Alcohol Extension

Learning objectives To understand alcohol is a source of energy. To understand measurements of alcohol. To know the safe alcohol intake recommendations. To understand that drinking too much alcohol may damage health.

What is alcohol? Alcohol is not a nutrient because it is not essential for the body. Alcohol is a source of energy in the diet. Each gram of pure alcohol provides 29kJ (7kcal) of energy.

How is alcohol produced? Alcohol is produced by a process called fermentation. During fermentation microbes called yeasts grow by feeding on the sugars (e.g. glucose). As they grow, the yeasts produce alcohol and carbon dioxide. This equation shows what happens: C6H12O6 2C2H5OH + 2CO2 + ENERGY Glucose Ethanol Carbon dioxide

Alcoholic drinks The amount of alcohol in drinks varies from 0 - 50%. Spirits such as whisky and vodka have a higher alcohol content than wines or beers. Fruits such as grapes and apples are used to make alcohol drinks such as wine and cider. Cereals such as barley and rye are used to make beer and spirits. Spirits are made using a distillation process.

Alcohol content of drinks Drink % alcohol Spirits 40 Sherry 16 Wine 10-14 Strong larger, beer or cider 3-4 Low alcohol larger, beer or cider 1-1.5

One unit of alcohol A standard way of measuring the alcohol content in drinks is in units of alcohol. One unit contains 8 grams of pure alcohol (ethanol). A single pub measure of spirits. 25ml ~40% alcohol A glass of sherry or fortified wine 50ml ~20% alcohol A glass of table wine 100ml ~10% alcohol ¼ pint of strong larger, beer or cider 142ml ~9% alcohol ½ pint of regular larger, beer or cider 284 ml ~6% alcohol 2 pints of low alcohol beer or cider 568 ml ~2% alcohol

What happens to alcohol in the body? Alcohol is absorbed from the stomach and the small intestine. This occurs more slowly if alcohol is drunk with food. It is soluble in water and carried around the body in the bloodstream. Alcohol is removed from the blood by the liver over a period of several hours. The rate at which this happens depends on age, sex, body weight, liver size and how much alcohol was consumed.

Sensible drinking The Department of Health has advised that those people who drink should limit intake according to the following guidelines. Men – not more than 3 to 4 units per day. Women – no more than 2 to 3 units per day. After a large consumption of alcohol (binge drinking) occurs in one session, it is recommended to leave 48 hours before consuming alcohol again. This allows the body to break down all the alcohol consumed.

Possible damage to health It is best, for pregnant women to avoid alcohol completely as it can damage the unborn baby. If they do drink, they should limit the amount to one unit of alcohol a day, once or twice a week. Heavy drinking during pregnancy can cause fetal alcohol syndrome.

How does alcohol affect the body? As the level of alcohol in the bloodstream increases it has an affect on a person’s behaviour. Short term: Reaction times are slower. Increased risk taking. Judgement becomes blurred. Co-ordination is poor. This is why it is dangerous to drink alcohol before driving a car. Long term: Can lead to liver damage such as cirrhosis and liver cancer and the vitamin B deficiency disease beri-beri.

Review of the learning objectives To understand alcohol is a source of energy. To understand measurements of alcohol. To know the safe alcohol intake recommendations. To understand that drinking too much alcohol may damage health.

For more information visit www.foodafactoflife.org.uk