Justin Stebbing: The role alcohol plays in new cancer cases

Justin Stebbing shared at theconversation.com:

“A little bit of alcohol was once thought to be good for you. However, as scientific research advances, we’re gaining a clearer picture of alcohol’s effect on health – especially regarding cancer.

The complex relationship between alcohol and cancer was recently highlighted in a new report from the American Association for Cancer Research. The report’s findings are eye-opening.

The authors of the report estimate that 40% of all cancer cases are associated with ‘modifiable risk factors’ – in other words, things we can change ourselves. Alcohol consumption being prominent among them.

Six types of cancer are linked to alcohol consumption: head and neck cancers, oesophageal cancer, liver cancer, breast cancer, colorectal cancer and stomach cancer.

The statistics are sobering. In 2019, more than one in 20 cancer diagnoses in the west were attributed to alcohol consumption, and this is increasing with time.

This figure challenges the widespread perception of alcohol as a harmless social lubricant and builds on several well-conducted studies linking alcohol consumption to cancer risk.

But this isn’t just about the present – it’s also about the future. The report highlights a concerning trend: rising rates of certain cancers among younger adults. It’s a plot twist that researchers like me are still trying to understand, but alcohol consumption is emerging as a potential frontrunner in the list of causes.

Of particular concern is the rising incidence of early-onset colorectal cancer among adults under 50. The report notes a 1.9% annual increase between 2011 and 2019.

While the exact causes of this trend are still being investigated, research consistently shows a link between frequent and regular drinking in early and mid-adulthood and a higher risk of colon and rectal cancers later in life. But it’s also important to realise this story isn’t a tragedy.

It’s more of a cautionary tale with the potential for a hopeful ending. Unlike many risk factors for cancer, alcohol consumption is one we can control. Reducing or eliminating alcohol intake can lower the risk, offering a form of empowerment in the face of an often unpredictable disease.

The relationship between alcohol and cancer risk generally follows a dose-response pattern, meaning simply that higher levels of consumption are associated with greater risk. Even light to moderate drinking has been linked to increased risk for some cancers, particularly breast cancer.

Yet it’s crucial to remember that while alcohol increases cancer risk, it doesn’t mean everyone who drinks will develop cancer. Many factors contribute to cancer development.

Damages DNA

The story doesn’t end with these numbers. It extends to the very cells of our bodies, where alcohol’s journey begins. When we drink, our bodies break down alcohol into acetaldehyde, a substance that can damage our DNA, the blueprint of our cells. This means that alcohol can potentially rewrite our DNA and create changes called mutations, which in turn can cause cancer.

The tale grows more complex when we consider the various ways alcohol interacts with our bodies. It can impair nutrient and vitamin absorption, alter hormone levels, and even make it easier for harmful chemicals to penetrate cells in the mouth and throat. It can affect the bacteria in our guts, the so-called microbiome, that we live with and is important for our health and wellbeing.

Alcohol consumption is also linked to other aspects of our own health and lifestyle and it’s important not just to consider this alone. Tobacco use and smoking, for instance, can significantly amplify the cancer risks associated with alcohol. Genetic factors play a role too, with certain variations affecting how our bodies metabolise (break down) alcohol.

Physical inactivity and obesity, often associated with heavy drinking, also separately increase cancer risks but on top of alcohol makes this much worse. Despite this, misconceptions persist. The type of alcoholic beverage, be it beer, wine, or spirits, doesn’t significantly alter the cancer risk. It’s the ethanol (the chemical name for alcohol) itself that’s carcinogenic (cancer-causing).

And while some studies have suggested that red wine might have protective effects against certain diseases, there’s no clear evidence that it helps prevent cancer.

The potential risks of alcohol consumption probably outweigh any potential benefits. The takeaway is not that we should never enjoy a glass of wine or a beer with friends. Rather, it’s about being aware of the potential risks and making choices that align with our health goals. It’s about moderation, mindfulness and informed decision-making.

Alcohol has lots of effects not just in terms of causing cancer. A recent large study of over 135,000 older drinkers in the UK has shown that the more people drink, the higher the risk of death from any cause.

These and similar findings underscore the importance of public awareness and education about the potential risks associated with alcohol consumption. As our understanding of the alcohol-cancer link grows, it becomes increasingly clear that what many consider a harmless indulgence may have more significant health implications than previously thought.

Unfortunately, not many people appear to be aware of these risks. In the US, around half of people don’t know that alcohol increases the risk of cancer. Clearly, a lot of work needs to be done to overcome this lack of awareness.”

More posts featuring Justin Stebbing on oncodaily.com

Justin Stebbing is a visiting Professor of Cancer Medicine and Oncology at Imperial College, London and a Professor of Biomedical Sciences at Anglia Ruskin University (ARU), Cambridge. He was appointed the first NIHR oncology professor in 2011.

He is editor-in-chief of Nature’s cancer journal Oncogene. Prof. Stebbing has published over 700 peer-reviewed papers in leading academic journals. He is a member of the American Society for Clinical Investigation, a fellow of the Royal College of Physicians, and the Royal College of Pathologists, and sits on many advisory boards. He is on the Editorial Board of OncoDaily.