Garlic
Garlic (Allium sativum L.) in the Management of Hypertension and Dyslipidemia – A Systematic Review
Wai-Jo J.Chan a Andrew J.McLachlan ab Edward J.Luca a Joanna E.Harnet ta
Abstract
The herb garlic (Allium sativum L.) has traditionally been used to promote ‘cardiovascular health’. The aim of this systematic review was to evaluate the available evidence for the efficacy and safety of garlic in the management of hypertension and dyslipidemia and the quality of that evidence by utilising the elaborated CONSORT checklist. Double-blind randomized controlled trials written in English from inception to April 2017 were identified and evaluated.
A total of 18 studies were included (n = 1069): 4 studies reported a statistically significant reduction in systolic blood pressure (mean SBP reduction of 11.2 mmHg) and 2 studies reported a statistically significant reduction in various lipid components (LDL-C p <0.05; TC p = 0.003). Aged garlic extract (1.2 mg – 2.4 mg s-allyl cysteine/ day) and to a lesser extent coated garlic powder tablets (600 mg - 2400 mg/ day) demonstrated a hypotensive effect. Evidence for the role of garlic in the management of dyslipidemia is, however, less clear. Minor side effects were reported.
Further high quality research is required to confirm these findings. The authors recommend researchers refer to the item 4 of the elaborated CONSORT checklist in the design and reporting phase of their studies.
Source : Journal of Herbal Medicine
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The effect of a garlic supplement on the pro-inflammatory adipocytokines, resistin and tumor necrosis factor-alpha, and on pain severity, in overweight or obese women with knee osteoarthritis
Sahar Dehghania Elham Alipoorb Ahmad Salimzadehc Mehdi Yaserid Mostafa Hosseinid Christine Feinle-Bissetef Mohammad Javad
Abstract
Background
Osteoarthritis (OA) is a prevalent degenerative joint disease, which is associated with chronic and disabling pain. The adipocytokines, resistin and tumor necrosis factor-alpha (TNF-α), might play a role in OA pathogenesis and outcomes.
PurposeThe aim of this study was, therefore, to assess the anti-inflammatory and analgesic effects of a garlic supplement on serum resistin and TNF-α concentrations and on pain severity in overweight or obese women with knee OA.
Study design
Randomized, double-blind, placebo-controlled, parallel-design trial.
Methods
In this study, 80 post-menopausal overweight or obese women (25 ≤ BMI ≤ 40 kg/m2, age 50–75 years) with mild to moderate knee OA were enrolled. Patients were randomly divided into two groups to receive twice-daily either garlic tablets (total: 1000 mg) or placebo for 12 weeks. The primary outcome measures were fasting serum concentrations of resistin and TNF-α, and pain severity (assessed using 0–10 point visual analogue scale (VAS)).
Results
At week 12, resistin concentrations were significantly decreased in the garlic group (6.41 ± 2.40 to 5.56 ± 2.16 ng/ml; P = 0.008). Serum TNF-α levels did not change significantly within or between the two groups. Pain scores were significantly reduced in the garlic (6.8 ± 2 to 5.3 ± 2.3; P = 0.002), but not in the placebo (6.7 ± 2.4 to 6.2 ± 2.5; P = 0.674), group. Pain scores were also significantly lower in the garlic, compared with the placebo, group following supplementation (5.3 ± 2.3 vs. 6.2 ± 2.5; P = 0.043).
Conclusions
The findings suggest that garlic supplementation for 12 weeks might reduce pain severity in overweight or obese women with knee OA, which may, at least in part, be mediated via a reduction in the pro-inflammatory adipocytokine, resistin.
