Cancer and alcohol

Alcohol is a modifiable risk factor for at least seven types of cancer.¹ This means it is a risk factor we can do something about. There are many different contributory factors for cancer. However, there are some positive actions we can take to reduce our own and our family’s cancer risk. Drinking less or cutting out alcohol entirely is one of the ways we can help to lower the cancer risk.²

The risk of developing alcohol-related cancers is lower for people who drink within the low-risk weekly alcohol guidelines. For cancer prevention though, it’s best not to drink alcohol at all.

Alcohol-related cancers

The link between alcohol and cancer is well established – each year in Ireland, 900 people are diagnosed with alcohol-related cancers and 500 die as a result.³ Evidence shows that alcohol is directly linked to the development of these seven cancers:

• • Bowel
  • Breast
  • Larynx (voicebox)
  • Liver
  • Mouth
  • Oesophagus (foodpipe)
  • Upper throat

How does alcohol cause cancer?

The Irish Cancer Society has some helpful information on the different ways that alcohol can cause different types of cancer in different ways:

• • Our bodies break down alcohol into acetaldehyde, which is a toxic chemical. Acetaldehyde can damage DNA (the genetic material that makes up genes) and stop our cells from repairing the damage.
  • The breakdown of alcohol in our bodies can also generate harmful molecules called reactive oxygen species. These molecules can damage DNA and proteins.
  • Alcohol weakens the body’s ability to break down and absorb a variety of nutrients that may protect you against cancer. These include vitamin A, folate, vitamin C, vitamin D and vitamin E.
  • Alcohol increases levels of the hormone oestrogen. Higher levels of oestrogen increase the risk of breast cancer.
  • Alcohol is high in calories and can cause weight gain. Being overweight or obese is known to increase the risk of many types of cancer.

If you would like to know more, the World Cancer Research Fund website has detailed information on the latest research evidence relating to alcohol and cancer risk.

Breast cancer

For women in Ireland, the greatest impact from alcohol is in relation to breast cancer. Alcohol is linked to 1 in 8 breast cancers in Ireland.⁴ The Healthy Ireland Survey found that 73% of women are not aware that drinking more than the low-risk weekly alcohol guidelines can increase breast cancer risk.⁵

According to the HSE⁶, compared with a woman who does not drink:

• • A woman who drinks 1 standard drink per day is associated with a 7% increase in the risk of developing breast cancer
  • Consuming 3-6 standard drinks per day increases breast cancer risk by 41%

Drinking alcohol doesn’t mean you will develop breast cancer – but it does mean the risk is higher.⁷ Everyone is different. And while there are many causes of breast cancer, lifestyle changes like cutting down or cutting out alcohol, is an action within our control to reduce the risk.⁸

Digestive cancers

A 2017 European study found that people who have two or more alcoholic drinks per day are at increased risk of developing a range of digestive cancers including bowel cancer.⁹ The report found that:

• • 1 drink per day increases the risk of oesophageal cancer
  • 1-4 drinks per day increases the risk of bowel cancer by 21%
  • 4 or more drinks per day increases the risk of gastric, pancreatic and liver cancers

Bowel cancer is one of the most common cancers diagnosed in Ireland. In 2019, 2688 people were diagnosed with bowel cancer in Ireland.¹⁰ For men, the most important impact from alcohol relates to bowel cancer. The HSE National Cancer Prevention Programme reports that among men, around 100 cases of bowel cancer are caused by alcohol each year (1 in every 12 cases).¹¹

Liver cancer

National Cancer Registry Ireland (NCRI) data shows a 300% rise in liver cancer diagnoses in Ireland in the past two decades. The average number of new cases each year has gone from 60 in the mid-1990s to more than 270 in 2014. The NCRI point to high alcohol consumption in recent decades as one of the biggest reasons for this four-fold increase.¹²

Alcohol, cancer and weight

Evidence shows being overweight or obese increases the risk of some cancers including bowel, pancreatic, breast and gallbladder.¹³ Alcohol has a high calorie content, but these are ‘empty calories’ with no nutritional value or benefit. Different alcoholic drinks can also contain a lot of sugar. So, your calorie and sugar intake will increase the more you drink which could lead to weight gain.

Alcohol, cancer and smoking

If you drink and smoke, your risk of certain cancers is even higher.¹⁴ Why? Alcohol makes it easier for other harmful chemicals, such as those found in tobacco smoke, to enter the cells lining the mouth, throat, larynx (voicebox) and oesophagus (foodpipe). This is why the combination of smoking and drinking is much more likely to cause these cancers than either smoking or drinking alone.

European Code Against Cancer

The European Code Against Cancer was developed by the World Health Organisation’s International Agency for Research on Cancer (IARC) in 2014.¹⁵ The code was prepared by cancer specialists, scientists and other experts to increase the awareness of European citizens about efficient ways to prevent cancer.

The code lists 12 ways to help people to adopt healthier lifestyles and of boosting cancer prevention, including drinking less or cutting out alcohol. The WHO estimates that about one half of all cancers could be avoided if everyone followed all the recommendations in the code.¹⁶

1. Do not smoke or use tobacco products.
2. Make your home and workplace smoke free.
3. Take action to be a healthy body weight.
4. Be physically active in everyday life.
5. Have a healthy diet.
6. If you drink alcohol of any type, limit your intake. Not drinking alcohol is better for cancer prevention.
7. Avoid too much sun, especially for children. Use sun protection.
8. Protect yourself against cancer-causing substances by following health and safety instructions in workplace.
9. Reduce exposure to radiation in your home through naturally occurring radon. Visit www.epa.ie
10. Advice for women:
    • Breastfeeding reduces the mother’s cancer risk. If you can, breastfeed your baby.
    • Hormone replacement therapy (HRT) increases the risk of certain cancers. Limit use of HRT.
11. Ensure your children take part in vaccination programmes for:
    • Hepatitis B (for newborns)
    • Human papillomavirus (HPV) (for girls).
12. Get screened for cancer. Visit www.screeningservice.ie