Drinking alcohol increases the risk of breast cancer in women and heavy drinking increases the risk in men.

The more alcohol a woman consumes the greater the risk, with no lower threshold.

Alcohol is metabolised into acetaldehyde, a cancer-causing compound. This occurs primarily in the liver but also in breast tissue.

Alcohol increases levels of circulating hormones including oestrogen, which increases breast cancer risk

Our tips to reduce your risk

Drink in moderation; as a minimum, do not exceed UK government guidelines of no more than 14 units of alcohol per week. The less you drink the less you are at risk.

Know what 14 units of alcohol represents for the drinks you like to consume.

Avoid binge drinking; to help with this, consider alternating between alcoholic and non-alcoholic drinks.

Aim to have at least some alcohol-free days each week.

Alcohol increases the risk of breast cancer

Alcohol increases the risk of breast cancer in women and heavy drinking may increase the risk in men (1). Drinking alcohol during pregnancy may increase the risk of breast cancer in daughters (2). In the UK it is estimated that 8% (around 4,400) of female breast cancer cases are linked to alcohol consumption (3, 4).

Does the type of alcoholic drink matter?

Any type of alcoholic drink increases the risk (5). All alcoholic drinks – be they beer, wine or spirits – contain ethanol, which is what causes harm. Different drinks contain different amounts of alcohol.

Type of drink

 

Alcohol by volume Volume of drink Alcohol

(grams)

Alcohol

(units)

Single-shot of spirits 40% 25ml 8g 1 unit
Alcopop 4% 275ml 8.8g 1.1 units
Pint of beer 4% 568ml 18.4g 2.3 units
A small bottle of beer 5% 330ml 13.6g 1.7 units
A small glass of wine 12% 125ml 12g 1.5 units
Standard glass wine 13% 175ml 18.4g 2.3 units
Pint of cider 12% 125ml 12g 1.5 units

How much alcohol increases breast cancer risk?

The more women drink the more breast cancer risk increases (6). Even very light drinking (1 drink/week) increases the risk (7). Binge drinking (more than 6 units or 4 drinks in a short period) may be especially harmful (8). One study found that pre-menopausal women who binge drink have twice the risk of breast cancer compared to non-binge drinkers (9). Some evidence suggests that drinking alcohol in adolescence and before a first pregnancy may increase risk more (10). For men, heavy drinking increases risk. Heavy drinking is twice the UK guidelines of 14 units/week which means 28 units or ~15 drinks/week). Light drinking may also increase male breast cancer, but more studies are needed.

Does alcohol increase the risk of all types of breast cancer?

Alcohol consumption is mainly associated with oestrogen receptor-positive (ER+) breast cancer.

Alcohol and breast density

Alcohol consumption increases breast density, which is strongly associated with increased breast cancer risk. It may also increase the risk of benign breast disease, which is itself a breast cancer risk factor (11, 12).

Alcohol and other risk factors

There may be a stronger association between alcohol and breast cancer risk among women who have hormone replacement therapy (HRT) (13). Risk is also increased for people who drink alcohol and smoke.

How does alcohol increase your risk of developing breast cancer?

  • Alcohol raises circulating oestrogen levels which increase breast cancer risk (14).
  • In the liver and breast tissue alcohol is broken down to acetaldehyde, a chemical compound that can cause cancer by damaging DNA.
  • Alcohol can cause weight gain, increasing the risk for post-menopausal women and men.
  • Alcohol may also affect the body’s immune system, and how well it absorbs vitamins and nutrients; alcohol can also affect whether certain genes are switched on or off.

More research is needed into how alcohol increases breast cancer risk (15).

For more prevention tips visit our Prevention Hub

For the full background briefing on alcohol and breast cancer

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You can download our FREE Ditch the Drink mocktail recipe e-book here too!

Chip in to help prevent breast cancer in future generations

Now more than ever, we need your help. Together we can help lower people’s risk of developing breast cancer. If you’ve found the information on our website helpful, then please consider making a donation today. Thank you.