Source : Journal Phytomedicine
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Effect of garlic supplement in the management of type 2 diabetes mellitus (T2DM): a meta-analysis of randomized controlled trials
Juan Wang, Xiuming Zhang, Haili Lan & Weijia Wang
Abstract
The present study was designed to systematically evaluate the clinical efficacy and safety of garlic supplement in the management of type 2 diabetes mellitus (T2DM). PubMed, EMBASE, the Cochrane Library, and China National Knowledge Internet (CNKI) were searched for relevant randomized controlled trials (RCTs) by using the terms garlic and T2DM up to April 2017. The quality of included RCTs was assessed by the Cochrane tool of risk of bias, and data of outcomes were pooled by REVMAN 5.3. Clinical factors were handled by meta-regression and subgroup analysis, and risk of publication bias was explored by inverted funnel plots. Nine RCTs involving 768 T2DM patients were included in the meta-analysis, and the dose of daily garlic (allicin) supplement ranged from 0.05g to 1.5g. A significant reduction in the level of fasting blood glucose in 1–2 weeks [SMD = −1.61, 95%CI (−2.89, −0.32)], 3–4 weeks [SMD = −2.87, 95%CI (−4.74, −1.00)], 12 weeks [SMD = −9.57, 95%CI (−12.39, −6.75)], and 24 weeks [SMD = −21.02, 95% CI (−32.47, −9.57)] was achieved in favour of the garlic group rather than the control group. Significantly decreased fructosamine and glycated hemoglobin (both in 12 and 24 weeks) were also found in garlic group. Meanwhile, significantly improved blood liquids of total cholesterol [SMD = −1.93, 95%CI (−2.98, −0.87), 3–4 weeks], high density lipoprotein [SMD = −0.41, 95%CI (−0.83, −0.00), 3–4 weeks] and low density lipoprotein [SMD = −3.47, 95%CI (−5.76, −1.18), 12 weeks] were confirmed after garlic administration. There was no significant difference in complications. Current data confirms that garlic supplement plays positive and sustained roles in blood glucose, total cholesterol, and high/low density lipoprotein regulation in the management of T2DM.
Source : Food and Nutrition Research
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Garlic (Allium sativum) Stimulates Lipopolysaccharide-induced Tumor Necrosis Factor-alpha Production from J774A.1 Murine MacrophagesAuthors
Jessica Sung, Youssef Harfouche, Melissa De La Cruz,Martha P. Zamora, Yan Liu, James A. Rego, Nancy E. Buckley
Abstract
Garlic (Allium sativum) is known to have many beneficial attributes such as antimicrobial, antiatherosclerotic, antitumorigenetic, and immunomodulatory properties. In the present study, we investigated the effects of an aqueous garlic extract on macrophage cytokine production by challenging the macrophage J774A.1 cell line with the garlic extract in the absence or presence of lipopolysaccharide (LPS) under different conditions. The effect of allicin, the major component of crushed garlic, was also investigated. Using enzyme-linked immunosorbent assay and reverse transcriptase-quantitative polymerase chain reaction, it was found that garlic and synthetic allicin greatly stimulated tumor necrosis factor-alpha (TNF-α) production in macrophages treated with LPS. The TNF-α secretion levels peaked earlier and were sustained for a longer time in cells treated with garlic and LPS compared with cells treated with LPS alone. Garlic acted in a time-dependent manner. We suggest that garlic, at least partially via its allicin component, acts downstream from LPS to stimulate macrophage TNF-α secretion.
.....Therefore, we believe that our findings support the notion that garlic is beneficial to the immune system.
Source : Journal Phytotherapy Research
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Effect of garlic on blood pressure: A systematic review and meta-analysis
Karin Ried1*, Oliver R Frank1, Nigel P Stocks1, Peter Fakler1 and Thomas Sullivan2
1 Discipline of General Practice, The University of Adelaide, Adelaide, South Australia
2 Discipline of Public Health, The University of Adelaide, Adelaide, South Australia
Abstract
Background Non-pharmacological treatment options for hypertension have the potential to reduce the risk of cardiovascular disease at a population level. Animal studies have suggested that garlic reduces blood pressure, but primary studies in humans and non-systematic reviews have reported mixed results. With interest in complementary medicine for hypertension increasing, it is timely to update a systematic review and meta-analysis from 1994 of studies investigating the effect of garlic preparations on blood pressure.
Methods We searched the Medline and Embase databases for studies published between 1955 and October 2007. Randomised controlled trials with true placebo groups, using garlic-only preparations, and reporting mean systolic and/or diastolic blood pressure (SBP/DBP) and standard deviations were included in the meta-analysis. We also conducted subgroup meta-analysis by baseline blood pressure (hypertensive/normotensive), for the first time. Meta-regression analysis was performed to test the associations between blood pressure outcomes and duration of treatment, dosage, and blood pressure at start of treatment.
