{"id":38,"date":"2012-11-24T03:53:46","date_gmt":"2012-11-24T03:53:46","guid":{"rendered":"http:\/\/www.howiewatkins.co.uk\/content\/?p=38"},"modified":"2012-11-25T16:07:07","modified_gmt":"2012-11-25T16:07:07","slug":"alcohol","status":"publish","type":"post","link":"https:\/\/www.howiewatkins.co.uk\/?p=38","title":{"rendered":"What\u2019s your poison?"},"content":{"rendered":"

Drinking Alcohol, often to dangerous excess, is an accepted part of many people\u2019s lives.\u00a0 The pressure on those that do not drink, particularly the young, to \u201cjoin in with the crowd\u201d is immense.\u00a0 Recent research shows that drinking by 12-20 year olds (particularly girls) is increasing, despite the efforts that are now being made to emphasise the hazards that young drinkers face: significantly higher chances of developing clinical depression, greater chance of causing permanent physical damage to their internal organs and increased likelihood of unwise, unprotected sexual activity (with the obvious consequences).<\/p>\n

The World Health Organisation (WHO) considers that alcohol is a significant threat to World health, causing as much death and disability as measles and malaria.\u00a0 In 1990, alcohol was responsible for \u00be million deaths (80% of them in rich countries like the UK), more than either tobacco or illegal drugs.\u00a0 In spite of this, many governments, whilst claiming publicly that they are concerned about the abuse of alcohol, seem unwilling to limit either production or consumption; possibly because worldwide, on average, governments earn nearly a quarter of their tax revenue from the drinks industry.<\/p>\n

To understand why something that causes so much harm is such an important part of the world economy and own our social lives, we need to take a long, hard, look at both ourselves and our close animal relatives.\u00a0 When it comes to boozing, it appears we are not alone.<\/p>\n

In the beginning, there was a bug\u2026<\/h1>\n

What most people call alcohol is actually ethanol (C2H50H), one of the alcohol \u201cfamily\u201d of organic (carbon containing) chemicals.\u00a0 It is made by certain micro-organisms, principally yeasts, as they break down sugars to provide the energy they need to live (fermentation).<\/p>\n

It\u2019s most likely that humans first started deliberately seeking to control this process for their own purposes as far back as 10,000 years ago.\u00a0 Fruit, left in water to ferment provided a snack that didn\u2019t go bad so quickly and a nice drink.<\/p>\n

This may have been the origins of the brewing industry, but getting drunk started long before.<\/p>\n

Blame it on the fruit.<\/h1>\n

Ripe fruit is packed full of sugars, ideal food for ethanol producing micro-organisms.\u00a0 Their spores, always present in the air, settle and germinate on the skin of the fruit.\u00a0 Thanks to the plentiful supply of food, they thrive, reproducing and spreading.<\/p>\n

Ripe fruit is also the food of choice for many animals: monkeys, apes, fruit-bats, birds and butterflies (to name a few).\u00a0 The challenge for any fruit hunter – particularly one that lives in a tropical forest where fruits ripen throughout the year – is to find the tastiest, ripest, fruit, with the minimum of effort.\u00a0 This could well explain how animals of all shapes and sizes, including our own fruit-eating ancestors first acquired a taste for ethanol.<\/p>\n

The theory goes something like this\u2026\u00a0 A tree bearing a quantity of perfectly ripe fruit, will, thanks to colonizing micro-organisms, also produce ethanol.\u00a0 Because ethanol is highly volatile, it turns to vapour and spreads through the air easily.\u00a0 Any animal that can detect ethanol vapour and track down its source is going to be able to find trees with ripe fruit faster than its competitors, giving it a distinct advantage in the battle for survival.\u00a0 To our noses, ethanol has a distinctive smell that is instantly recognizable.\u00a0 Perhaps this is no accident but is in fact because our noses are adapted for sniffing it out, a relic of our evolutionary past.<\/p>\n

Any animal that seeks out and consumes fruit that has a high ethanol content gets a double treat.\u00a0 Not only is such fruit rich in sugar, but ethanol itself, when broken down by the liver, is a rich source of energy that provides 29Kj\/g (carbohydrate provides 16Kj\/g, protein 17Kj\/g and Fat 37Kj\/g), but there is a risk.\u00a0 Any animal that consumes too much ethanol risks becoming intoxicated (drunk) and poisoned.\u00a0 So, where are all the drunk monkeys?<\/p>\n

Actually, there are quite a few examples of drunken animals that have been described, and I\u2019ve even lived with one.<\/p>\n

Drunk as a parrot.<\/h1>\n

Elton the parrot was (and still is) a Citron-crested cockatoo, hatched in Wales at the zoo where I used to work.\u00a0 She used to travel everywhere on my shoulder.\u00a0 One day, when I was drinking a glass of wine with some friends, she surprised me by forcing her head between me and the glass so she could get at the wine.\u00a0 I\u2019d never seen this behaviour when I was drinking tea and, intrigued, I let her take a sip.\u00a0 She didn\u2019t seem keen on the taste, so I assumed that she\u2019d leave wine alone in the future.\u00a0 However, whilst I was busy serving dinner, I saw, out of the corner of my eye, Elton, head in my wine glass, guzzling as much as she could.\u00a0 Soon after, she started staggering around, became aggressive towards one of my friends, flew into the wall and had to be put in a cage (for the safety of all).\u00a0 Next morning she was, \u201csick as a parrot\u201d.\u00a0 Interestingly, this unpleasant end to her evening didn\u2019t prevent her from trying to get her beak into wine glasses from then on, and she had to be restrained whenever a cork was pulled.<\/p>\n

