Effects of excess alcohol consumption

Alcohol is a popular drink consumed in large quantities throughout the world. In many countries, alcohol consumption is becoming great problem. Ethanol (ethyl alcohol) is oxidized to acetaldehyde in the process of its metabolism. Acetaldehyde is then transformed to acetate, 90% in the liver mitochondria. Acetate is released into the blood and then oxidized by peripheral tissues to carbon dioxide, fatty acids and water. Alcohol dehydrogenases are present in many tissues and it has been found that enzymes present in the gastric mucosa may contribute considerably to ethanol metabolism.

Ethanol itself releases 29.3 kj/g (8 kcal/g), but many alcoholic drinks also contain sugar, which increases their calorific value. For an example, one pint of beer provides 1045 kj (250 kcal), so the heavy drinker will be not be capable to lose weight if he or she continues to drink.


Effects of excess alcohol consumption

Excess consumption of alcohol leads to two major problems, both of which can be present in the same patient:

#Alcohol dependence syndrome
#Physical damage to various tissues.

Each unit of alcohol (defined as one half pint of normal beer, one single measure of spirit (25ml), or one small glass of wine) contains 8 g of ethanol. All the long-term effects of excess alcohol consumption are due to excessive intake of alcohol.

Daily maximum allowances are 3 units for men 2 units for women. To achieve the limit of alcohol intake the following regulations are useful:

#Use a standard measure.
#Do not drink during the daytime.
#Have alcohol-free days each week.

Remember these following facts

#Health can be damaged without being 'drunk'.
#Regular heavy intake is more harmful than occasional binges.
#Do not drink to drown your problems.

In many countries the drink-before-driving limit of alcohol in the blood is 800 mg/L (80 mg%). One unit of alcohol is eliminated per hour, therefore spread drinking time. Food decreases absorption and therefore results in a lower blood alcohol level. 4-5 units are sufficient to put the blood alcohol level over the legal driving limit in a 70 kg man (less in a lighter person).

Ethanol, irrespective of the type of alcoholic beverage; i.e. beer and spirits are no different in their long-term effects. Short-term effects, such as hangovers, depend on additional substances, particularly other alcohols such as isoamyl alcohol, which are known as congeners. Brandy and bourbon contain the highest percentage of congeners.

The amount of alcohol that produces damage differs and not everyone who drinks heavily will suffer physical damage. For example, only 20% of people who drink heavily develop cirrhosis of the liver. The effect of alcohol on different organs of the body is not the same; in some patients the liver is affected, in others the brain or muscle. The differences may be genetically determined. Thiamin deficiency contributes to both neurological (confusion, Wernicke-Korsakoff syndrome) and some of the non-neurological manifestations (cardiomyopathy). Susceptibility to damage of different organs is variable. Heavy persistent drinkers for many years are at greater risk than heavy sporadic drinkers.

In general the effects of a given intake of alcohol seem to be worse in women. The following figures are for men and should be reduced by 50% for women:

#160 g ethanol per day (20 single drinks) carries a high risk
#80 g ethanol per day (10 single drinks) carries a medium risk
#40 g ethanol per day (five single drinks) carries little risk.

Alcohol consumption in pregnancy

Women are advised not to drink alcohol at all during pregnancy because even small amounts of alcohol consumed can lead to 'small babies'. The fetal alcohol syndrome is characterized by mental retardation, dysmorphic features and growth impairment; it occurs in fetuses of alcohol-dependent women