People have used garlic for thousands of years as a food, spice and medicinal herb. You might take garlic to prevent head colds, as well as treat or prevent cardiovascular diseases and infections. Consult your doctor before taking garlic for head colds to discuss the possible health dangers and drug interactions, as well as the correct dosage. No widely accepted medical research confirms the use of garlic for common colds or any other health condition, however.
Benefits
Garlic has a wide variety of holistic medicinal benefits, including preventing and treating head colds. Garlic might also help if you have heart disease or atherosclerosis, yeast infections, ear infections, hypertension, immune system dysfunction, athlete's foot, high cholesterol and triglycerides, intermittent claudication, parasitic infections, sickle cell anemia or stomach ulcers. Garlic also has the potential to prevent or treat stomach, colon and esophageal cancers, says the University of Michigan Health System. Garlic is sometimes used a topical antibiotic as well.
Function
Garlic contains the active constituent called allicin, which accounts for may of the herb's potential medicinal benefits. Allicin is a powerful antibiotic and appears to boost the immune system's function in fighting or inhibiting viruses that cause the common cold, explains the Memorial Sloan-Kettering Cancer Center. Allicin and other important constituents in garlic have antibacterial and antiviral actions.
Dosage
You could eat one or two raw garlic cloves each day, or you might take 600 to 900 mg of garlic capsules or tablets each day containing 1.3-percent allin, says the University of Michigan Health System. If you take garlic pills to treat or prevent head colds, you should divide this amount into two or three separate doses. Ask your doctor about the garlic dosage that's right for you before taking any garlic supplement for common colds.
Scientific Evidence
Test-tube studies published in "Phytotherapy Research" in 1991 found that garlic has antifungal, antibacterial and antiviral actions, says the University of Michigan Health System. A Russian study in 2003 discovered that taking garlic tablets prevented respiratory viral infections such as colds in children. A 2001 three-month, double-blind clinical trial published in "Advances in Therapy" also discovered that taking garlic extracts reduced the study subjects' chances for contracting head colds, notes the University of Pittsburgh Medical Center.
Warnings
Because garlic is a common spice and food throughout the world, it's generally considered safe, but it could cause certain side effects, health risks and drug interactions in some people. While taking garlic, you might experience gastrointestinal upset, sweating, fatigue and headaches, notes the Memorial Sloan-Kettering Cancer Center. Garlic can inhibit your blood platelets' ability to form clots, so you shouldn't take garlic without first consulting a health-care professional if you have a bleeding disorder like hemophilia or are taking anticoagulants like Coumadin or aspirin. You could also have bleeding risks if you take garlic with ginkgo or high-dose vitamin E supplements, notes the University of Pittsburgh Medical Center. Garlic can also have negative interactions with HIV medications, as well as insulin or other medications for diabetes that lower your blood sugar levels.
