Favorite Answer

Garlic is known for causing halitosis as well as causing sweat to have a pungent 'garlicky' smell which is caused by allyl methyl sulfide (AMS). AMS is a gas which is absorbed into the blood during the metabolism of garlic; from the blood it travels to the lungs[citation needed] (and from there to the mouth causing bad breath) and skin where it is exuded through skin pores. Washing the skin with soap is only a partial and imperfect solution to the smell. Studies have shown that sipping milk at the same time as consuming garlic can significantly neutralize bad breath. Mixing garlic with milk in the mouth before swallowing reduced the odor better than drinking milk afterward. Plain water, mushrooms and basil may also reduce the odor, however, the mix of fat and water found in milk was the most effective.

Raw garlic is more potent; cooking garlic reduces the effect.[citation needed] The green dry 'folds' in the center of the garlic clove are especially pungent. The sulfur compound allicin, produced by crushing or chewing fresh garlic produces other sulfur compounds: ajoene, allyl sulfides, and vinyldithiins. Aged garlic lacks allicin, but may have some activity due to the presence of S-allylcysteine.

In a rat study, allicin, was found to be an activator of TRPA1. The neurons released neurotransmitters in the spinal cord to generate pain signals and released neuropeptides at the site of sensory nerve activation, resulting in vasodilation as well as inflammation.[Allicin is released only by cruching or chewing raw garlic and cannot be formed from cooked garlic. This explains short term back pain when garlic is eaten raw.

Some people suffer from allergies to garlic and other plants in the allium family. Symptoms can include irritable bowel, diarrhea, mouth and throat ulcerations, nausea, breathing difficulties, and in rare cases anaphylaxis. Garlic-sensitive patients show positive tests to diallyl disulfide, allylpropyldisulfide, allylmercaptan and allicin, all of which are present in garlic. People who suffer from garlic allergies will often be sensitive to many plants in the lily family (liliaceae), including onions, garlic, chives, leeks, shallots, garden lilies, ginger, and bananas.

Garlic can also cause indigestion, nausea, vomiting, and diarrhea. It thins the blood (as does aspirin);this had caused very high quantities of garlic and garlic supplements to be linked with an increased risk of bleeding, particularly during pregnancy and after surgery and childbirth,although culinary quantities are safe for consumption. There have been several reports of serious burns resulting from garlic being applied topically for various purposes, including naturopathic uses and acne treatment, so care must be taken to test a small area of skin using a very low concentration of garlic. On the basis of numerous reports of such burns, including burns to children, topical use of raw garlic, as well as insertion of raw garlic into body cavities, is discouraged. In particular, topical application of raw garlic to young children is not advisable. The side effects of long-term garlic supplementation, if any exist, are largely unknown, and no FDA-approved study has been performed. However, garlic has been consumed for several thousand years without any adverse long-term effects, suggesting that modest quantities of garlic pose, at worst, minimal risks to normal individuals. Possible side effects include gastrointestinal discomfort, sweating, dizziness, allergic reactions, bleeding, and menstrual irregularities. The safety of garlic supplements had not been determined for children. some breastfeeding mothers have found their babies slow to feed and have noted a garlic odour coming from their baby when they have consumed garlic.

Garlic may interact with warfarin, antiplatelets, saquinavir, antihypertensives, calcium channel blockers, and hypoglycemic drugs, as well as other medications. Members of the alium family might be toxic to cats or dogs. Some degree of liver toxicity has been demonstrated in rats, particularly in extremely large quantities exceeding those that a rat would consume under normal situations.