You can reduce your risk of breast cancer by limiting the amount of alcohol you drink. The earlier in your life you start to reduce your drinking, the better.

  • Regularly drinking alcohol increases your risk of developing breast cancer
  • The more you drink, the greater your risk
  • Cut down your regular drinking to keep your risk of breast cancer at a lower level

How much does alcohol increase my risk?

Research shows that regularly drinking alcohol is associated with a higher risk of developing breast cancer.

Your risk of breast cancer will depend on how much alcohol you tend to drink. The more alcohol you drink regularly, the more likely you are to develop breast cancer at some point in your life. Even drinking just one drink a day can increase risk.

The graph below shows how many women out of 50 will develop breast cancer in their lifetime, depending on how many units of alcohol they drink. Find out more about units in the next section.

  • In a group of 50 women who do not drink, about six will probably develop breast cancer in their lifetime. Find out how age affects breast cancer risk
  • But in a group of 50 women who drink two units of alcohol a day (for example, a standard glass of wine), about seven will develop breast cancer in their lifetime
  • So drinking two units a day causes one extra women out of every 50 to develop breast cancer

You can keep your risk of breast cancer at a lower level by drinking less alcohol over your life.

What are the national health guidelines for alcohol?

National health guidelines across the UK recommend that women drink no more than 14 units a week. This is the equivalent of six pints of lower-strength beer or six 175ml glasses of wine per week. If you can, try spreading your drinks over a few days and aim to have days off drinking each week. You can find out more about the national guidelines in our blog - Alcohol and breast cancer: how much is too much?

There is still a risk of breast cancer associated with this level of drinking, but it can be a useful limit to stick to when beginning to cut down.

How much alcohol is in my drink?

It’s easy to get confused about how much alcohol is in your drink, particularly with so many different sizes of glasses or bottles. Units are used as a simple way to express how much pure alcohol is present in a drink.

Another way of calculating alcohol content is using ABV (alcohol by volume). ABV is how much pure alcohol is contained in the volume of a drink, given as a percentage of the total amount of liquid in your drink.

You can use the guide below to see how many units of alcohol and ABV are in your drink of choice or use the alcohol unit calculator from Alcohol Concern.

What can I do to reduce my drinking?

Cutting out drinking completely can be quite difficult for many people. But there are plenty of ways and ideas you can use to start cutting down.

  • Try swapping strong beers or wine for ones with a lower strength (ABV)
  • If you’re drinking at home, measure out your drinks to track your intake
  • It can be useful to track your drinking with an app or diary
  • Try having an alcohol free day once or twice a week
  • Talk things over with friends or family who can help support you
  • Try spacing out your drinks in an evening with soft drinks or mocktails

You can find more ideas and advice from NHS Choices. You may also find it useful to visit Alcohol Concern or Alcohol Focus Scotland.

Soberistas is another website you may find helpful, where you can share your experiences and get support.

Reducing your drinking can also help improve your general health and wellbeing, as well as reducing your risk of other cancers and diseases.

If you are worried about alcohol and breast cancer, talk to your doctor. They will be able to give you more information and advice.

We are still not entirely sure how alcohol increases the risk of breast cancer. It might alter the levels of hormones in the body, including the female sex hormone oestrogen. Oestrogen performs many important roles in the body, but can also increase the growth of some breast cancers. There may be other ways that alcohol increases the risk of breast cancer, but these are not yet clear.

There isn’t enough evidence to suggest that a particular type of drink, for example drinking wine rather than beer, has more of a risk that others. But we do know that the size, alcohol content and the number of drinks can affect your risk.

It’s not yet known whether binge drinking – for women, this means drinking about six or more units in a few hours – on just one or two days of the week leads to a higher risk of breast cancer than drinking the equivalent amount spread evenly throughout the week. But we recommend that you follow the national health guidelines and try to spread your drinks evenly over a few days.

How is our data calculated?

We base our calculations on evidence that we judge to be reliable and of most relevance to the UK population. We’d like to thank the Statistical Information Team at Cancer Research UK for providing us with baseline data (June 2017).

Note: some figures have been rounded up for clarity.

References

Allen NE, Beral V, Casabonne D, Kan SW, Reeves GK, Brown A, Green J. Moderate alcohol intake and cancer incidence in women. J Natl Cancer Inst 2009; 101:296-305

Office of National Statistics. (2012) General Lifestyle Survey Overview

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Information last reviewed: November 2017

Next review due: November 2020

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