The discovery that Elton seemed drawn to wine, even before she knew what it was, got drunk as a result of consuming too much, and suffered afterwards with a hangover \u2013 all, weaknesses I\u2019d considered uniquely human up to then \u2013 started me looking for other examples of alcoholic animals.\u00a0 I didn\u2019t have to look far.<\/p>\n

In Sri Lanka, a popular local drink, Toddy, is made from the nectar of coconut flowers.\u00a0 Holes are made in the base of the flowers and cups tied underneath to catch the nectar that drips out.\u00a0 These are then left in the trees whilst the wild yeasts and fungi do their work.\u00a0 Monkeys that raid the pots and drink the fermenting Toddy often cause problems for local villagers.<\/p>\n

Worker wasps and hornets, deprived of their normal food at the end of summer, take advantage of over-ripe summer fruits, the erratic flight that results, with multiple collisions, is often put down to \u201csleepiness\u201d.\u00a0 Rubbish, they\u2019re drunk.\u00a0 Fruit eating birds like waxwings are similarly famous for falling off their perches and flying into walls.\u00a0 Nectar drinkers, like the lorikeets of Australia are also guilty of flying whilst \u201cover the limit\u201d.<\/p>\n

If the thought of a drunk parrot doesn\u2019t frighten you, how about a drunk elephant?\u00a0 After pigging out on their favourite fruit (from the Marula tree) followed by a big drink of water, their stomachs become giant fermenting vats.\u00a0 As a result, the elephants become uncoordinated, aggressive and incredibly dangerous.\u00a0 Presumably, the headache next morning must be pretty big as well.<\/p>\n

The list goes on, clearly supporting the \u201cnose for booze\u201d theory.\u00a0 One thing is still puzzling however: if drunkenness is an unpleasant side effect of eating alcoholic fruit, and animals are very good at detecting ethanol, why don\u2019t they avoid the fruit that would make them drunk, or at least be cautious about eating too much?\u00a0 Observations would seem to suggest that they seem especially drawn to the booze.<\/p>\n

Fatal Attraction<\/h1>\n

Ethanol is fascinating because it is an incredibly simple molecule and yet its effects on animals\u2019 brains and bodies are far-reaching and profound.\u00a0 Despite the terrible damage it does, animals continue to seek it out.\u00a0 To understand why, perhaps we should look at what it does.<\/p>\n

Ethanol is quickly absorbed into the blood stream as it does not need to be digested.\u00a0 This begins in the stomach but principally takes place in the small intestine.\u00a0 This is why alcohol that arrives in the stomach mixed with food takes longer to be absorbed.\u00a0 Once absorbed, it travels throughout an animal\u2019s body.\u00a0 Thanks to its chemical structure, it can dissolve in both water and fat.\u00a0 In a short time it is distributed evenly in every tissue.\u00a0 Because it is the level of alcohol actually circulating in the blood which determines how drunk an animal becomes small animals become intoxicated faster.<\/p>\n

Not all ethanol that enters an animal\u2019s bloodstream has an effect, some leaves straight away without being broken down.\u00a0 Between two and ten percent is removed by the kidneys and lungs.\u00a0 The exhaled ethanol vapour allows the police to catch drunk drivers.\u00a0 An ethanol content of 35mg per 100ml of exhaled air is equivalent to the current UK drink-driving limit of 80mg per 100ml of blood.<\/p>\n

The job of breaking down ethanol falls to the liver, which has to go into overdrive to cope with the extra work.\u00a0 It\u2019s a two part process that first sees the alcohol turned into acetaldehyde by the enzyme Alcohol dehydrogenase.\u00a0 This intermediate is toxic and thankfully, is normally converted by aldehyde dehydrogenase into acetic acid (vinegar).\u00a0 The acid is then further broken down into water and Carbon Dioxide elsewhere in the body.\u00a0 Whilst the liver is busy with alcohol breakdown, many of it\u2019s other, essential functions are affected.\u00a0 This can be especially dangerous for young drinkers.<\/p>\n

Interestingly, after consuming ethanol, animals become hungry.\u00a0 This is due to the breakdown of the glycogen-glucose shunt, a system that normally ensures that there is enough, but not two much glucose in the blood.\u00a0\u00a0 A healthy human has blood that contains 50-80mg of glucose per 100ml of blood.\u00a0\u00a0 The liver maintains this safe level.\u00a0 If the blood sugar rises too high, the liver converts the excess glucose into glycogen.\u00a0 When the glucose level starts to drop, the liver reverses the process.\u00a0 This allows you to eat irregularly yet function constantly.\u00a0 Alcohol blocks the system forcing the blood glucose levels to drop, setting off alarm bells in the brain, which instantly sends out chemical signals to stimulate appetite.\u00a0 The practise of having an aperitif, a moderately strong alcoholic drink before a meal to make all the diners feel hungry, takes advantage of this effect.\u00a0 It is also the reason why kebab shops do so much business after the pubs have closed.<\/p>\n

