Eat Warm Food: Charaka Samhita Vimanasthana 1.25 on Ushnam Ashniyat, Five Reasons and How Warm Is Warm

इस लेख को हिंदी में पढ़ें: गरम खाना क्यों खाएँ: चरक संहिता विमानस्थान 1.25 के पाँच कारण और सही तापमान

📖 19 min read · Charaka Samhita, Vimanasthana 1.24-1.25; Bhavaprakasha, Dinacharya 218; Sun (1988), Mishima (2009), Talavera (2005), IARC (2016)

The Cold Tiffin: Today's Habit and the One Thing We Get Wrong

The tiffin is packed at eight in the morning: two rotis, a dry sabzi, perhaps a small box of dal or rice. By lunchtime it has spent five hours in a bag, and it is eaten as it is, cold, at the desk. At home the fridge does the same job. Last night's dal comes out, a spoon goes in, and nobody waits for the stove.

Packed at eight, eaten at one: a closed tiffin waits on the desk all morning.

None of this feels like a mistake. Most of us think of warm food as a matter of taste: hot dal is nicer, cold dal is a small loss, and that is the end of it. That is the one thing we get wrong. In the Charaka Samhita, one of the oldest texts of Ayurveda, warmth is not a garnish. It is the first word in Charaka's list for the method of eating, and he gives five separate reasons for it. Taste is only the first of the five. The other four are about what happens after the food has been eaten.

Our reel asked: do you eat a cold tiffin every day? It named three of Charaka's reasons and promised the other two, with an answer to a fair question: how warm is warm? This page keeps both promises.

Ahara Vidhi Vidhana: Ushna Is the First Word (Charaka Samhita, Vimanasthana 1.24)

The rule comes from the first chapter of the Vimanasthana, the Rasa Vimana. In verse 1.24 Charaka sets out the method of eating (ahara vidhi vidhana) that is most wholesome by nature for the healthy, and for some of the sick at the right time. It is one long list, and its first word is ushnam, warm:

After warm come unctuous (snigdha), the right quantity (matravat), eating after the last meal is digested (jirne), and so on, down to not talking and not laughing (ajalpan, ahasan) and keeping the mind on the food (tanmana). Our article on the snigdha rule walks through the whole list under its own heading, Ahara Vidhi Vidhana, and our page on how fast to eat reads the speed rules (natidrutam, nativilambitam). Here we stay with the first word. The next verse, 1.25, explains each item, and the CSRTSDC edition (carakasamhitaonline.com) numbers warm food rule (1).

Ushnam Ashniyat: Vimanasthana 1.25, Clause by Clause

Verse 1.25 opens with a line of its own, tasya sadgunyam upadekshyamah: we will now tell their merits. Then comes the first rule with all of its reasons, in one sentence:

Here it is clause by clause, in plain words:

• Ushnam ashniyat. One should eat (ashniyat) warm food (ushnam). This is the rule. Everything after hi, "for", is the reason.
• Ushnam hi bhujyamanam svadate. For warm food, while it is being eaten (bhujyamanam), tastes good (svadate). Reason one.
• Bhuktam ca agnim audaryam udirayati. And once it has been eaten (bhuktam), it stirs up (udirayati) the fire (agni) of the belly (audarya, from udara, the belly). Reason two.
• Kshipram jaram gacchati. It goes (gacchati) quickly (kshipram) to digestion (jara). Reason three.
• Vatam anulomayati. It moves vata in its proper direction. Reason four.
• Shleshmanam ca parihrasayati. And it reduces shleshman, another name for kapha. Reason five.
• Tasmad ushnam ashniyat. Therefore (tasmad) one should eat warm food. The sentence ends where it began.

Count them and there are five reasons, each in its own clause. Two time words divide them: bhujyamanam, while it is eaten, belongs to the first reason only, and bhuktam, once eaten, to the other four. So only one of Charaka's five reasons is about the mouth.

Three things to know about the editions

A typo in the Sanskrit. The Devanagari on carakasamhitaonline.com prints the last verb as «परिह्राससयति», with one syllable too many. The word is परिह्रासयति (parihrasayati), "reduces", and that is how we print it above.

