Vibrant immunity requires a robust digestive fire, or agni. Here’s how to know when your agni may be struggling, and how to support it.

In her book, The Human Advantage, neuroscientist Suzana Herculano-Houzel points to the invention of cooking as the singular advancement that led to humans developing the largest primate brain.

“Cooking is essentially the act of using fire to pre-digest food, and thus to get more energy out of the same amount of food,” Herculano-Houzel writes. “This is what allowed our brains to get bigger in a relatively short period of time. Cooking also allowed us to support this large cerebral cortex, which in turn supports complex thought.”

We take it for granted now, but the discovery of fire was a game-changer. Fire gave warmth, fire gave light, and fire gave protection from wild animals. People gathered together around a fire, cultivating the social bonds essential to survival. Fire consumes waste—it is cleansing and purifying. Ancient people considered fire to be a god. That god, agni, is a force of nurturance, sustenance, and, potentially, destruction.