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.
Hirsch released the unpublished results to the media in 1992. The study, titled "Effect of an Ambient Odor on Slot Machine Usage in a Las Vegas Casino," was listed by Hirsch as published in Chemical Senses and Biological Psychiatry in 1993 and in Psychology & Marketing in 1995, all peer-reviewed journals.
Bausell found Hirsch's casino study the "most interesting" of those he reviewed. He added: "It might be true or it might not be. ... There could be other explanations for the results if they were true. Perhaps people were saying to each other, 'Did you smell that stuff over in the next aisle?' thereby generating a curiosity migration."
Hirsch's research has placed him in demand as a consultant to industry. In June, a news release announcing a partnership with Gain laundry detergent quoted Hirsch as saying: "My studies have shown that fresh-smelling clothes induce people to feel happier and more optimistic and may also affect, in a positive way, how they are perceived by others."
Last year he delivered the keynote address at the scent marketing industry's ScentWorld conference, titled "Research into Action: From Science to Market Implementation."
"He's certainly creative and a superb publicist," Doty said.
Some credit Hirsch with being the first to raise alarms about a possible link between a popular cold remedy and anosmia, or loss of smell. According to court documents, Hirsch told the manufacturer of Zicam nasal gel, Matrixx, in a 1999 call that applying zinc in the nasal area had been found to be problematic and that at least one of his patients had developed anosmia after using Zicam. A decade later, the U.S. Food and Drug Administration warned consumers about reports of smell loss associated with three specific Zicam products containing zinc.
But in a 2006 court case in which a Michigan man claimed he lost his sense of smell after using Zicam, U.S. Magistrate Judge Donald Scheer excluded Hirsch's expert testimony from the evidence. In a sharply worded opinion, the judge stated that Hirsch did not know the ingredients of Zicam, had failed to review scientific literature that contradicted his opinion that Zicam caused the man's loss of smell and had performed no tests on the spray.
Another judge, in 2007, found Hirsch was not qualified to testify as to what caused a woman's multiple sclerosis symptoms to worsen, though he could speak about her headaches and psychiatric symptoms. The woman had accused Wal-Mart of improperly filling a prescription, causing an allergic reaction that she said aggravated her MS.
"The relevant medical literature does not support Dr. Hirsch's conclusions regarding the connection between physical or psychological stress and the exacerbation of MS," federal Judge James Moran wrote in his opinion.
In 1998, a magistrate judge excluded Hirsch's testimony in support of Tennessee residents who said they suffered injuries from exposure to leaked PCBs. The judge said Hirsch had failed to identify scientific studies that supported his conclusion, according to court documents. One law firm that hired Hirsch as an expert witness in another case involving chemical exposure halted work with him and refused to pay the balance of his bill after his statements allegedly crumbled under questioning in a deposition.
"Dr. Hirsch's opinions and diagnosis of each of (the law firm's) clients was erroneous, misleading and not based upon any medically or scientifically accepted methods," the plaintiff's attorneys stated in court documents after Hirsch sued to collect the unpaid fees.
Hirsch's suit sought about $194,000 in pay, based on an hourly rate of $515, court records show. Hirsch dropped the lawsuit after the dissolution of the law firm.
Sensa's original crystals, a patented formulation of maltodextrin, tricalcium phosphate, silica and natural and artificial colors, are based on the concept of "sensory-specific satiety," which refers to the declining satisfaction people get from eating the same type of foods. New flavors or foods, meanwhile, are thought to stimulate appetite.
When the crystals, also called "tastants," are scattered on food, they "interact with and intensify the taste of foods and make the body perceive that it has eaten more than it had, reducing calories and thus achieving weight loss," Hirsch wrote in his book "Sensa Weight-Loss Program."
Dr. Barbara Rolls, a professor of nutritional sciences at Penn State who helped define the phenomenon of sensory-specific satiety, said she has been concerned about the lack of peer-reviewed publications related to Sensa's claims.
"We have shown that sensory-specific satiety affects food choices in a meal, but it is a short-term phenomenon and has never been shown to affect body weight," Rolls, director of the Laboratory for the Study of Human Ingestive Behavior, wrote in an email.
Sensa used two Hirsch studies to market the product as "clinically proven." The first, according to Hirsch's book on Sensa, found that 92 volunteers had lost an average of 33.6 pounds in six months. But according to the poster abstract for the study, presented at the 2003 meeting of the Association for Chemoreception Sciences, the average weight loss was 5.6 pounds.
The study did not include a comparison with a placebo-controlled group consuming an identical-looking, but inactive, substance. It is a critical flaw because "we know that placebo weight-loss pills do indeed lead to weight loss," said obesity expert Dr. Yoni Freedhoff, an assistant professor of family medicine at the University of Ottawa. In addition, the subjects' diet and exercise were not monitored and they self-reported their weight.
A 2004 follow-up study of 2,437 volunteers, which concluded that 1,436 volunteers had an average loss of 30.5 pounds in six months, had the same problems, according to the FTC.
Hirsch also did not include an additional 1,001 study participants in the final results. "That's a 41 percent loss to follow up with no mention whatsoever of why they may have dropped out," said Freedhoff, author of "The Diet Fix: Why Diets Fail." "Were there adverse effects? Did the crystals simply work because they made the food taste bad? Did they not lose weight and consequently give up?"
In 2011, a class-action lawsuit filed in California alleged a lack of scientific evidence behind some of Sensa's marketing claims. The complaint called Hirsch "a particularly sophisticated huckster — one with a medical degree and a thick stack of junk science to support the claim that his magic crystals are 'clinically proven' to promote weight loss without diet or exercise."
The company denied the allegations and settled the suit for $9 million without admitting fault.
The FTC, which polices companies' marketing practices, cannot ban a product from being sold, and Sensa's website says it will modify its advertising claims to comply with the agency's standards.
But some experts say consumers need to think twice before buying a weight-loss product that lacks proof.
"My concern is it's another product with no demonstrated benefit that people are desperately trying in order to manage weight," said Dr. Robert Kushner, clinical director of the Northwestern Comprehensive Center on Obesity. "Many of these are individuals who won't put down money to see a dietitian, but they will pay $100 to buy Sensa. We're diverting limited resources into a product that may not be beneficial."