Alcohol (in any dose) is toxic to the body and its consumption has been shown to also increase the risk of developing tumors. But does eliminating or limiting it reduce the chances of getting sick? The answer seems obvious, but concrete evidence is needed. And this is what a new report from the International Agency for Research on Cancer (IARC) published in the New England Journal of Medicine seeks to provide: in light of the available data, experts have concluded that limiting or eliminating alcohol consumption is associated to reduce the risk of oral cavity and esophageal cancers, while further studies are necessary for other tumor forms.
Alcohol and tumors: this is why it is better to keep the glass empty by Irma D’Aria 13 September 2023
The link between alcohol and cancer
That alcohol is an enemy to health has not been news for some time now. The main reason is that the ethanol contained in alcoholic beverages is metabolised in our body, particularly in the liver, by enzymes which transform it first into acetaldehyde and then acetate. The problem is that acetaldehyde is a genotoxic compound, meaning that it damages the DNA of cells and, consequently, increases the chances of developing cancer. Furthermore, alcohol consumption causes inflammation, oxidative stress and can alter sex hormone levels. For these reasons, ethanol is classified by IARC as a human carcinogen (group 1) and it is estimated that globally in 2020, 4.1% of new cancer cases (i.e. 741,300 new diagnoses) are attributable to its consumption.
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On this basis, experts believe that eliminating or significantly reducing exposure would lead to a reduction in the risk of developing cancer. Science, however, is not science without evidence. And verifying whether how much and in how long the damage caused by alcohol is reversible (as has already been done for smoking) is important information because it could influence clinical decisions and public health programs.
The prime prove
By analyzing over 90 studies, both cohort (i.e. observational investigations, in which a group of people are followed for a certain period of time, even decades) and case-control (i.e. those comparing two groups of people – in this case people with diagnosed of cancer and healthy – to highlight any differences), IARC experts have revealed that there is sufficient evidence to support that reducing or stopping alcohol consumption lowers the risk of developing cancer of the oral cavity and esophagus.
Breast cancer, high incidence in Friuli Venezia Giulia by Dario Rubino 22 February 2023
In particular, for oral cavity cancers, according to an analysis included in the report, eliminating alcohol over a period of 5 to 9 years is linked to a reduction in risk of 23%, which reaches 34% if abstinence is maintains for 10-19 years and up to 55% after at least 20 years. As far as esophageal cancer is concerned, stopping alcohol consumption within 5-15 years corresponds to a reduction in the risk of the disease by up to 15%, but if you go beyond 15 years the risk decreases by up to 65%.
More data is needed
In the case of other types of cancers in which alcohol consumption is considered a direct risk factor (for example in breast, pharynx and colorectal cancers), however, the evidence is limited and further studies are needed. As he reports Farhad Islamian epidemiologist at the American Cancer Society among the authors of the report, in an interview with Stat“the problem is that many of the available studies simply report the risk for former drinkers without showing when they stopped drinking, for how long they stopped drinking, or whether they continued drinking but reduced their drinking. […] It would be nice now to have studies that ask more questions about how long alcohol cessation or reduction lasts.” According to the expert, cohort studies in this context are the best, but they are very long research and it takes decades after people are involved for conclusions to be drawn.