How does alcohol affect our metabolism?
Alcohol consumption is becoming increasingly widespread in Spain. It is not surprising to see terraces crowded with people: it is a ritual that is cheap, accessible, disinhibits our behavior, promotes socialization, and is inseparable from leisure.
It seems almost like an obligation: the party doesn't exist without alcohol, even less so in summer. But the highly normalized integration of this drink implies, in turn, a lack of awareness regarding its consumption and all the health problems it entails.
Before starting, it is important to emphasize that every person is free to choose their reasons for drinking whenever and however they want. However, information must also be provided—based on outreach and scientific backing—about all the dangers that drinking poses. Because its consumption will never be safe or recommended.
In fact, there is a direct link between alcohol and the risk of developing cancer. There are some causally associated types, such as cancer of the oral cavity, larynx, liver, breast, pancreas, stomach, or colorectal cancer.
How many cases are detected per year?
The data supports it: in Spain alone, 45,000 new cases of colorectal cancer were detected in 2024, 10% of them associated with alcohol. And of the 36,000 new cases of breast cancer detected, 8% also had a direct link to this drink.
Finally, in the European Union, more than 180,000 cancer cases associated with alcohol consumption were recorded, according to data from the Spanish Society of Medical Oncology and the Spanish Network of Cancer Registries.
How is alcohol metabolized in the body?
The problem is not the type of drink; it doesn't matter if it's wine, beer, vodka, or gin. The real problem lies in the component they all have in common: ethanol. A colorless and volatile chemical compound that is also used as fuel or disinfectant.
The metabolism of this substance is carried out through two pathways in the liver: the main one is alcohol dehydrogenase (the enzyme that catalyzes the conversion of ethanol) and the secondary one is the microsomal pathway (a metabolic pathway found in the liver). A process that produces acetaldehyde, a metabolite (a molecule) that is highly toxic to our body.
What problems does acetaldehyde cause?
It is an organic, liquid, colorless, volatile, and carcinogenic chemical compound. It is responsible for causing facial flushing, nausea, palpitations, and hangovers.
However, one of the greatest dangers of this substance is that it manages to bind to our DNA, distorting and destroying its structure and promoting the appearance of malignant cells and free radicals.
This causes, among other things, liver toxicity, cellular oxidative damage, and a depletion of our antioxidant reserves such as vitamin C, coenzyme Q10, or glutathione.
As you can see, alcohol consumption doesn't just damage the liver, but our entire body.
The direct damage caused to DNA by acetaldehyde mutation, if replicated uncontrollably, also leads to a higher risk of tumors.
By blocking DNA repair systems, it increases the carcinogenic effect of other substances, inactivates tumor suppressor genes, and activates proto-oncogenes—genes that promote cancer.
The negative effects of alcohol on memory and the brain:
Alcohol also has a direct impact at a neurological level:
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It produces a neurotransmitter imbalance: it promotes GABA and inhibits glutamate, an effect that makes it difficult to generate new memories.
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It also reduces the absorption of vitamin B1 and B12, which carries a risk of reversible dementia.
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It promotes the loss of magnesium, key for neuronal function.
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It promotes the onset of neuronal oxidative stress: which implies a higher risk of suffering from Alzheimer's, Parkinson's, and dementia.
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It alters the REM phase during sleep, by preventing nocturnal brain repair: a consequence that worsens memory and aging.
How alcohol interferes with our hormonal system:
Alcohol consumption also causes an increase in aromatase, a key enzyme in estrogen synthesis:
It also produces:
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Lower intake of proteins and micronutrients
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Less physical activity due to hangovers and fatigue
A consequence that produces: greater loss of muscle mass, alteration of body composition, and low libido.
We leave you more information in this episode by Medical Scientist Dr. Isabel Viña: