What you don't know about alcohol!

Why are we thirsty the morning after a night out?

 

Our body is dehydrated. 

 

As well as drawing on our body's water reserves, Allen C.D. showed that alcohol disrupts the functioning of the pituitary gland in the brain, leading to a drop in the secretion of antidiuretic hormone. 

 

This hormone is involved in the reabsorption of water by the body in the kidneys. 

Put simply, the body eliminates more water than it absorbs. The person then shows symptoms of dehydration, such as fatigue and above all headaches. Don't wait until you're thirsty to rehydrate, because by then it will be too late. 

 

 

Why do we get a headache?

 

Several factors are behind the headaches caused by drinking alcohol.  

 

• Alcohol causes severe dehydration. 

 

• The sugar in alcohol prompts the body to produce insulin, causing our blood sugar to drop. Hypoglycaemia leads to headaches. 

 

• The build-up of acetaldehyde, a toxic metabolite of alcohol. Acetaldehyde is an intermediate product generated in the liver during the process of eliminating alcohol. It is also behind the symptoms associated with hangovers such as headaches.

 

Although alcohol is considered a sedative, drinking it disrupts our sleep. 

 

Alcohol binds to many receptors in the central nervous system, such as the GABAA receptors (the most important inhibitory neurotransmitter in the human brain). As a result, excessive consumption has a depressant effect on the central nervous system, and this affects sleep in several ways: 

 

Thakkar M.M. et al., (2015), showed that alcohol acts on sleep in several ways: 

• Disruption of the sleep cycle
• Reduced REM sleep and disrupted slow-wave sleep
• Night-time awakenings 
• Worsening of certain sleep disorders (snoring or even sleep apnoea) 

 

Sleep quality is therefore affected by alcohol consumption. *

 

Why are we tired?

 

Fatigue comes down to a combination of 3 factors:

 

 

Why do we crave fatty food?

There are 2 reasons behind this behaviour:

 

• Costardi J.V. et al., (1992), showed that alcohol activates the receptors of the endocannabinoid system, which triggers hedonic hunger. That is, hunger not driven by an actual need, with a craving for foods that give us pleasure, often fatty and/or sugary.
  (this phenomenon is also found after cannabis use) **

 

When we drink alcohol, the inhibition threshold in our brain is lifted. In other words, we give free rein to our emotions and cravings without considering the consequences or the context. Biologically, the disinhibiting effect of alcohol can be explained by the inhibition of two neurotransmitters: noradrenaline and serotonin. As we've already discussed, by binding to GABA receptors, alcohol has an inhibitory effect. Here, it acts on noradrenaline and serotonin and disrupts their secretion. 

 

- Noradrenaline controls our reactions in the face of danger. 

- Serotonin helps control emotions and mood.

 

Cains S. et al., (2017), showed that alcohol acts on the hypothalamus, particularly on Agrp neurons. Since these neurons are involved in regulating the feeling of hunger, the action of alcohol on them reduces our sense of fullness. 

 

Normally, it lets us control our food impulses and cravings for calorie-rich foods. But after a few drinks, the satiety barrier is lifted ***

 

Is there a type of alcohol to avoid?

 

A 2009 study from Brown University showed that dark spirits contain more impurities than clear ones.

Gin, vodka, sake, red wine, beer, whisky

These impurities are associated with more pronounced hangover symptoms. 

You should also choose a quality product, because the quality of the alcohol plays an essential role. For example, poorly distilled spirits will contain other types of alcohol, such as methanol, which can be dangerous in high doses.

 

Why is alcohol eliminated differently from one person to another? 

 

Regardless of the amount consumed, the liver can only metabolise a certain quantity of alcohol over a given time. This process quickly becomes saturated, and the speed of metabolism depends in particular on the amount of metabolising enzymes (cytochromes) present in the liver. An inter-individual factor determines this quantity, which varies from one person to another and appears to be genetically determined.

Allen, C. D., (2011). Immediate and prolonged effects of alcohol exposure on the activity of the hypothalamic–pituitary–adrenal axis in adult and adolescent rats.

Brain, Behavior, and Immunity, 25, S50‑S60.

https://doi.org/10.1016/j.bbi.2011.01.016

Cains, S.,  (2017). Agrp neuron activity is required for alcohol-induced overeating. Nature Communications, 8(1). https://doi.org/10.1038/ncomms14014

Costardi, J. V. V., (2015). A review on alcohol : from the central action mechanism to chemical dependency. Revista da Associação Médica Brasileira, 61(4), 381‑387. https://doi.org/10.1590/1806-9282.61.04.381

Thakkar, M. et al., (2015). Alcohol disrupts sleep homeostasis. Alcohol, 49(4), 299‑310. https://doi.org/10.1016/j.alcohol.2014.07.019

 

* https://www.educalcool.qc.ca/wp-content/uploads/2019/09/Alcool-et-sommeil.pdf

 

** According to a study published in the journal Sleep

*** A second study, published in the journal Health Psychology,

https://www.doctissimo.fr/sante/atlas-corps-humain/question-corps-humain/manger-gras-apres-une-soiree