"Functional food" refers to any food that has a positive benefit on any aspect of health including improving well-being, treating symptoms, and reducing risk of disease. These foods are somewhat subjective and defining whether they are "functional" often depends on their traditional usage as medicine in addition to whether they provide benefit according to the scientific literature. Many of the benefits of functional foods are for digestive health as 10-50% of these plants have a traditional indication as a remedy for gastrointestinal ailments. 

When deciding which functional foods to use it may be useful to understand the ailments they are said to traditionally improve, what the science says, and the action they have in the body. For example, some of these natural treatments may contain enzymes to help breakdown food while others may improve how the food moves through the gastrointestinal tract. This article will breakdown a few of the best functional foods for digestion as well as how they may improve gastrointestinal health.

Artichoke:

With the ingestion of certain bitter substances (like artichoke) the body has a protective reaction that has evolved to increase the speed that food moves through the gastrointestinal tract. These substances trigger the body to release many digestive enzymes and hormones that are responsible for improving digestion. Studies have shown artichoke to increase bile production while improving functional digestive symptoms like nausea, abdominal pain, bloating, flatulence, and constipation (1). 

Dandelion:

Likely due to the same stimulation of bitter receptors, dandelion has been shown to be a very effective herbal remedy for the treatment of digestive symptoms. A mixture of extracts from dandelion, artichoke, turmeric, and rosemary essential oil was shown to reduce the severity of digestive complaint (2). 

Lemon:

This has long been used as traditional digestive aid in both Eastern and Western cultures. The first way that lemon may improve digestion is by stimulating salivation in the mouth, which is how the body initially begins to break down nutrients. This same stimulus also increases the amount of certain digestive enzymes that are secreted from the stomach and pancreas; which ultimately influences how the body breaks down food. 

Peppermint:

Commonly given at restaurants in the form of peppermint candies, this has been an age-old traditional remedy to improve digestion and reduce spasm of the digestive tract. Studies have shown that the peppermint essential oil is effective at decreasing pressure within the colon, relaxing muscle within the digestive tract, and improving digestive symptoms (1). These improvements in symptoms may be due to peppermint's ability to slow the emptying of the stomach, which gives food more time to be broken down and digested before it moves along to the small intestine. Peppermint is one of the most well researched natural remedies for digestive issues and a recent meta-analysis concluded that it is a very safe and effective remedy for symptoms of Irritable Bowel Syndrome (IBS) (3). 

Chamomile:

Commonly used as a relaxing ingredient in tea and supplements, chamomile has also been shown effective for improving digestion. Many studies have shown that the relaxing effect of chamomile is also seen in the gastrointestinal tract as the herb has also been shown to reduce pressure and spasm of the digestive organs (1).

Ginger:

One of the oldest spices in history, ginger has been used in Asian medicine as a treatment for digestive complaints for hundreds of years. Ginger has been shown to have a complete effect on the digestive system by reducing spasm, stimulating digestive enzyme secretion to promote breakdown of food (1), and decreasing nausea and vomiting (4). 

Pineapple and Papaya:

These each contain a large amount of their own special digestive enzyme; Bromelain (in pineapple) and Papain (in papaya). These enzymes are said to be powerful digestive aids due to their ability to break down protein from foods. The fiber in these functional foods also help to push contents through the digestive tract. These features make pineapple and papaya excellent dessert choices that may improve the digestion of your meal.