Tapping into the Power of the Placebo Effect
When Wayne Jonas was in medical school 40 years ago, doctors would write out a prescription for placebos, spelling it out backwards in capital letters, O-B-E-C-A-L-P. The pharmacist would fill the prescription with a sugar pill, recalls Jonas, now director of integrative health programs at the Samueli Foundation. It fulfilled the patient's desire for the doctor to do something when perhaps no drug could help, and the sugar pills did no harm.
Today, that deception is seen as unethical. But time and time again, studies have shown that placebos can have real benefits. Now, researchers are trying to untangle the mysteries of placebo effect in an effort to better treat patients.
The use of placebos took off in the post-WWII period, when randomized controlled clinical trials became the gold standard for medical research. One group in a study would be treated with a placebo, a supposedly inert pill or procedure that would not affect normal healing and recovery, while another group in the study would receive an "active" component, most commonly a pill under investigation. Presumably, the group receiving the active treatment would have a better response and the difference from the placebo group would represent the efficacy of the drug being tested. That was the basis for drug approval by the U.S. Food and Drug Administration.
"Placebo responses were marginalized," says Ted Kaptchuk, director of the Program in Placebo Studies & Therapeutic Encounters at Harvard Medical School. "Doctors were taught they have to overcome it when they were thinking about using an effective drug."
But that began to change around the turn of the 21st century. The National Institutes of Health held a series of meetings to set a research agenda and fund studies to answer some basic questions, led by Jonas who was in charge of the office of alternative medicine at the time. "People spontaneously get better all the time," says Kaptchuk. The crucial question was, is the placebo effect real? Is it more than just spontaneous healing?
Brain mechanisms
A turning point came in 2001 in a paper in Science that showed physical evidence of the placebo effect. It used positron emission tomography (PET) scans to measure release patterns of dopamine — a chemical messenger involved in how we feel pleasure — in the brains of patients with Parkinson's disease. Surprisingly, the placebo activated the same patterns that were activated by Parkinson's drugs, such as levodopa. It proved the placebo effect was real; now the search was on to better understand and control it.
A key part of the effect can be the beliefs, expectations, context, and "rituals" of the encounter between doctor and patient. Belief by the doctor and patient that the treatment would work, and the formalized practices of administering the treatment can all contribute to a positive outcome.
Conditioning can be another important component in generating a response, as Pavlov demonstrated more than a century ago in his experiments with dogs. They were trained with a bell prior to feeding such that they would begin to salivate in anticipation at the sound of a bell even with no food present.
Translating that to humans, studies with pain medications and sleeping aids showed that patients who had a positive response with a certain dose of those medications could have the same response if the doses was reduced and a dummy pill substituted, even to the point where there was no longer any active ingredient.
Researchers think placebo treatments can work particularly well in helping people deal with pain and psychological disorders.
Those types of studies troubled Kaptchuk because they often relied on deception; patients weren't told they were receiving a placebo, or at best there was a possibility that they might be randomized to receive a placebo. He believed the placebo effect could work even if patients were told upfront that they were going to receive a placebo. More than a dozen so call "open-label placebo" studies across numerous medical conditions, by Kaptchuk and others, have shown that you don't have to lie to patients for a placebo to work.
Jonas likes to tell the story of a patient who used methotrexate, a potent immunosuppressant, to control her rheumatoid arthritis. She was planning a long trip and didn't want to be bothered with the injections and monitoring required in using the drug, So she began to drink a powerful herbal extract of anise, a licorice flavor that she hated, prior to each injection. She reduced the amount of methotrexate over a period of months and finally stopped, but continued to drink the anise. That process had conditioned her body "to alter her immune function and her autoimmunity" as if she were taking the drug, much like Pavlov's dogs had been trained. She has not taken methotrexate for more than a year.
An intriguing paper published in May 2021 found that mild, non-invasive electric stimulation to the brain could not only boost the placebo effect on pain but also reduce the "nocebo" effect — when patients report a negative effect to a sham treatment. While the work is very preliminary, it may open the door to directly manipulating these responses.
