Why Garlic Is the Bad Breath King
Nov. 27, 1999 (Atlanta) -- Mama mia! Who doesn't love a good lasagna,
or a big bowl of pasta with a healthy helping of marinara sauce? And after
indulging, who hasn't stood at the bathroom sink, trying to brush, floss, and
gargle away the dreaded garlic breath? Why, oh why, we wonder, does it seem to
return, to haunt us long after the last meatball has been consumed?
Researchers at the University of Minnesota, in Minneapolis, explain the
basis for 'garlic breath' in a study published in the American Journal of
"When you eat garlic you produce several sulfur-containing gases,"
lead researcher Fabrizis Suarez, MD, PhD, tells WebMD. "But what we found
is most of the sulfur-containing gases, with exception of one, [are of oral
origin]. AMS [allyl methyl sulfide] is the only one that is not metabolized by
[intestine] or the liver, and this is why this gas can go back and be released
in your mouth. It's coming from the [gut], not from the mouth, and that is what
gives you the odor that you have after you eat garlic." Suarez is an
assistant professor at the University of Minnesota and on the staff at the
Minneapolis VA Medical Center.
"This paper gives us the idea that sometimes you can have halitosis --
if you want to call the odor of garlic 'halitosis' -- that can come from the
intestine instead of your mouth," he says. "But in most cases, the
gases [that cause] halitosis are coming from your mouth, from the bacteria that
is [on] the tongue."
Suarez and colleagues tested the mouth air, lung air, and urine from five
healthy volunteers (with no history of halitosis) on two separate occasions. On
one day they were given 6 grams of raw garlic to eat, on the other day no
garlic was eaten. On the day when no garlic was eaten, the researchers detected
low levels of three sulfur-containing gases in the mouth air, indicating that
the mouth usually contains low concentrations of these gases. In contrast, when
garlic was eaten, the researchers found higher concentrations of those three
gases, plus two other sulfur-containing gases. For all gases except allyl
methyl sulfide, the concentration of gas was much higher in the mouth air than
in the lung air or the urine, suggesting that they originate in the mouth.
"Conversely, AMS concentrations in mouth air remained high for the four
hours after garlic ingestion and were similar to levels in the alveolar [lung]
and urine samples, indicating that this gas had undergone absorption form the
gut and was being released from systemic sites," write the authors. In
other words, the gas was going into the blood, circulating around the body, and
being excreted in the breath and urine.