Drugs A - Z

Garlic (Allium sativum L.)

an herbal product - treats Atherosclerosis, Heart attack prevention in patients with known heart dis... more

Generic Name: garlic

Brand Names: Garlic Oil

Category

Herbs & Supplements

Synonyms

2-propenesulfenic acid, aged garlic extract, aglio, ail, ail commun, ajo, ajoene, akashneem, alisat, alk(en)yl thiosulfates, allicin, Allicor®, Allii sativi bulbus, alliinase, allium, allitridium, allyl mercaptan, alubosa elewe, Amaryllidaceae (family), ayo-ishi, ayu, banlasun, camphor of the poor, clove garlic, da-suan, dai toan, dasuan, dawang, diallyl, diallyl disulphide, diallyl sulfide, diallyl sulphide, diethyl disulfide, diethyl hexasulfide, diethyl monosulfide, diethyl pentasulfide, diethyl tetrasulfide, diethyl trisulfide, dipropyl disulphide, dipropyl sulphide, dra thiam, (E)-ajoene, foom, garlic clove, garlic corns, garlic extract, garlic oil, garlic paste, garlic powder extract, Gartenlauch, hom khaao, hom kia, hom thiam, hua thiam, Karinat®, kesumphin, kitunguu-sumu, knoblauch, kra thiam, Krathiam, krathiam cheen, krathiam khaao, Kwai®, Kyolic®, l'ail, lahsun, lai, la-juan, lasan, lashun, la-suan, lasun, lasuna, lauch, lay, layi, lehsun, lesun, Liliaceae (family), lobha, majo, methyl allyl, naharu, nectar of the gods, Ninniku, pa-se-waa, poor man's treacle, rason, rasonam, rasun, rust treacle, rustic treacles, S-alk(en)yl cysteine sulfoxide, S-allylcysteine (SAC), seer, skordo, sluon, stinking rose, sudulunu, tafanuwa, ta-suam, ta-suan, tellagada, Tellagaddalu, thiam, thioallyl derivative, thiosulfinates, toi thum, tum, umbi bawang putih, vallaippundu, Velluli, vellulli, verum, vinyl dithiin, vinyldithiin, (Z)-ajoene.

Background

Numerous controlled trials have examined the effects of oral garlic on serum lipids. Long-term effects on lipids or cardiovascular morbidity and mortality remain unknown. Other preparations (such as enteric-coated or raw garlic) have not been well studied.

Small reductions in blood pressure (<10 millimeters of mercury), inhibition of platelet aggregation, and enhancement of fibrinolytic activity have been reported, and may exert effects on cardiovascular outcomes, although evidence is preliminary in these areas.

Numerous case-control/population-based studies suggest that regular consumption of garlic (particularly unprocessed garlic) may reduce the risk of developing several types of cancer, including gastric and colorectal malignancies. However, prospective controlled trials are lacking.

Multiple cases of bleeding have been associated with garlic use, and caution is warranted in patients at risk of bleeding or prior to some surgical/dental procedures. Garlic does not appear to significantly affect blood glucose levels.

Evidence

DISCLAIMER: These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

High cholesterol: Multiple studies in humans have reported small reductions in total blood cholesterol and low-density lipoproteins ("bad cholesterol") over short periods of time (4 to 12 weeks). It is not clear if there are benefits after this amount of time. Effects on high-density lipoproteins ("good cholesterol") are not clear. This remains an area of controversy. Well-designed and longer studies are needed in this area.
Grade: B

Alopecia areata (hair loss): Application of garlic gel on the skin may be beneficial in the treatment of alopecia areata (hair loss). Additional study is needed.
Grade: C

Anti-fungal (applied to the skin): Several studies describe the application of garlic to the skin to treat fungal infections, including yeast infections. Take caution as garlic can cause severe burns and rash when applied to the skin of sensitive individuals.
Grade: C

Anti-platelet effects (blood thinning): The effects of garlic on platelet aggregation have been assessed in several human trials. Because garlic has been associated with several cases of bleeding, therapy should be applied with caution (particularly in patients using other agents that may precipitate bleeding).
Grade: C