Results Eleven of 25 studies included in the systematic review were suitable for meta-analysis. Meta-analysis of all studies showed a mean decrease of 4.6 ± 2.8 mm Hg for SBP in the garlic group compared to placebo (n = 10; p = 0.001), while the mean decrease in the hypertensive subgroup was 8.4 ± 2.8 mm Hg for SBP (n = 4; p < 0.001), and 7.3 ± 1.5 mm Hg for DBP (n = 3; p < 0.001). Regression analysis revealed a significant association between blood pressure at the start of the intervention and the level of blood pressure reduction (SBP: R = 0.057; p = 0.03; DBP: R = -0.315; p = 0.02).
Conclusion Our meta-analysis suggests that garlic preparations are superior to placebo in reducing blood pressure in individuals with hypertension.
Source BMC Cardiovascular Disorders
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The Protective Effect of Aged Garlic Extract on Nonsteroidal Anti-Inflammatory Drug-Induced Gastric Inflammations in Male Albino Rats
Gehan Moustafa Badr1,2 and Jawaher Abdulaziz AL-Mulhim1
1Biological Sciences Department, Faculty of Science, King Faisal University, P.O. 380, Al Ahsa 31982, Saudi Arabia
2Zoology Department, Faculty of Science, Ain Shams University, Egypt
Abstract
Natural products have long gained wide acceptance among the public and scientific community in the gastrointestinal ulcerative field. The present study explore the potential effects of aged garlic extract (AGE) on indomethacin-(IN-) induced gastric inflammation in male rats. Animals were divided into six groups (n = 8) control group, IN-induced gastric inflammation group via oral single dose (30 mg/kg to fasted rats) two AGE orally administered groups (100 and 200 mg/kg for 30 consecutive days) two AGE orally administered groups to rats pretreated with IN at the same aforementioned doses. The results declared the more potent effect of the higher AGE dose (200 mg/kg) as compared to that of the 100 mg/kg dose in the gastroprotective effects reflected by significant gastric mucosal healing of damage and reduction in the total microbial induced due to indomethacin administration. In addition to the significant effect to normalize the significant increase in malondialdehyde (MDA), myeloperoxidase (MPO), tumor necrosis factor-α (TNF-α) values, and the significant decrease in the total glutathione (tGSH), superoxide dismutase (SOD), and catalase (CAT) values induced by indomethacin. The results support AGE antioxidant, anti-inflammatory, and antimicrobial potency reflected by the healing of the gastric tissue damage induced by indomethacin.
Conclusion
In conclusion, the healing activity of AGE at high dose (200 mg/kg) may be resulted from its ability to scavenge ROS produced by indomethacin administration that initiate lipid peroxidation. The mechanism of gastroprotective effects of the AGE on gastric damage induced by indomethacin may be related to its anti-inflammatory actions and its antioxidant properties, which reduce MDA levels and MPO activity and increase tGSH, SOD, and CAT activities. Therefore, our study suggest that AGE was safe and could be a promising new drug for the prevention of NSAIDs-induced gastric damage.
Source : Evidence Based Complementary and Alternative Medicine
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In vitro Antibacterial Activity of Aquatic Garlic Extract, Apple Vinegar and Apple Vinegar - Garlic Extract combination
Dr. Nada KhazalKadhim Hindi
Abstract
Background: Garlic (Allium sativum) has had an important dietary and medicinal role for centuries. It is a large annual plant of the Liliaceae family. Garlic is used in traditional medicine for infectious disease and some other cases.
Aims: The study aims at determining the antibacterial activity of of aquatic garlic extract, apple vinegar and apple vinegar - garlic extract combination against some bacterial isolates.
Methods: The antibacterial effects of aqueous garlic extract, apple vinegar, and apple vinegar- garlic extract combination against
9 Gram-positive and 5 Gram-negative bacterial isolates, including Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, Enterococcus feacalis, Streptococcus pneumoniae, Pseudomonas aeruginosa, Pseudomonas fluresence, Enterobacter aerugenes, Klebsiella pneumoniae, Escherchia coli, Salmonella typhi, Proteus mirabilis, Proteus vulgaris, and Acinetobacter, all of them were studied.
