A brand new study, published in The Lancet, has found that alcohol caused over 740,000 cancer cases, worldwide in 2020. This translates to 4% of all cancers or one in 25 cancers caused by alcohol. Men are the most affected, accounting for 77% of the cases (568,700) compared to 23% (172, 600) of women who were affected.
No level of alcohol consumption is safe, according to the study. While most cancers were caused by heavy (47%) or risky (39%) alcohol use, even low-risk alcohol use led to cancer 14% of the time.
There’s strong evidence that [consuming] alcohol can cause seven types of cancer, and the more someone [uses alcohol] the greater their risk. There’s no safe level of [alcohol use], but whatever your [alcohol use] habits cutting down can reduce your risk of cancer,” said Michelle Mitchell, Cancer Research UK’s chief executive, as per The Guardian.Michelle Mitchell, chief executive, Cancer Research UK
The largest proportion of new cancers caused by alcohol were cancers of the oesophagus (189,700 cases), liver (154,700 cases), and breast (98,300 cases).
Geographically, the largest number of alcohol caused cancers (6%) were from Eastern Asia, Central and Eastern Europe, while the lowest (1%) was found in Northern Africa and Western Asia.
The study’s scientific method
In this population based study the researchers established levels of alcohol intake per person per country for 2010 then combined it with estimated new cancer cases in 2020 to estimate the number of alcohol-associated cancers in each country.
Alcohol consumption was estimated in liters per year per adult, based on alcohol production data, tax and sales data, surveys and opinion on unrecorded alcohol intake, and tourist alcohol consumption data.
Low risk alcohol use as per the study was 0.1 to 20 grams per day, the equivalent of up to two alcoholic beverages. Risky alcohol use was 20 to 60 g per day, between two and six alcoholic beverages. Heavy alcohol use was more than 60 g per day, more than six alcoholic beverages.
The study did not include former alcohol users and only included cancers which are known to be caused by alcohol. It did not include cancers which emerging evidence show have links to alcohol use such as pancreatic and stomach cancers.
Since about a quarter of alcohol consumption goes unrecorded and the study excluded former alcohol users and certain cancers, alcohol’s cancer burden in the study could actually be an underestimation.
Achieving a solid understanding of the burden of cancer associated with alcohol use, underlying mechanisms, and how best to intervene rely on accurate measures of alcohol exposure… Until we address limitations in measurement, we might be underestimating health risks, especially cancer risks, associated with alcohol,” said Professor Amy C. Justice, Yale University, USA, as per Health Policy Watch.Professor Amy C. Justice, Yale University, USA
The researchers did analyze the data further incorporating former alcohol use, pancreatic and stomach cancers. The numbers of cancer cases shot up to 925,000 alcohol-related cancers caused by alcohol, meaning 5% of the global cancer burden.
How does alcohol cause cancer?
The study describes several biological pathways that lead alcohol to cause cancer. Ethanol, the chemical in all alcohol products breaks down to form the carcinogen called acetaldehyde. This carcinogen damages DNA and interferes with cells’ ability to repair the damage.
Alcohol increases levels of hormones, including estrogen. Hormones signal cells to grow and divide. With more cell division, there are more opportunities for cancer to develop.
Alcohol also reduces the body’s ability to absorb certain cancer-protective nutrients, including vitamins A, C, D, E and folate.
According to Dr. Kevin Shield an author of the study and head of the World Health Organization Pan American Health Organization Collaborating Center, when alcohol comes into direct contact with the cells in the head and neck as well as the digestive system, it damages the DNA. Moreover, he said that the association of breast cancer and alcohol consumption comes from alcohol-induced hormonal dysregulations.
The combination of smoking and alcohol use can increase cancer risk even more, with alcohol acting as a kind of solvent for the carcinogenic chemicals in tobacco.
Global trends in alcohol and cancer
The study found the following trends regarding alcohol’s cancer burden:
- At a country level, the proportions of cancer cases associated with alcohol were estimated to be highest in Mongolia (10%, 560 cases) and lowest in Kuwait (estimated at 0%, less than 5 cases).
- The UK had an estimated 4% of cancer cases linked to alcohol (16,800), with the United States at 3% (52,700), Brazil at 4% (20,500), India at 5% (62,100), China 6% (282,300), Germany 4% (21,500) and France at 5% (20,000 cases).
- Amongst women, the largest proportions of cancer cases that were attributed to alcohol were in Central and Eastern Europe (3%, 21,500 cases), and Australia and New Zealand (3%, 2,600 cases).
- Amongst men, the largest proportions of cancer cases linked to alcohol were found in Eastern Asia (9%, 275,900 cases) and Central and Eastern Europe (8%, 49,900 cases).
Trends suggest that although there is a decrease in alcohol consumption per person in many European countries, alcohol use is on the rise in Asian countries such as China and India, and in sub-Saharan Africa,” said Harriet Rumgay, lead author of the study from the International Agency for Research on Cancer (IARC) in France, as per Health Policy Watch.Harriet Rumgay, lead author of the study, International Agency for Research on Cancer (IARC), France
Researchers call for increase public awareness on alcohol’s cancer risk
The International Agency for Research on Cancer (IARC), the WHO’s cancer research body, classifies alcohol as class one carcinogen since 1988. Alcohol causes 7 types of cancer: mouth, throat (pharynx), food pipe (esophagus), voice box (larynx), breast (in women), bowel (colon and rectum), and liver cancer.
Despite alcohol’s proven cancer burden, awareness of alcohol’s cancer risk is low among the public and policymakers.
- A 2018 review of 32 studies examining ordinary people’s awareness of alcohol as a risk factor for cancer in 16 countries showed that awareness appears to be low internationally.
- In the U.S., the 2019 Cancer Risk Awareness Survey by the American Institute for Cancer Research (AICR) found only 45% of respondents recognized that alcohol causes cancer.
- In Europe, research finds that one in 10 Europeans are not aware of the connection between alcohol and cancer, and that one in five do not believe there is a connection between cancer and alcohol.
- In Australia, a survey by the Cancer Council in 2021 found that only one in five Australians knew that alcohol caused cancer.
The researchers of the new study call for increasing the public’s and policymakers’ awareness about the fact that alcohol causes cancer. They further call for alcohol policy solutions to reduce alcohol’s cancer burden including,
- Reducing the affordability of alcohol by increasing taxes or introducing minimum unit price (MUP),
- Banning alcohol advertising, sponsorship and promotion, and
- Health warning labeling on alcohol product packages.
We urgently need to raise awareness about the link between alcohol consumption and cancer risk among policymakers and the general public,” said Harriet Rumgay, lead author of the study from the International Agency for Research on Cancer (IARC) in France, as per Health Policy Watch.
Tax and pricing policies that have led to decreased alcohol intake in Europe, including increased excise taxes and minimum unit pricing, could also be implemented in other world regions. Local context is essential for successful policy around alcohol consumption and will be key to reducing cancer cases linked to [alcohol use].”Harriet Rumgay, lead author of the study, International Agency for Research on Cancer (IARC), France
Movendi International has long been advocating for alcohol policy solutions including the World Health Organization’s three best buys to reduce alcohol’s cancer burden.
Health Policy Watch: “Alcohol Consumption is Linked to 740,000 Cancer Cases, Particularly Affecting Men“
The Guardian: “Alcohol caused 740,000 cancer cases globally last year – study“
Philcain.com: “Four percent of cancers linked to alcohol“