Atherosclerosis ("hardening" of the arteries): Preliminary research in humans suggests that deposits of cholesterol in blood vessels may not grow as quickly in people who take garlic. It is not clear if this is due to the ability of garlic to lower cholesterol levels or to other effects of garlic.
Grade: C

Benign breast diseases: Taking garlic supplements by mouth may improve some symptoms of benign breast disease. Additional study is needed.
Grade: C

Cancer: Preliminary human studies suggest that regular consumption of garlic (particularly unprocessed garlic) may reduce the risk of developing several types of cancer including gastric and colorectal malignancies. Some studies use multi-ingredient products so it is difficult to determine if garlic alone may play a beneficial role. Further well-designed human clinical trials are needed to conclude whether eating garlic or taking garlic supplements may prevent or treat cancer.
Grade: C

Cryptococcal meningitis: Preliminary study documented potential benefits of oral plus intravenous garlic in the management of cryptococcal meningitis. Further research is needed before recommending for or against the use of garlic in the treatment of this potentially serious condition, for which other treatments are available.
Grade: C

Familial hypercholesterolemia: Familial hypercholesterolemia is a genetic disorder in which very high cholesterol levels run in families. Research in children with an inherited form of high cholesterol suggests that garlic does not have a large effect on lowering cholesterol levels in these patients.
Grade: C

Heart attack prevention in patients with known heart disease: It is not clear if garlic prevents future heart attacks in people who have already had a heart attack. The effects of garlic on cholesterol levels may be beneficial in such patients.
Grade: C

High blood pressure: Numerous human studies report that garlic can lower blood pressure by a small amount, but larger, well-designed studies are needed to confirm this possible effect.
Grade: C

Infections (bacterial, viral, fungal, other): In initial studies, garlic has been shown to be effective against bacteria, mycobacteria, viruses, and fungi. Small studies have been conducted using garlic for acute viral respiratory infections in children. Other studies have shown that garlic may have some effect on athlete's foot. More high-quality human studies are necessary to recommend garlic to treat or prevent infections.
Grade: C

Oral candidiasis: There is not enough evidence to suggest garlic is effective in the treatment of oral candidiasis.
Grade: C

Mosquito repellant: There is currently not enough evidence to suggest that garlic helps repel mosquitoes.
Grade: C

Peripheral vascular disease (blocked arteries in the legs): Some human studies suggest that garlic may improve circulation in the legs by a small amount, but this issue remains unclear. Better-designed studies are needed.
Grade: C

Pre-eclampsia (prevention): There is not enough evidence to recommend increased garlic intake for preventing pre-eclampsia and its complications.
Grade: C

Sickle cell anemia: Initial evidence suggests the antioxidant activity of garlic may benefit sickle cell anemia. Further study is necessary.
Grade: C

Systemic sclerosis: There is insufficient evidence to recommend the use of garlic in systemic sclerosis.
Grade: C

Tick repellant: In early study, self-reports of tick bites were significantly less in people receiving garlic over a placebo "sugar" pill. Further well-designed study is needed to confirm these results.
Grade: C

Upper respiratory tract infection: Preliminary reports suggest that garlic may reduce the severity of upper respiratory tract infections. However, this has not been demonstrated in well-designed human studies.
Grade: C

Diabetes: Animal studies suggest that garlic may lower blood sugar and increase the release of insulin, but studies in humans do not confirm this effect.
Grade: D

Stomach ulcers caused by Helicobacter pylori bacteria: Early studies in humans show no effect of garlic on gastric or duodenal ulcers.
Grade: D

Licensed from
The Healthline Site, its content, such as text, graphics, images, search results, HealthMaps, Trust Marks, and other material contained on the Healthline Site ("Content"), its services, and any information or material posted on the Healthline Site by third parties are provided for informational purposes only. None of the foregoing is a substitute for professional medical advice, examination, diagnosis, or treatment. Always seek the advice of a physician or other qualified healthcare provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on the Healthline Site. If you think you may have a medical emergency, call your doctor or 911 immediately. Please read the Terms of Service for more information regarding use of the Healthline Site.
Advertisement