Results: Antibacterial activity of aqueous garlic extract at 50% concentrations by well-diffusion method was characterized by
inhibition zones of 5 Gram-positive and 9 Gram-negative pathogenic bacteria. The maximum zone of inhibition of aqueous
garlic extract was observed in Salmonella typhi and the minimum was observed for Proteus sp. All organisms tested were highly
sensitive to apple vinegar- garlic extract combination, whereas all organisms tested were slightly sensitive to apple vinegar.
Conclusions: In summary, the aqueous garlic extract showed a wide spectrum activity and appears to satisfy all of the criteria
for antibacterial agents. These results suggest that garlic can be used to protect food and reduce the risk of contamination from
pathogenic microorganisms.
Source : American Journal of Phytomedicine and Clinical Therapeutics 2013; 1(1):42-51
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Haematological and Hepatotoxic Potential of Onion (Allium cepa) and Garlic (Allium sativum) Extracts in Rats
Enitan Seyi Samson1*, Ajeigbe Kazeem Olasunkanmi1, Josiah Sunday Joel2 and Ehiaghe Friday Alfred3
1Department of Physiology, School of Basic Medical Sciences, College of Health Sciences, Igbinedion University Okada, P.M.B. 0006, Edo state, Nigeria.
2Department of Biochemistry, School of Basic Medical Sciences, College of Health
Sciences, Igbinedion University Okada, P.M.B. 0006, Edo state, Nigeria.
3Department of Haematology, School of Clinical Medicine, College of Health Sciences, Igbinedion University Okada, P.M.B. 0006, Edo state, Nigeria.
Abstract
Aims: To evaluate and compare the effects of single and combined oral administration of fresh aqueous onion (Allium cepa) and garlic (Allium sativum) extracts at different concentrations (200mg/kg/d, 400mg/kg/d and 600mg/kg/d) on some haematological and
hepatotoxicity indicator parameters in treated rats.
Study Design: Cross-sectional nonclinical study in animal model.
Place and Duration of Study: The study was carried out at the Department of Physiology, Department of Biochemistry and Department of Haematology, College of Health Sciences, Igbinedion University Okada, Edo state, Nigeria between the month of
July and August, 2011.
Methodology: Following 30 days post-oral administration of extracts in 36 treated male albino rats as well as 4 controls, haematological parameters were determined using the Sysmex® Automated Haematology Analyzer, while serum levels of liver enzymes were evaluated using the Reflotron® Plus Auto-Analyzer and liver weight was determined using electronic sensitive weighing balance.
Results: Red blood cell count (RBC), Packed cell volume (PCV), Haemoglobin concentration (HGB), Total White blood cell count (TWBC), Absolute Count of Neutrophil (NEUT#), Absolute Count of Lymphocyte (LYM#), Absolute Count of the summation of
Monocyte, Eosinophil and Basophil (MXD#) and Platelet count (PLT) were significantly increased (P<0.05) to varied extent, except Mean cell volume (MCV), Mean cell haemoglobin (MCH) and Mean cell haemoglobin concentration (MCHC) while Alanine
aminotransferase (ALAT) and Aspartate aminotransferase (ASAT) serum levels were significantly decreased (P<0.001) and liver weight (LW) was non-significantly (P>0.05) reduced in a dose-dependent manner when compared to the control. Synergistic effect
was not observed in the haematological parameters when the two extracts were combined.
Conclusion: The results of this study reveal the haematological potential of onion and garlic extracts with no potential risk of hepatotoxicity (at the concentrations tested) as earlier anticipated. It also further confirms the higher efficacy of garlic over
that of onion, but the molecular mechanism behind their combined effect would require further investigation.
Source European Journal of Medicinal Plants, 2(4): 290-307, 2012
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Garlic compound fights source of food-borne illness better than antibiotics
Researchers at Washington State University have found that a compound in garlic is 100 times more effective than two popular antibiotics at fighting the Campylobacter bacterium, one of the most common causes of intestinal illness. Their work was recently published in the Journal of Antimicrobial Chemotherapy.
The discovery opens the door to new treatments for raw and processed meats and food preparation surfaces.
"This work is very exciting to me because it shows that this compound has the potential to reduce disease-causing bacteria in the environment and in our food supply," says Dr. Xiaonan Lu, a postdoctoral researcher and lead author of the paper.
