If one would dispel an evening’s unproductive lassitude, the meaning of ‘drink’ is tea … Tea gives one vigor of body, contentment of mind, and determination of purpose
Humans use plants for many purposes – for making food, for weaving clothes and for producing medicines. We also exploit the botanical world not only to enable our survival but to modify the functioning of our brain – to stimulate, to calm or to induce hallucinations. As conscious beings, we purposely consume substances with the sole intent of altering our state of mind. Indeed, enjoying getting out of our own minds is pretty much a universal of human cultures around the world.
Psychoactive drugs affect the functioning of the central nervous system – they alter our mood, our consciousness or our perception of the external world. We have learned how to self-administer various drugs to achieve different effects. In this chapter, we will examine four substances that change how the human brain functions and by doing so have changed the world: alcohol, caffeine, nicotine and opium. Alcohol and opium are depressants, whereas caffeine and nicotine are stimulants. Each has been used widely as a recreational drug – that is, one taken socially or for pleasure rather than for medicinal purposes. They affect our neurones in different ways, but they all trigger the reward centres of our brain, producing pleasure or elation. On the flip side of the cognitive coin, they are addictive and so drive further consumption.
This selection is not to imply that other plant products affecting our perception have not also been significant in certain cultures and societies. For example, for at least a thousand years, the indigenous peoples of the Amazon basin have been brewing ayahuasca to commune with the spirits of the natural world in social and shamanic rituals. Indigenous North Americans have consumed peyote, a small spineless cactus, as a source of the psychoactive drug mescaline for similar purposes for at least five thousand years. But these drugs did not become nearly as globally prevalent or influential as the four we are about to explore.
The most common method for altering our state of consciousness throughout human history has been the consumption of alcohol. Unlike particular plants with psychoactive properties, which are only available to societies living within its native range, alcohol can be brewed from a huge range of materials. In principle, any foodstuff containing sugars (such as fruit) or starch (such as grain or tubers), which can be broken down into sugars, can be fermented to produce alcohol.fn1
Fermentation is a general term for the use of microorganisms to change the properties of food and aid in the preservation of its nutrients; it is behind the production of yoghurt, cheese, soy sauce and pickled foods such as kimchi and kombucha.1 But the earliest use of fermentation by humans was probably in the creation of alcohol.2
Cultures around the world have developed their own local alcoholic beverages. Fermented sugar-rich substrates include wine from grape juice and cider from apples, while honey has been diluted with water and fermented to produce mead. Maple sap was fermented by the Iroquois in north-eastern America; the sweet pulp of cacao pods was used in Mesoamerica; and the sap of the agave cactus has been fermented in Mexico to form pulque. The starch-rich grains of cereal crops are also common starting materials and are used to produce Japanese rice wine or sake; maize beer or chicha in the Andes;3 and tiswin in the south-western region of North America. India has long brewed beer from rice or millet. Cassava roots were fermented along the north-east coast of South America to produce kasiri.
Brewing has been a near-universal human pastime. Early evidence of wine-making is provided by residues – including the anthocyanin pigments which give red wine its ruby hue – found in clay jars dating back to around 3000 BC from Godin Tepe, an ancient Mesopotamian trading outpost in western Iran. Grape pips from plants in the early stages of domestication suggest wine production as early as 4000 BC in eastern Macedonia.4 Wine became an important component of cultures in the Middle East before being adopted with bacchanalian passion by the ancient Greeks and then the Romans.
Some botanists even argue that ensuring a steady supply of fermentable grains was the driving motivation behind the earliest cultivation of cereal crops, suggesting farming was inspired by beer not bread.5 This is an intriguing idea, but the archaeological evidence points to deliberate fermentation arriving after the domestication of cereal crops, indicating that alcohol was more likely a happy consequence, rather than cause, of the earliest grain cultivation and storage.6 Nonetheless, brewing beer from grain certainly reaches back to the dawn of civilisation in Mesopotamia. And in a constitutional sense beer and bread are two sides of the same coin: beer is liquid bread, and bread is solid beer.7 Beer-making spread from Mesopotamia to Egypt and then throughout Europe, being preferred in northern climes too cold for vineyards.
Alcohol has played many different roles in human societies. Drunk in moderation, its mind-altering effects lend themselves to celebration and joviality – alcohol reduces social anxiety and inhibition. It has also been instrumental in religious rituals, from ancient Egyptians offering wine to their deities, to Incans consuming large quantities of chicha to commune with the gods, to Christians performing the sacrament of the Eucharist.8 But alcohol also served an important practical function: the presence of alcohol in fermented drinks such as beer and wine, or in distilled spirits added to water, kills many of the microorganisms that cause waterborne diseases.9 A key step in beer brewing is to steep barley or another grain in water so that it germinates, and then boil this wort before fermentation, which kills any germs in the raw materials. From the Middle Ages until the nineteenth century, weak alcoholic beverages were routinely consumed in Europe, and then also in its colonies in North America, including by children, as a safe source of hydration since rivers and wells were usually contaminated.fn2 (Other cultures took to drinking infusions of boiled water – such as tea in China.)
Alcohol is absorbed readily into the bloodstream, and within minutes, it binds to receptors in the brain to suppress the release of excitatory neurotransmitters and increase the effects of inhibitory ones. The overall effect of alcohol is therefore as a sedative. This may surprise you if you feel that a drink livens you up and makes you feel more social. But this is because even after your first drink the depressant effects of alcohol are already starting to take hold in regions of your brain such as the prefrontal cortex, which is responsible for higher functions such as moderating our social behaviour and constraining impulses. As this brain region becomes sedated, this control lessens and we start to loosen up, feeling less anxious or self-conscious and more extroverted. Thus small amounts of alcohol can elevate your mood and help you relax, acting as an indirect stimulant. If you continue to drink, however, more and more of your brain becomes stupefied. Higher doses of alcohol have a dangerously debilitating effect on your senses, motor control and cognition, as they poison the brain and cause blurred vision, loss of balance, slurred speech, confusion, blackouts, memory loss and nausea. Extreme levels can lead to loss of consciousness, a coma or even death.
The body breaks down ethanol using a group of enzymes called alcohol dehydrogenases. The dehydrogenase enzyme that is found in humans and our great ape cousins disposes of ethanol around forty times faster than those also found in other species. This fast-acting version seems to have evolved around 10 million years ago. This far predates the deliberate brewing of plant material, of course, and probably arose at the time when our ancestors came down from the trees and started spending more time on the ground, eating fallen fruit that had started to ferment naturally.11
We also possess a number of other enzymes that work on the break-down products of ethanol, such as the toxic compound acetaldehyde, the build-up of which is one of the causes of the hangover. Some variants of these produce an unpleasant reaction. For example, one gene variant common in East Asian populations leads to a flushed, red face, nausea and headaches after a drink, affecting over a third of people in China, Japan and Korea today.12 Historically, these cultures have consumed far less alcohol and their populations today are much less affected by alcohol abuse.13 These genetic differences were almost certainly driven by differing cultural practices around the world over the last 10,000 years, with variants of the enzyme that were more effective at scrubbing alcohol from the bloodstream selected for in those populations that drank more often.
