Exploring the Health Benefits of Drinking Water Infused with Garlic

Garlic with water is claimed to support heart health and immunity, but evidence is limited and it can upset the stomach.

Claims

Lower blood pressure, boost immunity, fight colds.

Evidence

Garlic may lower blood pressure slightly. Evidence for garlic water is limited.

Compounds

Allicin forms when raw garlic is crushed.

Side effects

Heartburn, bad breath, upset stomach, and bleeding risk with blood thinners.

Safe

1 to 2 cloves a day is common in food.

Talk to a doctor

If you take blood thinners or have surgery planned.

What the claim is

Drinking garlic water, made by soaking or boiling crushed garlic, is promoted for immunity, blood pressure and digestion. Garlic contains alliin, which turns into allicin when crushed. Allicin is unstable, and heating or long soaking reduces its content.

• A 2020 meta-analysis found garlic supplements lowered systolic blood pressure by about 8 mmHg in people with hypertension, but these used standardized extracts, not garlic water.
• A Cochrane review in 2014 found insufficient evidence that garlic prevents colds, with one small trial suggesting fewer colds.
• Garlic water has not been tested in large trials on its own.

Side effects

Raw garlic can cause heartburn, bad breath, stomach upset and, in large amounts, bleeding risk. It may interact with blood thinners such as warfarin and some HIV drugs like saquinavir. Stop high-dose garlic about 7 to 10 days before surgery. A typical culinary intake is 1 to 2 cloves daily. People on medication should talk to a doctor before starting garlic supplements or concentrated drinks.

What people claim

Drinking garlic water, made by soaking crushed garlic in water, is promoted for blood pressure, immunity and digestion. Garlic contains allicin, formed when cloves are crushed, and a meta analysis of randomized trials found that garlic supplements lowered systolic blood pressure by around 8 mmHg in people with hypertension, though garlic water has not been studied the same way. Evidence for preventing colds is weak, with one Cochrane review finding insufficient evidence.

Side effects

Garlic can cause bad breath, heartburn, nausea and gas. It may increase bleeding risk, so people on blood thinners or planning surgery should consult a doctor. Raw garlic on an empty stomach can irritate the stomach lining. Allergic reactions are possible. Water soaked garlic stored at room temperature for long periods may grow bacteria, so keep it refrigerated and use within a day.

Nutrition and preparation

One clove of garlic (3 g) has about 4 calories and 5 mg of allicin potential once crushed. Allicin degrades in water and heat in hours. Garlic water made by soaking cloves overnight contains water soluble compounds in small amounts. Studies in people used aged garlic extract 600 to 1,200 mg per day.

Cautions

Raw garlic can burn the stomach and mouth. It may interact with saquinavir, other HIV medicines and blood thinners. Stop high dose supplements 7 to 10 days before surgery. Do not apply raw garlic to skin, as it can cause burns. Eating garlic cooked in meals is a safe way to get benefits.

Based on data from the National Center for Complementary and Integrative Health