This Is the Key to a Healthy Immune System

This Is the Key to a Healthy Immune System

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.


The digestive fire, just like a fire pit, needs to be stoked to keep burning.

The Fire Within

Over time, people came to understand that we have an internal agni. That agni within is also a power that warms, protects, purifies, and transforms, binding what is beneficial and supportive, while destroying waste and non-essentials.

Our principle agni is our digestive fire, but we also have metabolic fires, synaptic fires, optic fires, and temperature-regulating fires. These fires of conversion help us turn food, information, and experiences into nourishment for our bodies, minds, and lives.

Many believe that every time we sit down for a meal, we are feeding our bodies and minds—and even a divine fire that resides within us as an aspect, or a reflection, of the original fire of creation.

What Does It Mean to Be Healthy?

Ayurveda says that health is more than the absence of disease. Vibrant health is balance, nourishment, and contentment in body, mind, senses, and soul. The Ayurvedic definition of health can be translated as:

  • Balanced doshas
  • Balanced digestive fire (digestion, assimilation, and metabolism)
  • Balanced conversion of food into the body's tissue layers
  • Proper waste elimination
  • Blissful soul, senses, and mind

Health is attained when all these things are present.


healthy woman smiling in front of a blue sky

Agni and Ojas: Our Partners in Wellness

When you feed wholesome food to a healthy digestive fire, the nourishment passes from the digestive tract to your entire body by way of the seven tissues which are nutrient plasma (rasa), blood (rakta), muscle (mamsa), fat (medha), bone (asthi), bone marrow and nervous tissue (majja), and the reproductive tissue (shukra).

Each of these seven tissues has its own fire, called the dhatu-agnis. These seven fires synthesize tissue layers and are everywhere in the body. The end result of the seven fires, and ultimately the end result of digestion, is ojas, which can be translated as your inner glow, immunity, and vitality. Balanced agni gives strong ojas.

Think of ghee, which is said to go through seven fires before it becomes that great elixir that it is. First, there is the fire of the sun that becomes metabolized into grass, which is then eaten by a cow, metabolized into milk, fermented into yogurt, cultivated into butter, and then cooked to make ghee.

Just like ghee, the end result of your seven fires is ojas. When your fires are balanced and bright, you could say you become like a bucket of ghee—golden, nourishing, and well-oiled!

Signs that Agni or Your Immune System May Be Struggling

Obviously, if you are getting sick often or recover slowly from colds, then you know your immune system is likely to be compromised. Additional clues may be sluggish digestion, lack of appetite, gas, bloating, cramping, constipation, diarrhea, tongue coating, skin irritations, chronic fatigue, excess kapha, stagnation, and brain fog.

7 Ways to Fire Up Agni for Better Immunity

1. Align: Follow the sun

Eat with the cycles. As nature changes with each season, so does your body's needs. Locally grown, seasonal foods offer the balancing nourishment the digestive fire seeks. Try to eat your meals at the same time each day, with warm, cooked, gently spiced foods at breakfast and dinner, and your biggest meal at lunchtime. Have your last meal of the day as the sun goes down, or at least three hours before you sleep for the night.

2. Ignite: Spice it up

Adding small amounts of sour and pungent tastes to each meal is like adding kindling to a fire. Sour tasting foods are acidic and include citrus, ferments, vinegars, yogurt, and kombucha. Pungent foods tend to be spices and herbs like ginger, cinnamon, cardamom, cumin, clove, coriander, fennel, mint, and black pepper.

3. Hydrate: Heat it up

Sip warm or hot water throughout the day. Accompany meals with a spice tea—cinnamon, mint, ginger, or CCF Tea. Add a dash of black pepper for more fire power and lemon for better hydration.

4. Respect: Give it a break

As one of my Ayurvedic teachers says, “Eat three meals a day and then zip it.” Some people call that intermittent fasting. Ayurveda calls it, Ayurveda.

5. Rest: Give yourself a break

Stress will put out the fire like a bully kicking the campfire. Prayer, meditation, mindfulness, nature walks, art, and journaling are just a few of the practices that help quiet the mind, soothe the heart, calm the nervous system, and encourage your body to rest and digest. Sleep, too, is essential medicine and I Sleep Soundly can help promote deeper rest. 

6. Circulate: Power up

Walking, hatha yoga with pranayama, and aerobic exercise support the inner fires.

7. Trust: You are you and there is nobody like you

Each one of us is uniquely designed. There is no one superfood or super diet that is perfect for all. Adjust your diet to your own individual needs. Let your intuition guide you. You have an incredible wisdom within.

However, if it feels overwhelming, or you would like some guidance, seek out an experienced Ayurvedic practitioner to help you develop a personalized plan. If you haven't already, you can also get started with the Ayurvedic Profile™quiz.

Feeding Your Fires

Feeding your own inner fires means feeding your inner radiance, your inner intelligence, your inner life force. Ayurveda reminds us that the right food and spices, right timing and practices, can not only feed you, but can feed your agni to make you glow like a god.

We may no longer consider digestion to be a divine being but given how powerful it is in maintaining and strengthening your life force, you could say it is one of your super powers.

About the Author

Laura Plumb, AP

Author of the best-selling book Ayurveda Cooking For Beginners and creator of numerous courses and series on Ayurveda, Laura promotes sacred, sumptuous living through Ayurveda, Jyotish,...

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