For reasons we’ll return to later, the psychotropic effects of alcohol are addictive. Both this addiction and the behaviour-altering effects of alcohol mean that its consumption does not only have a direct impact on the drinker but can harm those around them as well. The social ills caused by alcohol abuse are legion: alcohol causes more accidents, injuries and violence than any other drug. Smoking is also highly addictive and harmful, but no one starts a pub brawl or causes a motorway pile-up because they had one too many cigarettes.14fn3
The effects of alcohol are more potent in more concentrated alcoholic beverages. During brewing, yeast cells metabolise sugar into ethanol, proliferating until the alcohol content has increased to the point that it prevents any further growth and they start to die off, essentially poisoned by their own waste products. This happens at an alcohol concentration of around 14 per cent, which is the maximum booziness that fermented beverages can attain. To achieve a higher alcohol content a new technology is needed – distillation. This process exploits the fact that, at 78 °C, ethanol has a lower boiling point than water. So, if you heat a mixture of water and ethanol produced from fermentation, the ethanol vapour comes off first and can be cooled to condense back into a concentrated liquid. Distillation was used thousands of years ago in China and the Middle East to extract fragrant oils from rose petals to create perfumes or produce medicines as well as spirits. Simple stills such as the alembic, using a single side-arm to collect and cool the ethanol vapours, weren’t particularly efficient, but more complex apparatus, such as those equipped with a coil of copper pipe cooled in a reservoir of water, and accurate temperature control of the distilling vessel, can produce concentrated ethanol, especially if the distillation is repeated. If the distillate exceeds about 50 per cent ethanol, it can be set alight and is said to be 100 ‘proof’. The distillation of wine, for example, yields a potent alcoholic drink known in Dutch as brandewijn (‘burnt wine’), which became ‘brandewine’ in English, or simply ‘brandy’.
Not only do distilled spirits offer a concentrated form of alcohol, but they also don’t spoil like beer or wine and so can be transported long distances.fn4 This makes spirits useful and high-value trade items. For indigenous American cultures, for example, which were already familiar with intoxicating substances such as tobacco and peyote, alcohol, and especially distilled spirits, became an important component of the gift exchange and then trade with the first European colonisers.17
Distilled drinks also played a central role in the transatlantic slave trade. The African slavers who supplied the Europeans with captives valued a range of commodities in exchange, including textiles, metals and, especially, distilled spirits such as brandy, which they preferred to their own locally produced, and less concentrated, grain-based beers and wines. The link between spirits and slavery was only strengthened by the invention of a potent new distilled drink made from sugar cane. Rum had been made from cane juice in Brazil by the Portuguese from the early sixteenth century, but the British refined the process in Barbados in the mid-seventeenth century to use molasses, an otherwise worthless waste product of sugar production. Not only was rum therefore cheap, but as a distilled spirit it offered a compact, self-preserving form of alcohol and so became a key part of the transatlantic economy. Rum could be used to buy slaves, who laboured to cultivate sugar, the leftovers of which could be converted into rum to buy yet more slaves.
Distilled spirits also became a key enabler of longer sea voyages. Fresh water stored in barrels on board ships quickly went stale and developed microbial growth, and so this stagnant water was often sweetened with beer or wine to make it palatable. But these too spoiled on longer voyages. When concentrated spirits became affordable and widely available, they were used instead to temper the drinking water. After 1655, the English replaced a sailor’s daily ration of beer with rum, first in the Caribbean and then for all Royal Navy ships. Yet once sailors had developed a habit of saving up several rations to drink all at once to become intoxicated, in 1740, Vice-Admiral Edward Vernon ordered that the standard ration of half a pint of rum be diluted with four parts of water, thereby creating grog which was issued half at the noon bell and half at the end of the day.fn5
At the top of the brainstem – one of the most ancient parts of our brain and the critical connective for the spinal cord – sits a cluster of neurones known as the ventral tegmentum.19 The ventral tegmentum communicates with the nucleus accumbens, a behaviour-mediating region of the brain, via a tract of dopamine-releasing neurones called the mesolimbic pathway, and although they constitute only a minuscule portion of all the nerve cells in the brain – less than 0.001 per cent – these neurones are enormously important in motivating our behaviour towards survival and reproduction.20 Eating food, quenching thirst or having sex all result in the release of dopamine in the mesolimbic pathway. Watching porn or even thinking about sex is enough to trigger dopamine release.21 The dopamine system is also activated by other gratifying experiences, including getting revenge – such as we explored in Chapter 1 – or winning at a computer game.22
The reward signal is perceived as the sensation of pleasure, and so dopamine is often described as the pleasure chemical of the brain. And this dopamine-release mechanism doesn’t just operate in humans. The mesolimbic reward pathway is shared by all mammals – it is an ancient, fundamental part of the brain’s functioning – and indeed, similar systems involving dopamine or related neurotransmitters for directing behaviour are universal across the entire animal kingdom.23
The mesolimbic pathway flushes with dopamine in response to a favourable outcome, such as eating or drinking, and especially one that was unexpected; conversely, dopamine levels are decreased by a negative experience or an anticipated pay-off that doesn’t materialise. So in order to tune our behaviour to succeed in our natural habitat, our brain compels us to repeat the actions that activated the dopamine system last time and avoid those that previously suppressed it. Thus the neurochemical system of pleasure and reward is inextricably intertwined with that of learning. The dopamine pathway also connects the tegmentum to the prefrontal cortex, the wrinkly part right at the front of the brain that is greatly enlarged in humans compared to other animals. The prefrontal cortex orchestrates high-level ‘executive’ functions such as making decisions and planning towards particular goals and so is ultimately informed by the dopamine reward pathway.
This dopamine-mediated mechanism works exceedingly well at steering our behaviour towards the sort of actions that benefit us in the natural world. Problems arose, however, when humans discovered ways of triggering this reward-and-pleasure system with stimuli other than those associated with increasing biological fitness – namely, drugs.
Alcohol, caffeine, nicotine and opium effectively short-circuit our brain’s reward system. They induce the release of dopamine in the mesolimbic pathway – or inhibit the removal of dopamine or make the receptors on the surface of neurones more sensitive – and in some cases they can produce pleasure, even euphoria, far more intense than anything encountered in the natural world. And unlike natural dopamine triggers, such as eating, they never result in satiation.
Drugs create a false signal in the mesolimbic pathway that indicates the arrival of a huge survival benefit, and the learning mechanism driven by this system rewires the brain to seek out repeated hits. This is the basis of addiction, and it produces cravings and compulsive behaviour to achieve that instant gratification without having to pay the costs associated with dopamine rewards in the natural world, such as spending time hunting for food.
Experiments conducted in the 1950s surgically implanted wire electrodes deep into the brains of lab rats so that the nucleus accumbens would be stimulated every time they pushed a lever. They found that the rats would compulsively do this – up to 2,000 times an hour – foregoing drinking, eating, sleeping or any other normal behaviour to keep triggering buzzes of pure pleasure, until they collapsed with exhaustion.24 The sad truth is that humans can become caught in similar traps, administered not by electrodes directly stimulating the brain but by chemical substances similarly targeting the mesolimbic reward pathway. The problem is worse when the natural plant product has been refined and the psychoactive compound concentrated, or even chemically modified, to increase its potency – heroin synthesised from raw opium, for example. Delivering the active compound in a more rapid surge to the brain also greatly increases its euphoric effect and addictiveness, such as by smoking, snorting or especially injecting directly into the bloodstream, rather than ingesting orally.
The dopamine system also recalibrates itself, so that with repeated large rewards the dopamine release is dialled down back to its base level. This is the process of habituation and the reason junkies – whether they’ve developed a habit for coffee or cocaine – need ever-greater doses to experience the same buzz. As the neuroendocrinologist Robert Sapolsky puts it, ‘What was an unexpected pleasure yesterday is what we feel entitled to today, and what won’t be enough tomorrow.’25 Before long, the pleasurable sensations that the drug once produced have faded away, and continued use becomes motivated instead by trying to avoid the nasty effects of withdrawal. In this way, drugs very effectively hack our brain’s reward system for tuning behaviour for survival, and so substance abuse is a universal human vulnerability.
Alcohol has been the most widespread method for altering our state of consciousness through human history, and its ability to light up the dopamine pathway yields the warm glow of inebriation as well as the development of dependence. After alcohol, caffeine has been humanity’s second-most popular drug.