Another general effect of ethanol that seems to confuse many people, and one of the main causes of hangovers, is dehydration.\u00a0 You would think that if you were drinking something like lager, which is in the region of 90-95% water, you couldn\u2019t possibly dehydrate.\u00a0 Once again, the ethanol is playing tricks with the body, or, more accurately, the section of the brain that monitors the level of water in the blood.\u00a0 It blocks the production of vasopressin (anti-diuretic hormone), something that would only normally occur if there was too much water in your blood.\u00a0 This sets the kidneys into \u201cdump water\u201d mode and results in the loss of much needed body fluid.\u00a0 Along with all the extra fluid, the kidneys manage to lose essential mineral salts that are needed by your metabolism: magnesium, potassium, calcium and zinc.\u00a0 The blinding headaches that traditionally follow an excess of alcohol are often little more than brain shrinkage as a result of this dehydration combined with salt loss.<\/p>\n

So far, nothing in this list of effects explains why any creature would want to consume ethanol.\u00a0 To understand that, we have to look in a little more detail into the effects of ethanol on the brain.<\/p>\n

It\u2019s all in the mind<\/h1>\n

Unlike most drugs that affect mood, ethanol doesn\u2019t have a single \u201ctarget\u201d location in the brain.\u00a0 It affects a number of different sections of the brain and has varying effects based on the concentration present in the animal\u2019s blood.<\/p>\n

At relatively low levels ethanol makes the thinking, remembering and pleasure seeking parts of the brain (the cortex, hypocampus and nucleus accumbens) more sensitive to stimulation.\u00a0 Signals are transported more easily and the motor and reward (pleasure) centres fire more readily.\u00a0 In humans, these effects are usually observable after a single drink, whilst the levels of ethanol in the blood are relatively low (25mg\/100ml).\u00a0 A person who has this much ethanol will typically be more sociable, more willing to tell jokes, smile and laugh.\u00a0 They may feel less intimidated by strangers and more confident in themselves.\u00a0 They will also be more physically animated.\u00a0 At this level of intoxication there are few unpleasant side effects to speak of.\u00a0 Sadly, the feelings of empowerment that accompany the first drink invariably lead to a second.<\/p>\n

As the levels of ethanol increase (50-80mg\/100ml in humans) the above effects become more pronounced.\u00a0 The animal becomes more excitable.\u00a0 At this stage of drunkenness, people at a party would start talking louder and faster than ever as their inhibitions melted away.<\/p>\n

The feelings of happiness increase along with the ethanol levels in the blood for a little while longer before something interesting happens.\u00a0 The receptors that have been over-stimulated up to now suddenly stop responding.\u00a0 The ethanol now begins to act as a sedative, selectively reducing brain activity.\u00a0 The first section of the brain to slow down is the hippocampus, which affects memory, and the thalamus, which controls sensory and motor information.\u00a0 In humans this corresponds to a blood alcohol level of around 100mg\/ml (3-4 drinks).\u00a0 By now, our partygoers would be getting clumsy on the dance floor, swaying slightly as they tried to stand upright and losing the thread of conversations.<\/p>\n

Now that the switch from stimulation to sedation has occurred, further increases in the blood ethanol level just do more and more damage.\u00a0 When a person hits an ethanol level of around 120mg\/ml there are whole sections of their brains shutting down.\u00a0 Activity in the areas of the brain involved with motor coordination and posture (cerebellum) is reduced causing slurred speech and an increased likelihood of falling over.\u00a0 The sight centre (occipitial lobe) is also affected, causing blurred vision.<\/p>\n

Animals at and above this level of intoxication can become unpredictable as their seratonin receptors now start to be affected.\u00a0 Seratonin is an important brain messenger and it is known to control overall mood,\u00a0 aggression and sexual arousal.\u00a0 A human will, at this point either start a fight, start trying really hard to impress members of the opposite sex or go to sleep.\u00a0 Exactly which of the three possibilities is most likely depends on the personality of the individual and the exact circumstances.<\/p>\n

At around 200mg ethanol per 100ml of blood a human is usually in real trouble.\u00a0 If they haven\u2019t dropped off to sleep by now, they will probably be feeling very ill and confused.\u00a0 Their vision will be blurred, their hearing will be dulled, speaking and understanding speech will have become difficult, as will standing unsupported.\u00a0 Plus, thanks to the alcohol that has diffused into the fluid-filled balance centres of the inner ear, the room will be spinning alarmingly.<\/p>\n

If ethanol levels rise any further, the animal will be in real trouble as essential sections of the brain start to shut down.\u00a0 For humans, 500mg of alcohol per 100ml of blood is usually fatal.\u00a0 Breathing stops.<\/p>\n

If you, or someone you know is concerned about alcohol abuse, help and advice is available:<\/p>\n