"This is the first step in developing or thinking about new intervention strategies," says Michael Konkel, a co-author who has been researching Campylobacter jejuni for 25 years.
"Campylobacter", says Konkel, "is simply the most common bacterial cause of food-borne illness in the United States and probably the world." Some 2.4 million Americans are affected every year, according to the Centers for Disease Control and Prevention, with symptoms including diarrhea, cramping, abdominal pain and fever. The bacteria are also responsible for triggering nearly one-third of the cases of a rare paralyzing disorder known as Guillain-Barré syndrome.
Most infections stem from eating raw or undercooked poultry or foods that have been cross-contaminated via surfaces or utensils used to prepare poultry.
Lu and his colleagues looked at the ability of the garlic-derived compound, diallyl sulfide, to kill the bacterium when it is protected by a slimy biofilm that makes it 1,000 times more resistant to antibiotics than the free floating bacterial cell. They found the compound can easily penetrate the protective biofilm and kill bacterial cells by combining with a sulfur-containing enzyme, subsequently changing the enzyme's function and effectively shutting down cell metabolism.
The researchers found the diallyl sulfide was as effective as 100 times as much of the antibiotics erythromycin and ciprofloxacin and would often work in a fraction of the time.
Two previous works published last year by Lu and WSU colleagues in Applied and Environmental Microbiology and Analytical Chemistry found diallyl sulfide and other organosulfur compounds effectively kill important foodborne pathogens, such as Listeria monocytogenes and Escherichia coli O157:H7.
Konkel cautions that the recent work is still at the basic stage, well removed from an actual application. While eating garlic is a generally healthy practice, it is unlikely to prevent Campylobacter-related food poisoning. However, "diallyl sulfide may be useful in reducing the levels of the Campylobacter in the environment and to clean industrial food processing equipment, as the bacterium is found in a biofilm in both settings."
"Diallyl sulfide could make many foods safer to eat", says Barbara Rasco, a co-author on all three recent papers and Lu's advisor for his doctorate in food science. "It can be used to clean food preparation surfaces and as a preservative in packaged foods like potato and pasta salads, coleslaw and deli meats".
"This would not only extend shelf life but it would also reduce the growth of potentially bad bacteria," she says.
Source : MedicalXpress
Link to Source
Diallyl trisulfide induces Bcl-2 and caspase-3-dependent apoptosis via downregulation of Akt phosphorylation in human T24 bladder cancer cells
Source: Phytomedicine: International Journal of Phytotherapy & Phytopharmacology, April, 2010
LINK TO SOURCE
Strength of Evidence Garlic + Blood Cholesterol Levels
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Aged garlic extract lowers blood pressure in patients with treated but uncontrolled hypertension: A randomised controlled trial
Source : Maturitas Journal
Link to Source - Abstract
Researchers at Washington State University have found that a compound in garlic is 100 times more effective than two popular antibiotics at fighting the Campylobacter bacterium, one of the most common causes of intestinal illness. Their work was recently published in the Journal of Antimicrobial Chemotherapy.
The discovery opens the door to new treatments for raw and processed meats and food preparation surfaces.
"This work is very exciting to me because it shows that this compound has the potential to reduce disease-causing bacteria in the environment and in our food supply," says Dr. Xiaonan Lu, a postdoctoral researcher and lead author of the paper.
"This is the first step in developing or thinking about new intervention strategies," says Michael Konkel, a co-author who has been researching Campylobacter jejuni for 25 years.
"Campylobacter", says Konkel, "is simply the most common bacterial cause of food-borne illness in the United States and probably the world." Some 2.4 million Americans are affected every year, according to the Centers for Disease Control and Prevention, with symptoms including diarrhea, cramping, abdominal pain and fever. The bacteria are also responsible for triggering nearly one-third of the cases of a rare paralyzing disorder known as Guillain-Barré syndrome.
Most infections stem from eating raw or undercooked poultry or foods that have been cross-contaminated via surfaces or utensils used to prepare poultry.
Lu and his colleagues looked at the ability of the garlic-derived compound, diallyl sulfide, to kill the bacterium when it is protected by a slimy biofilm that makes it 1,000 times more resistant to antibiotics than the free floating bacterial cell. They found the compound can easily penetrate the protective biofilm and kill bacterial cells by combining with a sulfur-containing enzyme, subsequently changing the enzyme's function and effectively shutting down cell metabolism.