Caffeine is the most widely used psychoactive stimulant in the world, and coffee is one of the most valuable commodities exported by developing nations.26 (Alcohol has been more widely consumed by cultures throughout history but, as we have seen, is a depressant rather than a stimulant.) Around 90 per cent of the world’s population consume the drug regularly in some form or other, including children, given the caffeine in soft drinks. Besides tea and coffee, a few other plants also produce caffeine, such as cacao (chocolate), kola, guarana, yerba mate and yaupon – all of which have been infused in water to create caffeinated drinks by people living within their botanical range.27 Today, tea and coffee are consumed enthusiastically in all seven continents – including by the research scientists stationed on Antarctica – and there is even an espresso machine aboard the International Space Station called, punningly enough, the ISSpresso maker.28
The apocryphal story on the origins of coffee consumption goes something like this. A ninth-century goat herder in Ethiopia noticed that his goats became frisky and uncontrollable after eating the cherry-red berries of a particular bush. He then tried some himself and was pleasantly surprised by their invigorating effect. In time, processing developed, and the seeds were roasted and then ground into a powder to be infused in boiling water – and the practice of making a cup of coffee was born. But whoever discovered coffee, the Sufi mystics in Yemen, just over the Red Sea from Ethiopia, were early adopters of the drink.29 These Muslims customarily prayed late into the night, and coffee helped them stay awake and alert into the early hours. It was the invigorating effects of coffee that kept the whirling dervishes spinning in their religious rituals. The port of Mocha (or Al-Makha) in Yemen became a major trading hub for coffee from the Horn of Africa and provided one of the names for coffee (today often mixed with milk and chocolate). Coffee reached Constantinople in the sixteenth century and quickly spread throughout the Ottoman Empire and around the Mediterranean. Indeed, it is the Turkish word kahve, morphing into ‘caffe’ in Italian, that gave us our name for this compelling drink. The embracing of coffee by the Islamic world owed as much to its energising effects as to the fact that, unlike alcohol, it was not generally interpreted as being forbidden by the Qur’an – it became known as the ‘wine of Araby’.30fn6
Coffee seems to have arrived in the maritime trading hub of Venice in 1575, and by the mid-seventeenth century, it was readily available across Northern Europe. The first coffee house in London opened around 1652, and within a few decades there were thousands in the capital alone. This rapid growth was certainly driven by caffeine’s addictiveness: once a customer had drunk a cup and felt the effects, they were likely to return again and again. But just as important for the rise of coffee was the culture that came to surround its consumption. Unlike the alcoholic beverages drunk in taverns that dulled your senses and made you sleepy, coffee revived and energised its drinkers. Coffee houses therefore emerged as places not only for friends to relax and catch up in, but also for businessmen of the new mercantile class to negotiate deals, and for intellectuals to debate ideas at the dawn of the Enlightenment. They were a new kind of public space, great democratic levellers where men from across the class divide could congregate alongside each other and pick up an education by listening to surrounding conversations – they became known as ‘penny universities’. Coffee houses also came to provide newspapers and printed pamphlets, drawing customers in to catch up on the latest news and ideas and share rumours with their fellow drinkers. With coffee houses becoming hotbeds of debate, free thinking and political dissent, Charles II attempted to close them in 1675, especially because the main topic of chatter was the king himself and the fate of the Stuart restoration.32 The coffee houses of Paris too were alive with political discourse, even sedition, and played an instrumental role in the events of 1789. The Café Procope was frequented by Robespierre and other prominent revolutionaries, and it was from a table outside the Café de Foy that Camille Desmoulins roused the mob that stormed the Bastille – the insurgents fired up not on alcohol but on caffeine.
Particular coffee houses became closely associated with different areas of business, and patrons knew they would lose a competitive edge over their rivals unless they frequented the right establishment to keep abreast of developments. Lloyd’s of London, for example, began as a coffee house popular among merchants and shipping magnates and so was a crucial hub for the latest news on the coming and going of ships and their cargoes. It became a major centre for obtaining maritime insurance, and by the late nineteenth century, the corporation was one of the largest underwriters in the country. Likewise, the London Stock Exchange began in a coffee house. Coffee therefore lay right at the heart of not only intellectual development and the Enlightenment but capitalism and the birth of many of today’s financial institutions.
Our passion for tea and coffee was also a major force in driving long-distance maritime trade and shaping the global economy. Until the early 1700s, all coffee reaching Europe was cultivated in Yemen and came from Mocha. But the Dutch East India company (VOC) started planting the crop – descended from plants originally smuggled out of Yemen – in its colonies in the East Indies in the 1690s, and by the 1720s, Amsterdam had become the coffee capital of the world, with about 90 per cent of the beans moving through its exchanges originating from the Dutch-owned island of Java. Other European imperial powers took to supplying their domestic demand by growing coffee in their colonies too, most of it on the back of slave labour. The French took it to Martinique and Saint-Domingue, and by the 1770s, well over half of the world’s coffee was produced in Haiti. The slave revolt at the end of the century destroyed many of these plantations, and the refusal of the European states to recognise or deal with this first black republic ended this lucrative trade (as we explored in Chapter 3).
The Portuguese colonies in South America used slash-and-burn cultivation to grow the coveted crop, and when the soil became depleted, they moved on to another tract of land, resulting in the deforestation of the Atlantic seaboard of Brazil. These huge plantations and the slave labour – Brazilian coffee plantations used slaves as late as 188833 – were able to produce large quantities of high-quality coffee at low prices, supplying the growth in demand for coffee in America throughout the nineteenth century. Brazilian coffee exports leaped 75-fold between the country’s independence in 1822 and the end of the century, when it was producing almost five times as much as the rest of the world combined. It was this colossal Brazilian supply that led to plummeting prices and made a cup of coffee the mass-market commodity it is today.34, 35
Tea-drinking has had an even longer history than coffee consumption. Tea was originally used as a medicinal concoction in the Yunnan province of south-west China by about 1000 BC. But green tea became broadly popular as a stimulating hot drink across the whole of China, and then South East Asia, from the mid-eighth century AD during the Tang dynasty.36 As with the Sufis, it was adopted early by Buddhist monks striving to stay awake and focus during their long meditations.37
Tea leaves were first brought to Europe by the VOC in the early seventeenth century, and the beverage began appearing in English coffee houses in the 1650s. This international trade to the west favoured fermented and oxidised black tea, which kept better than green tea, and since the VOC dominated the coffee trade, the British East India Company came to focus its efforts on the tea grown in China.
Through the second half of the seventeenth century, the expense of tea in Britain meant it was largely consumed for its supposed medicinal properties or as an aristocratic status symbol. By the mid-eighteenth century, however, the British East India Company was importing so much tea from China that prices fell enough for tea drinking to become a domestic ritual for the middle classes, and soon it was widely consumed by the working classes too. Tea was now the national hot beverage, sipped and slurped right across society, from the royal palaces to the dwellings of rural labourers and the urban poor.38 British drinkers also took to another innovation, that of adding milk and sugar to their cup of tea – a practice unknown in China. This new habit contributed to the expansion of slavery in the sugar plantations of the Caribbean, as it further increased demand for the sweet stuff. The desire to break the Chinese monopoly on the invigorating leaves drove the East India Company to begin large-scale cultivation of the native tea plants in the north-east Indian region of Assam in the early nineteenth century. Then, in an early historical example of corporate espionage in 1850, Scottish botanist Robert Fortune smuggled tea plants out of China, and large plantations were established across Darjeeling.
In America, the story of tea took a very different trajectory. It was introduced to the Thirteen Colonies at around the same time as England and similarly grew in popularity. The East India Company endeavoured to supply this demand, but by the late 1760s, most of the leaves consumed in the colonies were smuggled Dutch tea. Indeed, the drinking of smuggled tea was encouraged by American patriots such as the Sons of Liberty as a political protest against British taxation. The East India Company saw surpluses of tea piling up in its London warehouses that it couldn’t sell. In an effort to prop up the financially beleaguered company by helping them to undercut the price of smuggled tea, the British parliament passed the Tea Act in 1773. This allowed the company to ship tea directly from China to America, without having to pay British import duty, and granted them a monopoly on the sale of tea in America. The tea was subject to tax only in the colonies.
