Alcohol facts and evidence

The International Agency for Research into Cancer (IARC; part of the World Health Organisation) has classified alcohol as a Group 1 carcinogen since 1988.[1,2] 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.[2-6]

A study published in 2018 found that drinking too much alcohol causes 3% of cancer cases in the UK, around 11,900 cases each year.[7,8] The proportion of cases down to alcohol was highest for mouth and upper throat (pharynx) cancers (more than a third), but breast cancer accounted for the greatest overall number of cases linked to alcohol (around 4,400 cases each year).[7]

References

1. International Agency for Research on Cancer. Alcohol drinking. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. Vol 44; 1988. View resource

2. International Agency for Research on Cancer. Consumption of alcoholic beverages. IARC Monogr Eval Carcinog Risks to Humans. 2012;100E. View resource

3. Scoccianti C, Cecchini M, Anderson AS, et al. European Code against Cancer 4th Edition: Alcohol drinking and cancer. Cancer Epidemiol. 2015;39:S67-S74. View summary on PubMed

4. World Health Organization (WHO). Global status report on alcohol and health 2014. 2014. View resource

5. World Health Organization (WHO). World Cancer Report. IARC Press. 2014. View resource

6. Department of Health. Alcohol Guidelines Review – Report from the Guidelines development group to the UK Chief Medical Officers. 2016 (January). View resource

7. Brown, K. et al. The fraction of cancer attributable to modifiable risk factors in England, Wales, Scotland, Northern Ireland and the United Kingdom in 2015. British Journal of Cancer 2018 https://www.nature.com/articles/s41416-018-0029-6

8. Calculated by the Cancer Research UK Statistical Information Team, based on figures from Parkin DM, Boyd L, Darby SC, Mesher D, Sasieni P, Walker LC. The Fraction of Cancer Attributable to Lifestyle and Environmental Factors in the UK in 2010. Br J Cancer. 2014. View resource

Alcohol increases the risk of cancers of the mouth, pharynx (upper throat), larynx (voice box) and oesophagus (gullet or food pipe).[1,2]

The more alcohol someone tends to drink, the higher the risk.[3] One review found that people having four or more drinks (where one drink has around 1.5 units of alcohol) a day had about five 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 one drink a day had a 20% higher risk.[4]

Another review found that when someone stops drinking they can reduce their alcohol-related risk of pharyngeal and laryngeal cancers by 2% for each year they remain alcohol-free, compared to if they had continued drinking alcohol.[5]

References

1. Corrao, G., et al., A meta-analysis of alcohol consumption and the risk of 15 diseases. Prev Med, 2004;38(5):613-9. View summary on PubMed

2. Bagnardi V, Rota M, Botteri E, et al. Alcohol consumption and site-specific cancer risk: a comprehensive dose-response meta-analysis. Br J Cancer. 2015;112(3):580-593. View summary on PubMed

3. Department of Health. Alcohol Guidelines Review – Report from the Guidelines development group to the UK Chief Medical Officers. 2016 (January). View resource

4. 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):497-503. View summary on PubMed

5. Ahmad Kiadaliri A, Jarl J, Gavriilidis G, Gerdtham U. Alcohol drinking cessation and the risk of laryngeal and pharyngeal cancers: a systematic review and meta-analysis. PLoS One. 2013;8(3):e58158. View summary on PubMed

Regularly drinking even small amounts of alcohol can increase the risk of breast cancer [1,2]. 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%.[1]  And the risk increases the more a woman drinks, several studies have found that each additional 10g of alcohol (around 1.25 units) drunk a day increases the risk of breast cancer by about 7 - 12%.[3-6]

Breast cancer is much rarer in men than in women, and less is known about things that may affect the risk. The small number of cases also makes this difficult to study. But a 2015 review that included 20 different studies suggested that alcohol wasn’t linked to breast cancer in men.[7]

References

1. Seitz, H., et al., Epidemiology and pathophysiology of alcohol and breast cancer: Update 2012. Alcohol and Alcoholism, 2012. View summary on PubMed

2. Bagnardi V, Rota M, Botteri E, et al. Light alcohol drinking and cancer : a meta-analysis. Annals of Oncology. 2013;24(3):301–8. View summary on PubMed

3. Smith-Warner, S., et al., Alcohol and breast cancer in women: a pooled analysis of cohort studies. JAMA, 1998;279:535-40. View summary on PubMed

4. 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):759-770. View summary on PubMed

5. 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):1234-45. View summary on PubMed

6. Allen, N., et al. Moderate alcohol intake and cancer incidence in women. J Natl Cancer Inst, 2009;101(5):296-305. View summary on PubMed

