Background
Breast cancer is the most common cancer among women in Ireland and alcohol use is estimated to be attributable to approximately 7% of breast cancer cases.1,2 Almost one-half of women in Ireland drink alcohol on a weekly basis (48%) and approximately one in five women report binge drinking on a typical drinking occasion (19%). However, despite alcohol being classified as a Group 1 carcinogen (cancer-causing) since 1988, many people appear unaware of this fact.3,4

Methods
The annual Healthy Ireland Survey, representative of the adult population of Ireland, examines various health behaviours, including smoking, alcohol use, weight, dental health, menstrual health, mental health, as well as information about the use of health services. The survey has included baseline questions about alcohol use every year since its inception in 2015 and occasionally has additional questions about alcohol. In Wave 2 of the Healthy Ireland Survey, 2016, respondents were asked to identify which of the five alcohol-related health conditions (liver disease, pancreatitis, high blood pressure, breast cancer, bowel cancer) they thought people were at an increased risk of developing if they regularly drank more than the low-risk limits recommended in Ireland (currently no more than 11 standard drinks per week for women or 17 standard drinks for men).4

Of the health conditions, awareness of the link between alcohol use and breast cancer was the lowest. A 2023 study therefore sought to examine their characteristics so that recommendations could be made to target specific groups.5

Results
Just one in five respondents correctly identified that alcohol use was associated with increased risk of breast cancer (21%). Women (27%) showed greater awareness than men (15%), as did those aged 45–54 years (27%), especially when compared with those aged 15–24 years (13%). When considering educational attainment, those educated to degree level or higher were almost twice as likely than those with no qualifications to know of the risk (29% vs 16%). Greater awareness was evident among those engaged in home duties (26%), those in employment (24%), those married or in a civil partnership (24%), and those in the least deprived deprivation category (23%).

Drinking patterns, such as how often and how much alcohol respondents drink, did not influence level of knowledge, with hazardous drinkers (20%), low-risk drinkers (23%), and non-drinkers (21%) showing an almost equally low level of awareness. Similarly, area of residence did not impact knowledge.

Discussion
The low level of awareness of the carcinogenic effect of alcohol is a cause for concern, especially given the drinking patterns of many women in the country. In Ireland, the Public Health (Alcohol) Act 2018 aims to reduce population-level alcohol use and related harm. The legislation includes components such as structural separation (alcohol products in mixed-retail outlets must be kept separate from other products), minimum unit pricing, restrictions on alcohol advertising and sports sponsorship, and restrictions on the sale and supply of alcohol. The Act has also legislated for health warning labels on alcohol products, although to date, these have not yet commenced due to an ongoing European Union consultation process.

These labels are intended to advise the public of the link between alcohol use and cancer, provide information about the number of standard drinks in the product, the calorie content of the product, the danger of alcohol use during pregnancy, and a website that provides impartial information about alcohol use and its harm. Such labelling on alcohol products has been found to be effective in providing information and in changing health behaviours in other jurisdictions where introduced. They are also recommended by the World Health Organization (WHO).

It is important that efforts be increased to raise awareness of the breast cancer risk associated with alcohol use. This can be achieved through social media campaigns, health practitioner advice, and education programmes in communities and schools, with strategic targeting of those identified as having particularly low levels of knowledge. As the risk is specific to female breast cancer, it is crucial that women are made aware, but also men, so that they can provide support to female family members, friends, and colleagues. To inform effective public health messaging to reinforce this message, a greater understanding of drinking motivations among women who drink and yet know of the risks involved is required. In highlighting this risk, it may contribute to a decrease in hazardous drinking as well as reducing breast cancer incidence.

The authors recommend that the low-risk drinking guidelines in Ireland be revised in view of WHO recommendations that there is no safe level of alcohol use. Finally, the findings from this study support the need for health warning labels on alcohol products, as set out in the Public Health (Alcohol) Act 2018.

1    Irish Cancer Society (2022) Cancer statistics. Dublin: Irish Cancer Society. Available from: https://www.cancer.ie/cancer-information-and-support/cancer-information/about-cancer/cancer-statistics

2    Health Service Executive (HSE) (2022) Alcohol
and cancer. Dublin: HSE. Available from: https://www2.hse.ie/wellbeing/alcohol/physical-health/alcohol-and-cancer.html

3    Ipsos MRBI (2018) Healthy Ireland survey 2018: summary of findings. Dublin: Government Publications. Available from: https://www.drugsandalcohol.ie/29851/

4    Department of Health (2016) Healthy Ireland survey 2016: summary of findings. Dublin: Stationery Office. Available from: https://www.drugsandalcohol.ie/26278/

5    Doyle A, O’Dwyer C, Mongan D, et al. (2023) Factors associated with public awareness of the relationship between alcohol use and breast cancer risk. BMC Public Health, 23: 577. Available from: https://www.drugsandalcohol.ie/37780/