Aromaric garlic
virusowy/E+/GettyImages

Garlic is a delicious ingredient added to Italian food and other aromatic dishes like soups, curries and beef dishes in Chinese and Indian cuisine. It's a bulb in the allium vegetable family, similar to onions, that has grown all over the world for more than 5,000 years. While eating prepared dishes with cooked garlic is perfectly safe in most cases, consuming, dosing and applying too much garlic – be it raw, garlic pills or garlic supplements – can have serious effects on one's health. When consumed in moderation, garlic is proved to have some wonderful benefits, but too much garlic can cause negative side effects. Most people should aim to consume 600 to 900 milligrams of garlic per day or roughly one half of a clove, assuming the average clove is generally close to three grams.

Side Effects of Garlic

While eating both raw and cooked garlic is generally safe, taking garlic pills and garlic supplements can have negative side effects. Of course eating garlic can result in bad breath, and eating too much garlic can cause nausea, vomiting, heartburn and gas. These symptoms largely come into effect when consuming raw garlic. Garlic is not only eaten, it can be applied to the skin in both prepared products and raw. When applied to the skin, damage similar to a burn can occur.

Garlic pills or supplements can cause negative effects when used over long periods of time. Other more serious effects to consider are liver damage, aggravated yeast infections and even an increased likelihood of bleeding. Consult a doctor before adding garlic pills or supplements to your daily diet.

Benefits of Garlic

While the list of illnesses and ailments that garlic has been said to cure is long, only some have been proved to be beneficially affected by the use of garlic. Eating most of a clove of garlic each day – around two and a half grams – may help cure or fend off the common cold. Garlic supplements are sometimes used as a means of lowering blood pressure, thanks to the active compound, acillin. The bulb is also promising for lowering cholesterol, which can help reduce the risk of heart disease. Some homeopathic doctors believe that diabetes is positively impacted by using garlic to lower blood sugar levels after eating. Minor health issues that can benefit from garlic include preventing tick bites and treating ringworm and jock itch as an antifungal medication.

Precautions to Take When Consuming Garlic

While consulting a doctor is always important when taking medications and supplements, certain combinations of drugs with garlic supplements should be carefully considered before dosing. Some results are more serious than others, but precaution is important before combining any two or more medications.

Serious medical interactions: Three key medications are highly reactive to garlic. Isoniazid, an antibiotic used to treat tuberculosis, may be less effective when combined with garlic because the body absorbs less of the antibiotic. Medications used to treat HIV/AIDS are broken down by the body, and when taken with garlic, the body breaks down those drugs more quickly, making them less effective. Also, the body breaks down saquinavir, an antiretroviral medication used with other HIV/AIDS drugs to treat or prevent the disease by removing the virus from the body. Yet again, the combination with garlic may limit the effectiveness of the drug by increasing how fast the body breaks it down.

Moderate medical interactions: Though less serious, combinations of garlic with estrogen-based birth control and medications changed by the liver can also be less effective. Once again, garlic increases the speed with which the body processes the drugs, which gives them less time to take effect. Medications that slow blood clotting, such as baby aspirin, can increase the chances of bruising and bleeding when combined with garlic. Avoid taking this combination, if you are prone to cuts or are facing surgery in the near future.