The Role Of Garlic In Promoting Heart Health

  • Sara Moheb Foad BPharm, Clinical Pharmacy, Faculty of Pharmacy, Cairo University, Egypt

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There are several questions about this interesting plant used in the treatment of different diseases and maintaining health from antiquity. This plant is garlic, which has several benefits and uses in medicine. Therefore, in this article, I will take you my reader to learn and know more about this incredible plant -garlic- and its benefits on health and treating diseases. 

Definition and historical use of garlic

Garlic has been known from antiquity to have medical uses in preventing and treating diseases throughout the ages. Garlic was found in Egyptian pyramids and ancient Greek temples, and its uses were recorded at the beginning of recorded history. Ancient medical texts from Egypt, Greece, Rome, China, and India prescribed medical applications for garlic. Garlic used in old ages like given to laborers to provide them with strength and increase their capacity, and it has been given to Olympic athletes as a performance-enhancing agent. Modern science is tending to confirm many of the beliefs of ancient cultures regarding garlic and discover more about its mechanism of action and more uses not known about garlic in the past. 1

Overview of heart health and its significance

the heart and blood vessels are the parts of The cardiovascular system. You should keep your heart's health from different diseases affecting the heart and blood vessels. This will be achieved by eating a healthy diet, stopping smoking, and exercising regularly. There is a wide array of problems that may affect the cardiovascular system, a few of which include endocarditis, rheumatic heart disease, and conduction system abnormalities. Cardiovascular disease, also known as heart disease, includes these refer 4 entities: coronary artery disease (CAD) which is also referred to as coronary heart disease (CHD), cerebrovascular disease, peripheral artery disease (PAD), and aortic atherosclerosis. CAD results from decreased myocardial perfusion that causes angina due to ischemia and can result in myocardial infarction (MI), and heart failure. 2 

Exploring the role of garlic in promoting heart health

As you know, dietary factors play an essential role in the development of different diseases, including cardiovascular diseases. Therefore, you should take care to include fiber, fruits, and green vegetables to help decrease the risk of cardiovascular diseases. Several clinical trials and different studies performed on garlic use in the prevention and treatment of cardiovascular and other metabolic diseases, atherosclerosis, hyperlipidemia, thrombosis, hypertension, and diabetes. Several of these studies reveal that garlic has beneficial effects on different diseases. These biological responses of garlic have been largely attributed to  3

  • Reduction of risk factors for cardiovascular diseases and cancer
  • Stimulation of immune function
  • Enhanced detoxification of foreign compounds
  • Hepatoprotection
  • Antimicrobial effect and antioxidant effect

Composition of garlic

Garlic is known to be used as a spice in food, but it is considered else as one of the medicinal plants used in different diseases in medicines as natural remedies. Due to its containing Allicin (allyl 2-propenethiosulfinate or diallyl thiosulfinate) which is considered the principal bioactive compound present in aqueous garlic extract or raw garlic homogenate (they are types of garlic preparations that are used mainly in intensive scientific study). 

When garlic is chopped or crushed, the alliinase enzyme inside garlic is activated and acts on alliin (present in intact garlic) to produce allicin which is inactivated by heat. The composition of garlic powder which is produced after dehydration and crushing is the same as raw garlic and alliinase activity is still working.

Alline possesses several biological properties including anticarcinogenic, antioxidant, antidiabetic, renoprotective, anti-atherosclerotic, antibacterial, antifungal, and antihypertensive activities in traditional medicines.

There are other important sulfur-containing compounds present in garlic homogenate are allyl methyl thiosulfonate, 1-propenyl allyl thiosulfonate, and γ-L-glutamyl-S-alkyl-L-cysteine.4

Different garlic preparation 

There is different garlic preparations used in clinical studies or used by normal people in ordinary days, some of these preparations are as follows:

  • Raw garlic homogenate is considered the major preparation of garlic subjected to intensive scientific study
  • Aged garlic extract (AGE) is formed through sliced raw garlic stored in 15–20% ethanol for 20 months. When garlic passes through this process this may lead to loss of allicin and increased activity of certain newer compounds, like S-allyl cysteine (SAC), S-allyl mercapto cysteine, allicin, and selenium which are stable, highly bioavailable, and significantly antioxidant
  • Medicinally used garlic oil is mostly prepared by the steam-distillation process. All the water-soluble contents including allicin are eliminated from the oil.  

