the “digestion cut” does not exist and science is clear why

There are some very ‘mother’ phrases that are very well ingrained in our minds and without a doubt one of them is the obligation to wait strictly two hours after eating before entering the pool or the beach. Under the pretext of ‘digestion cut‘, there are many children (and also adults) who have to wait before taking a dip for fear of drowning. However, this is a myth.

A popular fable. The concept of “digestion cut” It is not something that is included in the different medical guides nor is it categorized by the WHO as an existing disease. And this is what specialist societies such as the Spanish Society of Primary Care Physicians also point out, whose expert Ángel Jimeno Aranda clearly points out that cutting digestion is a popular term:

It really has nothing to do with digestion, although it is true that when you feel so bad after suddenly entering cold water, you begin to have a headache, blurred vision, fatigue, nausea, vomiting or abdominal pain. The symptoms have caused this popular belief that the problem has a digestive origin, but it has nothing to do with digestion. It is more of a vascular process

What really happens. If the ‘digestion cut’ does not exist, then… What happens? The answer lies in immersion syndrome, also technically called hydrocution or thermodifferential shock.

This phenomenon is triggered when there is a large temperature difference between a bather’s skin and the water, usually when the latter is below 27°C or there is a thermal difference equal to or greater than 5 °C with respect to body temperature.

In the body, This is instantly detected by the different receptors that begin to send signals to the brain to provoke an uncontrolled automatic response characterized by involuntary reflex inspiration, hyperventilation and severe cardiac arrhythmias that can lead to immediate drowning, regardless of the state of digestion. So, as we see, it is a completely vascular problem and has nothing to do with having had a sandwich just before going to the restaurant.

Matches the food. Despite being a myth, the historical relationship between eating and immersion syncope has a hemodynamic explanation, since during the time after eating, the body redistributes blood flow to the areas that need it most, which at that time is the stomach to be able to digest. This means that there is not as much blood in other parts of the body.

In this way, if a person is suddenly immersed in cold water in the middle of the digestive process, and especially if they have been in the sun, the body executes massive peripheral vasoconstriction to contain the heat in the body. Literally, there is a clash between the stomach’s demand for blood and this constricting response, which generates a conflict of signals for our brain, which does not know who to give priority to.

The result It is nothing more than hyperstimulation of the vagus nerve that produces a drop in heart rate and also blood pressure. And lowering pressure is not good news because it generates cerebral hypoperfusion, resulting in dizziness, nausea, loss of vision and, in the worst case, syncope.

The reality. With all this data it has become quite clear that waiting 2 clock hours after eating to bathe is false, since the determining factor is not the time, but the method of entering the water and the temperature difference. If we look at it from another perspective, if we talk about warm water, this is something almost impossible to happen, even if we have just eaten.

The recommendations The steps to follow focus on entering the water slowly, allowing the skin receptors to acclimatize to the temperature to which we are exposing them, first wetting the extremities, the back of the neck and the abdomen.

In addition, sudden changes must be avoided after physical exercise or sunstroke, since the body temperature here will be very high and can be a problem regardless of whether the stomach is full or empty.

Images | Callum Hill

In Xataka | It is increasingly common to find jellyfish on Mediterranean beaches before summer. And it’s a bad sign