What Causes Garlic Breath?
By Susan Fluegel, PhD
Love garlic but hate garlic breath? Don't worry, you are not alone. There are foods that can help reduce that garlic smell.
Garlic contains a high concentration of volatile sulfur compounds. While these compounds have many health benefits they also have a very distinct odor which can cause bad breath. The garlic compounds mainly to blame for stinky breath include allyl mercaptan, diallyl disulfide, methyl mercaptan, and allyl methyl sulfide. When garlic breath persists for hours after the meal you can blame allyl methyl sulfide which originates in the gut. Unlike other garlic compounds, allyl methyl sulfide is not metabolized very rapidly by the gut and liver so it tends to linger (Suarez et al. 1999).
Got Garlic Breath? Try Milk!
Drinking whole or fat free milk before, during or after a high octane garlic meal can reduce garlic breath. Hansanugrum and Barringer (2010) found that drinking milk lowered the concentration of garlicky sulfur odor-emitting compounds in the nose and mouth.
Why does milk neutralize garlic breath?
Milk deodorized the sulfur compounds that make garlic stink including diallyl disulfide, allyl methyl disulfide, allyl mercaptan, allyl methyl sulfide, and methyl mercaptan. Whole milk and fat free milk both worked to combat the garlicky smell, however, whole milk worked the best on hydrophobic garlic compounds diallyl disulfide and allyl methyl disulfide because of its fat (fat can dissolve hydrophilic compounds).
When should the milk be drunk?
For best results drink whole milk before the meal containing garlic. Drinking milk during or after a meal also helps.
Want to know more about the benefits of milk? Check out my website on the health benefits of milk and dairy at MooScience.com.
What else helps prevent garlic breath?
Plain water: According to Hansanugrum and Barringer (2010) plain water helps prevent garlic breath. It decreases the volatility of the more hydophilic or water soluble garlic compounds allyl mercaptan, allyl methyl sulfide, and methyl mercaptan. These compounds can dissolve in water.
Hydrogen peroxide: Hydrogen peroxide used as an oral rinse significantly reduces sulfur gas concentrations of hydrogen sulfide, methanethiol, and dimethylsulfide (Suarez et al. 2000). Brushing the teeth and tongue with hydrogen peroxide will also help reduce sulfur and bacterial odors.
Green tea: Lodhia et al. (2008) reported that both green tea and toothpaste reduced the concentrations of volatile sulfur compounds in the mouth (such as H2S and CH3SH). However, this study was focused on reducing halitosis and did not address lingering food odors. Green tea kills some of the bacteria that cause bad breath and dental caries (cavities) (Sasaki et al. 2004).
Picture: Eggplant may help cut the odor of garlic. Three Chesnok Red garlic bulbs wait next to a helpful eggplant.
Other compounds that may reduce garlic breath include prunes, basil, burdock, eggplants, and some species of mushrooms (Negishi and Negishi 1999; Negishi et al. 2002). The odor of garlic compound, diallyl disulfide, was reduced by cow milk, raw egg, boiled rice, kiwi fruit, spinach, cutting lettuce, parsley, basil, and mushrooms. These foods were tested on garlic compounds in vitro (in a petri dish) so they may not be as effective when consumed. The fruits and vegetables were not very effective against diallyl disulfide, one of the smellier garlic compounds. These foods reduced diallyl disulfide concentrations by 27-73%. Milk reduced diallyl disulfide concentrates by 95%. Negishi et al. (2002) reported that milk neutralized allium sulfide and disulfide volatiles such as propyl mercaptan, dipropyl sulfide, diallyl sulfide, dipropyl disulfide, and dimethyl disulfide.
How Does Food De-Stinkify Garlic?
Food deodorization of smelly garlic breath occurred through multiple mechanisms. These include chemical and physical interactions between volatile garlic sulfur compounds and different foods, enzymatic degradation of disulfides, and the addition of thiols to polyphenolic food compounds which is catalyzed by polyphenol oxidases or peroxidases.
- Areerat Hansanugrum, Sheryl A. Barringer. 2010. Effect of Milk on the Deodorization of Malodorous Breath after Garlic Ingestion. Journal of Food Science 75: C549. Pubmed. doi: 10.1111/j.1750-3841.2010.01715.x
- Lodhia P, Yaegaki K, Khakbaznejad A, Imai T, Sato T, Tanaka T, Murata T, and Kamoda T. Effect of green tea on volatile sulfur compounds in mouth air. J Nutr Sci Vitaminol. 2008. 54: 89-94. Pubmed. Full text.
- Negishi O, Negishi Y. 1999. Enzymatic deodorization with raw fruits, vegetables and mushrooms.
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- Negishi O, Negishi Y, Ozawa T. 2002. Effects of food materials on removal of Allium-specific
volatile sulfur compounds. J Agric Food Chem 50:3856–61. Pubmed.
- Sasaki H, Matsumoto M, Tanaka T, Maeda M, Nakai M, Hamada S, Ooshima T. Antibacterial activity of polyphenol components in oolong tea extract against Streptococcus mutans. Caries Res. 2004;38:2-8. Pubmed.
- Suarez FL, Furne JK, Springfield J, Levitt MD. Morning breath odor: influence of treatments on sulfur gases. J Dent Res. 2000;79:1773-7. Pubmed.
- Suarez F, Springfield J, Furne J, Levitt M. Differentiation of mouth versus gut as site of origin of odoriferous breath gases after garlic ingestion. Am J Physiol. 1999; 276:G425-30. Pubmed. Full text.