Drinking alcohol causes cancer, so why is this still socially acceptable?
Dr Shireen Kassam, Founder and Director of Plant-Based Health Professionals UK
As a doctor, I have always wondered why drinking alcohol is normalised within medical circles and the wider public. Not just that, we have bought into the myth that small amounts of alcohol, particularly red wine, may even be beneficial. Effective advertising and marketing strategies, compounded by the lack of sufficient regulation, have created our dysfunctional relationship with alcohol such that it is associated with celebrations, commiserations, relaxation and more. I even receive advertising for deals on buying wine with my weekly subscription of the BMJ journal. As a lifelong non-drinker, I have often felt stigmatised for my choice.
Decades of scientific data confirm that any level of alcohol consumption causes more harm than good and zero is the safest amount to consume. Deaths from alcohol use in England are at a record high. Globally, 1.34 billion people consume harmful amounts of alcohol, and 1.8 million deaths are due to high alcohol use. One of the major harms of alcohol use relates to cancer. Alcohol is metabolised in the body to acetaldehyde, a chemical that damages cells and makes it more likely that a cell will become cancerous. At the same time, alcohol disrupts hormone levels in our body, such as oestrogen and insulin, affecting the rate at which cells divide. In addition, alcohol makes it more likely that cells absorb other harmful chemicals. At least 7 cancers are directly associated with the consumption of alcohol, including some of our commonest such as breast and bowel cancer. Alcohol-related cancers account for around 5% of all cancers. Alcohol use is also likely to be part of the reason why cancer rates are rising in young people, under the age of 50 years.
Similarly for cardiovascular disease, consuming alcohol causes more harm than good, contributing to increased risks of hypertension, cardiomyopathy, atrial fibrillation and stroke. Thus, the World Heart Federation states that we have been ‘promoting a myth’ for over 30 years by suggesting that alcohol benefits heart health. They also remind us that alcohol use is contributing to health inequity, as people of lower socio-economic status experience a disproportionately greater harm than people of higher socio-economic status from similar or lower amounts of alcohol consumption. This week, the US Surgeon General, Dr Vivek Murthy has urged health warning labels on alcohol-containing beverages to include the cancer risk.
So where does the notion that small amounts of alcohol can be healthful come from? Several observational studies have shown that avoiding alcohol may be associated with increased risk of chronic conditions and premature death, the so-called J shaped curve, where both no and high consumption is problematic. However, these types of studies have suffered the impacts of confounding and reverse causation. That is, people with a chronic health condition may then decide to stop drinking and hence abstaining from alcohol consumption appears to be associated with worse health outcomes. However, a study from the UK Biobank using methods that can more accurately assess the health impact of alcohol consumption found that there was no protective impact of alcohol on premature mortality and even a low level of consumption was harmful.
Many of us fear developing cognitive decline and dementia more than we do cancer. Dementia is the leading cause of death in the UK accounting for 1 in 10 deaths. Alcohol consumption is a key risk factor. Data from 36,678 generally healthy middle-aged and older adults from the UK Biobank study showed an association between drinking alcohol and reduced brain volume that began at an average consumption of less than one alcohol unit a day and with a dose-response relationship; the more you drink the greater the reduction in brain volume. Going from one to two drinks a day was associated with changes in the brain equivalent to ageing two years. Going from zero to a daily average of one alcohol unit was associated with the equivalent of a half a year of ageing, the difference between zero and four drinks was more than 10 years of ageing. So once again, when it comes to brain health, the safest level of alcohol consumption is zero.
For these reasons, one of the pillars of lifestyle medicine is to avoid toxic substances such as alcohol. There are numerous benefits for physical and mental health of stopping alcohol consumption at all stages of life. Luckily, there are a number of social and societal trends that are supporting people to drink less and ultimately quit alcohol. Millions of people now take part in Dry January, a campaign run by the charity Alcohol Change UK, with well documented benefits. There is a growing market for alcohol-free drinks. Alcohol-free pubs and bars continue to pop up. The healthcare profession now needs to be honest with the science and advise patients and the public to quit drinking alcohol and signpost to support that is available in the community. With growing social acceptance of non-drinking and awareness about the health benefits, there has never been a better time to embrace an alcohol-free lifestyle.