7. Cook MB, Guenel P, Gapstur SM, et al. Tobacco and Alcohol in Relation to Male Breast Cancer: An Analysis of the Male Breast Cancer Pooling Project Consortium. Cancer Epidemiol biomarkers Prev. 2015;24(3):520-531. View summary on PubMed

Alcohol is one of the main risk factors for liver cancer.[1-4] 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. A review in 2014 estimated that people who drink more than 3 drinks per day (where one drink has around 1.5 units of alcohol) increase their risk of liver cancer by 16%.[2]

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.[5]

References

1. Stickel, F., et al., Cocarcinogenic effects of alcohol in hepatocarcinogenesis. Gut, 2002;51:132-139. View summary on PubMed

2. Turati F, Galeone C, Rota M, et al. Alcohol and liver cancer: a systematic review and meta-analysis of prospective studies. Ann Oncol. 2014;25(8):1526-1535. View summary on PubMed

3. Sidharthan S, Kottilil S. Mechanisms of alcohol-induced hepatocellular carcinoma. Hepatol Int. 2014;8(2):452-457. View summary on PubMed

4. World Cancer Research Fund. Diet, nutrition, physical activity and liver cancer. Contin Updat Proj. 2015. View resource

5. 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):323-31. View summary on PubMed

Studies have shown that alcohol can increase the risk of bowel cancer.[1,2] A review of 61 studies found that the risk went up the more alcohol people drank, and the heaviest drinkers' (four drinks a day or more) risk went up by about half.[1]

References

1. 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):1958-72. View summary on PubMed

2. Corrao, G., et al., A meta-analysis of alcohol consumption and the risk of 15 diseases. Prev Med, 2004;38(5):613-9. View summary on PubMed

So far, research hasn’t fully answered the question of 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.[1]

The theory with the strongest evidence is related to how our bodies process alcohol. It is converted into another chemical called acetaldehyde. Acetaldehyde can cause cancer by damaging our DNA and preventing it from being repaired.[2,3] 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.[4] Drinking alcohol greatly increases the level of acetaldehyde found in saliva.[5]  And a small initial study in 2012 found higher levels of DNA damage in the mouth cells of people after drinking alcohol.[6]

Alcohol can increase the level of hormones such as oestrogen in the body.[7-9]  Unusually high levels of oestrogen could cause breast cancer.[10]

Alcohol can cause cirrhosis of the liver, by repeatedly damaging the liver's cells. This is turn can cause liver cancer.[3,11]

Alcohol also makes it easier for cancer-causing chemicals, such as those found in tobacco, to be absorbed in the mouth or throat.[12]

Alcohol reduces the amount of folate in our blood. Folate is a B vitamin that our cells need to create new DNA correctly.[13] But it isn’t clear whether alcohol actually causes cancer through lowering folate levels, or whether people’s underlying folate levels affect the risk of cancer from alcohol.[4,14]

Alcohol can cause highly reactive molecules known as Reactive Oxygen Species or ROS, to be produced in our bodies and particularly in the liver.[2,11]  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.

References

1. Purohit V, Khalsa J, Serrano J. Mechanisms of alcohol-associated cancers: introduction and summary of the symposium. Alcohol. 2005;35(3):155-160. View summary on PubMed

2. Boffetta P, Hashibe M. Alcohol and cancer. Lancet Oncol. 2006;7(2):149-156. View summary on PubMed

3. Sidharthan S, Kottilil S. Mechanisms of alcohol-induced hepatocellular carcinoma. Hepatol Int. 2014;8(2):452-457. View summary on PubMed

4. International Agency for Research on Cancer. Consumption of alcoholic beverages. IARC Monogr Eval Carcinog Risks to Humans. 2012;100E. View resource

5. Homann N, Jousimies-Somer H, Jokelainen K, Heine R, Salaspuro M. High acetaldehyde levels in saliva after ethanol consumption: methodological aspects and pathogenetic implications. Carcinogenesis. 1997;18(9):1739-1743. View summary on PubMed

6. Balbo S, Meng L, Bliss RL, Jensen J a, Hatsukami DK, Hecht SS. Kinetics of DNA adduct formation in the oral cavity after drinking alcohol. Cancer Epidemiol biomarkers Prev. 2012;21(4):601-608. View summary on PubMed

7. Onland-Moret NC, Peeters PHM, van der Schouw YT, Grobbee DE, van Gils CH. Alcohol and endogenous sex steroid levels in postmenopausal women: a cross-sectional study. J Clin Endocrinol Metab. 2005;90(3):1414-1419. View summary on PubMed

8. Key TJ, Appleby PN, Reeves GK, et al. Circulating sex hormones and breast cancer risk factors in postmenopausal women: reanalysis of 13 studies. Br J Cancer. 2011;105(5):709-722. View summary on PubMed

9. Rinaldi AS, Peeters PHM, Bezemer ID, 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 and Control. 2006;17(8):1033-43. View summary on PubMed

10. Key T, Appleby P, Barnes I, Reeves G. Endogenous sex hormones and breast cancer in postmenopausal women: reanalysis of nine prospective studies. J Natl Cancer Inst. 2002;94(8):606-616. View summary on PubMed

11. Stickel F, Schuppan D, Hahn EG, Seitz HK. Cocarcinogenic effects of alcohol in hepatocarcinogenesis. Gut. 2002;51(1):132-139. View summary on PubMed

12. Howie NM, Trigkas TK, Cruchley T, Wertz PW, Squier C, Williams DM. Short-term exposure to alcohol increases the permeability of human oral mucosa. Oral Dis. 2001;7(6):349-354. View summary on PubMed

13. Giovannucci E. Epidemiologic Studies of Folate and Colorectal Neoplasia: a Review. J Nutr. 2002;132(8(Suppl)):2350S - 2355S. View summary on PubMed

14. Galeone C, Edefonti V, Parpinel M, et al. Folate intake and the risk of oral cavity and pharyngeal cancer: a pooled analysis within the International Head and Neck Cancer Epidemiology Consortium. Int J Cancer. 2015;136(4):904-914. View summary on PubMed

Tobacco is another cause of mouth, oesophagus (food pipe) and liver cancers and scientists have found that the effects of alcohol and tobacco together are much worse than either by itself.[1-3]

A meta-analysis published in 2012, which combined the results of 49 previous studies, found that non-smokers who drank alcohol were around one third more likely to develop mouth and upper throat cancer than those who didn't drink. But people who smoke or used to smoke, and who also drank alcohol, were around 3 times as likely to develop the disease.[3]  Another study found that the risk of liver cancer was almost 10 times greater in people who smoked and drank heavily.[4]

References

1. 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):541-50. View summary on PubMed 

2. Boyle, P., et al., European Code Against Cancer and scientific justification: third version (2003). Ann Oncol, 2003;14(7):973-1005. View summary on PubMed 

3. Turati, R., et al., A meta-analysis of alcohol drinking and oral and pharyngeal cancers: Results from subgroup analyses. Alcohol and Alcoholism, 2013;48(1):107-18. View summary on PubMed 

4. Kuper, H., et al., Tobacco smoking, alcohol consumption and their interaction in the causation of hepatocellular carcinoma. Int J Cancer, 2000;85(4):498-502. View summary on PubMed 

Research has shown that all types of alcoholic drinks, including wine, beer and spirits, can increase the risk of cancer.[1-5]  The risk is linked to the actual alcohol (ethanol) in the drink, and increases with the amount drunk.[6,7]

References

1. International Agency for Research on Cancer. Consumption of alcoholic beverages. IARC Monogr Eval Carcinog Risks to Humans. 2012;100E. View resource

2. World Health Organization (WHO). Joint WHO / FAO Expert Consultation on Diet, Nutrition and the Prevention of Chronic Diseases. WHO Tech Rep Ser. 2003;WHO: Genev:95-104. View resource

3. Blot WJ. Alcohol and Cancer. Cancer Res. 1992;Suppl(52):2119-2123. View summary on PubMed

4. Scoccianti C, Cecchini M, Anderson AS, et al. European Code against Cancer 4th Edition: Alcohol drinking and cancer. Cancer Epidemiol. 2015;39:S67-S74. View summary on PubMed

5. Marron M, Boffetta P, Møller H, et al. Risk of upper aerodigestive tract cancer and type of alcoholic beverage: a European multicenter case–control study. Eur J Epidemiol. 2012;27(7):499-517. View summary on PubMed

6. Corrao G, Bagnardi V, Zambon A, La Vecchia C. A meta-analysis of alcohol consumption and the risk of 15 diseases. Prev Med (Baltim). 2004;38(5):613-619. View summary on PubMed

7. Bagnardi V, Rota M, Botteri E, et al. Alcohol consumption and site-specific cancer risk: a comprehensive dose-response meta-analysis. Br J Cancer. 2015;112(3):580-593. View summary on PubMed

The more alcohol someone drinks, the more their cancer risk increases.[1]  But even quite small amounts of alcohol, around 1 drink a day, can increase cancer risk.[2-5] Expert reports have concluded that there is no safe lower limit of alcohol drinking where cancer risk isn't increased.[6,7]

The UK government recommends that men and women who drink regularly do not exceed 14 units of alcohol per week.[8] While drinking at this level can still increase cancer risk, the overall increase in risk for an individual person is likely to be small. But it is important to understand that the guidelines are for ‘low risk’ drinking, not ‘safe’ drinking’, and that any amount of alcohol will increase cancer risk to some extent.

