Alcohol and cancer risk
Drinking alcohol is a cause of cancer.
The world-leading cancer agency - the International Agency for Research on Cancer (IARC) - has classified alcoholic drinks and the chemical present in these drinks (ethanol) as a Group 1 carcinogen, which means there is no doubt that it causes cancer.
There is convincing evidence that alcohol can lead to cancers of the:
- breast (postmenopause)
There is also probable evidence that alcohol can lead to cancers of the:
- breast (premenopause)
Suprisingly, there is also probable evidence that alcohol can reduce the risk of kidney cancer. The risk has only been found to be lower for up to two alcoholic drinks a day. The increased risk on other cancer types from drinking alcohol is far greater than any benefit observed in terms of kidney cancer.
It is estimated that 3,208 cases of cancer (or 2.8% of all cancers) were due to alcohol use in 2010 in Australia.
When it comes to cancer risk, there is no safe level of alcohol consumption. It is not just heavy drinking that increases cancer risk. Even drinking small amounts increases the chance of developing cancer. The more you drink and the more often you drink, the greater your risk.
(Source: Alcoholic drinks and the risk of cancer. World Cancer Research Fund / American Institute for Cancer Research, 2018)
Other negative effects of alcohol
Drinking alcohol has a number of negative effects other than increasing cancer risk. Other health effects from risky alcohol drinking include damage to the liver, heart and brain, high blood pressure and stroke, and risks to unborn babies. Drinking alcohol at a young age can affect brain development and lead to alcohol-related problems in later life.
Drinking alcohol is also associated with injury, violence, crime and motor vehicle accidents.
But isn't alcohol good for my heart?
Previously, researchers believed that red wine had health benefits for heart disease. It now seems that the research on alcohol and heart disease overestimated the benefits. The World Health Organization and the Heart Foundation now say that there is no merit in promoting alcohol consumption as a preventive strategy.
There are other more effective ways to decrease your risk of heart disease, such as being physically active, having a healthy body weight, following a healthy diet and quitting smoking.
Does drinking matter if I smoke?
The combined effects of smoking and drinking alcohol are much greater than the individual risks from either smoking or drinking alcohol alone. This is because alcohol makes it easier for the mouth and throat to absorb the cancer-causing chemicals in tobacco.
Those who drink alcohol and smoke cigarettes have a much higher chance of getting head and neck cancers (cancer of the mouth, pharynx, larynx and oesophagus). In fact, the combination of drinking and smoking is thought to be responsible for more than 75% of cancers of the head and neck.
Can alcohol lead to weight gain?
Just like any food or drink you consume (except water), alcoholic drinks contain energy (kilojoules, kJ). In fact, alcohol contains few nutrients but is very energy dense.
- 1 gram of alcohol = 29kJ of energy; whereas
- 1 gram of protein or carbohydrate = 17kJ of energy
The energy found in alcohol is often called ‘empty kilojoules'. In Australia, one standard drink contains 10 grams of alcohol, which gives you 290kJ of energy. If mixed with other sugary drinks (mixers), it contains even more energy. For example, a can of bourbon and coke provides about 690kJ of energy.
Another downside of alcohol is that it is easy to consume much more than a standard drink. The drinks served in restaurants, pubs and at home are often much larger than one standard drink. For example, a small glass of wine in a restaurant is about 150mL, which is one and a half standard drinks.
When alcohol is added to your diet it can easily contribute to weight gain. Being overweight is a risk factor for many types of cancer including bowel, breast (after menopause), kidney and liver. So drinking alcohol increases cancer risk, and gaining weight can add to this cancer risk.
There is no safe level of alcohol when it comes to cancer. If you choose to drink alcohol, drink no more than 2 standard drinks a day, and have alcohol-free days.