Eating and digestion are daily, life-sustaining events. It's no wonder, then, that a healthy digestive system is revered in Ayurveda as a cornerstone of well-being and that every disease is believed to arise from inefficient digestion. The fiery metabolic energy of digestion, known as agni, allows us to assimilate food while ridding the body of wastes and toxins (ama). It transforms dense physical matter into the subtler forms of energy the body needs to be vital, generate internal warmth, and produce a clear mind.
There are many types of agni in the body. Within the digestive system, agni determines the production of hydrochloric acid in the stomach (where it's known as jathar agni), bile acids in the liver (bhuta agni), and sugar-digesting pancreatic enzymes (kloma agni). It also regulates the thyroid gland (jatru agni) and the metabolic transformations of the tissues (dhatu agni). Special agnis are even found in each cell. The metabolic pathway of agni begins with digestion and ends in the cells.
This might sound complex. But simply put, when agni is weak, there is not enough digestive power to metabolize food into energy. On a subtler level, indriya agni, known as the door of perception, helps digest and transform external information into knowledge. Thus, a stronger agni allows for a clearer and more vital body and mind.
You want a balanced agni that is neither too weak nor too excessive. The quality of agni varies depending upon one's dosha: vata, pitta, or kapha. In vata and kapha types, agni tends to be weak and the digestive system "cold," sluggish, or irregular, which can result in malabsorption disorders, chronic constipation, loose stools, and gas. In pittas, the fires of agni can become excessive and cause heartburn, acid reflux, colitis, and other burning sensations.
An easy way to support digestive agni is through the daily use of culinary herbs and spices, used to increase agni before and during meals. I have learned not to distinguish between the culinary and medicinal uses of herbs and spices. In ayurvedic cooking, it is believed that within them lies the medicine of optimal health and long life, aiding digestion and ensuring that more energy and fewer toxins are taken into the body.
A simple ayurvedic practice is to consume a small piece of fresh ginger with a few drops of lemon juice prior to eating a meal. This slowly and gradually awakens the flames of agni, preparing it to digest the main course. In addition to ginger, other aromatic spices that assist digestion include black, long, and cayenne pepper; cardamom; and licorice. They are believed to make foods more digestible by "predigesting" the food during cooking—heat combines and awakens their aromatic qualities, making the nutrients easier to digest once eaten. These spices also stimulate the secretion of saliva and digestive enzymes in the stomach and intestines, and the less work agni needs to do while digesting food, the less fatigue one will experience after eating.
Cooking herbs and spices also serve to prevent gas and ama. Undigested food is broken down by fermentation rather than digestion, and fermentation is what produces gas. The intestines can then absorb these gases, which causes the colon to become toxic and spastic. Fennel is an herb commonly consumed in Indian restaurants as a carminative after meals to prevent gas, discomfort, and fatigue. At home, chew on a teaspoon of fennel seeds, then spit out the pulp after swallowing the juice.
Hing is also used in ayurvedic cooking to remedy weak digestion. A resinous sap from the root of the asafetida plant, this spice is a potent digestive aid capable of removing impactions in the gastrointestinal tract. In the classic ayurvedic preparation hingavashtak, hing is mixed with other aromatic and carminative herbs and spices to promote deeper assimilation of nutrients. Their drying, warming, and stimulating actions awaken agni and tone the digestive system.