Alcohol and cancer: the evidence
This page explains how we know that alcohol causes cancer. There is an overview of the scientific evidence and further links so you can find out more if you wish.
A note about measurements
There are a variety of measurements in use when it comes to alcohol. Government advice officially relates to units. Researchers tend to classify people by how many grams of alcohol they drink. And the amount of alcohol in 'a drink' depends on both how high the alcohol content of the beverage is and the volume you pour.
On the other pages about alcohol, we have tried to only refer to drinks (e.g. 175ml wine or a pint of beer). Because this page also includes information on how the risk of cancer changes with the amount people drink, we have also given information on the grams or units of alcohol. Or you can use the information below to help you convert between the different measurements.
- 1 unit of alcohol contains 8g of alcohol, which is equivalent to 10ml of pure alcohol
- 10g of alcohol is equivalent to 1.25 units
- 12.5g of alcohol is equivalent to 1.56 units and is often defined as the amount in 1 drink by researchers.
Of course, drinks of different sizes and strengths have different amounts of alcohol in them, and you can find more examples here.
On this page
- Alcohol is one of the most well-established causes of cancer
- Alcohol increases the risk of mouth, throat, voice box and foodpipe cancers
- Alcohol increases the risk of breast cancer
- Alcohol increases the risk of liver cancer
- Alcohol increases the risk of bowel cancer
- Alcohol could cause cancer in many ways
The International Agency for Research into Cancer (IARC; part of the World Health Organisation) has classified alcohol as a Group 1 carcinogen since 1988. 1 IARC's rulings are the gold standard in terms of determining if something causes cancer, and Group 1 is their highest risk category. It means that there is convincing evidence that alcohol causes cancer in humans. More recent reviews by IARC and other agencies have also concluded that drinking alcohol causes cancer. 2, 3, 4, 5, 6
A study published in 2011 found that alcohol is responsible for around 4% of UK cancers, about 12,500 cases per year. 7
One review found that people having 4 or more drinks (where one drink has around 1.5 units of alcohol) a day had about 5 times the risk of mouth and pharynx cancers compared to people who never drank or drank only occasionally. And the same review also found that even lighter drinkers of no more than 1 drink a day had a 20% higher risk.9
Even small amounts of alcohol can increase the risk of breast cancer. A review of the evidence in 2012 concluded that having 1 drink a day (around 1.5 units) could increase the risk of breast cancer by 5%. 10 And the risk increases the more a woman drinks, several studies have found that each additional 10g of alcohol drunk a day increases the risk by about 7 - 10%. 11, 12, 13
Alcohol is one of the main risk factors for liver cancer. 14 Heavy drinking can lead to cirrhosis, a condition where the liver is repeatedly damaged and scar tissue builds up. Cirrhosis increases the risk of liver cancer.
And alcohol aggravates the risk of liver cancer in people with hepatitis B or C infections who are already at higher risk. People with these infections should avoid alcohol, as even small amounts could damage their livers. 15
Studies have shown that alcohol can increase the risk of bowel cancer. 8, 16 Even fairly small amounts can have an effect, the EPIC study found that for every 2 units a person drinks each day (less than a pint of premium lager or large glass of wine) their risk of bowel cancer goes up by 9%. 17
At the moment, we are not entirely sure how alcohol acts to cause different types of cancer but there are several theories with good evidence. It is likely that alcohol causes different types of cancer in different ways. 18
The theory with the strongest evidence is related to how our bodies process alcohol. It is converted into another chemical called acetaldehyde, which is the substance behind hangovers. And acetaldehyde can also cause cancer by damaging our DNA and preventing it from being repaired. 19 The International Agency for Research into Cancer (IARC) classes acetaldehyde associated with drinking alcohol as a Group 1 substance, which means it can cause cancer in humans. 6 Drinking alcohol greatly increases the level of acetaldehyde found in saliva. 20 And a small initial study in 2012 found higher levels of DNA damage in the mouth cells of people after drinking alcohol. 21
Alcohol can cause cirrhosis of the liver, by repeatedly damaging the liver's cells. This is turn can cause liver cancer. 14
Alcohol makes it easier for cancer-causing chemicals, such as those found in tobacco, to be absorbed in the mouth or throat. 26
Alcohol reduces the amount of folate in our blood. Folate is a B vitamin that our cells need to create new DNA correctly. 27
Alcohol can cause highly reactive molecules known as Reactive Oxygen Species or ROS, to be produced in our bodies and particularly in the liver. 14, 19 These molecules are damaging and they are usually kept at a low level, but when ROS levels are raised, they are known to damage DNA.