Some studies have reported that drinking small amounts of alcohol (usually less than 1 unit per day) may offer some health benefits, such as lowering the risk of heart disease.[9-11] But the review of evidence to help develop the new guidelines found that these benefits only apply to a very small group of people – women aged over 55 who drinks less than 5 units per week. The new guidelines therefore do not recommend drinking any amount of alcohol for health reasons.

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 patterns 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.[12-15]

References

1. Corrao G, Bagnardi V, Zambon A, La Vecchia C. A meta-analysis of alcohol consumption and the risk of 15 diseases. Prev Med (Baltim). 2004;38(5):613-619. View summary on PubMed

2. Bagnardi V, Blangiardo M, La Vecchia C, Corrao G. A meta-analysis of alcohol drinking and cancer risk. Br J Cancer. 2001;85(11):1700-1705. View summary on PubMed

3. Tramacere I, Negri E, Bagnardi V, 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):497-503. View summary on PubMed

4. Seitz HK, Pelucchi C, Bagnardi V, Vecchia CL. Epidemiology and Pathophysiology of Alcohol and Breast Cancer: Update 2012. Alcohol and Alcoholism. 2012;47(3):204-212. View summary on PubMed

5. Bagnardi V, Rota M, Botteri E, et al. Light alcohol drinking and cancer: a meta-analysis. Ann Oncol. 2013;24(2):301-308. View summary on PubMed

6. Boyle P. European Code Against Cancer and scientific justification: third version (2003). Ann Oncol. 2003;14(7):973-1005. View summary on PubMed

7. World Cancer Research Fund, American Institute for Cancer Research. Food, Nutrition, Physical Activity, and the Prevention of Cancer: A Global Perspective. Washington DC: AICR; 2007. View resource

8. Department of Health. Alcohol Guidelines Review – Report from the Guidelines development group to the UK Chief Medical Officers. 2016 (January). View resource

9. Thun MJ, Peto R, Lopez AD, et al. Alcohol consumption and mortality among middle aged and elderly US adults. N Engl J Med. 1997;337(24):1705-1714. View summary on PubMed

10. Ronksley PE, Brien SE, Turner BJ, Mukamal KJ, Ghali W. Association of alcohol consumption with selected cardiovascular disease outcomes: a systematic review and meta-analysis. BMJ. 2011;342(1):d671-d671. View summary on PubMed

11. Nichols M, Scarborough P, Allender S, Rayner M. 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;2(3). View summary on PubMed

12. Breslow R a, Chen CM, Graubard BI, Mukamal KJ. Prospective Study of Alcohol Consumption Quantity and Frequency and Cancer-Specific Mortality in the US Population. Am J Epidemiol. 2011;174(9):1044-1053. View summary on PubMed

13. Sun Q, Townsend MK, Okereke OI, et al. Alcohol Consumption at Midlife and Successful Ageing in Women: A Prospective Cohort Analysis in the Nurses’ Health Study. Hay PJ, ed. PLoS Med. 2011;8(9):e1001090. View summary on PubMed

14. World Health Organization (WHO). World Cancer Report. IARC Press. 2003. View resource

15. World Health Organization (WHO). World Cancer Report. IARC Press. 2014. View resource

The risk of alcohol-related cancers increases the more you drink.[1] 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 (food pipe) cancers reduces over time in people who have given up drinking, compared to those who continue.[2,3]

References

1. Corrao G, Bagnardi V, Zambon A, La Vecchia C. A meta-analysis of alcohol consumption and the risk of 15 diseases. Prev Med (Baltim). 2004;38(5):613-619. View summary on PubMed

2. 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):1132-7. View summary on PubMed

3. Ahmad Kiadaliri A, Jarl J, Gavriilidis G, Gerdtham U. Alcohol drinking cessation and the risk of laryngeal and pharyngeal cancers: a systematic review and meta-analysis. PLoS One. 2013;8(3):e58158. View summary on PubMed

Some studies have found that the children of women who drank alcohol during pregnancy had an increased risk of one type of leukaemia.[1] 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.[2]

Drinking alcohol during pregnancy has been linked to many other conditions and the government guidelines currently recommend that women stop drinking altogether while trying to conceive and during pregnancy to keep risks to the baby to a minimum.[3]

References

1. 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):1238-60. View summary on PubMed

2. International Agency for Research on Cancer. Consumption of alcoholic beverages. IARC Monogr Eval Carcinog Risks to Humans. 2012;100E. View resource

3. Department of Health. Alcohol Guidelines Review – Report from the Guidelines development group to the UK Chief Medical Officers. 2016 (January). View resource