Why Does Coffee Make You Poop?

iStock/Photo illustration by Lauren Spinelli
iStock/Photo illustration by Lauren Spinelli

Coffee can give you more than just a caffeine buzz. For a large number of people—about one-third of the population—it also prompts a run for the bathroom. While this effect is widely documented, scientists aren’t exactly sure what’s behind it.

“It’s widely understood that coffee has a laxative effect on some people,” the American Chemical Society’s Reactions series noted in a 2015 video, but it’s complicated to tease out which part of coffee causes it.

It’s not just the caffeine, because decaf coffee can inspire the same, um, urgency. And people don’t run to the bathroom immediately after swilling a Coke. So what's happening inside your gut that makes you bolt for the commode just after finishing your morning cup o' joe?

Coffee has been found to stimulate your large intestine within just four minutes of ingestion, and drinking it increases the levels of certain digestive hormones in the gut. Coffee's laxative properties might also have something to do with its acidity, which helps your stomach produce more gastric acid to break down proteins. A compound in coffee called chlorogenic acid boosts stomach acid levels. This applies whether your coffee is caffeinated or not. As a 1986 study found, both decaf and regular coffee cause significant stimulation of gastric acid. (Both may also promote acid reflux, unfortunately, though the research is a bit contradictory.)

But that doesn’t mean all coffees are alike when it comes to spurring an increase in stomach acid. Research presented to the American Chemical Society in 2010 found that N-methylpyridinium, a chemical compound created in the roasting process, blocks the stomach’s ability to produce acid, meaning that dark-roasted coffees might actually be a bit easier on irritable stomachs than light-roasted varieties.

Some studies have found that coffee can accelerate gastric emptying—meaning the rate it takes for your stomach contents to empty into the small intestine—but this, too, is controversial, and some studies say coffee doesn’t impact gastric emptying at all. Since coffee only makes a portion of the population poop, though, it might just be that smaller studies (one only looked at 12 individuals) happen to not include any people whose bowels are really affected by coffee.

But the fact of the matter is, of the many chemical compounds contained in coffee, scientists aren't entirely sure which one is the poop perpetrator.

Poop is not just a byproduct of coffee drinking, either. Sometimes, it’s a vital part of the production process. Civet coffee, or kopi luwak, is known as one of the most expensive coffees in the world. It’s made from partially digested beans harvested from the feces of a civet. Because the beans have already passed through one stomach (the animal’s), the resulting coffee is much less acidic, meaning it’s a much smoother tasting—and feeling—experience for the humans who later drink the civet’s castoffs.

If you’re one of the many people whose coffee habits land them in the bathroom, know that all that post-brew pooping might not be a bad thing. Studies find that most people in the U.S. don’t eat enough fiber in their diet, so it may be a blessing that the average American drinks three cups of coffee a day. Otherwise, they’d have to change it to “land of the free and home of the blocked.”

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Nike Is Releasing a Durable Slip-On Sneaker Designed for Medical Professionals

monkeybusinessimages/iStock via Getty Images
monkeybusinessimages/iStock via Getty Images

Nike is known for releasing footwear that covers just about every activity under the moon—impact-absorbing running shoes, sleek soccer cleats, snazzy fashion statements, and so much more. Now, they’ve developed a sneaker for nurses, doctors, and other medical professionals who spend long shifts on their feet.

According to a press release, Nike sent designers to the OHSU Doernbecher Children’s Hospital in Portland, Oregon, where they learned from healthcare providers exactly what their jobs entail. Then, they used their findings to create the Nike Air Zoom Pulse, a “traditional clog made athletic.”

nike air zoom pulse
Nike

If you’ve ever gone sightseeing in a new city or even just taken a longer-than-expected afternoon stroll, you might have experienced firsthand that even your most comfortable walking shoes stop being so comfortable after a few miles of non-stop action—and nurses experience that type of exercise every time they go to work. During a regular 12-hour shift, a nurse might walk between four and five miles and sit for less than an hour. To account for that, the Nike Air Zoom Pulse features a full-rubber outsole, a flexible drop-in midsole, arch support, and a “heel fit so secure [that] it feels like a soft, snug hug.”

nike air zoom pulse
Nike

Since healthcare professionals also need a shoe durable enough to withstand spills of any kind, Nike coated the top of the Air Zoom Pulse with a polyurethane layer that’s easy to wipe down. It’s also a laceless slip-on, so people won’t have to worry about tripping on untied laces—and they’ll also be able to slip their shoes off for a quick nap in the staff room.

nike air zoom pulse
Nike

Six patients at the OHSU Doernbecher Children’s Hospital have contributed vibrant, colorful designs for the Air Zoom Pulse, which Nike will release for online orders (in versions that include its own colorways) starting December 7.

