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How alcohol affects your body

According to the most recent National Drug Strategy Household survey, Australia’s most widely-used recreational drug is alcohol — and the ingredient that gives alcohol its ‘kick’ is ethanol. Ethanol is made by fermenting different foods. For example, fermenting grains makes beer and whisky, while fermenting fruit makes wine and brandy.

But how does ethanol give you that ‘kick’? How alcohol affects your body depends on a range of factors such as your gender, age and whether you have certain medical conditions. Biological differences mean that alcohol has more of an effect on women than on men. Young people under 15 are at the highest risk from alcohol’s effects — the best advice is that they avoid it altogether. Older people who are more likely to fall may be more at risk of alcohol’s effects too. Here’s a guide to some of the effects alcohol may have on your body.

What happens when we drink alcohol?

Alcohol goes directly into the bloodstream through the walls of the stomach and small intestine. From there it’s quickly distributed to all parts of the body, including the brain — all within a few minutes of sipping a drink. Food in the stomach slows down the rate of absorption but it doesn’t stop you from getting drunk.

But while getting alcohol into your system is quick, getting it out takes time. The liver takes about an hour to break down the alcohol in a standard drink — and nothing will hurry it up. Drinking coffee, taking cold showers or vomiting won’t speed up the rate at which alcohol leaves your body.

Alcohol and your liver

The liver does most of the work of breaking down alcohol in the body. But although it’s a resilient organ, long-term heavy drinking can eventually cause damage.

Each time your liver filters alcohol from your blood, some liver cells die. Although the liver can grow new cells, after too many years of too much alcohol it loses its ability to make new cells and the liver becomes damaged.

Warning signs that your liver may be in trouble are conditions such as fatty liver disease and alcoholic hepatitis. These are often reversible. But if the liver becomes chronically inflamed it can cause cirrhosis — also known as scarring of the liver — resulting in loss of liver function. This can be fatal. Cirrhosis isn’t reversible, but if scarring is only mild and the person stops drinking, this can prevent more damage and help the liver recover.

Alcohol and your heart — some good news and some bad news

For middle-aged people, drinking any type of alcohol, not just red wine, may have some benefit for the heart. However, the greatest amount of benefits comes from drinking small amounts of alcohol:

  • Less than one standard drink daily for women aged from about 45-50 years and over
  • One to two standard drinks per day for men aged from about 40-50 years.

There’s also strong evidence that low-risk drinking may be protective against stroke.

However, there doesn’t seem to be similar heart health benefits for younger people — and non-drinkers can get similar benefits from habits like regular exercise, not smoking and a heart-healthy diet.

Drinking large amounts of alcohol, on the other hand, may increase the risk of illness and death from heart disease and stroke. High blood pressure — a risk factor for heart disease and stroke — can be caused by too much alcohol.

Alcohol and the gender gap — how alcohol affects women differently

If a man and a woman are both drinking exactly the same amount of alcohol — say two glasses of wine each with dinner — the blood alcohol concentration (BAC) in the woman’s body will almost always be higher than that in the man’s. This is because women:

  • usually have smaller bodies with less water — this means the alcohol will be more concentrated in a woman’s body, causing a higher BAC
  • generally have smaller livers than men — the liver’s ability to break down alcohol is influenced by its size.

This is why women often get drunk faster than men, and recover from drinking more slowly than men. They may also develop liver damage and other health problems at lower levels of drinking than men.

Alcohol and your brain

You may think alcohol is a stimulant because it’s used as a party drug, but it’s actually a depressant. While it can initially make you relaxed and loosen your inhibitions, the more your drink the more it affects your brain, slowing your reflexes and affecting judgment, co-ordination and balance.

Drinking at risky levels over time can eventually damage the brain, causing alcohol-related brain injury. Symptoms include problems with memory, thinking and physical co-ordination.

Heavy alcohol use can cause long term effects on the brain because it:

  • has a toxic effect on the brain
  • interferes with absorption of vitamin B1 (thiamine) — an important brain nutrient
  • can cause dehydration, which may cause wastage of brain cells
  • can cause falls and accidents that injure the brain.

Young brains and alcohol

Research now suggests that because an adolescent’s brain is still developing, it’s more easily harmed by alcohol. That’s why Australian drinking guidelines recommend under 15s avoid alcohol altogether, while for 15-17 year olds it’s safest to delay drinking for as long as possible.

