How Do Placebos Work?

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iStock

There’s a reason eating your grandmother’s chicken soup or dabbing your temples with essential oil of peppermint might make you feel better if you’re sick, and it’s probably not because they're truly curative. Your relief is likely the result of the placebo effect.

A placebo is an inert substance, such as a sugar pill or saline solution, that is specifically given to a patient because it's not intended to have a measurable effect on their physiology. Placebos are often used as controls in clinical trials and experiments to set a baseline by which to compare the effects of new drugs and medical treatments. They’re not supposed to be treatments in and of themselves. And yet studies show that placebos not only often have a measurable effect on the people who take them, but can actually improve someone's condition.

Researchers have documented this effect for pain treatment, irritable bowel syndrome, and high-altitude sickness, among other conditions. Even sham knee surgeries have been shown to produce nearly identical pain relief to actual meniscus surgery.

What's going on here?

GREAT EXPECTATIONS

John Kelley, deputy director of the Program in Placebo Studies (PiPS) at Beth Israel Deaconess Medical Center at Harvard Medical School, tells Mental Floss that a patient's expectations about whether or not a medication will work are central to the placebo effect. Even the color and size of placebo pills have been shown to affect the power of fake medicine. Both small and large pills elicit a stronger placebo effect than middle-sized ones. People assume that a tiny pill "must be really powerful medicine if it’s so small,” Kelley explains, while an oversized pill makes people think, ‘Wow, there’s a lot of medicine there. I’m getting a big treatment.’”

Another factor at work is whether an individual has had previous experience with the form of treatment, called conditioning, and has thus developed what Kelley calls “a conscious expectancy” that it will work again. The greater the conditioning, often the greater the placebo effect.

The human element is key, too. A patient's sense of the competence and warmth of their practitioner, and their comfort in the treatment setting—"a fancy, prestigious medical school versus a ramshackle, dubious-looking office,” Kelley says—can influence the placebo effect.

THE BIOLOGY OF BELIEF

Having an expectation of healing leads to the physiological relief of symptoms because there's a biological process underpinning our responses. “Every thought, emotion, and feeling we have has a biological substrate,” Kelley says. For example, the brains of people given placebos for pain medication have been shown to release naturally occurring opioids, which provide actual pain relief. Research has shown that anticipation stimulates the brain’s reward system, just as opioid drugs do.

What’s more, Kelley says, in trials where patients were conditioned to receive pain relief from either the opioid morphine or a placebo, and then subsequently were given the opioid-blocking drug Nalaxone, the drug prevented both the morphine and the placebo from giving the patients pain relief. Researchers suspect that merely having an expectation of relief recruited the brain to release the endogenous opioids—which were then blocked by the Nalaxone.

Similarly, placebo trials of Parkinson’s medications have also found that patients' brains release dopamine in response to placebos, temporarily relieving symptoms such as tremors and stiff muscles. Kelley says the brain likely uses different mechanisms to respond to different conditions, which could explain why, for example, it produces endogenous opioids for pain and dopamine for Parkinson’s.

Placebos can work even when recipients know they're taking a placebo. That was the case in one seminal study involving patients with irritable bowel syndrome [PDF], in which researchers found that giving patients pills clearly labeled as placebos reduced the severity of their symptoms versus control participants who received no pills at all.

More research is necessary to understand why placebos can work even when we know they shouldn't, but the lead researcher of the IBS study, Ted Kaptchuk, also with the PiPS program, told NPR that “a trusting relationship between the doctor and patient” is likely important. Perhaps the expectation of being cared for is enough to bring relief to some.

Kelley believes it may come down to a kind of selective attention. Even if a patient knows they're taking a placebo, they're “paying attention to one set of stimuli and avoiding another,” he says, which redirects their focus from pain to an experience of relief.

While scientists continue to unravel the mysterious power of the mind to influence the body, the next time you have a headache, maybe try a sugar pill instead of an aspirin; it can’t hurt, and it might even help.

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Who Has Jurisdiction for Crimes Committed in Space?

iStock/nedelcupaul
iStock/nedelcupaul

It's 2050. Humans have mastered commercial space travel. Hundreds of people pay thousands of dollars to be sent into orbit in a spaceship. Maybe some decide to help colonize Mars.

Then, trouble. A jilted spouse. A smuggled firearm. Perhaps a struggle followed by suffocation. A space traveler is found dead on board a ship or on the Red Planet. Who has jurisdiction over such crimes? Is there such a thing as a cosmic Hercule Poirot? Could someone fall through the cracks and get away with space murder?

To date, no one has been victim of a space crime. But because no one nation can lay claim to ownership of space, the idea of a criminal offense committed outside of our atmosphere is something people have already given some thought to.

According to NASA engineer and instructor Robert Frost, the language of law for galactic felonies would be the Outer Space Treaty of 1967. In Article VIII of the treaty, nations engaging in space exploration agree that they will bear responsibility for the actions of personnel aboard their craft. In other words, if a privatized shuttle from China sees a fight break out among crew members, leaving one injured, China would be the entity responsible for handling legal repercussions.

