It's commonly asserted that 99 percent of all bad breath comes from oral bacteria, with plenty of cases being aggravated by smelly foods or tobacco use. However, a very small fraction of oral odor cases come from physiological disorders - like trimethylaminuria (try-METH-ull-uhm-in-YOUR-ee-uh), an inherited condition that prevents the metabolism of a particular molecule. This is one of the rarest causes of halitosis.
The UK Daily Mail recently featured Claire Rhodes, a 34-year-old mother who resorted to a restrictive diet in order to eliminate her trimethylaminuria odor. It's hard to blame her. After all, the condition causes people to have bad breath and body odor that both smell distinctly like fish.
How common is this condition? Doctors aren't sure. It's an inherited disorder, and according to a pair of researchers from London, between 0.5 and 1 percent of adults carry one copy of the gene that causes it. However, far fewer people have two copies, which results in an actual case of trimethylaminuria.
If you have this condition, your body cannot process trimethylamine, a naturally occurring molecule that can be found in foods like fish, milk and eggs. Because of this problem, people with trimethylaminuria exude sweat and oral odor that smell like fish.
As the Daily Mail reported, restrictive diets that rely on fruits and vegetables can result in improvements, as was the case for Rhodes. However, this is not a sure thing. Currently, researchers are also looking into charcoal-based dietary supplements, which have been found to help people with the condition reduce their odor levels.
Trimethylaminuria is one of the most uncommon causes of halitosis, but that doesn't mean that people with the disorder (as well as everyone else) can't benefit from using specialty breath freshening products. An all-natural mouthrinse or dye-free toothpaste can help relieve even the worst case of oral odor.