The digestive system plays a very important role in Ayurveda and in its understanding about health and disease. Although Ayurveda does believe that all diseases and conditions first take its origin in mind, but on a more physical and physiological level, this comes down to the metabolic processes that are disturbed in the body. Bearing this in mind Ayurveda gives immense importance to the digestive system and its function in the body.
According to Ayurveda, there are seven tissues in the body:
- Rasa Dhatu: Plasma and fluid
- Rakta Dhatu: Blood
- Mamsa Dhatu: Muscles
- Medhas Dhatu: Fat
- Asthi Dhatu: Bone
- Majja Dhatu: Marrow and nervous tissue
- Shukra Dhatu: Reproductive tissue
Ayurveda describes a very unique process in the body which says that the above seven tissues must always be mentioned in the above chronological order because their formation in the body also follows the same order. For example Rasa Dhatu is the first to be formed after digestion of food. Once Rasa is produced, it will help in the formation of Rakta. Through Rakta, Mamsa is formed. And thereafter, Medhas, Asthi, Majja, Shukra are formed in that particular order. Proper and complete formation of the previous tissue or Dhatu is vital for the healthy formation of the next Dhatu. Therefore it is important that the metabolic processes are running efficiently in all the seven stages of tissue formation.
Phases of digestion:
Ayurveda explains two phases in digestion. Digestion not only occurs in the digestive tract but also in the Dhatus or tissues (away from the digestive system). And Ayurveda clearly demarcates between the two processes.
Prapaka: This is the initial stage where conversion of food takes place in the digestive tract and is absorbed by the intestinal walls as nutrients
Vipaka: This is the second stage where the nutrients are used for the formation of the seven tissues or Dhatus.
Ayurveda also explains another entity called "Agni". This word literally means fire. But in this context it means digestive fire. Agni can also be defined as the biological fire or heat that governs metabolism. It can be compared to digestive enzymes and metabolic processes that take place in our body to help break down, digest, absorb and assimilate food. Ayurveda say that a man is as old as his "Agni" or digestive fire. As long as the digestive fire is strong, Ama cannot be formed in the body.
There various types of Agnis. The first and foremost is the Jatharagni which acts on the food that has been ingested and helps in its transformation into nutrition.
There seven different Agnis that correlate to the seven Dhatus or Tissues. They are Rasagni, Raktagni, Mamsagni etc. Each of this Agni acts on the related Dhatu or tissue to aid complete digestion at that level and helps in the formation of the next Dhatu or tissue.
The normal process that should take place in the body is as follows: All the food we eat should be fully digested. Half of it is absorbed into the body as nutrients and the rest of it expelled out of the body as waste products.
But sometimes due to external negative influences (e.g. stress, strain, adverse weather, inappropriate food and habits) not all the food we eat is fully digested. Perhaps just one third of the food is fully digested and absorbed as nutrients; the other third is fully digested and expelled out of the body as waste products. But there still remains a third of the food which is in a half digested condition. Because of this, it cannot be identified as either nutrients or waste products. Therefore it is neither absorbed nor expelled out. This half digested unmetabolised food product circulates in the body as toxins. Ayurveda has named such toxin as "Ama". Ama is a Sanskrit word which literally means undigested or uncooked. The first stage of any disease is also sometimes called Ama.
The inference of the above is that complete digestion of all foo