Alcohol and breast cancer.

Does drinking alcohol increase my risk of breast cancer?

Yes, drinking any amount of alcohol increases your breast cancer risk. Scientific studies have shown that for women, when it comes to breast cancer risk, the more alcohol you drink, the greater your risk. If you do drink, it is important to keep to the current UK guidelines of no more than 14 units a week. This should be spread over at least three days and have several alcohol-free days in between. 

Drinking alcohol is strongly linked to seven types of cancer: those affecting the mouth, throat, voice box (larynx), food pipe (oesophagus), bowel, and liver. It is also a significant risk factor for breast cancer. All types of alcohol increase the risk of cancer as it is the alcohol itself that causes the damage​. 

Key facts about alcohol and breast cancer risk.

• In the UK, it is estimated that 8% (around 4,400) of female breast cancer cases are linked to alcohol consumption. 
• Compared to non-drinkers, breast cancer risk is 9% higher in women who drink up to 2 units of alcohol per day, and 60% higher for women who drink 6 or more units per day. 
• Several studies have found that drinking alcohol is mostly linked to the development of hormone receptor-positive breast cancer. 
• Some evidence suggests that binge drinking (more than 6 units or 4 drinks in a short period) may result in a higher breast cancer risk, particularly for pre-menopausal women. 
• For men, the link between alcohol isn’t clear. Some evidence suggests heavy drinking (more than 7.5 units/day) may increase a man’s breast cancer risk.

How does drinking alcohol increase your breast cancer risk?

The exact way alcohol increases a woman’s risk of breast cancer isn’t fully known, but scientists believe it’s due to some or all of the following reasons: 

• Alcohol raises the levels of circulating hormones such as oestrogen, which can increase the number of times a cell divides. High levels of oestrogen are known to increase breast cancer risk. 
• In the liver and breast tissue, alcohol is broken down to acetaldehyde, a chemical compound that can cause cancer by damaging cells and preventing their repair. 
• Alcohol can damage the DNA inside the cell’s energy centres (mitochondria) and cause stress to the cells. Over time, this damages healthy cells and raises the risk of breast cancer. 
• Alcohol may negatively affect the levels of certain vitamins and nutrients in the body, which are important in producing DNA in cells.  
• Alcohol can promote weight gain, increasing the risk of breast cancer for post-menopausal women and men. 
• Alcohol may also influence or interact with other known breast cancer risk factors, such as breast density and benign (non-cancerous) breast disease, which may increase overall risk.

What is the recommended amount you should drink each week?

The UK guidelines on drinking alcohol recommend no more than 14 units of alcohol per week, spread across at least 3 days, with some alcohol-free days in between. 

Different alcoholic drinks contain different amounts of alcohol. The amount of alcohol in a drink is measured in units, with 1 unit equalling 10ml or 8g of pure alcohol (ethanol) found within that drink.

Alcoholic drinks are often also labelled with a percentage, followed by the abbreviation ‘ABV’. This stands for Alcohol By Volume. This number is the amount of alcohol in that drink.

Check the label; many bottled and canned drinks will list the number of units directly on the label. 

Use online tools, such as NHS.uk and Drinkaware , which offer simple calculators to do the math for you. 

Common drinks and their unit totals:

• Single shot of spirits (25ml at 40% ABV): 1 unit.
• Standard glass of wine (175ml at 13% ABV): 2.3 units.
• Bottle of wine (750ml at 13% ABV): 9.8 units. 
• Can of lager (440ml at 5.5% ABV): 2.4 units.
• Small bottle of beer (375ml at 4.5% ABV): 1.7 units.
• Pint of beer (568ml at 4% ABV): 2.3 units.
• Alcopop or flavoured mixed drinks (275ml at 4%): 1.1 units.

Start your prevention journey today.

To begin reducing how much alcohol you drink, choose one of these actions to commit to this week:

• Choose alcohol-free days: Pick two or three specific days this week, like Tuesday and Thursday, when you won't drink any alcohol at all.
• Alternate with water: For every alcoholic drink you have, follow it with a full glass of water.
• Try a new non-alcoholic drink: There are lots of non-alcoholic brands available now, or try a mocktail when you're out or make your own at home (download our free mocktail recipe book today).

Remember, these small steps can make a big difference. Which one will you try first?

Further reading

For more details, please see our Alcohol and Breast Cancer science review.  

If you need further support regarding alcohol, contact your GP, who will be able to provide confidential advice and support.

Last review: Aug-25 | Next review: Aug-28.