Why Does Alcohol Increase the Risk of Cancer?
According to the World Health Organization (WHO), the harmful use of alcohol is a risk factor for more than 200 diseases and injuries. Most people associate its chronic intake with liver problems, but the truth is that its impact goes further. We investigate the relationship between alcohol and the risk of cancer, and the mechanisms behind it.
As the American Cancer Society points out, alcohol is directly related to 6% of all cancers and 4% of cancer deaths in the US. The relationship is clear, something that all people who exceed the recommended alcoholic beverage average should know. We review what scientists know about alcohol as a risk factor for cancer.
Alcohol and the risk of cancer: basic principles
A study published in Lancet Oncology in 2021 estimated that in all of 2020, 741,300 cases of cancer attributable to alcohol intake were diagnosed. Among these, it’s thought that at least 100,000 cases were linked to light or moderate intake. The relationship between alcoholic beverages and increased cancer risk isn’t new, yet there’s very little public awareness of the causal link.
The best proof of this is the increase in the prevalence of drinking and the reduction in abstinence throughout the world. A study published in the Lancet in 2019 found that global per capita consumption in adults increased from 5.9 liters in 1990 to 6.5 liters in 2017.
At the same time, lifetime abstinence decreased from 46% in 1990 to 43% in 2017. It’s expected that by 2030 per capita alcohol consumption will be around 7.6 liters.
Specialists have known about the relationship between alcohol intake and an increased risk of cancer for decades. In 1988, the International Agency for Research on Cancer, a body attached to the WHO, classified alcohol as a Group 1 carcinogen. In 2018, the World Cancer Research Fund confirmed the relationship between the intake of alcoholic beverages and a higher chance of developing some types of cancer.
Find out more: Alcohol and Digestive Diseases: What’s the Link?
Why does alcohol increase the risk of cancer?
The mechanism by which alcohol induces cancer isn’t fully understood. Researchers have proposed various pathways through which alcohol can have this effect: inflammatory processes, the genotoxic effect of acetaldehyde, changes in folate metabolism, increased estrogen concentration, and cellular stress. Similarly, the genetic variants associated with increased susceptibility are the following:
- ADH1B
- ADH1C
- ALDH2
- CYP2E1
- MTHFR
So far, as the evidence suggests, alcohol isn’t thought to act as a full carcinogen. What we mean here is that other catalysts are needed for its development. Along with them, alcohol promotes or accelerates the development of cancer. To name just one example, the combination of alcohol and tobacco creates a synergy that increases the risk of developing some types of cancer.
On the other hand, it’s thought that the type of drink isn’t a determining factor in the process. Ethanol has been pointed out as the main culprit, but the frequency with which it’s ingested has a greater impact than the concentration of the drink itself (starting on the basis of the degree of alcohol and differentiating between fermented and distilled). In this sense, the risk is associated more with the amount of alcohol a person drinks over time than with the type of drink.
Alcohol and cancer risk
We have already established that the scientific community agrees that alcohol increases the risk of cancer. That said, what are the types that have been associated with its intake? We’ll leave you with the main ones according to the researchers.
Cancers of the pharynx and larynx
Alcohol consumption increases the risk of developing cancer in the upper aerodigestive tract. Consuming 10 grams per day is associated with a 15% increased risk of cancer of the oral cavity and larynx. The latter has been related in principle to moderate and excessive alcohol consumption.
Esophagus cancer
Squamous cell carcinoma of the esophagus is another of the complications associated with ethanol intake. In fact, it’s one of the main types of cancer associated with regular intake. In principle, the risk for developing esophageal adenocarcinoma (the second most common subtype of cancer in the esophagus) is much lower.
Colorectal cancer
The intake of 10 grams of alcohol a day increases the risk of developing colorectal cancer by 7%. Similarly, its regular consumption could increase the risk of developing precancerous lesions in the colon.
Discover more: Stages of Colon Cancer
Liver cancer
Hepatocellular carcinoma is the most common subtype of liver cancer associated with alcohol intake. On average, 10 grams a day increases the risk of developing it by 14%. It’s a condition that usually manifests itself in heavy drinkers.
Breast cancer
The risk of developing breast cancer rises up to 7% after the regular intake of 10 grams of alcohol per day. No conclusive evidence has been found regarding the risk as a function of menopausal status.
Stomach cancer
Excessive alcohol consumption is estimated to increase the risk of stomach cancer by up to 21%. So far it seems that light consumption doesn’t significantly increase the chances of developing it.
Pancreatic cancer
Although you’re unlikely to develop pancreatic cancer from a light or moderate intake of alcohol, the chances are increased by excessive intake. In principle, when you exceed 60 grams per day.
Other types of cancer
In addition to all of these, alcohol could increase the risk of lung cancer, gallbladder cancer, prostate cancer, kidney cancer, and thyroid cancer. Despite this, the association is lower compared to the previous ones.
Given the compelling evidence, and also considering that it’s a preventable factor, people should regulate alcohol intake to reduce the risk of cancer. Policies towards alcohol and knowledge about the complications associated with its intake are known to result in responsible consumption.
So, because of everything that we’ve mentioned, try to drink as little as possible, and remember that cancer isn’t the only adverse effect of alcohol.
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