The colonists, however, viewed this as an attempt to foist British taxes on them. They harassed East India Company consignees, refused to accept the tea and left it to rot on the dockside, or prevented the East Indiamen from landing the product. One of the most public – and famous – displays of rebellion flared in Boston Harbour, where in December 1773 protestors boarded the ships and destroyed over 340 chests full of tea by dumping them over the sides into the harbour waters. This Boston Tea Party triggered similar acts of rebellion in other ports, including New York. The situation escalated with parliament in 1774 passing the Coercive Acts – or the Intolerable Acts, as they were known in America – designed to make an example by punishing the defiance of Massachusetts, stripping the colony of self-governance and forcing the closure of Boston Harbour until the ruined cargo had been paid for. But these harsh reprisals only served to unite the colonies against the king, and tensions continued to mount until the War of Independence erupted the following spring.
The passion for coffee rather than tea in America today was not driven by the Tea Act and protests against British tea before the Revolutionary War. Tea remained popular, although it is perhaps telling that the Declaration of Independence was first read publicly outside the Merchant’s Coffee House in Philadelphia.39 But coffee grew in popularity in the decades after independence – it could be imported by the Americans directly from French and Dutch colonies in the Caribbean40 – and in particular after 1832 when import duty on coffee was scrapped, making it cheaper.41
Caffeine is a molecular mimic. Every minute we are awake, a chemical called adenosine accumulates in the brain, marking the time since we awoke like sand in a sand timer. It gradually slows our mental processes and prepares us for sleep – creating what is evocatively referred to as a mounting sleep pressure42 – so that after twelve to sixteen hours of being awake we once again feel the irresistible urge to lay back down to slumber.43 The particular shape of the caffeine molecule, however, just so happens to allow it to fit snugly into the same receptors that adenosine binds to, but it doesn’t trigger them; instead it effectively maintains a chemical blockade of the adenosine ports. So, if your brain is flushed with caffeine, adenosine can’t get to the receptors and the normal signalling is muted. Caffeine pharmacologically holds sleepiness at bay and keeps our brain in an alert, focussed state. The adenosine is still there, accumulating in the brain, but its signals are jammed by the caffeine. As the body breaks down the caffeine, the adenosine that has been building up behind the dam breaks through and releases an overwhelming wave of doziness – the dreaded caffeine crash.44
Caffeine is synthesised by plants as a natural pesticide, deterring insects from feeding on their leaves or seeds or even killing them.45 But curiously, several kinds of plant, including those of the coffee and citrus subdivision, also produce caffeine in their nectar – the sugar-rich fluid secreted by flowers to attract insects for pollination. Experiments have shown that caffeine enhances olfactory learning in honeybees – they are more likely to remember the scent of the flower associated with the nectar reward and thus keep returning to caffeinated flowers. It’s as if the plants are using the stimulant drug to hack the brains of the bees to recruit them as dedicated pollinators for their flowers; you could say that caffeine gives the bees their buzz.46
Another effect of caffeine is that it causes increased levels of dopamine in the nucleus accumbens, while it also heightens the sensitivity of dopamine receptors. This triggers the mesolimbic reward pathway we explored earlier, producing the buoyant, mood-enhancing properties of a good cup of tea or coffee but also its addictiveness.47 Humans adopted drinks like coffee and tea because of their effects on our brains, serving as stimulants and suppressing sleepiness, and, once started, the compulsion of caffeine addiction maintained the habit. And in turn, caffeine has had a lasting effect on history.
While coffee stimulated the minds and discourse of European intellectuals in coffee houses during the Age of Enlightenment, it was tea that enabled the bodies and minds of the English working classes to adapt to the changing industrial world. The Industrial Revolution swept aside traditional, specialised crafts such as weaving and blacksmithing and replaced them with heaving machinery. Artificial light, first gas lamps and then electric bulbs, enabled factories to operate late into the night. Caffeine not only kept the workers’ brains alert and attentive through the monotonous factory work but also suppressed the hunger pangs of the undernourished. The sugar in the tea provided calories to sustain people’s bodies through the long shifts. Caffeine transformed human workers into better accessories to the untiring iron machines they were serving.fn7
So, while coal powered the steam engines of the Industrial Revolution’s factories and mills, tea supplied by the East India Company, sweetened with sugar from the West Indies, fuelled the workers tending the machines.49 In this way, the history of tea is rooted in the exploitation of labour – from where it was grown in India to the sugar plantations in the Caribbean to the factories in Britain that squeezed every waking hour out of their workers.50
Today, caffeine plays a central role in controlling our natural sleep-wake cycles. Our fast-moving technological society no longer allows us to respond passively to our biological rhythms; we are expected to adapt them to the dictates of its digital clock. Many of us self-administer caffeine to help meet these demands – when rousing ourselves for the daily commute, pulling an all-nighter at the desk or re-synching our body’s rhythms to a new time zone after a long-haul flight. Many caffeine addicts are able to manage their own dosing of the drug to masterfully harness its positive effects and improve performance in the focus-demanding tasks of the modern world, while avoiding the negative consequences of overconsumption such as jitteriness, a racing heart or stomach irritation. But by enabling us to inhibit our brain’s own signalling mechanism for sleepiness, caffeine is one of the major causes behind the modern pandemic of sleep deprivation. And what’s so insidious about our relationship with coffee and tea is that the very thing we use to remedy the resultant chronic drowsiness is again caffeine.51 In fact, much of the prompt to reach for the first cup of coffee or tea in the morning – to clear a foggy mind or help us wake up – is to relieve the symptoms of drug withdrawal after an overnight absence.
As we saw in Chapter 4, the establishment of contact between the Old and New Worlds in the late fifteenth century irreversibly changed both. The diseases the European explorers brought with them utterly devastated the native populations of the Americas. In return, syphilis made its way across the Atlantic in the opposite direction, sailing back with Columbus’s crew after that first voyage. But the global shift in the Earth’s biota that ensued over the following decades and centuries, known as the Columbian Exchange, also brought back to the Old World something far more debilitating and deadly than the syphilis bacterium.
Today, tobacco use kills over 8 million people every year: about 15 per cent of all deaths worldwide result from the litany of cancers, cardiovascular and respiratory diseases it causes. Or to put it into perspective, it’s as if the 1918 influenza pandemic was occurring every decade. And it’s not just the actual users who are affected, but their children or anyone else breathing in their smoke.52 In short, tobacco is the largest preventable cause of death in the world today.53
Tobacco belongs to the Solanaceae family of plants, making it a close relative of the deadly nightshade, which also includes the potato and the aubergine. The botanical genus of tobacco, Nicotiana, contains around 70 different species of plant,54 but two have been most widely used by humans: Nicotiana rustica and Nicotiana tabacum.
Discoveries of nicotine residue in pipes show that tobacco smoking was practised in pre-agricultural hunter-gatherer societies in south-eastern North America over 3,000 years ago; and its use in South America can be dated to around the same time.55 But humanity’s relationship with the plant may be far more ancient. A recent archaeological find of charred tobacco seeds in a hunter-gatherer hearth in Utah suggests the use of tobacco as early as 12,300 years ago. This is not long after humans first arrived in the area after migrating into North America along the Bering land bridge during the last ice age.56 The earliest cultivation of tobacco started in the Peruvian Andes and spread as far north as the Mississippi valley by around 500 AD.57 Some North American tribes, such as the Blackfoot and the Crow, practised no other form of agriculture save planting and tending to their tobacco plants, showing just how central it was to their culture, while they gathered everything else they needed from the wild.
