The health benefits of garlic have been known since thousands of years. It is an important part of the Ayurveda system of medicine. It has also been used in other ancient medicinal systems including the Chinese, Egyptian, Babylonian, Greek and Roman. Its use has ranged from the treatment of hypertension, infections, snakebites and blood clots to the warding off of evil spirits.
Though the medicinal properties of garlic have not been completely established, garlic appears to have blood pressure and cholesterol lowering, anticancer and antimicrobial properties. Raw garlic appears to have more medicinal properties than cooked garlic.
AdvertisementResearchers reviewed various published articles on the effect of garlic on high blood pressure. Publications between 1955 and 2007 were included in the study. The researchers analyzed relevant information provided in the studies.
A total of 11 studies were carefully selected and included in the analysis. Most of the studies used 600 to 900 mg of garlic powder per day, which provide 3.6-5.4 mg of allicin, an active component of garlic that helps to reduce blood pressure.
The analysis showed that garlic appears to have an effect in reducing systolic and diastolic blood pressure in hypertensive patients as compared to those not taking garlic. Patients with high blood pressure at the beginning of the study showed a better effect as compared to those who did not have a high blood pressure at the beginning.
In fact, the blood pressure lowering effects of garlic may be comparable to other drugs used for high blood pressure like beta - blockers, ACE inhibitors and angiotensin II type 1 receptor antagonists.
Garlic may cause reduction in blood pressure by relaxing blood vessels and interfering with the function of angiotensin I (an enzyme which plays a role in the development of high blood pressure). It may also exert an indirect effect by reducing cholesterol and breaking down clots in the blood vessels.
Most of the studies included in the analysis were conducted for a short duration of around 12 to 23 weeks. Trials lasting for a longer duration are required to establish the long-term benefits of garlic in hypertension.
Using standardized garlic preparations could possibly help to establish the relationship between garlic and blood pressure even better. Garlic preparations have several advantages over raw garlic. They help in avoiding the odor of garlic and thus prevent bad breath. They also prevent damage of the active compounds during the cooking process.
Garlic could thus possibly be useful in the future to improve the effectiveness of antihypertensive medications. At the same time, it may help to keep the dosage of the medications under control, thus reducing the possibility of side effects.
1. Effect of garlic on blood pressure: A systematic review and meta-analysis; Karin Ried et al; BMC Cardiovascular diseases 2011