Chilli, chile, chili

Naming, discovery and science

6XC
5 min readOct 16, 2021
Photo by Mamun Srizon on Unsplash

One in 4 people eat chilli daily; but are they eating chilli, chile or chili? And, why peppers?

The word is regional and historical. The plants are native to South/Central America, and the word ‘chilli’ was the Latin translation from the Aztec Nahuatl language (an oral language). It has become standard spelling in the UK and Australia. In North America (including Mexico), it can be spelled chili or chile. More subtly, in the US the fruit can be called chile, whereas food prepared with the fruit is prefixed chili (e.g. chili con carne is made with chile).

In the US, chillies are often referred to as peppers, hot peppers or chile peppers. Chillies have nothing to do with pepper of course (which is an Indian vine; active ingredient piperine), so where did this confusing terminology come from? You can blame a delusional Columbus.

Columbus’ main objective was to find a route to Asia and to its lucrative spices, including pepper (Indian pepper). His goal was not to prove the Earth was ‘round’ — that was known by then.

When he landed on the Americas, he was convinced he was in Asia. He wanted to take some spices back to Spain (he couldn’t actually find any, but that didn’t stop him making some up). When he was introduced to the heat of chilli, he decided it was a new and improved pepper and so named it accordingly. The name has persisted in places, mainly in the US.

Unfortunately for Columbus, chillies were easy to cultivate and as they proliferated worldwide with expanding trade they became common and inexpensive. Unlike Indian pepper, there was no money to be made from chillies.

Ironically, the world’s largest producer of chillies today is India.

The active ingredient in hot chillies is capsaicin, which is found in greatest concentration in the placenta (the inner pale parts that the seeds attach to) and to some extent in the seed coverings themselves. Capsaicin is an amine formed by 3-hydroxy-2-methoxy-benzylamine and 8-methyl-6-noneneoic acid. The name makes ‘monosodium glutamate’ look like child’s play.

Capsaicin is antimicrobial and an irritant to herbivores (including mammals). It seems likely that the evolutionary drive for it was antimicrobial. A common microbial fungus that rots chilli seeds, fusarium, is killed by capsaicin. The fungus enters the fruit through tiny holes bored by insects of the order hemiptera. These insects come with a proboscis for piercing and sucking sap (e.g. aphids; there are >50,000 species of hemiptera though).

As well as being antimicrobial, the apparent heat of capsaicin deters herbivores. This is desirable because herbivores destroy the small fragile seeds as they chew. However, in rather a neat twist, birds do not have receptors for capsaicin and therefore have taken on the role of seed distributors — cheerfully swallowing the seeds as they eat the fruit and distributing them widely in their own little piles of fresh guano.

Take a moment to consider how remarkable this achievement is. The chilli juggles seed protection and seed dispersal while taking into account external life forms as diverse as herbivores, birds, insects and microbial fungi (and other microbes), while the whole time being stuck in one place, conspicuous and vulnerable.

At one time, the ‘world’s hottest chilli’ (Trinidad Scorpion Butch Taylor) was cultivated in Australia by feeding an already seriously hot chilli plant (Trinidad moruga scorpion) with a worm fertilizer that contained chitin(exoskeleton material) from the worms and other dead insects. The chitin tricked the plant into thinking it was being attacked by insects and it responded by increasing capsaicin production. The ‘Butch T’ (named after the person who supplied the seeds) was recognized by the Guinness Book of Records from 1 March 2011 until 20th of November 2013.

Consuming these things seems to be an example of an extreme sport (or benign masochism) more so than having any culinary purpose. The attraction seems to be the pain-related release of brain endorphins (even at lower doses). When the growers of the Butch T made a demonstration sauce with it in Melbourne, they theatrically wore full chemical breathing masks and protective suits.

How does capsaicin affect us? In mammals, this chemical has the right shape to bind (like a key in a lock) to the nerve terminals in the mouth lining and tongue that would normally register temperature and pain. This artificially activates these nerves, which then send a signal to the brain telling it that there is something hot in the mouth and there is a possible danger. This is an error of perception on the part of the brain; the capsaicin does no actual harm (at culinary doses) and there is no heat and no damage to the mouth — we are just being tricked.

We have concentrated nerve endings in other sensitive parts of the body and capsaicin can activate these also (finger tips, nose, eyes). It does not have a great effect internally, it seems to serve no important nutritional purpose, but because it survives digestion reasonably well it can have an effect when it comes out the other end.

Capsaicin is not water-soluble. So drinking water to ‘put out the fire’ is ineffective and can make matters worse by washing the capsaicin to other parts of the mouth and throat.

It is fat and alcohol soluble though. The traditional fat to drink is full-cream milk or yoghurt (and one reason why yoghurt is added to mellow some curries or supplied as a condiment). Ice-cream makes sense too. If choosing something alcoholic, don’t choose a carbonated beverage. These beverages taste bright because the CO2 is an irritant; it just makes matters worse.

Humans have been eating chillies (in South America, Mexico) since at least 7500 BCE. They were soon cultivating them (~6000 BCE). Why? The consensus is that it was because chillies were antimicrobial and therefore made food safer to eat before other food preservation techniques were developed. There is a significant correlation between chilli intake and mean annual temperature. Hotter climates favoured microbe and fungal proliferation and more chillies were added to the diet as a protection against food-borne illness. The hypothesis that chillies were eaten in hot climates to promote cooling by sweating does not stand up to scrutiny.

This applies to other spices too — most spices are antimicrobial and their range of use in cooking has been shown to correlate with the local climate. Thus, it is thought that spices were first incorporated into food to slow spoilage, rather than as flavour-enhancers. The number of spices used increased over time as microbes adapted. In hot climates, families that cooked with spices would have had an evolutionary advantage because their food was not only safer to eat but could be stored longer to overcome periods of shortage or last longer in periods of glut. Children of these families would be healthier, and learn (and inherit) an appreciation of spices from their parents.

Further reading:

Tewksbury, JJ et al. (2008) Evolutionary ecology of pungency in wild chilies. Proceedings of the National Academy of Sciences 105(33):11808–11811 [link]

Sherman, PW and Billing, J (1999) Darwinian gastronomy: Why we use spices. BioScience 49(6): 453–463 [link]

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6XC
6XC

Written by 6XC

Science of cooking, eating and health. Retired neuroscientist.

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