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

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.”

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

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New Patient Test Could Suggest Whether Therapy or Meds Will Work Better for Anxiety
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Like many psychological disorders, there's no one-size-fits-all treatment for patients with anxiety. Some might benefit from taking antidepressants, which boost mood-affecting brain chemicals called neurotransmitters. Others might respond better to therapy, and particularly a form called cognitive behavioral therapy, or CBT.

Figuring out which form of treatment works best often requires months of trial and error. But experts may have developed a quick clinical test to expedite this process, suggests a new study published in the journal Neuropsychopharmacology.

Researchers at the University of Illinois at Chicago have noted that patients with higher levels of anxiety exhibit more electrical activity in their brains when they make a mistake. They call this phenomenon error-related negativity, or ERN, and measure it using electroencephalography (EEG), a test that records the brain's electric signals.

“People with anxiety disorders tend to show an exaggerated neural response to their own mistakes,” the paper’s lead author, UIC psychiatrist Stephanie Gorka, said in a news release. “This is a biological internal alarm that tells you that you've made a mistake and that you should modify your behavior to prevent making the same mistake again. It is useful in helping people adapt, but for those with anxiety, this alarm is much, much louder.”

Gorka and her colleagues wanted to know whether individual differences in ERN could predict treatment outcomes, so they recruited 60 adult volunteers with various types of anxiety disorders. Also involved was a control group of 26 participants with no history of psychological disorders.

Psychiatrists gauged subjects’ baseline ERN levels by having them wear an EEG cap while performing tricky computer tasks. Ultimately, they all made mistakes thanks to the game's challenging nature. Then, randomized subjects with anxiety disorders were instructed to take an SSRI antidepressant every day for three months, or receive weekly cognitive behavioral therapy for the same duration. (Cognitive behavioral therapy is a type of evidence-based talk therapy that forces patients to challenge maladaptive thoughts and develop coping mechanisms to modify their emotions and behavior.)

After three months, the study's patients took the same computer test while wearing EEG caps. Researchers found that those who'd exhibited higher ERN levels at the study's beginning had reduced anxiety levels if they'd been treated with CBT compared to those treated with medication. This might be because the structured form of therapy is all about changing behavior: Those with enhanced ERN might be more receptive to CBT than other patients, as they're already preoccupied with the way they act.

EEG equipment sounds high-tech, but it's relatively cheap and easy to access. Thanks to its availability, UIC psychiatrists think their anxiety test could easily be used in doctors’ offices to measure ERN before determining a course of treatment.

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Food
A Pitless Avocado Wants to Keep You Safe From the Dreaded 'Avocado Hand'
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The humble avocado is a deceptively dangerous fruit. Some emergency room doctors have recently reported an uptick in a certain kind of injury—“avocado hand,” a knife injury caused by clumsily trying to get the pit out of an avocado with a knife. There are ways to safely pit an avocado (including the ones likely taught in your local knife skills class, or simply using a spoon), but there’s also another option. You could just buy one that doesn’t have a pit at all, as The Telegraph reports.

British retailer Marks & Spencer has started selling cocktail avocados, a skinny, almost zucchini-like type of avocado that doesn’t have a seed inside. Grown in Spain, they’re hard to find in stores (Marks & Spencer seems to be the only place in the UK to have them), and are only available during the month of December.

The avocados aren’t genetically modified, according to The Independent. They grow naturally from an unpollinated avocado blossom, and their growth is stunted by the lack of seed. Though you may not be able to find them in your local grocery, these “avocaditos” can grow wherever regular-sized Fuerte avocados grow, including Mexico and California, and some specialty producers already sell them in the U.S. Despite the elongated shape, they taste pretty much like any other avocado. But you don’t really need a knife to eat them, since the skin is edible, too.

If you insist on taking your life in your hand and pitting your own full-sized avocado, click here to let us guide you through the process. No one wants to go to the ER over a salad topping, no matter how delicious. Safety first!

[h/t The Telegraph]

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