The researchers found the diallyl sulfide was as effective as 100 times as much of the antibiotics erythromycin and ciprofloxacin and would often work in a fraction of the time.
Two previous works published last year by Lu and WSU colleagues in Applied and Environmental Microbiology and Analytical Chemistry found diallyl sulfide and other organosulfur compounds effectively kill important foodborne pathogens, such as Listeria monocytogenes and Escherichia coli O157:H7.
Konkel cautions that the recent work is still at the basic stage, well removed from an actual application. While eating garlic is a generally healthy practice, it is unlikely to prevent Campylobacter-related food poisoning. However, "diallyl sulfide may be useful in reducing the levels of the Campylobacter in the environment and to clean industrial food processing equipment, as the bacterium is found in a biofilm in both settings."
"Diallyl sulfide could make many foods safer to eat", says Barbara Rasco, a co-author on all three recent papers and Lu's advisor for his doctorate in food science. "It can be used to clean food preparation surfaces and as a preservative in packaged foods like potato and pasta salads, coleslaw and deli meats".
"This would not only extend shelf life but it would also reduce the growth of potentially bad bacteria," she says.
Source : MedicalXpress
Link to Source
Diallyl trisulfide induces Bcl-2 and caspase-3-dependent apoptosis via downregulation of Akt phosphorylation in human T24 bladder cancer cells
- It is well known that the garlic-derived organosulfur compounds (OSCs) are effective to inhibit a variety of human cancers such as prostate, breast, colon, skin, lung, and bladder cancers.
- Herein, the pro-apoptotic effects of diallyl trisulfide (DATS), one of garlic-derived OSCs, on T24 bladder cancer cells were investigated.
- The results demonstrated that DATS suppressed proliferation of T24 bladder cancer cells in a dose- and time-dependent manner which was associated with induced G2/M Phase cell cycle arrest and apoptosis. Mechanistically, DATS inhibits phosphatidylinositol 3'-kinase/Akt activation that, in turn, results in modulation of Bcl-2 family proteins, leading to enhanced apoptosis of T24 cells.
- These findings suggest that Diallyl trisulfide may be an effective way for treating human bladder and other types of cancers.
Source: Phytomedicine: International Journal of Phytotherapy & Phytopharmacology, April, 2010
LINK TO SOURCE
Strength of Evidence Garlic + Blood Cholesterol Levels
- Much research has been conducted on the effects of various garlic supplements on blood cholesterol levels.
- Some evidence indicates that taking garlic supplements can slightly lower blood cholesterol levels; studies have shown positive effects for short-term (1 to 3 months) use. However, an NCCAM-funded study on the safety and effectiveness of three garlic preparations (fresh garlic, dried powdered garlic tablets, and aged garlic extract tablets) for lowering blood cholesterol levels found no effect.
- Garlic supplements appear to be safe for most adults.
- Side effects can include breath and body odor, heartburn, upset stomach, and rarely allergic reactions. These side effects are more common with raw garlic.
- There is evidence that garlic supplements may thin the blood (reduce the ability of blood to clot) in a manner similar to aspirin. This effect may be a problem during or after surgery. Use garlic with caution if you are planning to have surgery or dental work, or if you have a bleeding disorder.
- Garlic supplements have been found to interfere with the effectiveness of saquinavir, a drug used to treat HIV infection. Its effect on other drugs has not been well studied.
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Aged garlic extract lowers blood pressure in patients with treated but uncontrolled hypertension: A randomised controlled trial
- Daily for 12 weeks 50 patients with treated but uncontrolled hypertension took either a placebo or 4 capsules of aged garlic extract (containing 2.4mg S-allylcysteine) in addition to their existing antihypertensive medication.
- Over the 12-week treatment period garlic significantly reduced systolic blood pressure compared with the placebo in patients who had unacceptably high systolic blood pressure at the beginning of the study.
- Therefore aged garlic extract was superior to the placebo in lowering systolic blood pressure in patients with treated but uncontrolled hypertension.
Source : Maturitas Journal
Link to Source - Abstract