Over the years I have received a lot of questions on alcohol and alcoholism. I have written donkey times on alcoholism, especially when festivities are near. Easter beckons and time for us once again to indulge.
So I am going to embark on tripartite write up on alcohol, to educate us on what chemicals we consume at sobriety as we head towards inebriation, this Easter.
Most readers couch their questions on alcohol in an explorative manner, as if to say, “This alcohol we consume with gusto” what is the chemical composition and why do their percentages vary. We shall get into all these as we progress.
Let us, first of all, understand that alcohols are volatile, colourless, pungent liquids, composed of three chemical elements: carbon, hydrogen, and oxygen. Ethyl alcohol (ethanol) is the type taken in alcoholic drinks.
Alcohol may also be prescribed medically, to stimulate the appetite, or form a medicinal base in which other ingredients are dissolved. Methyl alcohol (methanol or “wood alcohol”) is used commercially, as a fuel for solvent. It is poisonous, and drinking it causes blindness and death.
In the domestic and industrial production of alcoholic drinks, ethyl alcohol is produced by fermentation – that is the degeneration of a starch (such as maize, barley, cassava, rice, potatoes grapes), by bacteria action. The drinks that result depend on the starch used. For instance, malt and barley give beer, grapes give wine. Cassava ultra-filtrate gives hot drinks. Beers and wines are produced by fermentation alone. Only about a 15 pecent level of alcohol is possible by this method.
“Spirits” with their higher alcoholic level (kai-kai-gin, whisky, vodka, liqueurs etc), also require distillation that is, the alcohol is evaporated off, leaving water behind, and resulting in a higher alcoholic concentration in the eventual liquid. Distilled alcohol may also be added to wines (sherry, part, morrulla, etc), and beers, to strengthen them.
Commercially, the strength of alcoholic beverage is expressed as so many “degrees proof.” This refers to the liquid’s specific gravity – not to the percentage of alcohol it contains. Proof measurement regulation varies between countries.
With the USA, proof measures the percentage of alcohol which is half the figure for degrees proof. For example, a spirit that is 100 proof (written “100”), contains 50% alcohol.
Typical alcohol contents are: lager up to 8%, beer up to 8%, cider up to 8%, wines 9 to 15% fortified wine 20%, aperitif 25%, marulla – 25%, spirits, liqueurs 40 to 50%.
About 20% of any alcohol drunk is absorbed in the stomach, and 80% in the intestines. It is then carried around the body by the bloodstream to the liver. The liver breaks down (oxidizes) the alcohol at an almost constant rate: usually about 2 and half bottles (1pint) of beer or 1 ounce of whisky per hour.
This process eventually disposes of about 90% of the alcohol, forming carbon dioxide and water as end products. The remaining 16% is eliminated through the lungs and in the sweat.
Alcohol in the body has four main effects:
It provides energy (alcohol has high caloric value, but contains no nutrients.
It acts as anaesthetic on the central nervous system, slowing it down and impairing its efficiency.
It stimulates urine production. With heavy alcohol intake, the body loses more water than is taken in and the body cells become dehydrated.
It puts part of the liver temporarily out of action – after heavy drinking as much as two – thirds of the liver can be non-functioning, but it usually recovers fully within a few days.
The effect of alcohol on behaviour depends on the amount reaching the brain via the bloodstream. This blood alcohol level is determined by several factors apart from the quantity of alcohol drunk.
The size of the liver decides the rate of oxidation and elimination. The size of the person, decides the amount of blood in the system; because blood volume is proportionate to size. The larger the person, the greater the diluting effect of the blood on the alcohol consumed, and the more it takes to produce the same effect.
The speed and manner in which the alcohol is consumed is important. The longer one takes to drink a given quantity, the less effect it has. Alcohol consumed on an empty stomach will have a greater and more immediate effect than that consumed during or after eating. Food acts as a buffer to absorption.
If we assume a person of average size say 68kg (150lbs), drinking at an average rate on an empty stomach, then any one of the following would give a blood alcohol level of 0.03%. This will be 50 mls of spirit, or 100mls of fortified sherry or wine or 150mls of table wine, or 2 bottles of beer. Twice there qualities will give twice the blood alcohol level (0.06%) and so on.
As the level of alcohol in the blood rises, the drinker’s brain and nervous system are increasingly affected, and changes occur in his behavior.
At 0.02% sense of warmth, friendliness and visual reaction time slows.
At 0.04% – driving ability and speed is impaired.
At 0.06 feelings of mental relaxation and general well being. Plus slight decrease in skulls.
At 0.09% exaggerated emotions and behavior. Tendency to be loud and talkative. Loss of inhibitory control. Sensory and motor nerves increasingly dulled.
At 0.12% – staggering and fumbling with words.
At 0.15% intoxication.
At 0.20% – incapacitation, depression, nausea, loss of sphincter control.
At 0.30% – Drinking stupor.
At 0.40% – Coma.
At 0.60% + – lethal dose that leads to death through heart and respiratory failure.
Fortunately, lethal doses seldom occur, as unconsciousness and vomiting, force the drinker to stop.
The behavioural effects of alcohol make drinking and driving very dangerous, both to the drinker and to others. Tests have shown that errors of judgment and control increase as soon as there is any alcohol in the bloodstream.
Therefore many countries prescribe a legal limit to the blood alcohol level of anyone in charge of a vehicle. In the USA this varies from 0.10 to 0.15%, except for Utah where it is 0.08% Alcohol is a psychological depressant; that is as consumption occurs the transmission of impulse in the nervous system becomes slowed.
First to be affected are higher levels of the brain. Inhibition, worry and anxiety are dissolved, resulting in a sense of well-being and euphoria. As the lower levels of the brain become affected, co-ordination, vision and speech are impaired.
The small blood vessels of the skin become dilated (widen). Heat is radiated and the drinker feels warm. This means that blood has been diverted from the internal body organs, where the blood vessels are already constricted by the effect of alcohol on the nervous system. So at the same time, the temperature of internal body organ fails.
Any increase in sexual desire is due to the depression of the usual inhibitions.
Alcohol is not an aphrodisiac – physical sexuality is more and more impaired as blood alcohol rises but the desire increase. Eventually, the poisoning effect of excess alcohol causes nausea and possible vomiting, and may leave the drinker with the usual symptoms of a hangover.
Always be medically guided
Please follow me on twitter @DRSUN