Decaf Coffee: A Natural Laxative?

Coffee is well-known for its laxative effects, but does decaf have the same impact? While it was previously thought that caffeine was the key factor in coffee's laxative effects, recent studies suggest that decaf can also have a laxative effect, though it is not as strong as caffeinated coffee. The reasons for this are currently unknown and require further research.

Decaf can have a laxative effect, but it's not as strong as caffeinated coffee

Decaf coffee can have a laxative effect, but the effect is not as strong as caffeinated coffee. While it was previously thought that caffeine was the main factor in coffee's laxative effects, recent studies suggest that decaf coffee can also stimulate the colon.

A 1998 study found that caffeinated coffee, decaf coffee, and a 1,000-calorie meal all stimulated the colon. However, caffeinated coffee stimulated the colon 23% more than decaf coffee and 60% more than plain water. Similarly, a 1990 study showed that drinking caffeinated or decaf coffee increased rectosigmoid motility, which is the movement at the intersection of the large colon's end and the upper rectum. This increase in motility was observed within four minutes in 29% of participants, while drinking plain hot water did not have the same effect.

Another study by the National Cancer Institute in Lithuania in 2015 found that decaf coffee had a significant effect on bowel movements for those with postoperative ileus, a digestive problem that occurs after abdominal surgery. These findings suggest that decaf coffee can indeed have a laxative effect, although it may be less potent than that of caffeinated coffee.

The reasons for the laxative effects of decaf coffee are currently unknown and require further research. While caffeine may contribute to the effect, it does not explain it entirely. Other factors, such as coffee's interaction with stomach acid and the gastrocolic reflex, may also play a role.

A 1990 study found that 29% of participants had increased rectosigmoid motility after drinking decaf

Decaf and the 1990 Study

The results of the questionnaire showed that 29% of participants, or 63% of women, claimed that coffee induced a desire to defecate. To further investigate this, the researchers studied the rectosigmoid motor responses to black, unsweetened coffee in 14 healthy subjects (12 men and 2 women), 8 of whom had reported that coffee caused a desire to defecate ("responders"). The researchers used multiport manometry to measure the motility index, which increased within four minutes of ingesting both regular and decaffeinated coffee in the "responders" but not in the "non-responders". This increase in rectosigmoid motility lasted for at least 30 minutes and was not observed after drinking hot water.

The findings suggest that drinking coffee, regardless of caffeine content, can stimulate a motor response in the distal colon in some individuals. However, it's important to note that the study had a small sample size and only included healthy young participants, so further research is needed to understand the effect of coffee on digestion in a more diverse population.

The Link Between Coffee and Digestion

The 1990 study is not the only one to explore the link between coffee consumption and digestion. A 1998 study found that caffeinated coffee, decaf coffee, and a 1,000-calorie meal all stimulated the colon, with caffeinated coffee having a stronger effect than decaf. Additionally, a 2015 study showed that decaffeinated coffee had a significant impact on bowel movements for individuals with postoperative ileus (digestive issues after abdominal surgery) compared to caffeinated coffee and water. These studies indicate that coffee, including decaf, may have a laxative effect for some people, but the underlying reasons are still unclear.

A 1998 study found that decaf stimulated the colon more than water but less than caffeinated coffee

A 1998 study published in the *European Journal of Gastroenterology and Hepatology* found that decaffeinated coffee does have a laxative effect. The study, titled "Is Coffee a Colonic Stimulant?", found that decaf coffee stimulated the colon more than water but less than caffeinated coffee.

The study was conducted by researchers at the University of Iowa College of Medicine, who investigated the effects of coffee on colonic motor activity in healthy humans. The researchers placed a six-sensor solid-state probe up to the mid-transverse colon in 12 healthy subjects. The following day, over a 10-hour period, the subjects received four stimuli: 240ml of three drinks at 45 degrees Celsius in random order (black Colombian coffee with 150mg of caffeine, decaffeinated coffee, or water) and a 1000-calorie meal.

The results showed that caffeinated coffee, decaf coffee, and the meal induced more activity in the colon than water. However, caffeinated coffee stimulated the colon 23% more than decaf coffee and 60% more than plain water. The effects of decaf coffee on colonic motility were not significantly different from those of water or caffeinated coffee, but they were lower than the effects of the meal.

The study concluded that caffeinated coffee stimulates colonic motor activity and that its magnitude is similar to that of a meal, significantly stronger than water, and stronger than decaf coffee. This suggests that while decaf coffee may have a milder laxative effect than caffeinated coffee, it can still stimulate the colon to a greater extent than water or no stimulus.

Decaf may stimulate the production of the hormone gastrin, which promotes digestion

A 1990 study found that 29% of participants experienced an increase in rectosigmoid motility within four minutes of drinking decaf coffee. Rectosigmoid motility is the movement that occurs at the intersection of the large colon's end and the upper rectum. The study also found that this increase in motility lasted at least 30 minutes.

A 1988 study by scientists at the College of Medicine at the University of Iowa found that decaffeinated and caffeinated coffee, when taken with a 1000-calorie meal, stimulated the colon. However, the study also found that caffeinated coffee had a 23% stronger effect than decaffeinated coffee.

A 2015 study found that decaffeinated coffee had a significant effect on bowel movements for those with postoperative ileus, compared to caffeinated coffee and water. Postoperative ileus refers to digestive problems that occur after abdominal surgery.

While the exact reasons for the laxative effects of coffee are currently unknown, it is clear that decaf can stimulate the production of gastrin, which promotes digestion.

The gastrocolic reflex is triggered by the stomach stretching and causes the colon to increase its motility

The gastrocolic reflex is a physiological reflex that controls the motility, or peristalsis, of the gastrointestinal tract following a meal. It involves an increase in the motility of the colon, which consists primarily of giant migrating contractions in response to stretch in the stomach following ingestion and byproducts of digestion entering the small intestine.

The gastrocolic reflex is mediated by enteric nerves and enhances colonic motility after a meal, leading to defecation. The reflex propels existing intestinal contents through the digestive system to make way for ingested food. It is a normal physiological response that occurs soon after eating food, in which the large intestine (colon) suddenly has rhythmic contractions, called peristalsis, that stimulate the urge to defecate.

The gastrocolic reflex is instigated by hormones called cholecystokinin and motilin. As you eat, the expansion of the stomach triggers the release of these hormones in the small intestine, causing a normal and perfectly natural chain of events. Cholecystokinin triggers the release of digestive fluids from the gallbladder and pancreas into the small intestine. While this is happening, cholecystokinin stimulates contractions to move food out of the stomach and suppresses appetite so the stomach doesn't get overfilled. Motilin stimulates peristalsis in the stomach and small intestine motility, causing undigested food to move into the colon. This, in turn, stimulates the urge to defecate.

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