Mechanisms of garlic in heart health

The health of your heart is essential for your healthy life. Therefore, you should learn how to prevent and treat cardiovascular diseases. As a result, several studies and trials have been on the beneficial effects of garlic as a natural remedy to treat cardiovascular events. Some of these beneficial effects are listed as follows

 Reduction of cholesterol levels 

  • Garlic helps protect your arteries' wall from atherosclerosis by reducing lipid content in the arterial wall. Garlic has a direct antiatherogenic this is a preventive effect of garlic and has an antiatherosclerotic effect which means that causes regression at the level of the artery wall.  
  •  Garlic stops the hepatic activities of lipogenic and cholesterolemia enzymes such as malic enzyme, fatty acid synthase, glucose-6 phosphate dehydrogenase, and 3-hydroxy-3-methyl-glutaryl-CoA (HMG CoA) reductase
  •  Garlic increases cholesterol excretion, as manifested by increased excretion of acidic and neutral steroids after garlic feeding.
  •  Garlic suppresses LDL oxidation, which benefits in atherosclerosis.
  • It is known that all mechanisms of garlic in treating and preventing atherosclerosis are due mainly to its active compound which is called allicin but in recent studies, researchers found that other water-soluble organosulfur compounds especially S-allyl cysteine (SAC), present in aged garlic extract and diallyl-di-sulfide (DADS), present in garlic oil are also potent cholesterol synthesis inhibitors. 

Blood pressure regulation 

  • Different studies made on the effect of garlic as an antihypertensive and how it works. So studies assigned to its prostaglandin-like effects which decrease peripheral vascular resistance due to gamma-glutamylcysteines which is one of garlic compounds. They do that by their ability to inhibit angiotensin-converting enzyme.
  • Garlic controls the production and function of both endothelium-derived relaxing and constricting factors, which may contribute to its protective effect against hypoxic pulmonary vasoconstriction.
  • Garlic also excites nitric-oxide-dependent relaxation in pulmonary arteries. That is due to the effect of allicin as a pulmonary vasodilator independent of the synthesis of NO, ATP-sensitive (K+) channel, and activation of cyclooxygenase enzyme.

Antioxidant and anti-inflammatory effects

Antioxidant effect 

Garlic and its bioactive compounds (such as phenols and saponins)  have an antioxidant effect, which involves the enhancement of antioxidant enzyme activities and the regulation of the Nrf2-ARE pathway. The way of consuming garlic affects antioxidant activity therefore raw garlic had a stronger antioxidant activity than cooked garlic, and the antioxidant activity of fermented garlic, such as black garlic, was stronger than that of crude garlic.

Anti-inflammatory effects 

Garlic has anti-inflammatory effects used in treating diseases like arthritis and any other inflammatory diseases due to its low toxicity. This effect is mediated by inhibiting inflammatory mediators, such as NO, TNF-α, and IL-1 due to the ethyl linoleate in garlic which reduces the production of nitric oxide and prostaglandin E-2 by down-regulating the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX2) in lipopolysaccharide-stimulated RAW 264.7 macrophages. 

The 14-kDa protein is another substance present in garlic responsible for inhibiting the inflammatory mediators including NO, TNF-α, and interleukin (IL) -1β by inhibiting the transcription factor nuclear factor-kappa B (NF-κB) signalling pathway in lipopolysaccharide-stimulated J774A.1 macrophages. 