That varies slightly with the International Space Station, or ISS, which is home to a number of personnel from different nations. In the case of the ISS, an intergovernmental agreement signed in 1998 mandates that the home country of the offender will handle any investigation or prosecution. If the victim is a national of another country, that country will have the right to inquire as to the criminal status of the offender and seek to have jurisdiction over the matter if they feel justice isn't being meted out.

In most cases, space crime sprees would be treated the same as if an offender was traveling in a foreign country or in international waters. If you're a U.S. citizen and decide to bludgeon someone at sea or on the Moon, the various international agreements and national laws would determine how you get prosecuted. (Assuming, of course, you returned to Earth to answer the charges.)

Space crimes pose another intriguing wrinkle. In terra firma investigations, authorities can secure crime scenes, question witnesses, and preserve evidence. Aboard a spaceship or on a distant planet, these procedures would be difficult to perform, and almost impossible to do in a timely fashion. Even if a criminal investigator is on Mars, low gravity will affect blood spatter and bodies may even decay at a different rate than they do on Earth. While an American may be found liable for murder, proving it was malicious and not the result of the dangerous environment would give any prosecutor a headache. A defense attorney, on the other hand, would have a field day questioning defective spacesuits or toxic exposure to strange space chemicals.

Then again, prosecutors may not have to concern themselves with evidence. Thanks to airlocks and restrictive suits, the movement of space travelers is highly monitored. It would be hard to make any plausible deniability about one's whereabouts.

The closest thing to space crime that law enforcement has yet encountered may be crimes committed in Antarctica, the frigid and isolated continent that's unaffiliated with any country but operates under the Antarctic Treaty signed by 54 nations. The agreement declares that the suspect is likely under their home country's jurisdiction. In some cases, the country owning the research station where the alleged crime took place steps in. In 2018, a Russian researcher at Bellingshausen Station on King George Island went after his victim with a knife in the station's dining room. He was charged in Russia, though reports indicate the case has since been dropped. And in 2000, an Australian astrophysicist suspected of being fatally poisoned had an autopsy performed in New Zealand. The exam showed he had ingested methanol, but it remains unknown whether he did so accidentally or whether someone gave it to him. New Zealand police were unable to determine the source.

A person committing murder in space would certainly be held responsible. But whether they'd ever be found guilty beyond a reasonable doubt remains very much up in—and beyond—the air.

Why Do Dogs Eat Grass?

iStock/K_Thalhofer
iStock/K_Thalhofer

If something is edible (or even if it's not), many dogs will gladly make a meal of it. But if you see your pet grazing on your front lawn like cattle, it may be driven by something more than its undiscerning appetite. Eating grass frantically can be a sign that a dog is sick.

It's not unusual to see a dog vomit after consuming grass, prompting some pet owners to wonder if their dog ate the grass to soothe its own upset stomach or if the grass is what caused its symptoms in the first place. According Dr. Jerry Klein, chief veterinary officer for the American Kennel Club, this behavior is sometimes a response to symptoms that were already present. "When dogs go outside and gobble grass really quickly, there's usually a reason, an instinctual behavior to try to induce some kind of gastrointestinal reaction," he tells Mental Floss. "When they realize they're nauseous or something else, the only thing they know how to do is to force themselves to vomit. Some dogs that eat grass chomp it down without really chewing it, and often times may vomit something up and that's how they treat themselves."

Despite it being a common issue for pet owners, little research has been done into why dogs eat grass. It's likely that stomach problems only explain this behavior part of the time. In other situations, a dog may eat grass for the same reason it eats your shoes or the groceries you left on the kitchen counter: Because it's hungry, anxious, or bored.

So how can you tell when your dog is munching grass for pleasure and when it's trying to induce itself to vomit? Pay attention to the way it eats. Dogs are omnivorous, meaning they eat both plants and animals, so just eating grass alone normally won't be enough to make it sick. But if a dog is gorging on grass faster than it can chew it, that may be an indication that something is wrong. Whole blades of grass can irritate a dog's throat and stomach lining, potentially causing them to throw up if they swallow a lot of them in a short amount of time.

No matter the reason for your dog's grass-eating habits, Klein says that they aren't a major issue. The behavior shouldn't be encouraged, as grass in public places can potentially carry harmful chemicals like pesticides, so stop your dog if you see it grazing. But if it shows no signs of illness or discomfort afterward, there's no need to rush it to the vet. "If I see a dog eating grass, I'm not going to panic. I would try to stop it and then monitor it to see how it acts in the next 15 to 20 minutes. Look at how the dog's acting, its body shape and movement, and the feeling you get from the dog."

One condition related to vomiting that would warrant a trip to the vet is something called bloat. This happens when a dog's stomach fills with air, causing it to retch without actually throwing anything up. This is a medical emergency and can be deadly if left untreated.

A dog who vomits after eating grass and looks happy afterward, on the other hand, is probably not a cause for concern—though you may argue otherwise when you're steam-cleaning your carpet.

Have you got a Big Question you'd like us to answer? If so, send it to bigquestions@mentalfloss.com.

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