Alcohol and cancer risk
Alcohol and cancer - how big a problem is it?
It is well known since 1988 that alcohol causes cancer when it was classified as a group 1 carcinogen by the International Agency for Research into Cancer (1). This means there is convincing evidence that alcohol causes cancer in humans. Drinking alcohol can increase the risk of 7 different types of cancer including cancer of the mouth, upper throat (pharynx), voice box (larynx), food pipe (oesophagus), bowel, liver and breast. 4% of cancer cases in the UK are linked to alcohol consumption according to a study done in 2011 (2).
How does alcohol cause cancer?
There are a number of theories about how alcohol can cause cancer, however, we still need more research in this area to find out exactly what happens. The most evidence is behind a chemical called acetaldehyde. Alcohol is converted to acetaldehyde by enzymes in our livers. This chemical can damage our DNA, and therefore can cause cancer to develop. This was shown in a new study just published this week in Cambridge which looked at the effects of alcohol on the DNA of mice who did not have the enzymes that usually breaks down this harmful chemical and they found that these mice ended up getting damage to their DNA as a result. Other theories include alcohol causing an increase in hormones that we know can lead to cancer including oestrogen, damaging liver cells leading to cirrhosis and then cancer, increasing absorption of other cancer-causing chemicals such as those found in tobacco from smoking, and alcohol can also cause reactive oxygen species to be produced which are known to damage DNA (3).
What is the risk of drinking alcohol?
58% of adults in Great Britain consume alcohol at least once a week. 54% consume over the recommended daily limit for alcohol at least once a week (4). However, we know that the more alcohol someone drinks, the higher their risk of cancer. This is true for all types of alcoholic drinks as the risk is linked to the actual amount of alcohol you consume. One study found that even lighter drinkers of no more than one drink a day had a 20% higher risk (2). If you already are a heavy drinker, there are still benefits of cutting down on your alcohol intake now to reduce your risk going forward (5).
What are the benefits of cutting down on your alcohol intake?
I know some of you will be wondering about your heart health as there were talks previously on how some alcohol intake may benefit your heart health. The latest evidence suggests that the benefits of drinking alcohol for heart health are less than previously thought and only apply to women over 55 years old – and even for them, the greatest reduction in risk is seen in women who drink 5 units or less a week (6, 7). As well as reducing your risk of cancer, heart disease and stroke, cutting down on alcohol intake can also help you reduce your risk of liver disease, pancreatitis and osteoporosis, it can help you save money, sleep better, improve your mood and improve your skin as alcohol dehydrates the skin and deprive it of important nutrients (8). Cutting out or cutting down on drinking can also help you lose weight as it contains a lot of empty calories that most people are not aware of!
Calorie content of alcoholic drinks:
1 pint of beer/lager (170 calories) = 3 chocolate chip cookies
1 medium glass of wine (124 calories) = 1 small packet of crisps
That means 1 bottle of wine gives you an extra 530 calories – this is equivalent to a Big Mac from McDonald's! All of these hidden calories from even occasional drinking can cause your weight to then slowly creep up. This doesn’t even include your increased appetite after drinking and that trip to the chipper before your taxi home!
What can I do to lower my risk of cancer?
For cancer prevention, it is advised that people avoid alcohol completely. If you do drink, then try to keep it within the government recommendations of no more than 14 units a week on a regular basis to lower your risk (9). Try to spread your drinking over three or more days if you regularly drink and aim to have several drink free days each week if possible.
What is a unit of alcohol or what classifies as one drink?
Current drinking guidelines refer to units of alcohol rather than the number of drinks which can be confusing for you to know practically how many drinks you usually have. As the strength of alcoholic drinks varies widely, the amount that contains one unit also varies a lot between drinks (1 unit = 8 grams of alcohol, 1 drink = 10–15 grams of alcohol). These examples of what 1 drink is can help guide you:
- ½ pint of normal strength beer, lager or cider (3–5% ABV*)
- 1 small glass (125ml) of wine (12–13% ABV*)
- 1 single measure (25ml) of spirits (40% ABV*), such as vodka or whisky
ABV* = units of alcohol per litre
Top tips for cutting down on your alcohol intake:
- Choose the smallest serving size, for example, a small glass of wine instead of a regular one.
- Avoid double measures of spirits even if they are on offer or part of happy hour.
- Have a glass of water or a diet soft drink/no added sugar squash before you start drinking alcohol if you are thirsty.
- Alternate between alcoholic drinks and water or diet soft drinks/ no added sugar squash to slow you down.
- Dilute alcoholic drinks to make them last longer for example having a small white wine spritzer with soda water rather than a large glass of wine.
These tips will make a big difference overall in the volume of alcohol you then consume so you don’t feel quite so rough the next day and your liver will be very grateful! Even better, why not join me for dry January, your wallet and waistline will be very grateful too!
References:
International Agency for Research on Cancer. Alcohol drinking. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. Vol 44; 1988.
Parkin, DM., et al., Cancers attributable to the consumption of alcohol in the UK in 2010. Br J Cancer. 2011. 106(S2): S14- S18.
Cancer Research UK http://www.cancerresearchuk.org/about-cancer/causes-of-cancer/alcohol-and-cancer/alcohol-facts-and-evidence#alcohol_facts
Cancer Research UK http://www.cancerresearchuk.org/health-professional/cancer-statistics/risk/alcohol
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.
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.
Cancer Research UK http://www.cancerresearchuk.org/about-cancer/causes-of-cancer/alcohol-and-cancer/alcohol-facts-and-evidence#alcohol_facts
https://www.wcrf-uk.org/sites/default/files/closer-look-alcohol-factsheet.pdf
https://www.nhs.uk/livewell/alcohol/Pages/Alcoholhome.aspx