Two brackets that are not in the Sanskrit. The edition's English reads: One should eat warm (freshly cooked food) because it tastes well and the food consumed stimulates the digestive process, gets digested quickly, normalizes functions of vata dosha and reduces kapha dosha (which obstructs digestion process). Both brackets are the translator's glosses. The Sanskrit says only ushna, warm. It says nothing about when the food was cooked, and nothing about kapha obstructing anything. Charaka does have a rule about food kept from an earlier cooking, but it is a separate rule in another chapter (Sutrasthana 8.20), and our article on stale food (paryushita) reads it. Warmth and freshness are two questions, and this verse asks only the first.

Cold and set, straight from the fridge: the coldest way to meet a meal.

A chart that counts four. The second English version we read, the Charaka Samhita: Handbook on Ayurveda (Vol. I), sets the rules out as a chart. Its row for warm food reads: stimulates Agni, digests quickly, carminates flatus, reduces mucus. That is four reasons. "Tastes good" is missing from the row, although the chart gives it to unctuous food in the next row. The Sanskrit has svadate for both. Counted from the Sanskrit, the reasons for warm food are five.

Svadate, Agni and Jara: The Three Reasons Our Reel Named

The reel had room for the first three. They are Charaka's reasons for his rule, in his words, not a promise about any meal.

1. Svadate: warm food tastes good while it is eaten

Ushnam hi bhujyamanam svadate. The verb svadate means it is relished, it tastes good. The edition: it tastes well. Anyone who has eaten the same khichdi hot from the pan and cold an hour later knows the difference the text is pointing at. The reason is tied to a moment, bhujyamanam, while it is being eaten: in this verse, warmth is part of the taste itself.

2. Agnim audaryam udirayati: it stirs up the fire of the belly

Bhuktam ca agnim audaryam udirayati. Once eaten, it stirs up the agni of the belly. Agni, fire, is the word Ayurveda uses for the power that digests food; the fire of the belly is often called jatharagni. The verb udirayati means to stir up or set going, the way one stirs embers. The edition renders the clause as stimulates the digestive process, the Handbook as stimulates Agni. Charaka's unctuous-food rule uses almost the same words, and our snigdha article notes the one word that changes.

Agni is a concept of Ayurveda, not a thermometer reading. Keep that in mind when we set a measurement of the stomach's temperature beside it below.

3. Kshipram jaram gacchati: it is digested quickly

Kshipram jaram gacchati. It goes quickly to digestion. Kshipram is quickly; jara here is digestion, from the same root as jirne, "when digested", the fourth item of the list in 1.24. The edition: gets digested quickly. The Handbook: digests quickly.

Charaka's Other Two Reasons: Vata Moved in Its Proper Direction, Kapha Reduced

This is the part the reel promised. The last two reasons name two of the three doshas of Ayurveda, vata, pitta and kapha, the text's terms for the working principles of the body. As before, these are Charaka's concepts, not health claims.

4. Vatam anulomayati: it moves vata in its proper direction

Anuloma means "along the hair", or, as we would say, with the grain. Its opposite is pratiloma, against the grain. To make vata anuloma (vatanulomana) is to send it the way it naturally goes. Which way is that? The same verse answers a few lines later. In rule (4), eat after the last meal is digested, Charaka lists the signs that the earlier meal is done, and one of them is vatanulomya, vata moving in its proper direction, set right beside the release of the body's natural urges:

So in this chapter, vata in its proper direction is vata moving down and out, the way the body is built to move it. The edition renders the reason as normalizes functions of vata dosha, and the Handbook, in plainer body words, as carminates flatus. The Sanskrit says only vatam anulomayati.

5. Shleshmanam ca parihrasayati: it reduces kapha

Shleshman is another name for kapha, the heavy, cold and stable dosha in Charaka's list of qualities below. Parihrasayati means it makes less, it reduces. The edition: reduces kapha dosha, followed by its bracket. The Handbook: reduces mucus. Once again the Sanskrit names only the dosha, and the body words are the translators' own.

Warm food on a cold morning: the verse says warmth moves vata in its direction and reduces kapha.

Why vata and kapha, and not pitta?

Verse 1.25 does not say why warm food acts on these two. But the first chapter of the Charaka Samhita gives each dosha a list of qualities (gunas), and the lists point to an answer.

