Fishy body odor (trimethylaminuria)

Originally Published: September 11, 2009
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Dear Alice,

After many years of confusion, I have been diagnosed with trimethylaminuria. It is an awful disease that has caused much emotional pain in my life. I was hoping that if the disease was discussed on your site that people's awareness may increase and perhaps people would not be quite so quick to judge others. I would appreciate it if you could post my message for this reason. Also, if the disease is caused by the lack of a certain hormone in my body, then would an injection of this hormone be a possible solution? In all of my research, I have not seen this discussed.

Dear Reader,

You are not alone in feeling pained by this unusual disorder. Many people who suffer from trimethylaminuria, known colloquially as "fish malodor syndrome," also suffer from depression as a result of disruptions trimethylaminuria can cause to social life, relationships, or career. It may be beneficial to seek counseling to learn ways of dealing with feelings of social isolation and embarrassment this genetic condition can sometimes trigger.

Trimethylaminuria is an uncommon genetic disorder (currently there are about two hundred cases of the condition reported world-wide) in which the body can't break down trimethylamine, a naturally occurring dietary compound. The condition is related to mutations in the FMO3 gene, which normally produces an enzyme that converts fishy-smelling trimethylamine into an odorless molecule. But when the FMO3 gene isn't working properly and trimethylamine is not processed, it can accumulate and cause the body, breath, sweat, and urine to smell strongly like fish.

Trimethylaminuria seems to be more common in women than in men. Some scientists chalk this up to female sex hormones like progesterone and/or estrogen — several reports suggest that the condition worsens around puberty, before and during menstrual periods, and after taking oral contraceptives; all times when female hormones are high. Researchers also believe that stress and diet can play a role in triggering symptoms. To help decrease the symptoms of trimethylaminuria, you may want to try:

  • Avoiding foods containing trimethylamine and its precursors like:
    • Milk obtained from wheat-fed cows
    • Eggs
    • Liver
    • Kidney
    • Peas
    • Beans
    • Peanuts
    • Soy products
    • Brassicas (brussel sprouts, broccoli, cabbage, and cauliflower)
    • Lecithin and lecithin-containing fish oil supplements
    • Seafood (Freshwater fish have lower levels of trimethylamine N-oxide)
  • Taking low doses of antibiotics to reduce the amount of bacteria like trimethylamine in the gut
  • Taking activated charcoal or other supplements to decrease the concentration of free trimethylamine in the urine
  • Using body soaps with a moderate pH, between 5.5 and 6.5
  • Taking riboflavin (vitamin B2) supplements to enhance FMO3 enzyme activity. Recommended intake is 30 to 40mg taken 3 to 5 times per day with food.
  • Avoiding factors that promote sweating, such as exercise, stress, and emotional upsets.

Although the condition is caused largely by a missing enzyme, at this time replacement therapy for FMO3 is not an option. While the above suggestions may help some, it is important that people with trimethylamuinuria develop a treatment plan with their primary health care providers rather than trying to treat themselves. Mixing medications and supplements can have undesirable results, and dietary restrictions can result in nutritional deficits. It's especially important for pregnant and breast-feeding women to consult with their health care providers before restricting their diets to temper the effects of trimethylamuinuria. Columbia students can meet with a health provider through Health Services. To make an appointment you can call x4-2284 or log in to Open Communicator.

Dealing with trimethylamuinuria can be emotionally painful and isolating, but therapy and appropriate medical treatment can prove really helpful in alleviating some of its symptoms and repercussions. You've made great progress already by investing time to solve your mystery, dealing with some of the emotional issues, and seeking to share information and your experience. All the best going forward!