A meta-analysis published in 2012, which combined the results of 49 previous studies, found that non-smokers who drank alcohol were around a third more likely to develop mouth and upper throat cancer than those who didn't drink alcohol. But smokers who also drank were nearly 3 times as likely to develop the disease. 29 Another study found that the risk of liver cancer was almost 10 times greater in people who smoked and drank heavily. 30
The more alcohol someone drinks, the more their cancer risk increases. 8 But even quite small amounts of alcohol, around 1 drink a day, can increase cancer risk. 9, 10, 32, 33 Expert reports have concluded that there is no lower limit of alcohol drinking where cancer risk isn't increased. 3, 4
Drinking small amounts of alcohol can offer some protection for people who are at risk of heart disease, which normally applies to people over the age of 40. 34 A review published in 2011 of 84 studies found that although drinking up to 15g of alcohol a day (about 2 units) reduced the risk of dying from heart disease and stroke, the benefits quickly start to disappear as drinking levels increase. 35 A study has calculated that the best balance between benefits and harms is for people who drink less than 1 unit a day. 36
Because of this many sources, including the European Code Against Cancer and the World Cancer Research Fund, have suggested that women should drink no more than one drink a day, and men should drink no more than 2 drinks. 3, 37 Similarly, the UK government recommends that men don't regularly drink more than 3 - 4 units in a day, and women no more than 2 - 3 units. 38 While these levels can increase the risk of cancer, the effects are likely to be small.
Most research into the links between alcohol and cancer has looked at the total amount people drink. This research has found that the more a person drinks, the more their cancer risk increases. Much less research has been done into the effect of pattern of drinking, for example whether drinking is spread evenly across the week or concentrated in binges. At the moment, this research does not point in any clear direction. As the number of studies grows, we should be able to better decide whether the pattern of drinking has any effect on cancer risk or health generally. 5, 39, 40
The risk of alcohol-related cancers increases the more you drink. So by cutting down on what you drink, you could reduce the risk of these cancers.
If you are a heavy drinker, it is not too late to start cutting down. Scientists have found that the risk of mouth, throat and oesophageal (foodpipe) cancers reduces over time in people who have given up drinking. 41, 42
Some studies have found that the children of women who drank alcohol during pregnancy had an increased risk of one type of leukaemia. 43 It is not yet possible to say for sure whether there is a real link, more studies involving larger numbers of people are needed to investigate.
Drinking alcohol during pregnancy has been linked to many other conditions and NICE currently recommend that women stop drinking alcohol altogether while trying to conceive and for at least the first 3 months of their pregnancy. After that time, pregnant women should have no more than a small drink once or twice a week and should avoid binge drinking or becoming drunk. 44
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- IARC, IARC Monographs on the evaluation of carcinogenic risks to humans. Volume 44 Alcohol drinking. 1988. Link
- WHO/FAO Expert Consultation on Diet, Nutrition and the Prevention of Chronic Diseases, in WHO Technical Report Series. 2003, WHO: Geneva. P. 95-104. Link
- Boyle, P., et al., European Code Against Cancer and scientific justification: third version (2003). Ann Oncol, 2003. 14(7): p. 973-1005. PubMed
- WCRF and AICR, Food, nutrition and the prevention of cancer; a global perspective. 1997, American Institute for Cancer Research: Washington. p. 37-145.
- IARC, World Cancer Report, ed. B. Stewart and P. Kleihues. 2003, Lyon IARC Press. Link
- IARC Monographs, Volume 100E: Personal habits and indoor combustions. 2012, Lyon IARC Press p377 – 503. Link
- Parkin, M., et al., Cancers attributable to the consumption of alcohol in the UK in 2010. Br J Cancer, 2011. 106 (S2) p. S14- S18. PubMed
- Corrao, G., et al., A meta-analysis of alcohol consumption and the risk of 15 diseases. Prev Med, 2004. 38 (5): p. 613-9. PubMed
- Tramacere, I., et al., A meta-analysis of alcohol drinking and oral and pharyngeal cancers. Part 1: overall results and dose risk relation. Oral Oncol, 2010. 46(7): p. 497-503. PubMed
- Seitz, H., et al., Epidemiology and pathophysiology of alcohol and breast cancer: Update 2012. Alcohol and Alcoholism, 2012. PubMed
- Smith-Warner, S., et al., Alcohol and breast cancer in women: a pooled analysis of cohort studies. JAMA, 1998. 279: p. 535-40. PubMed
- Key, J., et al., Meta-analysis of studies of alcohol and breast cancer with consideration of the methodological issues. Cancer Causes Control, 2006. 17(6): p. 759-770. PubMed