Researchers think placebo treatments can work particularly well in helping people deal with pain and psychological disorders, areas where drugs often are of little help. Still, placebos aren't a cure and only a portion of patients experience a placebo effect.
Nocebo
If medicine were a soap opera, the nocebo would be the evil twin of the placebo. It's what happens when patients have adverse side effects because of the expectation that they will. It's commonly seem when patients claims to experience pain or gastric distress that can occur with a drug even when they've received a placebo. The side effects were either imagined or caused by something else.
"Up to 97% of reported pharmaceutical side effects are not caused by the drug itself but rather by nocebo effects and symptom misattribution," according to one 2019 paper.
One way to reduce a nocebo response is to simply not tell patients that specific side effects might occur. An example is a liver biopsy, in which a large-gauge needle is used to extract a tissue sample for examination. Those told ahead of time that they might experience some pain were more likely to report pain and greater pain than those who weren't offered this information.
Interestingly, a nocebo response plays out in the hippocampus, a part of the brain that is never activated in a placebo response. "I think what we are dealing with with nocebo is anxiety," says Kaptchuk, but he acknowledges that others disagree.
Distraction may be another way to minimize the nocebo effect. Pediatricians are using virtual reality (VR) to engage children and distract them during routine procedures such as blood draws and changing wound dressings, and burn patients of all ages have found relief with specially created VRs.
Treatment response
Jonas argues that what we commonly call the placebo effect is misnamed and leading us astray. "The fact is people heal and that inherent healing capacity is both powerful and influenced by mental, social, and contextual factors that are embedded in every medical encounter since the idea of treatment began," he wrote in a 2019 article in the journal Frontiers in Psychiatry. "Our understanding of healing and ability to enhance it will be accelerated if we stop using the term 'placebo response' and call it what it is—the meaning response, and its special application in medicine called the healing response."
He cites evidence that "only 15% to 20% of the healing of an individual or a population comes from health care. The rest—nearly 80%—comes from other factors rarely addressed in the health care system: behavioral and lifestyle choices that people make in their daily life."
To better align treatments and maximize their effectiveness, Jonas has created HOPE (Healing Oriented Practices & Environments) Note, "a patient-guided process designed to identify the patient's values and goals in their life and for healing." Essentially, it seeks to make clear to both doctor and patient what the patient's goals are in seeking treatment. In an extreme example of terminal cancer, some patients may choose to extend life despite the often brutal treatments, while others might prefer to optimize quality of life in the remaining time that they have. It builds on practices already taught in medical schools. Jonas believes doctors and patients can use tools like these to maximize the treatment response and achieve better outcomes.
Much of the medical profession has been resistant to these approaches. Part of that is simply tradition and limited data on their effectiveness, but another very real factor is the billing process for how they are reimbursed. Jonas says a new medical billing code added this year gives doctors another way to be compensated for the extra time and effort that a more holistic approach to medicine may initially require. Other moves away from fee-for-service payments to bundling and payment for outcomes, and the integrated care provided by the Veterans Affairs, Kaiser Permanente and other groups offer longer term hope for the future of approaches that might enhance the healing response.
This article was first published by Leaps.org on July 7, 2021.
Dr. Steffanie Strathdee, an infectious disease epidemiologist, saved her husband Tom from a superbug infection by mobilizing scientists around the world to help him access experimental phage therapy.
[Editor's Note: This is the fifth episode in our Moonshot series, which explores cutting-edge scientific developments that stand to fundamentally transform our world.]
Kira Peikoff was the editor-in-chief of Leaps.org from 2017 to 2021. As a journalist, her work has appeared in The New York Times, Newsweek, Nautilus, Popular Mechanics, The New York Academy of Sciences, and other outlets. She is also the author of four suspense novels that explore controversial issues arising from scientific innovation: Living Proof, No Time to Die, Die Again Tomorrow, and Mother Knows Best. Peikoff holds a B.A. in Journalism from New York University and an M.S. in Bioethics from Columbia University. She lives in New Jersey with her husband and two young sons. Follow her on Twitter @KiraPeikoff.
The latest tools, like whole genome sequencing, are allowing food outbreaks to be identified and stopped more quickly.
