By Greg Arnold, DC, CSCS, January 14, 2015, abstracted from “Effect of Garlic on Blood Pressure: A Meta-Analysis” printed online January 5, 2015 in the Journal of Clinical Hypertension

High blood pressure is a growing health risk in the United States and most countries [1]. It has been identified as the leading burden of death [2], substantially increasing the risk of stroke, vision loss, kidney disease, heart failure and heart attack [3]. Risk rises with age and further after 65. Its potential economic burden in coming years is substantially above the $76 billion it cost the US health system in 2010 [4]. Hypertension causes seven million deaths worldwide annually [5].

A new review [6] shows that garlic may help maintain normal blood pressure. It included 17 studies with 799 participants taking 300–2400 mg garlic powder daily for 2–24 weeks. Researchers noted a “significant difference favouring the garlic group,” with overall reductions of 3.75 mmHg systolic and 3.39 mmHg diastolic compared with controls.

The study closest to the overall findings was a 2013 study [7] of 47 mildly hypertensive participants (26 men, 21 women). Taking 300 mg dried garlic daily for 12 weeks reduced systolic pressure by 3.9% in 23 participants (142.7 to 137.2 mmHg), compared with 0.5% in 24 placebo participants (42.3 to 141.6 mmHg). Diastolic pressure fell by 5.1% (90.2 to 86.0 mmHg), while placebo showed no change (91.2 to 91.2 mmHg).

This meta-analysis suggests that garlic supplements are preferable for controlling blood pressure reduction. Further studies should investigate how dose and duration relate to changes in blood pressure.

Reference:

[1]  Cutler JA, Sorlie PD, Wolz M, Thom T, Fields LE, Roccella EJ. Trends in hypertension prevalence, awareness, treatment, and control rates in United States adults between 1988-1994 and 1999-2004. Hypertension. 2008;52:818–827.

[2] Lim SS, Vos T, Flaxman AD, et al. A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet. 2012;380:2224–2260

[3]   “Why Blood Pressure Matters” posted on the American Heart Association Website

[4] Lloyd-Jones D, Adams RJ, Brown TM, et al; Writing Group Members; American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics–2010 update: a report from the American Heart Association. Circulation. 2010;121:e46–e215

[5] Fagard RH. Resistant hypertension. Heart. 2012;98:254–261

[6] Wang HP. Effect of Garlic on Blood Pressure: A Meta-Analysis. J Clin Hypertens (Greenwich) 2015 Jan 5. doi: 10.1111/jch.12473. [Epub ahead of print]

[7] Nakasone Y, Nakamura Y, Yamamoto T, Yamaguchi H. Effect of a traditional Japanese garlic preparation on blood pressure in prehypertensive and mildly hypertensive adults. Exp Ther Med. 2013;5:399–405.

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