Preti was a leading expert on human odors who sought to understand the chemistry of odor in the underarm and the behavior aspects of human scents, and an ambassador to patients suffering from rare metabolic diseases who provided communities worldwide with knowledge about their condition and how to cope with it. Preti was also dedicated to using odor biomarkers to detect cancer in its early stages, contributing both research and money to the cause, according to a Monell Center press release.
Born on October 7, 1944 in Brooklyn, New York, Preti received a bachelor’s degree in chemistry from the Polytechnic Institute of Brooklyn in 1966. He then went on to MIT, where he earned a PhD in chemistry in 1971. His thesis was titled, “A Study of the Organic Compounds in the Lunar Crust and in Terrestrial Model Systems,” according to the Monell Center’s statement. Preti coauthored a paper published in Science on the same topic, and reportedly saved a vial of “moon dust” that he sometimes showed off to visitors to his lab.
Upon completing his doctorate in 1971, he immediately accepted a postdoc at Monell and later become a member of the Monell Chemical Senses Center and an adjunct professor at the University of Pennsylvania School of Medicine. While Preti and his colleagues investigated a range of odors in different species—anal sac emissions from dogs, scent marks by marmoset monkeys, urine from guinea pigs and mice—Preti’s main focus was on the meaning of human odors. He studied the scents of human underarms and melanoma cells as well as the odors associated with generalized stress. Along with his collaborator, Charles Wysocki, Preti published papers on how human physiology and behavior are affected by body odor. Preti was skeptical of human pheromones and their associated hype, telling The Scientist in 2018, “I am not compelled by any studies that are out there that say there is an active steroid component from the underarm that causes [sexual attraction].”
In 1996, he published a study in PNAS that showed how odor from male underarms forms as a result of bacteria acting on glandular secretions that are bound to a protein and released into the air. Bad breath was another research focus for Preti, and he became an expert on trimethylaminuria, also known as fish malodor syndrome, in which patients lack an enzyme to break down the unpleasant smelling trimethylamine, which accumulates and is then released in their sweat, urine, breath, and reproductive fluids. He could often detect the metabolic disorders of strangers, sharing with The New York Times in 2013, “I often tell people I work with, ‘I bumped into the guy with isovaleric acidemia today.’” (The condition is associated with the smell of sweaty feet due to isovaleric acid build up).
“Body odor as a diagnostic function has a long history going back to Hippocrates,” Preti told Penn Today in a 2018 article exploring his research with dogs who were taught to “sniff out” early-stage ovarian cancer in blood samples. “And if you think about it, going back a couple thousand years, physicians didn’t have much beyond their own senses to diagnose a disease with.”
Preti was a member the Committee of Arts and Sciences for the Franklin Institute and on the Sensory Advisory Board for Fragrances and Oral Care for Symrise, Inc., according to the statement. He was also the executive editor of Chemosensory Perception and in 2002 was recognized by the American Chemical Society for his work in promoting chemistry to the general public.
Preti is survived by his wife, two children, a sister, and three grandchildren.
Amy Schleunes is an intern at The Scientist. Email her at email@example.com.