For the peoples of both North and South America, tobacco was a spiritual herb, consumed in highly ritualised ways. North American tribes smoked tobacco in long pipes as part of sacred ceremonies or to seal a treaty, the rising smoke serving as an offering to the gods. To inhale smoke was to receive into your body the ethereal; and on exhaling, your questions and desires were carried forth in a form fit for the spirits.58 A shaman might bestow a blessing or protection on a warrior before battle by ritualised smoke blowing. In the South American civilisations, too, tobacco held profound religious importance. A Mayan manuscript referred to as the Madrid Codex, written in the fourteenth or fifteenth century, before much of the Mayan culture was obliterated by the Spanish conquest, depicts three deities smoking cigars.59
This connection between tobacco smoking – or sometimes chewing – and the spiritual can perhaps be explained by the fact that the species of tobacco plant used traditionally in the Americas, Nicotiana rustica, is much stronger than other varieties, such as that grown commercially today. Its leaves contain five to ten times the concentration of nicotine and can produce a narcotic effect like drunkenness or even bring on a trance and hallucinations. Shamans or priests would use high doses to commune with the spirits or induce visions.60
Tobacco was used for more practical applications too. It was known to alleviate thirst and hunger61 (predating supermodels smoking to suppress their appetite).62 Tobacco was also believed to have medicinal properties – somewhat ironic to us in the modern world now aware of the wide range of health problems it causes. It was taken to relieve or cure conditions such as asthma, toothache, earache, digestive problems, fever and depression, and was spread as a poultice onto wounds, insect bites or burns.63 In Europe, too, tobacco was initially believed to cure cancer,64 as well as offer many other restorative properties for an individual’s constitution, including invigorating the spirits or helping expel excess phlegm.65fn8 But tobacco could also be purely recreational. When Columbus and his crew arrived in the Americas, they witnessed the Taíno people walking around with tobacco pouches strung around their necks, always on hand for a quick smoke, in the way someone today might leave home on a night out with a pack of twenty shoved in their back pocket.67
American indigenous cultures consumed tobacco in many different ways, often reflecting environmental conditions. Across Central and North America, tobacco was most commonly consumed by curing the leaves and smoking them as cigars or in pipes; the latter could be impractically large, highly decorated implements befitting their spiritual, and communal, usage. In the wetlands of the Amazon basin, where kindling a fire was trickier, tobacco was made into a drink; whereas in the thin air high in the Peruvian Andes, where smoking leaves you a little breathless, powdered tobacco snuff was snorted instead.68 It was also chewed and held pressed against the gum as a wet wad of leaves or applied as eye drops. The Maya even administered it as an enema,69 with the bulb made from an animal bladder and the shaft fashioned from the hollow femur of a small deer.70 (Unsurprisingly, this last method never took off with Europeans.)
Europeans first encountered the plant when Columbus made landfall in Cuba, where the friendly islanders presented the visitors with food and exotic fruits they had never seen before. The gifts also included some dried tobacco leaves, but the puzzled Spanish found them utterly inedible and threw them overboard.71 They realised that they weren’t intended to be eaten, when they saw them being rolled into tubes, lit at one end, and smoked. Smoking was a totally novel experience for Europeans; while they burned incense in their churches, they did so for the scent and not to breathe in the smoke.
Early explorers in the New World even struggled to find the words to describe the practice. The Dominican friar Bartolomé de las Casas, one of the first European settlers in the Americas,72 records how messengers sent ashore in Cuba found ‘men with half-burned wood in their hands and certain herbs to take their smokes, which are some dry herbs put in a certain leaf, also dry, … and having lighted one part of it, by the other they suck, absorb, or receive that smoke inside with the breath, by which they become benumbed and almost drunk, and so it is said they do not feel fatigue. These, muskets as we will call them, they call tabacos.’ Las Casas commented, ‘I knew Spaniards on this island of Española who were accustomed to take it, and being reprimanded for it, by telling them it was a vice, they replied they were unable to cease using it.’73
Not only was this the explorers’ first contact with smoking as a practice, therefore, but they also encountered the gnawing urge of chemical dependency: nicotine is far more addictive than alcohol, for instance. A century later, the philosopher and scientist Sir Francis Bacon similarly observed, ‘In our time the use of tobacco is growing greatly and conquers men with a certain secret pleasure, so that those who have once become accustomed thereto can later hardly be restrained therefrom.’74
Consuming tobacco, in whatever form, delivers nicotine into the bloodstream, from where it is rapidly transported to the brain. Just as caffeine acts as a chemical mimic of the neurotransmitter adenosine, nicotine has a structure similar enough to another of the brain’s signalling molecules, acetylcholine, to bind to acetylcholine receptors on the surface of neurones.75 This triggers a cascade of other neurotransmitters into action, including dopamine in the mesolimbic reward pathway, producing the pleasurable effects of tobacco.76 Inveterate tobacco-users keep their brain in a continual bath of nicotine, which alters its chemistry as the neurones adapt to the supply of the drug. The initial psychoactive rewards diminish as this tolerance builds, and nicotine use is continued mostly in order to avoid the negative sensations of withdrawal from the drug, such as irritability and anxiety. As with other addicts, when they try to quit, smokers (and more recently vapers) are held hostage by the unpleasantness of the withdrawal symptoms.
Rodrigo de Jerez, one of Columbus’s messengers in Cuba and so one of the first Europeans to observe smoking, caught the habit himself and brought it back to Spain. His contemporaries were so horrified by the sight of smoke pouring out of his mouth and nose, making him look like a fuming demon, that he was locked up by the Inquisition for seven years.77 But even so, by the 1530s, cigar smoking had become popular in Spain and Portugal. The French ambassador Jean Nicot, sent to Lisbon to arrange a royal marriage, picked up the habit and sent tobacco seeds to his queen. The ‘Nicotian herb’ quickly became wildly popular in the French court.78 By 1570, botanists were referring to the weed as nicotiana, which also gave us the name for the active compound.
Genoese and Venetian merchants took tobacco to the Levant and Middle East, the Portuguese brought it to Africa, and before long, global maritime trade delivered tobacco to India, China and Japan.79 So, while Columbus never realised his goal of reaching the Orient, the compelling weed he discovered on his voyage did make it to China.
Europeans adopted different means for consuming tobacco, depending on how they had first encountered its use. Cigar smoking became popular in Spain from the early sixteenth century, but later that century, Englishmen preferred to puff on a clay pipe, a habit they copied from North American natives in what became Virginia and the Carolinas. In the Middle East, the pipe was adapted into the waterpipe, or hookah, which cooled the smoke before inhalation and also emphasised smoking as a shared, communal activity.80
Tobacco therefore spread rapidly around the world once it had been discovered by European explorers. With its mind-altering chemistry it also became a key factor in the colonisation of the eastern seaboard of North America, with tragic and long-lasting consequences.
Tobacco was relatively slow to reach England, probably not arriving there before the second half of the sixteenth century. The privateer and slave trader Sir John Hawkins is believed to have made the first delivery of the leaf, captured during his raids of the indigenous peoples along the Florida coastline. Other swashbuckling pirates, such as Sir Francis Drake, targeted Spanish colonial settlements in the Americas and preyed on their shipping to loot tobacco and other treasures. But tobacco’s most ardent advocate in England was Sir Walter Raleigh, who used his standing and influence at the court of Queen Elizabeth to promulgate its virtues. Very soon smoking was all the rage within the upper classes, and rapidly propagated throughout the population. And smoking was not yet another short-lived fad: nicotine’s addictiveness meant that the habit grew and persisted, perniciously permeating the fabric of society.81
With no permanent presence in the Americas, and instead relying on pillage and piracy to enjoy the treasure they offered, the problem was that England had no reliable source of the plant. The little tobacco grown on home soil was deemed grossly inferior to that nurtured in the tropical sun of the West Indies.82 Raleigh attempted to found the first permanent English settlement in North America on an island just off the coast of Virginia, its name honouring the presumed virtue of the Queen. The first Roanoke colony failed, and a second settlement was found mysteriously abandoned in 1590. While the Spanish had spent the past century consolidating an expansive empire across the New World, the English (and other European powers) were still struggling to establish a single successful colony.
