Food that we consume is transformed into energy through a magical process. We call this digestion, the process by which the body breaks down the food that we consume and assimilates it into our physiological systems. Ayurveda attributes this process to Agni, the element which, in its multidimensional forms, ensure that the food is transformed into energy and excreta.
This is a complex process of acceptance and rejection, done at different levels within the body. According to the functions and site of action, Agni has been divided into 13 types, i.e. one Jatharagni, five Bhutagni and seven Dhatvagni. Jadharagni is considered to be the most important among these as it digests four types of food and transforms it into Rasa and Mala. The five Bhutagnis act on the respective bhutika portion of the food and thereby nourish the Bhutas in the body. The seven Dhatvagnis act on the respective dhatus by which each Dhatu is broken into three parts.
Food is basically the substance that can be utilized by the body-systems to make create tissues and nurture them. But such a substance can deliver its duty only if it is acceptable to the biological system. Consider the example of poisons. They may contain proteins, but these proteins are not acceptable to the body and, if consumed, they kill the system. This is because, Agni cannot process a poison.
The capacity of the Agni to process food is miraculous. It breaks the complex structures into simpler forms, makes a pool of basic elements and facilitates re-organization of such basic elements to form the body-tissues. In this process, it adapts in a thousand ways to make sure that every stage of this complex transformation is executed properly. It tries to nullify the toxic elements of the food stuffs. If it fails in this effort, it makes sure that such things do not get entry into the system.
Every object that enters the body in the form of food is processed, detoxified, digested, reorganized and assimilated into the system to ensure that re-building of tissues takes place unhindered. In short, the very survival of an individual is based completely on the capacity of his/her Agni to perform. That is how Agni became a representation of divinity, if not God herself.
Ayurveda gives the topmost priority to the capacity of Agni to perform its function to heal as well as nurture. Chikitsa (healing) is, in effect, nothing but Agnichikitsa (maintenance of Agni). And the ultimate aim of any Chikitsa is to preserve and sustain Agni. It may be interesting to note that all the seven types of Shamanachikitsa in Ayurveda that seeks to pacify the Doshas are geared towards manipulation of Agni for the betterment of physical health.
