breast cancer and alcohol consumption

Last reviewed 12/2022

• there is evidence, based on data from 53 studies involving 150,000 women, that a woman's risk of breast cancer is increased by consuming alcohol.
  • compared with women who reported drinking no alcohol, the relative risk of breast cancer was 1.32 (1.19-1.45, P<0.00001) for an intake of 35-44 g per day alcohol, and 1.46 (1.33-1.61, P<0.00001) for >/=45 g per day alcohol. The relative risk of breast cancer increased by 7.1% (95% CI 5.5-8.7%; P<0.00001) for each additional 10 g per day intake of alcohol, i.e. for each extra unit or drink of alcohol consumed on a daily basis
• the study team estimated that alcohol accounts for about 2,000 breast cancer cases per year
• the study team suggested that
  • the balance between alcohol's harmful effects on the breast and its beneficial effects on the heart (if moderate consumption) depended on age
  • up to around 60 years of age - the risk of breast cancer associated with alcohol outweighed its protective effect on the heart
  • over the age of 60 (and particularly over the age of 80 years), the benefits of moderate drinking on heart disease conferred much greater than the conferred risk of breast cancer

A review stated (2):

Female breast cancer

• alcohol consumption is causally associated with female breast cancer. Increasing alcohol consumption increases risk in a dose-dependent manner
• statistically significant increased risk at low, medium and high alcohol intakes

Notes:

• Typical alcohol content in grammes and UK units of different alcoholic beverages

  	Typical Alcohol by Volume (ABV) (%)	Typical volume of a drink (mL)	Ethanol content (g)	UK units of alcohol
  Beer	4.5	568 (pint)	20	2.5
  Wine	13	175 (glass)	18	2.3
  Spirits	40	20 (single)	8	1

  UK 1 unit of alcohol = 8g ethanol

  In describing levels of alcohol consumption, the terms 'low', 'medium' and 'high' were used to represent intakes averaging approximately <12.5 g ethanol/day (< approximately 1.5 units/day), 12.5-50 g ethanol/day (approximately 1.5-6 units/day), and >50 g ethanol/day (> approximately 6 UK units/day), respectively.

Reference:

1. British Journal of Cancer 2002,87,1234-45.
2. Public Health England (2015). Committee on Carcinogenicity of Chemicals in Food, Consumer Products and the Environment (COC) Statement 2015/S2 - Statement on consumption of alcoholic beverages and risk of cancer.