Does drinking alcohol increase the risk of breast cancer?

New research released by the Department of Health's Know Your Limits campaign during Breast Cancer Awareness Month reveals that 82% of UK women are unaware that regularly drinking alcohol can increase the risk of developing breast cancer.

The Know Your Limits campaign was launched in May 2008 to highlight the health problems that could be caused by regularly drinking too much alcohol.

They warn that women who regularly exceed the recommended limit of 2-3 units per day could be at increased risk of developing breast cancer. According to the General Household Survey, around 4 million women in the UK drink more than the recommended limit. [1]

What does this mean?

We know that regularly drinking alcohol can slightly increase the risk of developing breast cancer. Drinking, on average, one unit of alcohol per day increases a woman's risk of breast cancer by about 6%. This is the same as saying that for every 100 women who drink one unit of alcohol per day there will be one extra case of breast cancer compared to 100 women who don't drink alcohol.

Number of units of alcohol in common drinks:

• A pint of ordinary strength lager, bitter or cider = 2 units
• A pint of strong lager = 3 units
• A 175ml glass of wine = around 2 units
• A pub measure of spirits = 1 unit
• An alcopop = around 1.5 units

This risk increases by a further 6% for each additional unit of alcohol consumed on a daily basis. For example, if you drink two units per day each and every day of your adult life your risk of breast cancer increases by about 12%. [2]

Current evidence suggests that all types of alcohol, including wine, beer and spirits, are associated with an increased risk of breast cancer.

It is not possible to predict exactly who will get breast cancer. But we do know that, on average, women of all ages who drink alcohol have a slightly higher risk of developing breast cancer than those women who do not.

Drinking alcohol is one of the few identified risk factors for developing breast cancer. We don't yet know all the causes of the disease but it's thought to be a combination of hormonal, genetic, lifestyle and environmental factors. For most women, the biggest risk factor for developing breast cancer is increasing age.

Unlike many other established breast cancer risk factors, alcohol consumption is something we can change. The important message is to be aware of how many units of alcohol you are consuming and to drink in moderation.

Alcohol and Breast Cancer Risk: The Facts

Breakthrough has produced a factsheet Alcohol and Breast Cancer Risk: The Facts with more information about the link between alcohol and breast cancer risk.

To find out more about the Know Your Limits campaign visit www.nhs.uk/units

[1] The 'around 4 million' figure is based on 21,119,500 women aged 16 or over in England (ONS 2006 population estimates). General Household Survey data shows that in 2006, 20% of English women drank more than 14 units in the week. Using this, the Know Your Limits campaign estimates that 4,223,900 women aged 16 or over exceeded the 14 units in 2006.

[2] These figures are estimates and reflect the incidence of breast cancer in the UK population and the size of alcoholic units in the UK.