Another attempt was made shortly after the new king, James I, made peace with Spain in 1604 after a generation of war. Yet the crown was wary about funding any more colonial ventures after the failure of Roanoke, and so the next expedition would be privately financed. The Virginia Company was chartered by the king in 1606, and after funds had been raised by selling shares and willing settlers recruited, Jamestown was founded the following spring on the banks of a major river spilling into the mouth of Chesapeake Bay.fn9
Yet the early years were tough. Over half of the settlers died within the first twelve months. Two relief convoys brought further colonists and supplies, but by 1610, 80 per cent of the settlers had perished, most succumbing to malaria and other diseases as well as hunger, especially during the previous winter, which became known as the ‘starving time’.83 A third supply fleet to Jamestown was scattered by a hurricane during the crossing, with the flagship badly damaged and only just able to make it to an uninhabited island in the Bermudas. Here, crew and passengers were marooned for ten months while they built two small ships to carry them on to their destination. (Their adventures were immortalised by Shakespeare in The Tempest, which is based on the real-life story of the Sea Venture.)84 When they arrived at Jamestown, however, they found the settlement in ruins, with a surviving population of only 60 people. It was decided to abandon the colony and sail home with the remaining settlers. Yet in what proved to be a case of fortuitous timing, they had just set sail when they met another resupply fleet and so returned to the settlement. Now, with more supplies and a fresh influx of colonists, Jamestown seemed to be on a healthier footing.85 But the Virginia colony still struggled to generate a profit for its backers: so far it had produced nothing suitable for export. No gold or silver had been found, and various ill-conceived farming attempts – including olive groves, vineyards and even the cultivation of silkworms – had failed.86 The Virginia Company made it clear to the settlers that its financial backers expected a return on their investment and if the colonists didn’t start delivering, they would be cut off. The future of the Jamestown settlement was now hanging by a thread.
But then, John Rolfe, who had been one of the castaways on Bermuda before making it to Jamestown, turned his hand to a potential cash crop. The colony had already been growing small amounts of an indigenous species of tobacco, Nicotiana rustica, but its smoke was harsh and there was little demand for the weed in England. The English much preferred the milder, sweeter leaf of Nicotiana tabacum, which they imported at great expense from the Spanish-controlled West Indies. Rolfe had been able to procure seeds of N. tabacum from Trinidad and spent several years trying to master the cultivation of the plant in the Virginia soil and climate, as well as the curing process of the harvested leaves.87 In the meantime, he had married Pocahontas, the teenage daughter of the chief of the Powhatan tribe, as part of a deal to seal a fragile peace and trade agreement with the indigenous population.
When Rolfe’s first tobacco crop was shipped back to London in 1613, it was well received – and, crucially, it turned a tidy profit. The English market was hungry for high-quality tobacco to feed its addiction. Jamestown quickly went from bust to boom. In 1618, the colony was told that it would no longer be financed by the Virginia Company but by its own tobacco farming. That year, it shipped 20,000 pounds of tobacco, rising to 60,000 pounds in 1622, 500,000 pounds in 1627, and 1.5 million pounds in 1629.88 By the 1660s, Virginia was exporting an astonishing 25 million pounds of tobacco leaf every year.89
By the time Rolfe died in 1622, he had permanently reversed the fortunes of Jamestown. It served as the colonial capital until the end of the seventeenth century, by which point Virginia had a burgeoning population of nearly 60,000 settlers.90 Tobacco continued to sustain and drive the growing English colonies in Virginia and Bermuda throughout the seventeenth and eighteenth centuries before sugar, coffee and cotton provided an additional economic base. As the colonisation of North America progressed, Virginia tobacco was not just exported back to England but sold throughout the eastern seaboard and the Caribbean. Indeed, the Thirteen Colonies came to use the sought-after leaf as a currency to trade with their neighbours – tobacco was not just a lucrative cash crop, it was literally used as cash.
Thus John Rolfe had planted the seeds for the creation of English America. Having come so perilously close to utter failure and abandonment, it was tobacco and its addictive properties that had secured the success of Jamestown – and ultimately the predominance of English language, culture, laws and other institutions in what would eventually become the most powerful nation on Earth.
The cultivation of tobacco in the Virginia colony had three profound and far-reaching consequences for history. First, the focus on tobacco as a cash crop marked a critical shift from subsistence farming to an agrarian economy in the colonies, making them commercially viable and self-supporting, while generating a handsome profit for the financial backers of these colonial ventures at home. And as tobacco had made the first English colony in the Americas viable, it paved the way for further expansion and settlement, with the colonies becoming enticing destinations, pulling more and more colonists towards North America.
Second, the tobacco plant is a hungry crop, drawing lots of nutrients out of the ground while it grows.91 This means that tobacco cultivation quickly depletes the soil, and after just three years the ground must be left to recover for a decade or two92 – or fresh soil be brought under the till. By the end of the seventeenth century, an estimated half a million acres of Virginia had been deforested and cleared, largely for tobacco plantations.93 Tobacco was therefore a powerful driver for constant expansion and the settling of new lands to the west. This brought the colonists into direct conflict with the indigenous peoples living there, leading to mounting hostilities and ending in massacres and expulsion of the native tribes.
Third, the cultivation of tobacco was extremely labour-intensive. In the early years, the colonies relied on indentured labourers: settlers were offered passage to the New World but on arrival had to pay off this debt by working on the plantations for five to seven years. They were free when their service was finished, and as part of their contract were often promised a grant of land. But neither this supply of indentured labourers nor the transport of convicts to the American colonies was able to meet the rapidly growing demand for plantation workers – particularly with the heavy burden of diseases in the region, as we saw in Chapter 4.94 It was cheaper to import slaves from Africa, who were already hardened against tropical diseases, could be forced to work without a fixed-term contract and existed on a level of bare subsistence. Thus tobacco in North America, like sugar in the Caribbean, drove the expansion of the transatlantic slave trade in the early seventeenth century.
The Nicotiana herb remained central to the American economy, with the big tobacco companies emerging as some of the largest corporations in the country, and also able to wield great political power. This central position within the American economic and political development is plain to see in the Capitol building, the home of US Congress, where every Corinthian column in the grand Hall of Columns is topped with tobacco leaves, figuratively holding together the entire institution.95
Tobacco continued to be consumed by the ancient methods – chewed, snorted or smoked in pipes and cigars – but after 1880 a new delivery method for the nicotine fix became available: a pack of cigarettes. Previously, cigarettes had been crafted by hand from a pouch of tobacco and thin papers on an ad hoc basis – ‘rollies’ that you may be familiar with from your student days. Buying pre-rolled cigarettes was prohibitively expensive as a worker could hand-roll only a few a minute. The shift came with the invention in Virginia of a way to industrialise the process – a cigarette-rolling machine that could spit out over 200 cigarettes every minute. But initially, demand remained low for pre-rolled cigarettes, which were still perceived as pricey luxury items. At the dawn of the twentieth century, cigarettes only accounted for around 2 per cent of tobacco consumption in America. This all changed with unprecedented budgets spent on advertising, including campaigns after the First World War that were aimed at women.96 Crucially, governments supplied their soldiers with cigarettes to keep up morale in the First and Second World Wars, thereby creating legions of loyal (addicted) customers for the cigarette manufactures in peacetime.
As we have seen, plant products such as caffeine and nicotine became widespread around the world because they produce a pleasurable buzz and are addictive. They mimic signalling molecules in our brains and activate the mesolimbic reward pathway, an evolutionarily ancient system whose function is to motivate and tune the behaviour that would have aided our survival and reproduction in our natural environment. But why are such plant compounds able to hack the human brain’s signalling system so effectively? Why would an otherwise unremarkable shrub growing natively in a pocket of the Ethiopian highlands, for example, just so happen to produce such a profound effect on our neurochemistry and so influence human history?
Caffeine, nicotine and morphine (which we’ll come to) are all examples of alkaloids. These are organic compounds mostly made up of carbon atoms, some of which are arranged into rings, and containing at least one nitrogen atom.97 They are an incredibly diverse family of natural compounds – around 20,000 are known – many of which are produced by plants to protect themselves from herbivorous animals,98 which also explains why most of them taste bitter.
