Aged Garlic For High Blood Pressure

Garlic is one of the most effective natural remedies for high blood pressure, and is one of the most popular supplements among people with hypertension. Aged and black garlic are even more powerful as their sulphur-containing components are converted into derivatives with greater antioxidant properties and can lower blood pressure even further. They also have the advantage of being less smelly and more socially acceptable.

Garlic lowers blood pressure

A large analysis of seven trials found that taking garlic for hypertension lowered a high blood pressure by an average of 6.71/4.79 mmHg, compared to placebo, with no serious side effects. Interestingly, one study from Australia suggests that some people respond better to garlic than others.

This study divided 88 people with uncontrolled hypertension into two groups – one group took two capsules providing 1.2g aged garlic extract every night, for 12 weeks, while the other group took two identical-looking capsules that contained inactive placebo. Activated charcoal was added to disguise any tell-tale garlic odour so neither the volunteers nor the doctors knew who was taking what.

Throughout the study, all blood pressure measurements were taking after volunteers had sat quietly for 5 minutes, and at least two hours after eating, having a caffeinated drink or smoking.

After 12 weeks, average blood pressure readings reduced by 5/1.9 mmHg in those taking garlic, compared with those taking inactive placebo. However, in those taking garlic, it seems that around one in two people had a minimal response, while the other half responded really well.

In fact, for the half that responded, taking aged garlic extracts resulted in blood pressure reductions of, on average, 11.5/6.3 mmHg. This is better than the response to many prescribed drugs.

How do you respond to garlic?

The way you respond to any blood pressure treatments is due to the genes you have inherited. Unless there is something unusual about these volunteers, from Melbourne, Australia, this study suggests that aged garlic may work really well for one in two people with hypertension, and may have a lesser but still useful effect in others.

Drug class versus garlic

Average fall in systolic blood pressure

ACE Inhibitor 6.8mmHg
Thiazide diuretic 7.3 mmHg
Alpha blocker 8.0 mmHg
Calcium channel blocker 8.4 mmHg
Beta-blocker 9.3 mmHg
Aged garlic 11.5 mmHg
Angiotensive II receptor blocker 14.3 mmHg


The only way to know if you are a good garlic responder or not is to take a standardised supplement for up to three months. Check your blood pressure readings before starting, then take them at least once a week for the next 12 weeks, to see if it brings down your current average readings.

If there is little difference, then save your money and move on to a different approach such as drinking beetroot juice or cherry juice daily.

Aged garlic versus normal garlic for high blood pressure

Garlic extracts from ‘normal’ garlic and from aged or black garlic are both effective at lowering blood pressure, and you may find you respond better to one form than the other.

Aged garlic is made by allowing fresh garlic bulbs to mature at room temperature, so the active ingredient, allicin, breaks down into other, more powerful, sulfur-containing antioxidants.

Black garlic is made by maturing fresh bulbs at higher temperature and humidity so the bulbs undergo a fermentation process. This again produces a range of powerful antioxidants, plus a black pigment. As aged and black garlic have at least four times more antioxidant activity than ‘normal’ garlic, it has the potential to improve the elasticity of artery walls and improve blood pressure more effectively.

Continue to add garlic to meals, too, adding it towards teh end of cooking for the best effect.


Image credit: Isle of Wight Garlic Farm; jiang_jongyan/shutterstock

About DrSarahBrewer

Dr Sarah Brewer MSc (Nutr Med), MA (Cantab), MB, BChir, RNutr, MBANT, CNHC qualified from Cambridge University with degrees in Natural Sciences, Medicine and Surgery. After working in general practice, she gained a master's degree in nutritional medicine from the University of Surrey. Sarah is a registered Medical Doctor, a registered Nutritionist and a registered Nutritional Therapist. She is an award winning author of over 60 popular self-help books and a columnist for Prima magazine.

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