But while teenagers are more vulnerable than adults to alcohol’s effects on learning, memory and judgment, they also seem to be less easily sedated by alcohol and their co-ordination is less affected. In other words, they can stay awake and drink for longer than adults — which may partly explain why some adolescents have binge drinking habits.

The main health concerns about adolescent drinking are:

  • it may permanently disrupt some of the brain’s ‘wiring’, causing long-term memory and learning problems
  • because young people are more likely to drink a lot in a short time they are more at risk of drink-driving, injury, violent behaviour and risky sex
  • under 15s who drink alcohol are five times more likely to abuse alcohol than those who start drinking at 21or older. This increases the risk of alcohol-related problems in later life, including dependence.

Alcohol in older people

Older people may not be able to tolerate as much alcohol as when they were younger — and this can have implications for both driving and the risk of injuries, according to the Department of Veterans’ Affairs.

  • As we get older — especially over 70 or 75 — the amount of water in our body decreases. This means that alcohol reaches a higher concentration in the body and it takes less alcohol to make us drunk.
  • Alcohol also increases the risk of falls — two thirds of admissions to hospital for people over 84 result from alcohol-related falls.
  • Older people are also more likely to take medicine — alcohol may interact with some medicine and cause side effects.

Further information

Australian Drug Foundation www.adf.org.au

Sources

Australian Institute of Health and Welfare (AIHW). 2007 National Drug Strategy Household Survey. Canberra, ACT: AIHW. 2008 [accessed 20 Aug 2010] Available from: http://www.aihw.gov.au/publications/index.cfm/title/10674

Better Health Channel. Alcohol and brain damage. Melbourne, VIC: State Government of Vic. c2010 [last updated Oct 2009, accessed 20 Aug 2010] Available from: http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Alcohol_related_brain_damage

DrugInfo Clearinghouse. Alcohol. [online] Melbourne, VIC: Australian Drug Foundation. 2006. [accessed 20 Aug 2010] Available from: http://druginfo.adf.org.au/

DrugInfo Clearinghouse. The effects of alcohol on the young brain: for workers. [online] Melbourne, VIC: Australian Drug Foundation. 2005. [accessed 20 Aug 2010] Available from: http://druginfo.adf.org.au/

National Alcohol Strategy. Health benefits of alcohol. Canberra, ACT: Commonwealth of Australia. c2002 [accessed 20 Aug 2010] Available from: http://www.alcohol.gov.au/

National Drug and Alcohol Research Centre. The Harmful Effects of Alcohol. [online] Kensington, NSW: University of NSW Faculty of Medicine. c2005 [accessed 19 Aug 2010] Available from: http://ndarc.med.unsw.edu.au/

National Health and Medical Research Council. Australian Guidelines: To Reduce Health Risks from Drinking Alcohol. Canberra, ACT: Commonwealth of Australia. 2009 [accessed 19 Aug 2010] Available from: http://www.nhmrc.gov.au/_files_nhmrc/file/publications/synopses/ds10-alcohol.pdf (PDF 2.3Mb)

NHS Choices. Alcoholic liver disease. London, UK: National Health Service. [last updated 3 Dec 2009, accessed 20 Aug 2010] Available from: http://www.nhs.uk/conditions/liver_disease_%28alcoholic%29/Pages/Introduction.aspx

Pearson TA. Alcohol and heart disease. Circulation. 1996; 94: 3023–3025.

The Right Mix. Alcohol and older people. Woden, ACT: Commonwealth Department of Veterans’ Affairs. 2009 [accessed 20 Aug 2010] From: http://www.therightmix.gov.au/

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Disclaimer
This information has been developed and reviewed for Bupa by health professionals. To the best of their knowledge it is current and based on reputable sources of medical research. It should be used as a guide only and should not be relied upon as a substitute for professional medical or other health professional advice.

Bupa Australia Pty Ltd makes no warranties or representations regarding the completeness or accuracy of the information. Bupa Australia is not liable for any loss or damage you suffer arising out of the use of or reliance on the information. Except that which cannot be excluded by law. We recommend that you consult your doctor or other qualified health professional if you have questions or concerns about your health. For more details on how we produce our health content, visit the About our health information page.

Last published 31 October 2010