Alongside caffeine, nicotine and morphine, many other compounds we encounter in this book, such as quinine, cocaine, codeine and mescaline, are also alkaloids. (Their names are a giveaway: the naming convention for alkaloids is to slap the suffix ‘-ine’ onto the formal scientific name of the plant it was extracted from.) In fact, alkaloids possess a staggering range of medical effects on the human body. They serve as anti-inflammatory and anticancer drugs, analgesics and local anaesthetics, and muscle relaxants. They suppress abnormal heart rhythms, widen or constrict blood vessels, lower blood pressure and reduce fever – alongside exerting stimulant or hallucinogenic effects on our brain. So what is behind this disproportionate potency of alkaloids in influencing the human body?
The answer is partly a numbers game. The botanical world produces a staggering number of different compounds, and so you might expect, purely by chance, some of them to incidentally have an effect on human biochemistry. But there’s more to it than this. Unlike animals, plants can’t move to run away from a threat or find resources they need. They’re rooted to the spot and instead need to rely on their internal biochemical machinery to manufacture a diverse repertoire of chemicals to influence animal behaviour. These compounds serve to attract animals to the plant, perhaps to help with pollination, or to deter an insect herbivore, such as a caterpillar or beetle, chewing on its leaves. They are also deployed in the competition with other plants or against attacks from fungi.
Over evolutionary time, plants have become extremely adept at producing compounds that have a specific effect on animals. Many characteristics are shared between animals, because we descend from a common ancestor and certain features are conserved by evolution if they serve an important function. This applies not just to the physical design of organs but also to the precise structure of the molecules that allow our cells to communicate or run vital biochemical processes. So a plant molecule that has been designed by evolution to have a powerful effect on, say, an insect’s digestive, circulatory or nervous system, is also likely to have a similar effect on the human body. Still, the alkaloid-producing plants that have had by far the greatest impact on human history are those that affect the mesolimbic pathway in our brain, such as caffeine, nicotine and, as we’ll see shortly, morphine.fn11
When early humans noticed the intoxicating effects of these plants, they began seeking them out and cultivating them. Today, stimulant crops occupy an enormous area of farmland. Coffee is grown on roughly 10 million hectares worldwide, and tea and tobacco about 4 million hectares each. Together, this constitutes well over half the total land area used for growing all the rice in China.102 And all this for crops that provide no nutrition for hungry mouths, nor fibres for clothing – just molecules with mild psychotropic effects.
In this sense, the nicotine synthesised by the tobacco plant to defend itself from insect herbivores103 turned out to be a stunningly effective adaptation for propagating itself around the planet by exploiting human neurochemistry. Countless people worldwide are dedicated to nurturing the plants in the field, tending to their every need: keeping them carefully watered and nourished with concentrated fertiliser; weeding and removing other plants competing for light; and eradicating pests that may attack the plant. Seen this way, we might wonder who has really domesticated whom.
As we saw earlier, the demand for tea in Britain grew steadily through the eighteenth century. Yet by the 1790s, most of it came from China, with the East India Company shipping 23 million pounds of tea leaves from the Far East to London every year.104 The profits earned by the company for its shareholders were enormous, but the tea trade was also very lucrative for the British government – in the early 1800s, tea was taxed at 100 per cent of its value.
But there was one major problem: China didn’t want anything the British Empire could offer in return. It had little interest in any of Britain’s raw materials or industrially manufactured goods. China bought a little metal and some mechanical novelties,105 but not on the scale needed to balance the volume of tea imported to Britain. The Qianlong Emperor wrote to King George III in 1793, ‘Our Celestial Empire possesses all things in prolific abundance and lacks no product within its borders. There was therefore no need to import the manufactures of outside barbarians in exchange for our own produce.’106 Britain was facing a colossal trade deficit.
The only European commodity that China desired was hard cash in the form of silver. Throughout the second half of the eighteenth century, therefore, about 90 per cent of Britain’s trade exports to China were bullion.107 The British government was struggling to raise enough silver to keep this trade going, and the East India Company was becoming concerned about maintaining its profits. At first, the company was able to operate a three-step triangular trade system: British, industrially manufactured goods were shipped to India, Indian cotton to China, and Chinese tea back to Britain, with the East India Company profiting handsomely on each leg. (This was a similar system to the transatlantic triangular trade that had operated from the sixteenth century, successively transporting European manufactured goods, African slaves and cash crops grown on the American colonial plantations such as sugar – or rum distilled from it – tobacco and, later, cotton.) While the direct exchange of tea for silver worked out badly for Britain, the three-stage cycle neatly exploited disparities in supply and demand in different commodities around the world. But the Chinese demand for imported cotton waned, and once again England was haemorrhaging precious silver to the East.108
But then the shrewd agents of the East India Company realised they could create a growing market for something that they could source in bulk. While the Chinese government would only consider silver for official trade, the Chinese people were keen on something else: opium.
Opium is the latex fluid exuded from cuts made in the immature seed capsules of certain varieties of poppy, which is then dried to a powder. This latex contains the analgesic compound morphine (and also codeine) that provides pain relief and produces a warm feeling of relaxation and detachment. Poppies were cultivated for their opium in Mesopotamia by the Sumerians from the end of the third millennium BC and named ‘plants of joy’. Opium use continued in the Middle East, as well as in Egypt, and the drug was known in ancient Greek medicine at least as early as the third century BC. By the eighth century AD, Arab traders had taken opium to India and China, and between the tenth and thirteenth centuries it made its way across Europe.109
Taken orally, opium was used medically to treat pain. The morphine is able to bind to nerve cell receptors (which are normally targets for the body’s own hormones such as endorphins) in parts of the brain involved in the sensation of pain, such as the thalamus, brainstem and spinal cord. But opiates also bind to receptors in the mesolimbic reward pathway, and so beyond its medicinal properties, opium was therefore craved as a recreational drug.
Opium was legal in Britain in the early 1800s, with Brits consuming between ten and twenty tonnes of the stuff every year. 110 Powdered opium was dissolved in alcohol as a tincture called laudanum, which was freely available as a painkiller and even present in cough medicine for babies. Many late-eighteenth and nineteenth-century literary figures were influenced by opium, including Lord Byron, Charles Dickens, Elizabeth Barrett Browning, John Keats and Samuel Taylor Coleridge; Thomas De Quincey found fame with his autobiographical Confessions of an English Opium-Eater.111 Drinking opium in this way produced mild narcotic effects but was also habit-forming – society at this time was therefore pervaded by high-functioning opium addicts, including many among the lower classes who were looking to numb the tedium of working and living in an industrialised urban world.112 But while laudanum helped inspire a few poets and fuelled bouts of aristocratic debauchery, drinking it delivered a relatively slow release of opiates into the bloodstream.113
The Chinese, on the other hand, had taken to smoking opium. This delivers a much more rapid hit, which is consequently far more potent and addictive. The Chinese probably first came across opium smoking in the seventeenth century in the Dutch colonial outpost in Formosa (Taiwan); the Portuguese then began shipping the drug from their Indian trading hub in Goa to Canton in the eighteenth century.114 So, although the East India Company didn’t create the initial demand for opium in China, they certainly hammered a wedge into this crack to pour in the drug. They could bank on the property of addictive substances: once you’ve gained a clientele for your product, you can be assured that your customers will keep coming back. Instead of sending silver to China, the East India Company trafficked opium – and they could effectively grow as much of this new currency as they needed.115 Before long, the company was pushing the drug in amounts never seen before. Ultimately, it boiled down to one addiction being traded for another – caffeine for opium – but the British were forcing a far more destructive substance on the Chinese. In order for the English mind to be focussed with tea, the Chinese mind was fogged with opium.116
The East India Company had seized control of Bengal from the Mughal Empire after the Battle of Plassey in 1757. It came to establish a monopoly on opium cultivation in the region and started running the drug into China. Opium consumption for non-medicinal uses was outlawed in China – the first laws banning opium had been enacted in 1729117 – and so the East India Company couldn’t be seen to be illegally importing opium as that would force a response from the emperor. Instead, it used independent ‘country firms’ as middlemen – Indian merchants licensed by the company to trade with China. These firms sold the opium for silver in the Pearl River estuary, where it was then smuggled ashore. This was a thinly veiled effort by the company to wash their hands of their formal involvement in the trafficking. As historian Michael Greenberg has put it, the East India Company ‘perfected the technique of growing opium in India and disowning it in China’.118 Meanwhile, a network of opium distribution spread through China, helped by corrupt officials who’d been paid off to look the other way.
