Paul Giamatti’s ‘Holdovers’ character smells like fish. That’s a real condition, with a Philly backstory

In The Holdovers, Oscar-nominated actor Paul Giamatti plays cantankerous boarding-school teacher Mr. Hunham, who reveals that he struggles with body odor due to a condition called trimethylaminuria.

It’s a real condition, and for decades, a Philadelphia scientist was one of the world’s leading experts.

George Preti, a chemist at the Monell Chemical Senses Center who died in 2020, developed a test to diagnose TMAU, and he also advised patients how they could reduce their fishlike body odors by altering their diets.

Though not a physician, Preti would even render an unofficial diagnosis after smelling people who came to his lab seeking relief, recalled colleague Dani Reed, chief science officer at the independent research institute in West Philadelphia.

He did it because patients often have difficulty finding physicians with expertise, said Reed, a geneticist. The condition has no impact on the patient’s health, so it falls between the cracks of traditional medical specialties, she said. But it nevertheless can be socially debilitating, often leaving people desperate for answers.

“It’s really a lonely, lonely condition,” she said. “There’s no health consequences other than the smell that we’re aware of. It just never got traction in the medical community.”

The movie does a good job of describing the science behind trimethylaminuria (pronounced tri-methull-ami-NOOR-ee-ah), Reed said. When a student bluntly asks Giamatti’s character about his body odor, the teacher correctly describes it as a metabolic disorder that prevents him from breaking down a pungent byproduct of digestion called trimethylamine.

One of the first scientific descriptions of the condition was published in 1970, around the time the events in the movie are said to take place. But sporadic references to this type of malodor have occurred in popular culture for centuries. In The Tempest, Shakespeare described Caliban as having “a very ancient and fishlike smell.”

The inability to break down trimethylamine is associated with various genetic mutations, several of which Reed discovered in a 2017 study with Preti.

The biological chain of events leading to the unusual body odor starts with an essential nutrient called choline, which is especially prevalent in eggs, liver, certain seafoods, and legumes such as soybeans.

Bacteria in the large intestine break down this nutrient into smelly trimethylamine, which in most people is then metabolized into a non-odorous substance by an enzyme in the liver.

But people with trimethylaminuria have a faulty version of that enzyme, so the odorous substance is excreted in their urine, sweat, saliva, and breath.

Preti developed a urine test for diagnosing the condition. Patients would eat foods rich in choline, then they provided a urine sample that Preti sent to a testing lab in Colorado.

People who test positive for the condition have several options. One is to limit foods rich in choline, but that should be done only with expert supervision, as a choline deficiency can harm the liver and lead to other medical consequences.

Preti also recommended a dietary supplement called copper chlorophyllin complex, which can help absorb excess trimethylamine.

“He helped thousands of people,” Reed said of Preti. “He was not the first to do anything about this, but he was the best.”

Since Preti’s death, Reed continues to get requests for help as often as once a week. She now refers inquiries directly to the lab in Colorado. (Information on how to contact the lab, at Children’s Hospital Colorado, can be found at monell.org/tmau. Testing is done only with a request from an authorized provider.)

While the condition is described correctly in The Holdovers, Reed has one quibble. It is rare in men, especially white men like the character played by Giamatti. Exact numbers are hard to come by, but the condition is far more common in women and Black people, she said.

The strength of the odor varies from person to person, and it can come and go throughout the day. For women, the odor can fluctuate as the result of hormones. While the condition is commonly referred to as “fish odor syndrome,” in some people the odor is closer to that of smoke.

Reed said she and other scientists who know about the condition were curious as to how it came to be included in the film. She speculated that perhaps someone involved in making the movie had a personal connection to the disorder. The filmmakers did not respond to a media request for comment.

The Holdovers was nominated for five Academy Awards, including Giamatti’s nomination for best actor and Philadelphia native Da’Vine Joy Randolph as best supporting actress.

The movie also is a candidate for best picture, best original screenplay, and best film editing.