Health risks of alcohol consumption

Alcohol is an addictive substance and adverse effects of drinking occur at moderate to heavy levels in some individuals. Current evidence suggests that moderate drinking is associated with a lower risk for coronary heart disease in some individuals. However, higher levels of alcohol intake raise the risk for high blood pressure, stroke, heart disease, certain cancers, accidents, violence, suicides, birth defects, and overall mortality (deaths). Too much alcohol may cause cirrhosis of the liver, inflammation of the pancreas, and damage to the brain and heart. Heavy drinkers also are at risk of malnutrition because alcohol contains calories that may substitute for those in more nutritious foods. The digestion system of alcoholics has reduced ability to absorb certain nutrients, causing other illnesses.

Alcoholic liver disease is one of the most serious medical consequences of chronic alcohol use. The three alcohol-induced liver conditions are fatty liver, alcoholic hepatitis, and cirrhosis: (1) Some degree of fat deposition usually occurs in the liver after short-term excessive use of alcohol. However, fatty liver rarely causes illness. (2) In some heavy drinkers, alcohol consumption leads to severe alcoholic hepatitis, an inflammation of the liver characterized by fever, jaundice, and abdominal pain. Severe alcoholic hepatitis can be confused with many serious abdominal conditions, such as cholecystitis (inflammation of the gall bladder), appendicitis, and pancreatitis. It is important to be aware of this potential confusion because some of these other conditions require surgery, and surgery is contraindicated in patients with alcoholic hepatitis. These patients have a high death rate following surgery. (3) The most advanced form of alcoholic liver injury is alcoholic cirrhosis. This condition is marked by progressive development of scar tissue that chokes off blood vessels and distorts the normal architecture of the liver.

A patient may have only one of the three alcohol-induced conditions or any combination of them. Traditionally, they have been considered sequentially related, progressing from fatty liver to alcoholic hepatitis to cirrhosis. However, some studies have demonstrated that alcoholics may progress to cirrhosis without passing through any visible stage resembling hepatitis. Thus, alcoholic cirrhosis can appear insidiously, with little warning. Trauma linked to alcohol is the fourth highest cause of death, after coronary disease, cerebro-vascular accidents and cancer (the two latter illnesses are also exacerbated by alcohol). It is the main cause of death before the age of 40 years.

Numerous studies suggest that consuming more than two drinks a day over the long term can raise blood pressure in some people and increase the risk for stroke and other diseases. Overconsumption of alcohol is linked to cancers of the oesophagus and liver. Chronic alcoholism increases the risk of cancer of the upper respiratory and digestive tracts (mouth, upper pharynx, larynx). The risk increases greatly with tobacco addiction. Alcohol is the main cause of inflammation in the stomach (acute erosive gastritis). Alcohol causes poor absorption of nutrients in the intestine, hence some nutritional deficiencies, such as vitamin A and C. Large quantities of alcohol can cause haemorrhagic lesions in the internal wall of the intestine. Chronic alcohol consumption can lead to cardiac rhythm problems (tachycardia, palpitations). Alcoholism is the main cause of late onset epilepsy in adults. One Danish study found that heavy drinkers, having more than 42 units a week had a significantly increased risk of premature death. (A unit is equivalent to an average glass of wine or a "stubby", or 0.3 litre, bottle of lager beer). Another, however, found the mortality rate for those who drink up to 69 units of alcohol a week was equal to the rate for teetotallers, and that gender makes no difference (unlike most previous research which sets a lower limit for women). Smoking is considered by most researchers to increase the health risk factor from alcohol.

Deficiency of vitamin B-1 (thiamine), caused by reduced digestive absorption of this essential nutient in alcoholics, causes Wernicke's encephalopathy, characterized by impaired memory, confusion and lack of coordination. Further deficiencies of thiamine can lead to Korsakoff's syndrome, characterized by amnesia, apathy and disorientation.