Alcohol and diet: the impact on my body

Alcohol is the most consumed psychoactive substance in France: according to Public Health France, 41% of adults say they drink alcohol at least once a week. However, its effects on nutrition and metabolism remain largely unknown to the general public. Alcohol is not a nutrient but it provides calories, interferes with the absorption of many essential nutrients, mobilizes the metabolic resources of the liver and interacts with virtually all of the body's biological systems. Understanding these mechanisms is not a moral exercise: it is health prevention information that everyone deserves to have in order to make informed choices.

1. Alcohol, a caloric anti-nutrient

Ethanol (alcohol) provides 7 kcal per gram - more than carbohydrates (4 kcal/g) and proteins (4 kcal/g), and almost as much as fats (9 kcal/g). These calories are called empty because they are not accompanied by any beneficial nutrients: no vitamins, no minerals, no fiber, no essential amino acids.

Here are the caloric intakes of the most common drinks:

Beyond calories, alcohol is primarily metabolized by the liver before any other nutrient. When I drink, my body pauses the metabolism of fats, carbohydrates and proteins to process ethanol first. This phenomenon promotes the storage of dietary fats consumed at the same time as alcohol.

2. The impact on the absorption of micronutrients

One of the lesser known effects of alcohol is its direct interference with the absorption and metabolism of many essential micronutrients. Regular consumption, even moderate, can lead to significant nutritional deficiencies:

3. The effects of alcohol on organ systems

Alcohol does not spare any body system. Here are the best-documented effects on major organs and functions:

• ●The liver: the first organ to metabolize alcohol, it bears the heaviest impact. Hepatic steatosis (alcoholic fatty liver) can set in during the first months of regular consumption. It can progress to alcoholic hepatitis then cirrhosis. The liver can regenerate if consumption is stopped early enough, but cirrhosis is irreversible.- The brain and the nervous system: alcohol is a neurotoxic substance. In the short term, it inhibits glutamate (excitatory neurotransmitter) and potentiates GABA (inhibitory), creating the effect of relaxation then disinhibition. In the long term, regular consumption is associated with a reduction in brain volume and a decline in cognitive functions, independent of age.

• ●The cardiovascular system: if the alcohol-cardiovascular health relationship has long been presented as U-shaped (moderate benefit at low doses), the most recent randomized Mendelian studies call this benefit into question. A review published in The Lancet (2018) covering 195 countries concluded that the safest level of alcohol consumption for health is zero.

• ●Cancer: the IARC classifies alcohol as a group 1 carcinogen (certain carcinogenicity in humans), responsible for at least 7 types of cancer: mouth, throat, esophagus, larynx, liver, colon-rectum and breast. This risk exists from the first consumptions and increases with the dose.

• ●Sleep: alcohol makes it easier to fall asleep but deeply fragments paradoxical sleep (REM), reducing cognitive recovery. Sleep quality is degraded even with moderate consumption.

• ●The intestinal microbiota: alcohol disrupts the balance of the microbiota, increases intestinal permeability and promotes bacterial translocation to the liver, a mechanism involved in chronic hepatic inflammation.

4. Alcohol and food: the interactions to know

The relationship between what I eat and the impact of alcohol on my body is bidirectional:

• ●Eating before or during alcohol consumption: Food slows down gastric emptying and the absorption of alcohol, reducing the blood alcohol peak and spreading the effect over a longer period. Foods high in protein and fat are most effective at slowing absorption. A full meal can reduce peak blood alcohol levels by 30 to 50% compared to the same consumption on an empty stomach.

• ●Alcohol increases appetite: it lowers blood sugar and stimulates the dopamine reward system, promoting snacking and less healthy food choices. Studies have shown that consuming alcohol before or during a meal increases total caloric intake.

• ●Sugar cocktails: they combine the calories of alcohol with those of sugars, reaching 300 to 500 kcal per glass. The feeling of satiety and hunger signals are blurred, promoting overconsumption.

• ●Hydration: alcohol is diuretic and promotes dehydration, which amplifies the effects the next day (headaches, fatigue). Drinking a glass of water between each glass of alcohol is the most effective strategy to limit dehydration.

5. Current recommendations: what to remember

The current French recommendations from Public Health France, revised in 2017, are as follows:

• ●Maximum 10 standard glasses per week for both men and women (one standardized unit = 10 g of pure alcohol = 1 glass of wine of 10 cl, 1 beer of 25 cl, 3 cl of spirits)

• ●Maximum 2 standard glasses per day

• ●At least 2 days without alcohol consumption per week

• ●Never more than 4 glasses on a single occasion

These benchmarks are risk limitation thresholds, not risk-free doses. As the study published in The Lancet (2018) reminds us, there is no dose of alcohol without risk to health. These recommendations are intended to reduce the risk to an acceptable level, not to eliminate it.

In the context of a health prevention approach, understanding your own alcohol consumption habits is valuable information. A health check-up is an opportunity to evaluate the biological markers associated with alcohol consumption (GGT, transaminases, VGM) and to discuss them calmly with a health professional.