The East India Company readily expanded its pipeline pumping opium into China until, in 1806, the tipping point was reached and the trade deficit had been forcibly reversed. The large numbers of Chinese opium addicts were now collectively paying so much to feed their habit that the import revenue from the smuggled opium exceeded that of the British tea exports. The silver tide had been turned and the precious metal began flowing from China to Britain for the first time.119 The amount of opium imported into China by the East India Company trebled between 1810 and 1828, and then almost doubled again by 1832, to around 1,500 tonnes every year.120 The British Empire, fuelled in the early days of its expansion across the Atlantic by one addictive plant, tobacco, was now wielding another, the poppy, as a tool of imperial subjugation.
We may never know for sure just how many Chinese men (it was mostly a male habit) were addicted to opium by the 1830s, but estimates at the time ranged between 4 and 12 million.121 Although opium did destroy the lives of those heavily addicted – transforming them into stupefied zombies when high and at all other times listless and craving their next visit to the opium den – it didn’t directly harm a large fraction of the whole population. The drug remained relatively expensive and so largely limited in accessibility to the mandarin and merchant classes in China.122 The catastrophe for China wasn’t so much the public health consequences as the economic disruption. As the silver paid to the British opium traffickers flowed out of China, the domestic supply diminished and the value of the precious metal rose. A farmer who had never touched an opium pipe now had to sell more of his crops to raise enough silver to be able to pay his taxes. By 1832, taxes were twice as high in real terms as they had been 50 years earlier123 and the outflow of bullion was having a direct impact on the Chinese imperial treasury.124 There was moral outrage in China against British opium and its harmful health effects, but the imperial court was far more concerned by the fiscal devastation it was wreaking.125
Some mandarins urged the emperor to legalise the drug and undercut the price of the British imports, or to prescribe that it only be traded for tea, so as to staunch the flow of silver out of the country.126 But as a good Confucian, the Daoguang Emperor wanted to help save his people from themselves. In 1839, he declared a war on the drug and appointed a high-flying and moralistic bureaucrat, Lin Zexu, to stamp out the opium trade coursing through the coastal Canton province, where the drug was landed by merchants at the port of Guangzhou.
When he arrived at the foreign trading post, or ‘factory’, in Guangzhou, Commissioner Lin peremptorily ordered the British and other foreign merchants to immediately cease selling opium and hand over all the stock they had in the port’s warehouses to be destroyed. The traders refused, and in response Lin had the doors of the factories nailed shut and their food supply cut off.127
The chief superintendent of trade for the British in China, Captain Charles Elliot, attempted to diffuse the standoff. He was able to persuade the traders in Guangzhou to turn over a staggering 1,700 tonnes of opium from the port storehouses by promising that the British government would reimburse them for their losses. Lin had the seized opium – worth an absolute fortune – disposed of by mixing it with water and lime in huge pits and then dumping the sludge into the Pearl River. The drugs bust was so large that it took three weeks to destroy it all.128 Commissioner Lin thought he was doing his honourable duty to stamp out the illegal smuggling of opium that was eating away at his countrymen; but the events that day would lead to a clash of empires and a humiliating defeat for China.
The deal struck by Elliot in Guangzhou seemed to have satisfied everyone: Lin successfully seized the drugs cache and destroyed the contraband; the traders accepted the offer of getting paid full price anyway; and Elliot defused the flashpoint and kept the port open to British trade. Everyone, that is, apart from the prime minister, Lord Melbourne, who soon learned that the superintendent in Canton had jauntily promised this huge payout on his behalf. The government now had to find £2 million (equivalent to £164 million today) to compensate the drug dealers.129 A local drugs bust had become an international incident, not just affecting merchants but challenging national pride. Lord Melbourne felt backed into a political corner, left with no other choice but to use military action to force China to reimburse Britain for the destroyed goods.
The response was to become a common theme of European imperialism: gunboat diplomacy. A taskforce of 4,000 British troops and 16 ships was dispatched to China, in a conflict known as the First Opium War (1839–1842).130 Within the Royal Navy fleet was a new kind of ship, the Nemesis: a steam-powered warship made of iron, unmatched by anything the Chinese possessed. The Nemesis proved a devastating weapon of the newly emerging industrial age of warfare, protected by her thick iron armour and blasting Chinese junks out of the water with large, pivot-mounted cannons and rockets.131 She was also able to steam through shallow water and penetrate far up rivers that deeper-draught wooden ships could not access. The British fleet blockaded the mouth of the Pearl River at Canton and captured a number of ports along the coast, including Shanghai and Nanking.132 On land, Chinese armies were torn apart by British rifles and military training. China had invented gunpowder and the blast furnace, but now a European imperial power was arriving on its shores turning these innovations against it.
In July 1842, British ships and troops effectively closed off the Grand Canal, a crucial artery distributing grain throughout China. Beijing was threatened with famine, and the Daoguang Emperor was forced to sue for peace. The Treaty of Nanking was humiliating. China was forced to pay huge reparations for the confiscated opium and subsequent conflict, cede Hong Kong (the ‘fragrant harbour’) to the British as a colony and open five ‘treaty ports’, including Canton and Shanghai, to British merchants and other international trade. But the British were still not satisfied, leading to the Second Opium War (1856–1860) and the greater opening of China to foreign merchants as well as the full legalisation of the opium trade.
Opium imports rose to a peak in 1880 – after which they were superseded by the Chinese-grown opium supply – when almost 95,000 chests, or some 6,000 tonnes, of the drug were shipped from India.133 Recreational opium use expanded across China, extending from the urban elites and middle class to rural workers.134 By the time Japan invaded China in 1937, 10 percent of the population – some 40 million Chinese – were believed to be addicted to opium. It was not until after the communist takeover in 1949 and the arrival of the totalitarian regime of Chairman Mao that rampant opium addiction was finally stamped out in China.135
China endured an opioid crisis lasting 150 years, forced upon it by corporate greed and imperial coercion. Today, over a quarter of a million hectares of land are used for opium poppy cultivation, the vast majority of it grown illicitly in Afghanistan. Afghan poppies account for virtually all of the heroin available in Europe and Asia, while most heroin in the US is supplied from Mexico. In a recent survey, about ten million people in the US self-reported the non-medical use of opioids, although this figure is likely to be an underestimate (the survey data does not include the homeless or institutionalised populations, for instance). However, over 90 per cent of this opioid consumption is not heroin but legally produced, painkilling pharmaceuticals misused by those who have become addicted to such medication.136
This current opioid epidemic, echoing that in nineteenth century China, is not a uniquely American problem, but the US healthcare system created the conditions for the crisis to flourish. The US does not provide universal healthcare paid for by taxes, and instead, medical treatment must be covered by health insurance, which often favours the cheaper option of a painkiller pill over alternatives like physical therapy.
In the late 1990s, drug companies, including Purdue Pharma, looking to increase the prescription of opioid drugs, and thus their profits, were able to convince the regulators and medical community in the US that their oxycodone pills (sold under the brand name of OxyContin, among others) were not addictive. Patients were prescribed ever-higher opioid doses as they built up a tolerance, until many developed a dependence and became reliant on the drug to avoid nasty withdrawal symptoms. Millions of addicts continued to seek opioids on the black market, and between 1999 and 2020, more than half a million died from an opioid overdose.137
The US Department of Health and Human Services declared a nationwide public health emergency in 2017, and steps are being taken to control the opioid crisis,138 but overdose deaths from synthetic opioids such as tramadol and fentanyl continue to rise.139 Opium itself is today a minor recreational drug, but humans are just as susceptible to the pleasurable – and addictive – properties of opioid compounds.