Smell and taste researcher Dr. Alan Hirsch has long argued that certain aromas can help people lose weight, improve athletic performance or increase sexual arousal. One of his studies found that the smell of buttered popcorn or strawberries helps exercisers burn more calories, another that a whiff of jasmine can improve bowlers' scores.
Hirsch's boldest and most controversial research finding, however — that sprinkling flavored granules on food can help people lose weight without diet or exercise — is one he can no longer advertise.
This month the Federal Trade Commission announced it had reached a $26.5 million settlement with the marketers of Sensa Weight Loss System after accusing the company and Hirsch of false and deceptive advertising practices.
Hirsch, who patented Sensa's "tastant" crystals and holds an ownership stake in Sensa Products, is barred under the agreement from making weight-loss claims about dietary supplements, food or drugs unless they are backed up with two adequate and well-controlled human clinical trials.
The decision represents a highly public rebuke for Hirsch, a neurologist and psychiatrist who operates the Smell & Taste Research and Treatment Foundation in Chicago and describes himself as "one of the nation's foremost experts on smell and taste."
A popular, engaging speaker, Hirsch is frequently quoted in national newspapers, magazines and on television about his latest research conclusions on provocative and entertaining topics such as how people's food preferences can help them find true love. His seven books include "What Flavor is Your Personality?" and "Scentsational Sex."
His foundation's website states that Hirsch has conducted and published more than 200 research projects on sensory disorders and how certain smells and tastes affect mood, perception and behavior. But a Tribune review found that few of Hirsch's original studies on sensory stimuli were published in peer-reviewed medical journals, and many of his conclusions are based on small studies with questionable or unclear methodology.
"The journals that Hirsch publishes his actual studies in are low-impact, obscure journals," said R. Barker Bausell, a retired University of Maryland biostatistics professor and expert on clinical research design, after reviewing a sample of Hirsch's published work. "He does not supply sufficient details to evaluate his studies and he seems to have little understanding of research design."
The foundation website states that Hirsch has published work in several major journals, including the Journal of the American Medical Association, Neurology and the American Journal of Psychiatry. But those contributions are limited to book reviews, commentaries or letters to the editor. The site lists three current research projects with NASA, but a spokesman for the space agency said a records search turned up no work with Hirsch in at least 15 years.
In addition, court records show that judges in three lawsuits excluded Hirsch's testimony as an expert witness.
Hirsch did not respond to repeated requests for comment for this story; his office said he might have time in the spring or early summer. "Unfortunately, due to Dr. Hirsch's hectic, overwhelming schedule, he is not currently available to conduct an interview with you," an administrator at the foundation wrote in an email.
Sensa Products didn't respond to specific questions. In a statement, the company said the settlement involves no admission of wrongful conduct by Sensa and does not challenge the product's safety. "The company has invested millions of dollars in clinical research," the statement said. "With over 3 million customers, Sensa helps users engage in portion control."
Before the FTC settlement, the crystals were marketed as "clinically proven to cause substantial weight loss without dieting or exercise, averaging 30 pounds in six months," based on two of Hirsch's studies. Sensa racked up $364 million in U.S. sales from 2008 to 2012; a two-month starter kit sells for $118.
The FTC charged that the product had no clinical evidence to support it and cited major flaws with Hirsch's research, including the lack of placebo controls.
"The man is making money preying on patients who are desperate to lose weight, with very little tools to help them that are safe and effective," said Dr. Caroline Apovian, director of the Nutrition and Weight Management Center at Boston Medical Center and an expert in drugs that promote weight loss.
Some colleagues in the world of smell and taste research say Hirsch has brought much-needed attention to a field that is often overshadowed by the other senses and neglected in medical school training.
"He is a controversial figure," said Dr. Richard Doty, an olfactory researcher and the director of the University of Pennsylvania's Smell and Taste Center. "A number of members of the scientific community have felt that his research isn't as strongly grounded in solid science as one would like. But I find him an interesting person, an intriguing individual, and I try to focus on that. He has gone places no (other researchers) have been willing to go."
Hirsch, 58, opened the Smell & Taste Treatment and Research Foundation in 1987. The neuropsychiatrist is affiliated with Rush University Medical Center. The foundation website also describes him as a member of the medical faculty at Mercy Hospital and Medical Center, but a spokeswoman said Hirsch "does not actively practice" at Mercy and "does not function in a type of faculty or teaching role."
His research interests are wide ranging. In one of his better-known studies, Hirsch piped pleasant but different aromas into two separate areas near slot machines at a Las Vegas casino and found that one of the two odorants seemed to enhance the gambling mood of casino patrons.