With the pandemic at the forefront of everyone's minds, many people have wondered if food could be a source of coronavirus transmission. Luckily, that "seems unlikely," according to the CDC, but foodborne illnesses do still sicken a whopping 48 million people per year.
Whole genome sequencing is like "going from an eight-bit image—maybe like what you would see in Minecraft—to a high definition image."
In normal times, when there isn't a historic global health crisis infecting millions and affecting the lives of billions, foodborne outbreaks are real and frightening, potentially deadly, and can cause widespread fear of particular foods. Think of Romaine lettuce spreading E. coli last year— an outbreak that infected more than 500 people and killed eight—or peanut butter spreading salmonella in 2008, which infected 167 people.
The technologies available to detect and prevent the next foodborne disease outbreak have improved greatly over the past 30-plus years, particularly during the past decade, and better, more nimble technologies are being developed, according to experts in government, academia, and private industry. The key to advancing detection of harmful foodborne pathogens, they say, is increasing speed and portability of detection, and the precision of that detection.
Getting to Rapid Results
Researchers at Purdue University have recently developed a lateral flow assay that, with the help of a laser, can detect toxins and pathogenic E. coli. Lateral flow assays are cheap and easy to use; a good example is a home pregnancy test. You place a liquid or liquefied sample on a piece of paper designed to detect a single substance and soon after you get the results in the form of a colored line: yes or no.
"They're a great portable tool for us for food contaminant detection," says Carmen Gondhalekar, a fifth-year biomedical engineering graduate student at Purdue. "But one of the areas where paper-based lateral flow assays could use improvement is in multiplexing capability and their sensitivity."
J. Paul Robinson, a professor in Purdue's Colleges of Veterinary Medicine and Engineering, and Gondhalekar's advisor, agrees. "One of the fundamental problems that we have in detection is that it is hard to identify pathogens in complex samples," he says.
When it comes to foodborne disease outbreaks, you don't always know what substance you're looking for, so an assay made to detect only a single substance isn't always effective. The goal of the project at Purdue is to make assays that can detect multiple substances at once.
These assays would be more complex than a pregnancy test. As detailed in Gondhalekar's recent paper, a laser pulse helps create a spectral signal from the sample on the assay paper, and the spectral signal is then used to determine if any unique wavelengths associated with one of several toxins or pathogens are present in the sample. Though the handheld technology has yet to be built, the idea is that the results would be given on the spot. So someone in the field trying to track the source of a Salmonella infection could, for instance, put a suspected lettuce sample on the assay and see if it has the pathogen on it.
"What our technology is designed to do is to give you a rapid assessment of the sample," says Robinson. "The goal here is speed."
Seeing the Pathogen in "High-Def"
"One in six Americans will get a foodborne illness every year," according to Dr. Heather Carleton, a microbiologist at the Centers for Disease Control and Prevention's Enteric Diseases Laboratory Branch. But not every foodborne outbreak makes the news. In 2017 alone, the CDC monitored between 18 and 37 foodborne poison clusters per week and investigated 200 multi-state clusters. Hardboiled eggs, ground beef, chopped salad kits, raw oysters, frozen tuna, and pre-cut melon are just a taste of the foods that were investigated last year for different strains of listeria, salmonella, and E. coli.
At the heart of the CDC investigations is PulseNet, a national network of laboratories that uses DNA fingerprinting to detect outbreaks at local and regional levels. This is how it works: When a patient gets sick—with symptoms like vomiting and fever, for instance—they will go to a hospital or clinic for treatment. Since we're talking about foodborne illnesses, a clinician will likely take a stool sample from the patient and send it off to a laboratory to see if there is a foodborne pathogen, like salmonella, E. Coli, or another one. If it does contain a potentially harmful pathogen, then a bacterial isolate of that identified sample is sent to a regional public health lab so that whole genome sequencing can be performed.
Whole genome sequencing can differentiate "virtually all" strains of foodborne pathogens, no matter the species, according to the FDA.