Both lists contain the same word: shita, cold. And this very chapter of the Vimanasthana states, at 1.14, the principle that links them: विरुद्धगुणसन्निपाते हि भूयसाऽल्पमवजीयते, when opposite qualities meet, the lesser is overcome by the greater. Its example is oil, which in the edition's English possesses unctuousness, hotness and heaviness and so pacifies vata, because vata possesses roughness, coldness and lightness. Warmth meeting cold is the same logic. Read together, the three passages give one way to see why a warm meal is said to move vata and reduce kapha. That is our reading of them, not a sentence the text writes.

Notice also the dosha that is missing. Pitta's own list (Sutrasthana 1.60) includes hot, ushna, itself. Verse 1.25 says nothing about warm food and pitta, and we will not say it for the text.

The Modern Reading: A Cold Drink Inside the Stomach, and a Hot Meal

No study has tested Charaka's verse, and none could measure agni, which is not a laboratory quantity. But researchers have asked a narrower question: what does the temperature of a meal or a drink do inside the stomach?

Sheffield, 1988: the stomach after a cold drink

At the Department of Surgery of the University of Sheffield, Sun WM, Houghton LA, Read NW, Grundy DG and Johnson AG studied six healthy volunteers aged 19 to 24 (Gut 1988;29(3):302-5; PubMed 3356361). In a series of tests, the volunteers drank an orange-juice drink at one of three temperatures: 4 °C (cold), 37 °C (the control, about body temperature) or 50 °C (warm). The team measured the temperature inside the stomach and how fast the stomach emptied. Their abstract reports:

One drink at three temperatures: the Sheffield team tested orange juice at 4, 37 and 50 °C.

• After the cold drink, the mean lowest temperature inside the stomach was 21.2 °C, reached 45 seconds after drinking began.
• After the warm drink, the mean highest was 43.0 °C, at 60 seconds.
• After both, the stomach came back to body temperature within 20 to 30 minutes.
• The initial rate of gastric emptying (how fast the stomach passes its contents on) was significantly slower for the cold drink than for the control.
• For the warm drink, the difference from the control was not statistically significant.

That last point matters. In this study the drink at body temperature emptied fastest; the authors write that Warm and cold drinks appeared to empty from the stomach more slowly than the control drink. So Sheffield does not show that hotter is better; it shows that cold was slower at the start.

Set that beside Charaka. His word for what warm food does once eaten is agni, the fire of the belly; the Sheffield team's word is temperature, a stomach that dropped to about 21 °C after a cold drink. These are different words from different worlds, and the measurement does not prove the verse. The reader can draw the link, or not.

Shimane, 2009: a hot meal and the first phase of emptying

At Shimane University in Japan, Mishima Y and colleagues (J Gastroenterol 2009;44(5):412-8; PubMed 19308311) gave a liquid meal to 25 healthy volunteers and a solid meal to another 25, each at 4, 37 and 60 °C, and followed the emptying of the stomach with a breath test. With both meals, the lag phase, the first stretch before emptying gets going, was significantly shorter at 60 °C than at 37 °C. The half-emptying time, the time for half the meal to leave the stomach, showed no difference. The authors concluded: These findings suggest that a hot meal significantly accelerates gastric emptying.

Both studies used small groups of healthy volunteers, and the speed at which a stomach empties is not the same thing as Charaka's jara, digestion.

Leuven, 2005: why warm food may taste sweeter

Charaka's first reason is svadate, warm food tastes good. At KU Leuven in Belgium, Talavera K and colleagues (Nature 2005;438:1022-5; PubMed 16355226) studied TRPM5, a channel in the taste buds of the tongue that has a key role in sweet, umami and bitter taste. They found that its currents increase steeply at temperatures between 15 and 35 degrees C, and that warming over that range markedly enhances the gustatory nerve response to sweet compounds in normal mice, though not in mice bred without the channel. The authors suggest this may underlie known effects of temperature on perceived taste in humans, including enhanced sweetness perception at high temperatures. It is a study of mice and of sweet taste, and the authors say "may": beside svadate, a hint, nothing more.

How Warm Is Warm? Ushna, the Studies' Temperatures and the 65 °C Line

Charaka's word is ushna, and his verse gives no number. The word covers a range. In the same chapter, at 1.14, the edition translates the ushna quality of oil as "hotness", while in the method of eating it chooses "warm". For a meal, warm is the right English.

