1) Around 5% of alcohol in the body is processed through the lungs and exhaled in the breath.  Alcohol can be detected by breathalyzer devices. 

2) The kidneys also eliminate approximately 5% of alcohol from the body.  The kidneys control the bodys correct fluid levels and alcohol acts as a diuretic which means it increases urine formation. 

Alcohol inhibits the pituitary secretion of anti-diuretic hormone (ADH), which acts on the kidneys to reabsorb water.  Elimination via urine reduces the circulating levels of ADH.  When these levels drop, the kidneys do not reabsorb as much water, consequently, the kidneys produce more urine.

3) The liver metabolises 90% of alcohol.  Alcohol is effectively a cell poison.  It takes the liver approximately one hour to burn up one unit of alcohol.  Once metabolised by the liver, alcohol oxidizes (unites with oxygen to produce heat and energy). 

When the alcohol enters the liver, some of it is changed into acetaldehyde by a liver enzyme called alcohol dehydrogenase. 

The acetaldehyde then breaks down to form acetic acid, which is, in turn, dispersed throughout the body where it combines with oxygen to form carbon dioxide and water.  

The liver can only oxidize a certain amount of alcohol at a time - the alcohol that is not being metabolised in the liver continues to circulate throughout the body.  In addition to its role in the oxidation of alcohol it maintains the bodys blood-sugar level - but the elimination of alcohol from the body supersedes the livers other tasks.  Excessive alcohol intake can result in hypoglycaemia where little food is eaten, and hyperglycaemia if food is consumed.

Technically it is possible to drink at the same rate as the alcohol is being oxidized out of the body.  Most people, however, drink faster than this, and so the concentration of alcohol in the bloodstream keeps rising.  Tolerance to many effects of alcohol is easily developed. 

Repeated exposure of the metabolizing system (mainly the liver) to alcohol increases the levels of alcohol dehydrogenase and aldehyde dehydrogenase.  As a result of this, the body becomes more efficient at eliminating the high levels of alcohol in the blood. 

Therefore, the alcohol is metabolized more quickly and the duration and intensity of the desired effects are considerably reduced.  This is known as metabolic tolerance. 

To regain the desired effect of the alcohol, the individual must increase the dosage and / or frequency of consumption.  Generally, cessation of alcohol consumption will cause the body to revert to its original tolerance levels, i.e. when it first experienced the presence of alcohol.

Alcohol makes considerable demands on the body

When alcohol is fortified and purified by distillation, it is separated from the vitamins and minerals in the original fruit or grain, which is needed to metabolise the alcohol as fuel.  Other food sources are needed to relieve the poisonous effects as quickly as possible.

Spirits and fortified wines are therefore a drain on nutrition.  This is why sherry and cocktails are such effective aperitifs - they lower the blood sugar, inducing hunger.  In excess the opposite effect occurs, dulling the palate and neutralising the benefit.

Medical problems related to consumption of alcohol are varied.  Alcohol in excess can be harmful to many different organs and tissues over a period of several years.

Brain - loss of memory, intellectual deterioration, depression and eventually dementia.

Skin - persistent facial flushing as a result of blood-vessel damage.

Heart and circulation - increased risk of high blood pressure, heart attacks and stroke.

Liver - cirrhosis, hepatitis, liver cancer.

Digestive system - gastritis, pancreatitis, peptic ulcer and cancer of the mouth, throat or oesophagus.

Nerves - temporary or permanent numbness, tingling and weakness.

Sex organs - infertility due to sperm damage, or impotence due to hormonal changes.

19/05/2009