At the end of this article, we identify garlic and its active compound which is mainly allicin, and know different garlic preparations and the content of each. After that, we learn about the beneficial effects of garlic in the prevention and treatment of cardiovascular diseases due to its beneficial effects as an anti-atherosclerotic agent, antihypertensive, anticoagulant agent, and also its effects as an antioxidant, and anti-inflammatory agent. All that dear reader encourages you to start including such important and useful plants in your diet to use them as a natural remedy as well as spice in food. 


Does garlic increase heartbeat?

Studies conclude that there are beneficial effects for garlic on the rate, rhythm, and force of contraction of the heart, but higher doses of garlic give undesirable effects like decreased force of contraction and that is a bad thing for the heart.5

How many cloves of garlic should I take for my heart?

The recommended dose for patients with heart problems is two cloves of raw garlic in the morning to help them decrease atherosclerosis, strokes, and heart attacks and help control their hypertension.6

What are the side effects of garlic on the heart?

Different studies and trials on the use of garlic in treating and preventing heart diseases have reported the beneficial effects of garlic on heart health when given at the recommended dose, but other studies reported also side effects that may arise when consuming higher doses of garlic. These side effects like lower blood pressure than normal leading to severe hypotension, decreased force of contraction leading to slow heart rate, an anticoagulation effect more than normal leading to a life-threatening hemorrhage, and other side effects related to garlic itself if consumed in high amounts like Gastrointestinal discomfort, nausea, bloating, headache, dizziness, and profuse sweating.3

Can too much garlic damage the liver?

Yes, some of the animal and clinical studies report that consuming large doses of garlic like 0.5 g/ Kg per day has the potential ability to induce liver damage but consuming lower dose of garlic (0.1 or 0.25 g/Kg per day) that consider more safer doses on the liver and not showed any morphological changes in the liver.6


  1. Rivlin RS. Historical perspective on the use of garlic. J Nutr. مارس، 2001;131(3s):951S-4S.
  2. Olvera Lopez E, Ballard BD, Jan A. Cardiovascular disease. في: StatPearls [انترنت]. Treasure Island (FL): StatPearls Publishing; 2024 [وثق 26 يناير، 2024]. موجود في:
  3. Banerjee SK, Maulik SK. Effect of garlic on cardiovascular disorders: a review. Nutr J [انترنت]. 19 نوفمبر، 2002 [وثق 26 يناير، 2024];1:4. موجود في:
  4. Qidwai W, Ashfaq T. Role of garlic usage in cardiovascular disease prevention: an evidence-based approach. Evid Based Complement Alternat Med [انترنت]. 2013 [وثق 27 يناير، 2024];2013:125649. موجود في:
  5. Yadav RK, Verma NS. Effects of garlic (Allium sativum) extract on the heart rate, rhythm and force of contraction in frog: a dose-dependent study. Indian J Exp Biol. يونيو، 2004;42(6):628–31.
  6. Rana SV, Pal R, Vaiphei K, Singh K. Garlic hepatotoxicity: safe dose of garlic. Trop Gastroenterol. 2006;27(1):26–30.
  7. Rahman K, Lowe GM. Garlic and cardiovascular disease: a critical review12. The Journal of Nutrition [انترنت]. 1 مارس، 2006 [وثق 28 يناير، 2024];136(3):736S-740S. موجود في:
  8. Shang A, Cao SY, Xu XY, Gan RY, Tang GY, Corke H, وآخرون. Bioactive compounds and biological functions of garlic(Allium sativum L.). Foods [انترنت]. 5 يوليو، 2019 [وثق 28 يناير، 2024];8(7):246. موجود في:

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This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Sara Moheb Foad

BPharm, Clinical Pharmacy, Faculty of Pharmacy, Cairo University, Egypt

Sara graduated from the faculty of pharmacy at Cairo University and then earned a pharmacovigilance diploma after that found my passion in writing and translation, especially in the medical field so started taking courses in both of them. After that, I gained several years of experience in medical writing in both English and Arabic language. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
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