Four friends holding wine glasses "cheering" at a celebration with the words "The adverse effects of alcohol" written in white font

The adverse effects of alcohol

Alcohol is Australia’s most socially acceptable legal drug. The consumption of alcohol within Australia is widespread and is associated with many social and cultural activities. Alcohol consumption is the second leading cause of preventable morbidity and mortality in Australia, contributing to more than 3000 deaths and 100,000 hospitalisations each year.
What exactly is alcohol? Alcohol is the ingredient (ethanol or ethyl alcohol) that is found in beer, wine and spirits. It is formed when yeast ferments the sugars from different foods e.g. wine is made from the sugar in grapes, beer is from the sugar in malted barley, cider is from the sugar in apples and vodka is from the sugar in potatoes, beets or other plants.
Excessive drinking of alcohol is known to cause many adverse health outcomes. Drinking heavily can increase the risk of cardiovascular and liver disease, metabolic disturbances, nutritional deficiencies, cancers (i.e. mouth, stomach, colon, liver and breast), neurological disorders and foetal abnormalities.

Cardiovascular system:

Extensive studies have been conducted to assess the association between drinking and cardiovascular diseases including hypertension, coronary heart disease, stroke, peripheral artery disease and cardiomyopathy. Limiting alcohol consumption to lower levels (low-to-moderate consumption) can mitigate mechanisms that affect atherosclerosis and inflammation and pathophysiologic processes integral to the development of cardiovascular disease. However, moderate-to-high consumption can have serious pathological effects including mitochondrial dysfunction, changes in circulation, inflammatory responses, oxidative stress, programmed cell death and anatomical damage to the cardiovascular system and the heart itself.


Alcohol is metabolised by the liver and the liver can tolerate mild alcohol consumption. When the consumption of alcohol increases it can disrupt metabolic function of the liver. Alcoholic liver disease occurs as a result of the overconsumption of alcohol that damages the liver, leading to a build-up of fat, inflammation and scarring. If continued alcohol consumption occurs, the liver disease progresses to severe damage of the liver cells also known as ‘alcoholic cirrhosis’, which is irreversible and increases the risk of developing liver cancer.

Endocrine System:

The endocrine system controls metabolism, energy levels, electrolyte balance, growth, development and reproduction. It also plays an important role in the body’s response to change in temperature, electrolyte composition, stress and injury. Chronic alcohol consumption has been shown to have serious adverse effects on certain components of the endocrine system by inducing hormonal disturbances. The hormonal dysregulation that results can contribute to various disorders including stress abnormalities, reproductive deficits, body growth defects, thyroid problems, immune dysfunction, cancer, bone disease and psychological and behavioural disorders.
The pancreas is one of the most important organs of the endocrine system, involved in the control of blood glucose concentration through the synthesis and secretion of insulin from β-cells. Heavy alcohol consumption is a stand-alone risk factor for the development of Type 2 Diabetes Mellitus.
The neuroendocrine and immune system are highly interrelated. Acute and chronic alcohol exposures have been shown to cause immunosuppression and dysregulation of the immune system. The alcohol-induced suppressive effects on the immune system have been shown to be primarily due to a blunted response of the hypothalamic-pituitary axis to external stressors such as infections.


Evidence indicates that the more alcohol a person drinks–particularly the more alcohol a person drinks regularly over time–the higher his or her risk of developing an alcohol-associated cancer. Chronic excessive alcohol consumption is associated with the following cancers:

  • Head and neck cancer: oral cavity, pharynx, and larynx cancers.

  • Oesophageal cancer, particularly oesophageal squamous cell carcinoma (SCC). In addition, people who inherit a deficiency in an enzyme that metabolizes alcohol have been found to have substantially increased risk of oesophageal squamous cell carcinoma if they consume alcohol.

  • Liver cancer

  • Breast cancer: Studies have consistently found an increased risk of breast cancer in women with increasing alcohol intake. Women who consume about 1 drink per day have a 5 to 9 percent higher chance of developing breast cancer than women who do not drink at all.

  • Colorectal cancer

Thiamine (Vitamin B1) Deficiency:

Vitamin B1 is one of the essential nutrients that uses the food we eat (fats, proteins and carbohydrates) and converts them into energy to fuel the heart, brain and nerves. Studies have shown that up to 80% of those who have an addiction to alcohol will develop a thiamine deficiency. Heavy consumption of alcohol causes inflammation to the lining of the stomach and digestive tract which in turn reduces the body's ability to absorb nutrients. Early stages of thiamine deficiency can result in symptom such as decreased appetite, constipation and fatigue and if left untreated it can lead to serious and potentially fatal conditions including:

  1. Beriberi - dry beriberi damages nerves and can lead to decreased muscle strength and paralysis; wet beriberi affects the circulatory system and heart and can cause heart failure
  2. Wernicke-Korsakoff’s syndrome - occurring commonly in alcohol-dependent individuals again affecting the nerves and brain, has two phases. Wernicke encephalopathy occurs first and can cause confusion, loss of memory activity, loss of muscle coordination and leg tremors, double vision, abnormal eye movements and eyelid drooping. This can then progress to Korsakoff syndrome, which is a chronic and disabling condition characterised by severe short-term memory loss, hallucinations and impaired ability to acquire new memories.

Foetal Alcohol Exposure:

Research has shown that binge drinking or regularly heavy drinking while pregnant can place the foetus at greater risk of significant health problems. Alcohol is able to easily pass from the mother’s bloodstream into the developing baby’s blood which can interfere with development of the brain including impaired behavioural and cognitive functioning and changes in physical structure of body systems and critical organs.

Guidelines for ‘safer’ consumption of alcohol:

It is important to note that no level of alcohol consumption can be defined as completely ‘safe’. However, health authorities have developed guidelines that can help to minimise risk associated with drinking. The National Health and Medical Research Council (NHMRC) revised the Australian Alcohol Guidelines in 2020 to reduce the health risks associated with drinking alcohol. These guidelines advise healthy adults to drink no more than 10 standard drinks a week and no more than 4 standard drinks on any one day. The image below demonstrates examples of standard drink volumes.

Examples of standard drinks with relevant alcohol content

Safety tips this festive season:

  1. Make sure you eat - avoid drinking on an empty stomach to avoid becoming intoxicated too fast
  2. Drink plenty of water - for every standard drink you consume aim to have a glass of water
  3. Don’t go too fast too soon - drink slowly to give your body plenty of time to process the alcohol. Your liver can process about 1 unit of alcohol every hour
  4. Don’t mix with other substances - mixing alcohol with caffeine can hide the depressant effects of alcohol, making you drink more than you might otherwise. Combining alcohol with other drugs can also have adverse effects
  5. Don’t drink and drive - never drive while intoxicated. Even if you feel like you’ve sobered up, you may still have alcohol in your system that can affect your reaction time.

Alcohol support services:

Follow this link for a list of organisations, websites and services that offer alcohol support, counselling and information


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