Low rates of alcohol consumption are more harmful than previously thought. Alcohol consumption is the lifestyle factor most consistently associated with increased breast cancer risk. Women with high levels of alcohol consumption have a 40–50% higher risk of developing breast cancer than abstainers, regardless of the type of alcoholic beverage consumed. Research released in August 2020 has challenged views that small amounts of alcohol are harmless, reporting that the consumption of 1 glass of alcohol per day was associated with a 25% higher risk of ER+ breast cancer than no consumption, with more than 1 glass of alcohol per day was associated with a 34% higher risk of ER+ breast cancer. Furthermore, a dose–response relationship between alcohol consumption and ER+ breast cancer was also found, with a 13% increase in risk per 10 g/day (100ml wine) increment. Postmenopausal women have been found to be a greater risk due to their alcohol consumption, than pre-menopausal women.
An earlier 2016 NZ study into alcohol-attributable cancer deaths in NZ, found that drinking alcohol was responsible for 236 cancer deaths in people under 80 years of age in 2012. Lead author Professor Jennie Connor of the Department of Preventive and Social Medicine at Otago Medical School, said “the findings about breast cancer were particularly sobering. Breast cancer is the leading cause of alcohol-attributable cancer deaths in both Māori women and non-Māori women, accounting for 61.1% of all alcohol-attributable cancer deaths in women and more than one-third of alcohol-attributable breast cancer deaths were due to an average consumption of less than 2 standard drinks per day (200ml wine).”
Why is awareness of the increased cancer risk from alcohol so poor? More than 100 studies have shown a causal relationship between alcohol consumption and female breast cancer and relative risks elevated at as low as one or two drinks a day. However, awareness of the link between alcohol and cancer is low in Aotearoa. In a survey of 1000 New Zealanders only 9% mentioned drinking alcohol as a potential risk factor for breast cancer or bowel cancer. When specifically asked about the risk posed by drinking more than 1 alcoholic drink per day, 14% said this amount of alcohol would not increase the risk of breast cancer and 8% said this amount of alcohol would not increase the risk of bowel cancer. A further 1 in 5 people did not know if this amount of alcohol would increase the risk of breast (22%) or bowel cancer (17%).
What can we do about this? Professor Connor supports the use of population-level strategies to reduce consumption because, apart from the heaviest drinkers, people likely to develop cancer from their exposure to alcohol cannot be identified, and there is no level of drinking under which an increased risk of cancer can be avoided. “We hope that better understanding of the relationship of alcohol with cancer will help drinkers accept that the current unrestrained patterns of drinking need to change”.
Clearly all health professionals need to take on board the importance of asking and providing brief but accurate advice about the impact of even small amounts of alcohol on people’s health. More so, strategies which address the normalisation of alcohol are also needed to redress the increasing negative health effects we are seeing in our communities.
READ: One woman’s story – Did drinking give me breast cancer?
Except from the Take 5 newsletter created by Dave ‘Bear’ Hookway-Kopa
Manu Hapori Hauora | Community Wellbeing Advisor
Te Tai Hapori / Nga Tai Ora / Te Tai Tokerau / Northern Region