- Hamajima, N., et al., Alcohol, tobacco and breast cancer – collaborative reanalysis of individual data from 53 epidemiological studies, including 58, 515 women with breast cancer and 95, 067 women without the disease. Br J Cancer, 2002. 87(11): p. 1234-45. PubMed
- Stickel, F., et al., Cocarcinogenic effects of alcohol in hepatocarcinogenesis. Gut, 2002. 51: p. 132-139. PubMed
- Donato F., et al.,, Alcohol and hepatocellular carcinoma: the effect of lifetime intake and hepatitis virus infections in men and women. Am J Epidemiol, 2002. 155(4): p.323-31. PubMed
- Fedirko, V., et al., Alcohol drinking and colorectal cancer risk: an overall and dose-response meta-analysis of published studies. Annal Oncol, 2011. 22(9): p. 1958-72. PubMed
- Ferrari, P., et al., Lifetime and baseline alcohol intake and risk of colon and rectal cancers in the European Prospective Investigation into cancer and nutrition (EPIC). Int J Cancer, 2007. 121(9): p. 2065-72. PubMed
- Purohit, V., et al., Mechanisms of alcohol-associated cancers: introduction and summary of the symposium. Alcohol, 2005. 35(3): p. 155-60. PubMed
- Bofetta, P., and M. Hashibe, Alcohol and Cancer. Lancet Oncol, 2006. 7(2): p. 149-56. PubMed
- Homann N., et al., High acetaldehyde levels in saliva after ethanol consumption: methodological aspects and pathogenetic implications. Carcinogenesis, 1997. 18(9): p.1739-43. PubMed
- Balbo, S., et al., Kinetics of DNA adduct formation in the oral cavity after drinking alcohol. Cancer Epidemiol Biomarkers Prev, Epub Feb 1 2012. PubMed
- Onland-Moret, N., et al., Alcohol and endogenous sex steroid levels in postmenopausal women: a cross-sectional study. J Clin Endocrinol Metab, 2005. 90(3): p. 1414-9. PubMed
- Key, T., et al., Circulating sex hormones and breast cancer risk factors in postmenopausal women: reanalysis of 13 studies. Brit J Cancer, 2011. 105(5): p. 709-22. PubMed
- Rinaldi, S., et al., Relationship of alcohol intake and sex steroid concentrations in blood in pre- and post-menopausal women: the European Prospective Investigation into Cancer and Nutrition. Cancer Causes Control, 2006. 17(8): p.1033-43. PubMed
- Key, T., et al., Endogenous sex hormones and breast cancer in postmenopausal women: reanalysis of nine prospective studies. J Natl Cancer Inst, 2002. 94(8): p. 606-16. PubMed
- Howie, N., et al., Short-term exposure to alcohol increases the permeability of human oral mucosa. Oral Dis, 2001. 7(6): p. 349-54. PubMed
- Giovannucci, E., Epidemiologic studies of folate and colorectal neoplasia: A review. J Nutr, 2002. 132(S8): p. 2350S-2355S. PubMed
- Hashibe, M., et al., Interaction between tobacco and alcohol use and the risk of head and neck cancer: pooled analysis in the International Head and Neck Cancer Epidemiology Consortium. Cancer Epidemiol Biomarkers Prev, 2009. 18(2): p. 541-50. PubMed
- Turati, R., et al., A meta-analysis of alcohol drinking and oral and pharyngeal cancers: Results from subgroup analyses. Alcohol Alcohol., 2012. PubMed
- Kuper, H., et al., Tobacco smoking, alcohol consumption and their interaction in the causation of hepatocellular carcinoma. Int J Cancer, 2000. 85(4): p. 498-502. PubMed
- Blot, W.J., Alcohol and cancer. Cancer Research, 1992. 52(S): p. 2119-2123. PubMed
- Bagnardi, V., et al., Alcohol consumption and the risk of cancer: a meta-analysis. Alcohol Res Health, 2001. 25(4): p. 263-70. PubMed
- Bagnardi, V., et al., Light alcohol drinking and cancer: a meta-analysis. Annal Oncol., 2012. PubMed
- Thun, M., et al., Alcohol consumption and mortality among middle aged and elderly US adults. N Engl J Med, 1997. 337(24): p. 1705-14. PubMed
- Ronksley, P., et al., Association of alcohol consumption with selected cardiovascular disease outcomes: a systematic review and meta-analysis. BMJ, 2011. 342:d671. PubMed
- Nichol M., et al., What is the optimal level of population alcohol consumption for chronic disease prevention in England? Modelling the impact of changes in average consumption levels. BMJ Open, 2012. PubMed
- WCRF/AICR, Food, Nutrition, Physical Activity and the Prevention of Cancer: Second Expert Report. WCRF, 2007. Ch 12: p. 368-393. Link
- Department of Health, Change4Life website
- Breslow, R., et al., Prospective study of alcohol consumption quantity and frequency and cancer-specific mortality in the US population. Am J Epidemiol, 2011. 174(9): p., 1044-53. PubMed
- Sun, Q., et al., Alcohol consumption at mid-life and successful ageing in women: A prospective cohort analysis in the Nurses’ Health Study. PLoS Med, 2011. 8(9): e1001090. PubMed
- Castellsague, X., et al., Independent and joint effects of tobacco smoking and alcohol drinking on the risk of esophageal cancer in men and women. Int J Cancer, 1999. 82(5): p. 657-64. PubMed
- Rehm, R., et al., Alcohol drinking cessation and its effect on esophageal and head and neck cancers: A pooled analysis. Int J Cancer, 2007. 121(5): p. 1132-7. PubMed
- Latino-Martel, P., et al., Maternal alcohol consumption during pregnancy and risk of childhood leukaemia: a systematic review and meta-analysis. Cancer Epidemiol Biomarkers Prev, 2010. 19(5): p. 1238-60. PubMed
- National Institute for Health and Clinical Excellence, NICE Clinical Guideline 62: Antenatal Care. 2010. Link