Do you know someone who has a fishy body odor? Don’t be too quick to blame it on their personal hygiene – or lack of. A fishy body smell can be a sign of a condition called trimethylaminuria, a disease dubbed the fish odor syndrome.
What is Trimethylaminuria?
Trimethylaminuria is a syndrome where a person can’t break down chemicals called trimethylamines that come from foods containing choline and carnitine. These “fishy” chemicals are formed when a person eats choline and carnitine-containing foods such as legumes, eggs, fish and some meats. These chemicals build-up and are excreted through sweat and urine and via the lungs. This causes fishy breath odor and a noticeable fish body smell. The symptoms of trimethylaminuria, or fish odor syndrome, can fluctuate based on diet and hormonal fluctuations.
Needless to say, this condition is a handicap from a social perspective, and people with trimethylamiuria, although usually health from a physical standpoint, can experience mental stress and depression because of people’s reaction to their strong fishy body smell.
What Causes Trimethylaminuria?
People with fish odor syndrome lack the enzyme that breaks down trimethylamine. Trimethylamine is produced when bacteria in the intestines digest foods that contain choline or carnitine. The missing enzyme comes from a gene defect inherited as an autosomal recessive trait. In normal people who have this enzyme, trimethylamine is converted to an oxide, which is odorless.
Some normal people who take large doses of the amino-acid carnitine develop a fishy body odor, because they flood the body with so much carnitine that the enzyme that converts it to an odorless oxide is overwhelmed.
Is There a Treatment for Fish Odor Syndrome?
The treatment centers around avoiding foods that increase trimethylamine levels and reducing the bacteria in the intestines that convert these foods to trimethylamines. People with this condition should avoid any foods containing carnitine and choline since intestinal bacteria readily convert them to trimethylamines. Anyone who has this condition should get a comprehensive list of foods to avoid to reduce the fishy body odor.
Some doctors prescribe antibiotics for people with trimethylaminuria to lower the number of intestinal bacteria that convert the offending foods to trimethylamines.
Trimethylaminuria is a condition that can’t be cured, but avoiding foods that aggravate the condition can reduce the fishy body odor and make people with this condition feel more socially acceptable.
References:
Genetics Home Reference. “Trimethylaminuria”
Merck Manual. Eighteenth edition. 2006.
