Factors associated with public awareness of the relationship between alcohol use and breast cancer risk
Public awareness of the carcinogenic effects of alcohol is low, particularly the association between alcohol use and the risk of developing breast cancer.
Breast cancer is the third most common cancer in Ireland and alcohol use remains high. This study examined factors related to awareness of the association between alcohol use and breast cancer risk.
Using data from Wave 2 of the national Healthy Ireland Survey, a representative sample of 7,498 Irish adults aged 15 + years, descriptive and logistic regression analyses were conducted to investigate relationships between demographic characteristics, type of alcohol consumer and awareness of breast cancer risk.
A low level of awareness of the risk of alcohol use (consuming more than the recommended low–risk limit) associated with breast cancer was found, with just 21% of respondents correctly identifying the relationship. Multivariable regression analyses found that factors most strongly associated with awareness were sex (female), middle age (45—54 years) and higher educational levels.
As breast cancer is a prevalent disease among women in Ireland, it is essential that the public, in particular women who consume alcohol, are made aware of this association. Public health messages that highlight the health risks associated with alcohol use, and which target individuals with lower educational levels, are warranted.
- In 2019, alcohol use was the ninth leading risk factor attributable to deaths and disability–adjusted life–years (DALYs) in the world.
- For those aged 25 – 49 years, alcohol was the leading risk factor, and second highest for those aged 10 – 24 years.
- Globally, alcohol use was attributable to 0.374 million (0.298–0.461) deaths in females.
- The link between alcohol use and risk of seven cancer types – liver, oesophagus, larynx, upper throat, mouth, bowel and female breast – has been well recognised in scientific literature.
- Despite these well– and long–established relationships, public knowledge remains poor, especially for the risk of female breast cancer.
In 2020, it was estimated that globally, approximately 4.1% of all new cases of cancer were attributable to alcohol use and that after cancers of the oesophagus and the liver, female breast cancer was the third most common cancer attributable to alcohol.
The World Health Organization (WHO) has advised that there is no safe level of alcohol consumption and that even low levels of alcohol use can have harmful consequences, with low-dose alcohol use (< 20 g per day) contributing to one in seven alcohol–attributable cancer cases.
A prospective study of 105,986 women showed even lower levels of alcohol use to be harmful; consuming ½ —1 standard alcoholic drink per day (5—10 g) was associated with breast cancer and the risk was found to increase with episodes of binge alcohol use.
Another study (1,508 cases and 1,556 controls) found that consuming 15—30 g per day was associated with a 35% increase in breast cancer risk.
Studies from the United Kingdom (UK) and the United States (US) indicate that public awareness of the link between alcohol use and risk of developing breast cancer is low.
Previous Irish research has shown that, with the exception of liver disease, awareness of the link between alcohol use and five health conditions (liver disease, pancreatitis, high blood pressure, female breast cancer and bowel cancer) (all of which are caused by alcohol use) is also low, with the fewest respondents aware of the breast cancer link.
Given that two in every 10 female alcohol users in Ireland engage in hazardous alcohol use on a typical alcohol consumption occasion, and that breast cancer is the most common cancer among women in Ireland, the aim of this study was to investigate the level of public knowledge of the association between alcohol use and risk of developing breast cancer, and also to identify characteristics related to awareness, using a representative random sample of the Irish population.
Awareness of the relationship between alcohol use and breast cancer
Respondents’ knowledge of the link between alcohol use and breast cancer risk was found to be low, with just 21.2% of all Healthy Ireland respondents, representing the Irish population, correctly identifying the association.
- Females were significantly more aware of the association than males (26.7% compared to 15.4%).
- Age was significantly associated with knowledge of the link between alcohol use and breast cancer, with highest awareness among those in the 45—54 years age bracket (26.5%), while the youngest age group (15—24 years) (12.5%) reported the lowest level of awareness.
- There was a significant linear association between increasing educational attainment and greater level of awareness;
- those educated to degree level or higher were more likely to be aware of the risk (29.4%) compared to those with no qualifications (15.8%).
- Respondents who were engaged in home duties (26.3%) and those in employment (23.5%) reported a greater level of awareness.
- Subjects who were married or in a civil partnership were also more likely to be aware of the risk (24.1%) compared to those who were single or never married (17.0%), as were those in the least deprived deprivation category (23.0%) compared to those in the most deprived (19.2%).
- Awareness of the association between alcohol use and breast cancer was found to be higher among those who were classified as lower risk alcohol consumers (indicated by a score less than five in the AUDIT–C) (22.9%) compared to hazardous alcohol users (indicated by a score of five or greater in the AUDIT–C) (19.7%), although non–alcohol users showed an almost equally low level of awareness (20.9%).
- Females were almost twice as likely than males to be aware of the link between alcohol use and risk of developing breast cancer.
- Those aged 45—54 years were significantly more likely to be informed when compared to those aged 15—24 years.
- Participants who were educated to degree level or higher were twice as likely than those with no qualifications to be aware of the association and those who had below degree level qualifications were also more likely than those without qualifications to be aware of the association.
