg after 12 weeks (p less than 0.01). Serum cholesterol and triglycerides also fell significantly after eight and 12 weeks of treatment. In the placebo group, by contrast, there were no significant changes.

Aim of the study: Hypertension is the most common preventable condition encountered in primary healthcare. If it is not treated early, it can lead to cardiovascular and kidney disease.

Results: A total of 200 participants were selected through purposive sampling and assigned to an intervention group (n=100) or a non-equivalent control group (n=100). The intervention group showed a significant reduction in mean systolic blood pressure from 152.34±8.76 to 128.45±6.23 mmHg and in diastolic blood pressure from 96.78±6.45 to 82.34±5.12 mmHg (p<0.001). Post-test blood pressure levels were significantly lower in the intervention group than in the control group (p<0.001). Thus, we show that eating raw garlic cloves is an effective and practical complementary strategy for managing hypertension in the community.