Whole genome sequencing is a method for reading the entire genome of a bacterial isolate (or from any organism, for that matter). Instead of working with a couple dozen data points, now you're working with millions of base pairs. Carleton likes to describe it as "going from an eight-bit image—maybe like what you would see in Minecraft—to a high definition image," she says. "It's really an evolution of how we detect foodborne illnesses and identify outbreaks."
If the bacterial isolate matches another in the CDC's database, this means there could be a potential outbreak and an investigation may be started, with the goal of tracking the pathogen to its source.
Whole genome sequencing has been a relatively recent shift in foodborne disease detection. For more than 20 years, the standard technique for analyzing pathogens in foodborne disease outbreaks was pulsed-field gel electrophoresis. This method creates a DNA fingerprint for each sample in the form of a pattern of about 15-30 "bands," with each band representing a piece of DNA. Researchers like Carleton can use this fingerprint to see if two samples are from the same bacteria. The problem is that 15-30 bands are not enough to differentiate all isolates. Some isolates whose bands look very similar may actually come from different sources and some whose bands look different may be from the same source. But if you can see the entire DNA fingerprint, then you don't have that issue. That's where whole genome sequencing comes in.
Although the PulseNet team had piloted whole genome sequencing as early as 2013, it wasn't until July of last year that the transition to using whole genome sequencing for all pathogens was complete. Though whole genome sequencing requires far more computing power to generate, analyze, and compare those millions of data points, the payoff is huge.
Stopping Outbreaks Sooner
The U.S. Food and Drug Administration (FDA) acquired their first whole genome sequencers in 2008, according to Dr. Eric Brown, the Director of the Division of Microbiology in the FDA's Office of Regulatory Science. Since then, through their GenomeTrakr program, a network of more than 60 domestic and international labs, the FDA has sequenced and publicly shared more than 400,000 isolates. "The impact of what whole genome sequencing could do to resolve a foodborne outbreak event was no less impactful than when NASA turned on the Hubble Telescope for the first time," says Brown.
Whole genome sequencing has helped identify strains of Salmonella that prior methods were unable to differentiate. In fact, whole genome sequencing can differentiate "virtually all" strains of foodborne pathogens, no matter the species, according to the FDA. This means it takes fewer clinical cases—fewer sick people—to detect and end an outbreak.
And perhaps the largest benefit of whole genome sequencing is that these detailed sequences—the millions of base pairs—can imply geographic location. The genomic information of bacterial strains can be different depending on the area of the country, helping these public health agencies eventually track the source of outbreaks—a restaurant, a farm, a food-processing center.
Coming Soon: "Lab in a Backpack"
Now that whole genome sequencing has become the go-to technology of choice for analyzing foodborne pathogens, the next step is making the process nimbler and more portable. Putting "the lab in a backpack," as Brown says.
The CDC's Carleton agrees. "Right now, the sequencer we use is a fairly big box that weighs about 60 pounds," she says. "We can't take it into the field."
A company called Oxford Nanopore Technologies is developing handheld sequencers. Their devices are meant to "enable the sequencing of anything by anyone anywhere," according to Dan Turner, the VP of Applications at Oxford Nanopore.
"The sooner that we can see linkages…the sooner the FDA gets in action to mitigate the problem and put in some kind of preventative control."
"Right now, sequencing is very much something that is done by people in white coats in laboratories that are set up for that purpose," says Turner. Oxford Nanopore would like to create a new, democratized paradigm.
The FDA is currently testing these types of portable sequencers. "We're very excited about it. We've done some pilots, to be able to do that sequencing in the field. To actually do it at a pond, at a river, at a canal. To do it on site right there," says Brown. "This, of course, is huge because it means we can have real-time sequencing capability to stay in step with an actual laboratory investigation in the field."
"The timeliness of this information is critical," says Marc Allard, a senior biomedical research officer and Brown's colleague at the FDA. "The sooner that we can see linkages…the sooner the FDA gets in action to mitigate the problem and put in some kind of preventative control."
At the moment, the world is rightly focused on COVID-19. But as the danger of one virus subsides, it's only a matter of time before another pathogen strikes. Hopefully, with new and advancing technology like whole genome sequencing, we can stop the next deadly outbreak before it really gets going.