Think again about that glass of chardonnay! Drinking alcohol may be riskier than we previously thought.
New Daffodil Centre research has found the number of deaths caused by alcohol over the past 30 years may have been underestimated.
A research team, led by Dr Peter Sarich of the Daffodil Centre, a joint initiative between Cancer Council NSW and the University of Sydney, looked at systematic reviews of alcohol use and mortality published in the medical literature from 1993 until 2022.
Understanding the 'Sick Quitter' phenomenon
According to Dr Sarich's findings, more than 70% of these evidence reviews included former drinkers who have since quit drinking in their comparison groups.
This is because many studies use non-drinkers (people who don't drink any alcohol) as a comparison group without discerning whether they are people who have never drunk alcohol or people who were previously drinkers but have since stopped drinking alcohol.
Why is this an important issue? "Many people identified as non-drinkers in cohort studies are in fact former high-risk drinkers," says Dr Sarich. These people have often quit drinking after experiencing serious health issues. This means they may be classified in studies as a non-drinker who has a health condition, when in fact their previous alcohol use may have contributed to their health condition.
This is known as the 'sick quitter effect' - "When a study includes former drinkers in their comparison group, it can falsely make the harms of drinking appear smaller or non-existent, or even make it seem like drinking small quantities of alcohol protects against harms," says Dr Sarich.
What did the study find?
This means that most studies that have looked at alcohol use and health may have been biased by considering former drinkers the same as never-drinkers.
Dr Sarich's study, published in the journal Addiction in March, tried to address this "sick-quitter effect" by only looking at studies that used "lifetime abstainers" - people who have never consumed alcohol, and occasional/low-volume alcohol drinkers - as comparison groups.
His team found only five studies that met these criteria and "all five reviews reported significantly increased risk of death with higher levels of alcohol use".
Only one study was considered to be of high quality, and it found that that across all levels of alcohol use, the more a person drinks, the higher their risk of alcohol-related death. This study is a timely reminder to follow the alcohol health guidelines. The National Health and Medical Research Council guidelines state that a healthy adult should drink no more than 10 standard drinks per week and no more than four standard drinks on any one day. This is still well below what Dr Sarich's study defined as low-volume drinking.
About one in three Australians drink alcohol at levels above this guideline, according to the National Drug Strategy Household Survey 2022-2023. The survey also found one in ten people consume more than 10 standard drinks a week.
Alcohol increases cancer risk
Even drinking small amounts of alcohol increases your cancer risk. The type of alcohol - beer, wine or spirits - doesn't make any difference.
Drinking any alcohol increases the risk of developing mouth, throat, oesophagus, stomach, bowel, liver and breast cancer. Oral cancers are six times more common in those who drink alcohol.
In the wake of this Daffodil Centre study, Cancer Council NSW is calling on governments to invest in initiatives, policies and campaigns to support people to reduce alcohol use. This is because it's much easier for people to cut back or stop drinking if their environment supports this.
Cancer Council NSW recommends restricting alcohol advertising, promotion and availability, making changes to alcohol pricing and enhancing public education about the health risks of alcohol.