- Respondents who scored less than five on the AUDIT-C were less likely to be aware of the association compared to non-alcohol users.
This nationally representative study of 7,498 respondents demonstrates a lack of awareness of the carcinogenic effects of alcohol, with just one in five respondents being aware of the link between exceeding the recommended weekly low–risk alcohol guidelines and developing female breast cancer.
Multivariable regression analysis found that factors most strongly associated with awareness were sex (female), middle age (45—54 years) and higher educational levels.
Almost two–fifths of respondents scored five or higher on the AUDIT–C indicating that hazardous alcohol use patterns are highly prevalent in Ireland and, although higher among males (54.6%), almost one–quarter of females scored five or more on the AUDIT–C (24.5%).
Among all participants, although levels of awareness were similar across AUDIT–C categories, just 19.7% of respondents who scored five or higher on the AUDIT–C were aware of the association between consuming more than the recommended weekly low–risk alcohol guidelines and increased risk of developing breast cancer. This is a serious concern because their alcohol use patterns place them at higher risk of alcohol-related conditions.
The low level awareness of the association between alcohol use and risk of developing breast cancer the researchers found among the general population in Ireland is similar to that seen elsewhere.
- A UK study found that unprompted, less than one in five (17.8%) of a representative sample of 2,100 adults believed that the risk of breast cancer could increase as a result of alcohol use;
- females (19.8%) were more likely than males (15.7%) to be aware of the link.
- In the United States, just under one-quarter (24.6%) of a sample of 10,940 women aged 15 – 44 years were aware that alcohol consumption was a risk factor for developing breast cancer.
- A further study in the UK found similar low levels of awareness, with just 19.5% of those attending a breast screening programme correctly identifying the link.
- The study also found that less than one–half of the health professional staff at the service (48.5%) were aware that alcohol use is a risk factor for developing breast cancer.
Despite alcohol being classified as a Group 1 carcinogen since 1988, the poor public awareness of the association between alcohol use and breast cancer risk is concerning.
Actions to be taken
The absence of health warning messages on alcohol products may account for this lack of knowledge and the provision of such labels could encourage recognition of the risks associated.
Previous research examining the effectiveness of health warning labelling found that such messages increase knowledge of the health–related risks associated with alcohol use, are effective in communicating information about low–risk alcohol guidelines and motivate changes in alcohol use behaviours, particularly among women.
In 2018, the Public Health (Alcohol) Act was enacted in Ireland aiming to reduce alcohol consumption at a population level, delay alcohol initiation among schoolchildren, reduce the harms caused by alcohol use and to regulate and control the price and availability of alcohol based on the principles set out by the WHO’s ‘best buys’ to reduce alcohol–related harms. A majority of components of the Act have commenced to date, including structural separation of alcohol products in mixed retail outlets, minimum unit pricing, restrictions on alcohol advertising and sports sponsorship and restrictions on the sale and supply of alcohol, particularly price–based promotions, to reduce the affordability and availability of alcohol. However, a number of components have yet to be implemented, including Sect. 13 of the Act restricting the content of alcohol advertisements, Sect. 18 limiting advertising in print media and Sect. 19 which provides for a broadcast watershed on alcohol advertising.
Also not yet commenced is Sect. 12 of the Act, stipulating that all alcoholic products contain information about the calorie content, the quantity of grams of alcohol in the container (number of standard drinks) as well as displaying health warning information of the health risks associated with alcohol use, the danger of alcohol use when pregnant, details of an independent website providing public health information in relation to alcohol use, along with a specific warning informing the public of the direct link between alcohol and fatal cancers. This section of the Act also stipulates that this health information be displayed in on–licenced premises and on websites that sell alcohol products.
Ireland is one of only two countries in the world (along with South Korea) that has enacted legislation mandating the display of cancer warning messages on alcoholic products and to date.
As breast cancer is the most prevalent cancer among women in Ireland, it is therefore essential that women are made aware that breast cancer risk increases with alcohol use through targeted campaigns. Age was also significantly associated with awareness; those aged 45 – 54 years more likely to know of the risk between alcohol use and breast cancer. Younger respondents showed poorer awareness and, along with the 25 – 34 years age group, represented the highest level of hazardous alcohol use and thus undoubtedly require a strategic awareness campaign. Also importantly, education level was significantly associated with awareness; those with lower levels of educational attainment were less likely to be aware of the association. Therefore, it is important that public health messages are strengthened to highlight the health risks due to alcohol use and that individuals with lower levels of education are targeted.
Consideration should be given to revising the low-risk alcohol use guidelines in Ireland in view of WHO recommendations that there is no safe level of alcohol use.
Considering alcohol use is a modifiable risk factor, increasing alcohol users’ knowledge of this risk could help contribute to a decrease in hazardous alcohol use as well as reducing breast cancer incidence. Raising awareness among women, especially younger female alcohol users, is important. In addition, health warning labels on alcohol products are needed. Public health messages that highlight the health risks associated with alcohol use, and which target individuals with lower educational levels, are also warranted.