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Why Does Coffee Make Me Poop?
Like opening the blinds and stepping into the shower, a cup of coffee gets people moving in the morning — in more ways than one. This satisfying brew revs energy levels with a dose of caffeine and, for many people, quickly and reliably jump-starts gut activity and an urgent need to poop.
But given coffee’s popularity, it’s surprising that we know so little about how it affects the gastrointestinal tract, said Dr. Robert Martindale, a professor of surgery and the medical director for hospital nutrition services at Oregon Health and Science University.
Some studies on the topic — which tend to be small, old and limited — have suggested that it’s probably not the caffeine that triggers the urge to go. One paper published in 1998, for instance, found that decaffeinated coffee had a similar stimulatory effect on the colon as caffeinated coffee, whereas a cup of hot water did not.
Coffee is a complex beverage containing more than 1,000 chemical compounds, many of which have antioxidant and anti-inflammatory properties. And determining how they affect the intestines is challenging.
One thing we do know is that coffee doesn’t affect everyone the same way. In one study published in 1990 in the journal Gut, 92 young adults filled out a questionnaire about how coffee affected their bowel habits; just 29 percent of the respondents said it “induced a desire to defecate,” and most of them — 63 percent — were female. (Though Dr. Martindale said that the percentage of people who have a bowel response after drinking coffee is likely much higher in the general population — he estimated that around 60 percent of his patients do — and he hasn’t noticed any differences between men and women.)
We also know that a gut response to coffee can happen fast. In the same study, some volunteers agreed to have a pressure-sensing probe inserted into their colon to measure intestinal muscle contractions before and after drinking a cup of Joe. Among those who said that coffee usually stimulated a bowel movement, the probe showed a significant increase in pressure within four minutes of drinking coffee, while the so-called nonresponders had no change in colon activity.
That drinking a cup of coffee can stimulate the opposite end of the gastrointestinal tract within minutes means “it’s probably going through the gut-brain axis,” Dr. Martindale said. That is, the arrival of coffee in the stomach sends a message to the brain, which then “stimulates the colon to say, ‘Well, we’d better empty out, because things are coming downstream,’” he explained. The coffee itself would move through the intestines much more slowly, likely taking at least an hour to traverse the long path from the stomach through the small intestine and to the colon.
This communication between the stomach, brain and colon, called the gastrocolic reflex, is a normal response to eating. But coffee seems to have an outsize effect; one study published in 1998 found that eight ounces of coffee stimulated colonic contractions similar to those induced by a 1,000-calorie meal. Researchers have hypothesized that coffee’s gut-brain messaging is likely caused by one or more of coffee’s many chemicals, and perhaps mediated by some of our own hormones that play important roles in the digestive process, like gastrin or cholecystokinin — both of which can spike after coffee drinking.
While the mechanism remains murky, coffee’s effects on the gut may be helpful for some people, including those recovering from certain types of surgery. Impaired bowel function is common after abdominal surgeries, for instance, which can lead to bloating, pain and an inability to pass gas or tolerate food. A 2020 analysis combined the results of seven clinical trials and found that drinking coffee allowed patients who had undergone colorectal or gynecological surgery to tolerate solid foods an average of 10 and 31 hours sooner, respectively. Coffee also reduced the time to their first bowel movement, by an average of 15 to 18 hours.
“A couple of sips of coffee can do it. It doesn’t take much,” said Dr. Martindale, who routinely offers his patients a cup of coffee the morning after surgery.
Dr. Martindale also suggests coffee, along with other dietary changes, when he counsels patients with chronic constipation. And he said it’s not uncommon for patients who have given up coffee for one reason or another to tell him, “Doc, I can’t go to the bathroom without a coffee.”
Sonya Angelone, a registered dietitian and spokeswoman for the Academy of Nutrition and Dietetics, cautioned against relying too much on coffee to stay regular. If someone is constipated, “it is not because they have a deficiency of coffee,” she said. Ms. Angelone recommends eating more fruits and vegetables, which are high in fiber, as well as increasing fluid intake and physical activity to address constipation. “What I find for a lot of people is they don’t start off with a fiber punch in the morning,” she said. Brewed coffee contains a small amount of fiber, about one gram per eight-ounce cup.
Some people find that coffee causes an upset stomach and loose stools, as well as side effects linked to excess caffeine, like insomnia, anxiousness, heart palpitations and headache, Ms. Angelone added. The Food and Drug Administration says that it’s safe for most people to drink 400 milligrams of caffeine — the amount in about four or five cups of coffee — per day. Though keep in mind that people metabolize caffeine differently, so this threshold can vary from person to person. “Coffee is one of those things, unlike other foods, that if it bothers you, you know it,” Ms. Angelone said.
But for the rest of us, coffee can be part of a comforting morning routine, waking us up in a multitude of ways.
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US follows Canada, Europe on Russian aircraft ban******
A Russian Aeroflot Airlines plane takes off from Los Angeles International Airport on February 22.
The United States will follow the European Union and Canada in banning Russian flights from its airspace, President Joe Biden said on Tuesday evening, in a move likely to trigger Russian retaliation.
United Airlines and United Parcel Service said on Tuesday they had suspended flying over Russian airspace, joining other major US carriers Delta Air Lines and American Airlines.
"I am announcing that we will join our allies in closing off American airspace to all Russian flights, further isolating Russia and adding an additional squeeze on their economy," Biden said in his State of the Union address.
The White House had held extensive talks with US airlines about the issue in recent days.
The ban will take effect by the end of Wednesday.
Russian flights were already effectively barred from US destinations for the most part in recent days because of bans on the use of Canadian and European airspace.
Some foreign governments had privately questioned why the United States did not move faster to ban Russian planes, as had some US lawmakers.
The European Union had said on Tuesday that it was speaking to US counterparts about extending the ban as it gave more details of the EU's closure of airspace to Russian aircraft imposed after Moscow's invasion of Ukraine.
Airlines already face potentially lengthy blockages of key east-west flight corridors after the EU and Moscow issued tit-for-tat airspace bans.
Global supply chains, already hit hard by the pandemic, will face increasing disruption and cost pressure from the closure of the skies which will affect over a fifth of air freight.
Hardest hit are likely to be Russian carriers, which make up approximately 70 percent of the flights between Russia and the EU.
Transport between Europe and North Asian destinations like Japan, South Korea and China is in the front line of disruption after reciprocal bans barred European carriers from flying over Siberia and prevented Russian airlines from flying to Europe.
Airlines responsible for moving around 20 percent of the world's air cargo are affected by those bans, Frederic Horst, managing director of Cargo Facts Consulting, told Reuters on Tuesday.
Germany's Lufthansa, Air France KLM, Finnair and Virgin Atlantic have already canceled North Asian cargo flights over closed access to airspace.
Scandinavian airline said it would re-route its once-weekly Copenhagen-Shanghai service to avoid Russian airspace, and had also paused its Copenhagen-Tokyo service.
Major Asian carriers like Korean Air Lines and Japan's ANA Holdings are still using Russian airspace, however, as are Middle Eastern airlines.
Russian airlines are also feeling the pinch with airline Pobeda, state airline Aeroflot's low-cost carrier, facing requests from a number of leasing companies to return their planes, the Interfax news agency reported.
Pure cargo carriers like Russia's AirBridgeCargo Airlines and Luxembourg's Cargolux are subject to the bans in a move that could send air freight rates – already elevated due to a lack of passenger capacity during the pandemic – soaring further.
"The flights become more expensive due to the longer routes," said Stefan Maichl, an analyst at Germany's Landesbank Baden-Wuerttemberg."