Coffee & digestive health: What the science says

MYTH 1: Coffee aids digestion

TRUE: Drinking coffee in moderation (3-5 cups per day¹) helps to stimulate the digestive process².

Coffee stimulates the secretion of the digestive hormone gastrin and hydrochloric acid present in gastric juice, both of which are involved in the breakdown of food in the stomach². Coffee also stimulates the secretion of cholecystokinin (CCK), a hormone that increases the production of bile, a fluid that helps to break down fats in the digestive tract².

MYTH 2: Coffee reduces the risk of constipation

TRUE: Coffee may stimulate motility in the colon to a greater extent than both decaffeinated coffee and water^2-4.

Most food and drink stimulate movement in the large intestine, as part of the digestive process^2,3. Regular coffee may stimulate motility in the colon as much as cereals, 23% more than decaffeinated coffee or 60% more than a glass of water⁴, and it may be linked to a reduced risk of chronic constipation^2-4.

MYTH 3: Coffee triggers heartburn

FALSE: Research has found no significant association between coffee consumption and the risk of heartburn or chronic acid reflux (GORD)^6-8.

Coffee consumption has been suggested as a possible cause in some cases, however there is no evidence that it affects the symptoms of gastroesophageal reflux disease (GORD)6-8. One study proposed that large meal volume and high calorie content may be more important factors⁷.

Furthermore, science suggests no significant relationship between coffee consumption and the four major upper gastrointestinal disorders (gastric ulcer, duodenal ulcer, reflux esophagitis, and non-erosive reflux disease)⁵.

MYTH 4: Coffee is good for gut bacteria

TRUE: Whilst this is a growing area of research, coffee consumption is generally reported to increase gut microbiota diversity^9-11.

The polyphenols present in coffee can induce positive changes in the composition of the gut microbiota, mainly at the population level of Bifidobacteria, considered to be ‘good bacteria’^3,9-11. A healthy microflora can help to protect against infections, support the immune system, and contribute to healthy digestion. The role of food and drink consumption on gut microflora is a complex and growing area of research, which will continue to benefit from further studies^3,9.

More information on coffee and gastrointestinal function can be found here.