Breast cancer and alcohol

Alcohol is known to cause seven types of cancer, including breast cancer, mouth cancer and liver cancer.

Breast cancer is the fourth biggest cause of cancer deaths in the UK, and is by far the most common cancer in women.

According to Breast Cancer Now, breast cancer is thought to be caused by a combination of our genes, lifestyle choices and the surrounding environment.

One of the biggest risk factors is age. At least four out of five breast cancers occur in women over 50.

Why does drinking alcohol increase the risk of breast cancer?

There are several studies underway looking into the link between alcohol and breast cancer. Latest research shows there is a significant increase in the risk of breast cancer among women who drink alcohol1Estimates from Breast Cancer Now suggest that even moderate drinking is associated with increased risk.

  • In a group of 50 women about 6 will develop breast cancer in their lifetime.
  • In a group of 50 women who drink two units of alcohol a day (e.g. a standard glass of wine) about 7 will develop breast cancer in their lifetime.

So drinking two units a day causes one extra woman out of every 50 to develop breast cancer. Or 100 extra women in every 5,000.

It is not entirely clear how alcohol increases the risk of breast cancer. Scientists believe older women are particularly susceptible to breast cancer because of their increased lifetime exposure to the hormone oestrogen, which is a known risk factor for breast cancer.

If older women also happen to be drinking alcohol, the combination is especially risky.

When alcohol is consumed it is broken down to acetaldehyde, which is a known cancer causing substance that can impact on breast tissue.

How much alcohol can you safely drink?

There’s no ‘safe’ limit for alcohol when it comes to cancer, but the risk is smaller for people who drink within the government guidelines.

The Chief Medical Officer recommends that to keep the health risks from drinking alcohol to a low level you should not drink more than 14 units a week and that these units are spread over three days or more. Alcohol free days are a good way to cut back.

Credit Breast Cancer Now Units Graph

1A number of studies have proved conclusively that you increase your risk of breast cancer by between 9% and 11% for every 10 grammes of alcohol you drink per day. NB. Eight grammes of alcohol is equivalent to 10mls, which I one unit. So 10g is a little over one unit.

There isn’t enough evidence to suggest a particular type of drink e.g. wine as opposed to  beer, has more of a risk than others.

But we do know that the amount of alcohol we consume and the strength of the drinks (measured in units) can affect our risk.

If you want to reduce your risk of breast cancer, we recommend you limit the amount of alcohol you regularly drink throughout your life.

Increased effects of alcohol on older adults

As we get older, our bodies are less able to break down alcohol in order to make it less toxic. There is also a lower amount of water in the blood as part of ageing. This means that for the same amount of alcohol, older adults may be more likely to experience alcohol-related harm compared to younger people.

We might also be suffering from other health conditions. Or taking medication, which – when combined with alcohol – can lead to harmful side effects.

Reducing the risk

There is a lot you can do to reduce your risk of breast cancer and improve your health and well-being.

  • Use our drink checker tool to check how much you are drinking at the moment.
  • It’s easy to lose track of what you are drinking, particularly if you are pouring your own measures at home. You can buy unit cups or alcohol measures for a few pounds online. Or you may be able to pick up a unit cup from your GP or pharmacist.
  • There are lots more great tips on how to cut back here.
  • Reducing your alcohol consumption can help you lose weight, increase your energy levels and, in turn, improve physical fitness, which not only reduces the risk of breast cancer, but boosts your health and well-being overall.
  • There are plenty of other benefits to reducing your drinking.
  • If you live in Glasgow, Sheffield, Devon, Cwm Taf University Health Board area or the Western Trust area in Northern Ireland, we provide one-to-one and group support, as well as a range of activities to help improve your health and well-being. You can find contact details here.
  • Our web chat advisers are happy to help you wherever you live in the UK.
  • You should check your breasts regularly for any unusual changes. If you spot any changes to your breasts, make sure you get checked by your doctor as soon as possible.

There is more guidance at

1World Cancer Research Fund/American Institute for Cancer Research. Continuous Update Project Expert Report 2018. Alcoholic Drinks and the risk of cancer. Available at