9 Facts About Narcolepsy

Korrawin/iStock via Getty Images
Korrawin/iStock via Getty Images

Everyone experiences occasional daytime sleepiness, but just a small fraction of the population knows what it’s like to have narcolepsy. The disorder is defined by persistent drowsiness throughout the day, and in some cases, sleep paralysis, hallucinations, and the sudden loss of muscle control known as cataplexy. Having narcolepsy can make doing everyday activities difficult or dangerous for patients, but unlike some chronic conditions, it’s also easy to diagnose and treat. Here are some facts you should know about the condition.

1. There are two types of narcolepsy.

If everything you know about narcolepsy comes from movies and TV, you may think of it as the disease that causes people to go limp without warning. Sudden loss of muscle control is called cataplexy, and it’s the defining symptom of type 1 narcolepsy. Type 2 narcolepsy, on the other hand, is mainly characterized by fatigue. Losing motor function while awake isn’t a problem for those with type 2.

2. Type 1 narcolepsy stems from a chemical deficiency.

Almost every patient with type 1 narcolepsy has low levels of hypocretin. Hypocretin is a neurochemical that regulates the wake-sleep cycle. When there isn’t enough of this chemical in the brain, people have trouble staying conscious and alert throughout the day. Most people with the second, less severe type of narcolepsy have normal hypocretin levels, with about a third of them producing low or undetectable amounts. Type 2 narcoplepsy has been studied far less than type 1 of the disorder, and scientists are still figuring out what causes it.

3. The exact causes of narcolepsy aren’t always clear.

So why do some people’s brains produce less hypocretin than others? That part has been hard for scientists to figure out. One possible explanation is that certain autoimmune disorders cause the body to attack the healthy brain cells that make this chemical. This disorder can be the result of genetic and environmental factors. Although people with narcolepsy rarely pass it down to their offspring (this happens less than 1 percent of the time), the sleep condition does occasionally crop up in family clusters, suggesting there is sometimes a genetic component at play. Head trauma that impacts the area of the brain responsible for governing sleep can also lead to narcolepsy in rare cases.

4. There are tests to diagnose narcolepsy.

If patients believe they might have narcolepsy, their doctors might ask them to detail their sleep history and keep a record of their sleep habits. There are also a few tests potential narcoleptics can take to determine if they have the condition. During a polysomnography test, patients spend the night at a medical facility with electrodes attached to their heads to monitor their breathing, eye movement, and brain activity. A multiple sleep latency test is similar, except it gauges how long it takes patients to fall asleep during the day.

5. Strong emotions can trigger cataplexy.

Cataplectic spells can sometimes be predicted by triggers. In some patients, feeling strong emotions—whether they’re crying, laughing, angry, or stressed—is all it takes for them to lose muscle control. These triggers vary from patient to patient, and they can even affect the same person randomly. Some people deal with them by avoiding certain situations and closing themselves off emotionally, which can disrupt their social lives.

6. Narcolepsy can make sleep terrifying.

Narcoleptics don’t just worry about their disorder during their waking hours. When they’re trying to fall asleep at night or wake up in the morning, narcolepsy can complicate things. One symptom is experiencing vivid, dream-like hallucinations while transitioning in or out of consciousness. These visions are often scary and may involve an intruder in the room with the sleeper. If they happen as the patient falls asleep, the hallucinations are called hypnagogic, and if they occur as they wake up, they’re hypnopompic.

A related symptom is sleep paralysis. This happens when a person’s brain cuts off muscle control of their body before they’re fully asleep or as they’re waking up. This combined with hypnagogic or hypnopompic nightmares can cause frightening experiences that are sometimes confused for real encounters.

7. Narcoleptics sometimes do activities half-asleep.

To outside observers, narcolepsy is sometimes hard to spot. A narcoleptic patient overcome by sleepiness won’t necessarily pass out in the middle of what they’re doing. Some act out “automatic behavior,” which means they continue with their actions—whether that’s walking, driving, or typing—with limited consciousness. This can cause poor performance at work or school, and in worst case scenarios, accidents while driving a car or operating machinery.

8. Harriet Tubman may have had narcolepsy.

One of the most famous likely narcoleptics in history is Harriet Tubman. The African American abolitionist was known to suffer from what were probably sudden narcoleptic episodes. The condition may have stemmed from the severe head trauma she sustained when a slave master threw an iron at another slave and hit her instead. The injury left her with permanent brain damage: In addition to narcolepsy, she also experienced chronic seizures and migraines throughout her life.

9. Medications and lifestyle changes are common narcolepsy treatments.

Though there’s no way to cure narcolepsy completely, there are many treatment options available. Taking medication is one of the most common ways to manage the disorder. Stimulants such as modafinil and armodafinil can be used to combat mild sleepiness, while amphetamines are often prescribed for more severe forms of fatigue. For hallucinations and sleep paralysis, selective serotonin reuptake inhibitors and serotonin and norepinephrine reuptake inhibitors—drugs that suppress REM sleep—can help.

As an alternative or supplementary treatment to medications, doctors may recommend lifestyle changes. Sticking to a sleep schedule, exercising regularly, avoiding nicotine and alcohol, and taking naps during the day can all reduce the symptoms of narcolepsy.

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