Study Shows Fish Odor Syndrome May Be More Common Than Thought
By Denise Mann
WebMD Health News
Reviewed by Laura J. Martin, MD
Sept. 15, 2011 -- Imagine showering all you can, using deodorant, essentially being squeaky clean, yet your body odor still resembles fish, or maybe even garbage.
For some people, it's an unwelcome reality. It's called "fish odor syndrome," but it's technically a genetic condition called trimethylaminuria. And it may be a lot more common than previously believed.
Until now, this condition was thought to be relatively rare, affecting less than 200,000 people in the U.S. But scientists from the Monell Chemical Senses Center in Philadelphia now report that about one-third of people who report such body odor may have the metabolic disorder trimethylaminuria (TMAU).
The findings appear in the American Journal of Medicine.
"It is not as uncommon as people may have thought," says study researcher George Preti, PhD, an organic chemist at Monell. The good news is that once it is diagnosed, changes to your diet can all but eliminate this foul, fishy odor.
What Is TMAU?
TMAU is a genetic disease. A specific, hereditary gene hinders the body's ability to break down trimethtylamine (TMA), which is found mainly in choline-rich foods such as:
- Wheat germ
- Saltwater fish
- Organ meats such as livers, brains, and hearts
- Certain legumes
To put it bluntly, when excess TMA builds up in your body, you stink. It's released via sweat, urine, and breath.
Levels of TMA and the odor it produces wax and wane based on what a person eats and when they eat it, Preti says. "Even in the most severe cases, you only have the odor when you eat choline foods such as refried beans and eggs."
This makes testing a challenge. What's more, there is no readily available test to measure levels of TMA in urine. But there are reportedly a few labs in the U.S. that can test for the condition, including Monell.
The new study included 353 people who had come to Monell due to unexplained, distressing odor. Researchers tested participants' urine levels for TMA after they ate choline-rich foods. Of these, 118 had higher levels of the chemical in their urine. As many as 65% of people in the study did not have this disease.
There is something fishy about calling it fish odor syndrome, too, Preti says. Not everyone with TMAU smells like fish.
"That's hooey," he says. Only people with severe cases smell like rotten fish, and even they don't smell all the time, he says. In the study, just 3.5% of people complained of the "fishy" odor.
The treatment is to avoid eating foods that are rich in choline, Preti tells WebMD.
In some cases, antibiotics may help. "If you are attending a special event or wedding and know you will be eating and not watching what you eat, consider antibiotics," he says.
The findings suggest that TMAU is more common than we anticipated, says Alan Hirsch, MD, director of the Smell and Taste Treatment and Research Foundation in Chicago.
"These people say that they have a bad smell from one area of their body and you can't convince them otherwise," he says. "These people shower 12 to 15 times a day and have been to so many doctors."