A later classical text says the other half out loud. The Bhavaprakasha (Purva Khanda, Dinacharya, verse 218), in the Hindi-commentary edition we read, puts it in one line:

So the classical picture has two edges: not cold, and not too hot. Our article on the Bhavaprakasha's meal rules (bhojana vidhi) reads this verse with its neighbours.

Modern sources give numbers. The studies above used 4 °C for cold, 37 °C for body temperature, 50 °C for a warm drink (Sheffield) and 60 °C for a hot meal (Shimane). Above that range there is a line worth knowing.

An old habit: chai poured into a saucer to cool before it is drunk.

The 65 °C line for very hot drinks (IARC, 2016)

In June 2016, the International Agency for Research on Cancer (IARC), which is part of the World Health Organization, evaluated drinking very hot beverages (press release No. 244, 15 June 2016; IARC Monographs Volume 116). It defines its term plainly: “Very hot” refers to any beverages consumed at a temperature above 65 °C. Its finding: Drinking very hot beverages was classified as probably carcinogenic to humans (Group 2A). The evidence concerned the oesophagus, the food pipe, and the agency calls it limited. It came from studies in places where, the release says, tea or maté is traditionally drunk very hot (at about 70 °C).

Three more lines from the same release keep this in proportion. Group 2A names a hazard; it is not a measure of how large any risk is: The classification does not indicate what level of risk exists to people’s health associated with exposure to a classified hazard. The concern is the temperature, not the drink: for maté drunk at temperatures that are not very hot, the release found No conclusive evidence. And it cites a WHO report which states that people should not consume drinks when they are at a very hot (scalding hot) temperature. The message is not to give up tea. It is to let a scalding cup cool before you drink it.

What this means at the table

Charaka asks for warm. The Bhavaprakasha warns against too hot. IARC draws its line above 65 °C for drinks. For reheated food, the UK Food Standards Agency (FSA) has its own rule, written for food safety rather than taste: make sure it is steaming hot all the way through. Heat it that far, then give it a minute or two to settle to a comfortable warmth before you eat. A rough test of our own, not from any source: if you have to blow on every spoonful, it is still too hot; if you can eat at an easy pace without waiting, it is warm.

The Office Tiffin Through Charaka's First Rule

Our reel's comment word is TIFFIN, so here is the practical part. These are our own suggestions for bringing a packed lunch closer to Charaka's first rule. They are editorial, not medical advice, and none of them is a promise about anyone's health.

A warm tiffin at the desk: Charaka's first rule, applied to lunch at work.

Heat it at work, all the way through. If your office has a microwave or a hot plate, heat the dal, sabzi or rice until it is steaming hot all the way through, as the FSA advises for reheated food, then let it settle to a comfortable warmth. Our stale-food article sets out the FSA's reheating rules, including why to stir halfway.

Or pack it hot in an insulated tiffin. An insulated steel tiffin, or an electric one that heats at the desk, keeps the meal closer to ushna than a plain box. Fill an insulated one straight from the stove and eat at the first lunch break. Food that has drifted down to lukewarm over many hours is no longer warm food, and our stale-food article explains why it needs care.

Fridge food: take out a portion and heat it. Eating dal or rice straight from the fridge is the coldest way to meet a meal. Take out only what you will eat, heat that, and put the rest back at once. How long food should be kept at all is Charaka's other rule, na paryushitam (Sutrasthana 8.20), set out with the FSA's limits in the same stale-food article.

Add one warm thing. If the rotis and sabzi must stay as they are, a warm dal, rasam or soup beside them changes the meal. For water with food, the classical texts have their own rules for warm water (ushna jala) and cool water (sheetala jala), which our article on Vagbhata's water chapter reads.

Cook fresh where you can. A tiffin made in the morning is fresher than last night's dinner packed again. A quick khichdi, poha or upma made at breakfast and packed hot answers both of Charaka's rules at once: warm, and not stale.

Do not let it go cold on the plate. The same verse gives a reason for not eating too slowly: the food goes cold. Our page on how fast to eat reads that clause.

Keep the quantity in view. Warmth is the first rule and quantity the third. Our article on the three parts of the stomach (Vimanasthana 2.3) reads that one.

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