Demystify science | Swim after eating

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It is a myth, according to Laurie Plotnick, urgentologist at the Montreal Children’s Hospital.

“The idea that digestion can cause cramps when swimming has never been scientifically proven,” says the D^re Plotnick. It would come from an old scout manual. »»

Very few studies have specifically examined this question. One of the problems is that we have to compare people who have drowned after eating with a control group.

“The American Red Cross studied drowning in 2011, and eating before swimming was not selected as a possible drowning cause,” says the D^re Plotnick. Inadequate supervision, lack of swimming for swimming and the absence of barriers were the main causes of drownings. »»

Consult the sources of this 2011 literature review of the Red Cross illustrates the difficulty of scientifically studying the question. Four of the 17 studies – which all date from the 1960s – look at the performance of athletes who took a snack before swimming. The researchers did not find a negative effect on their speed. The only other experimental study cited, which leaned over the gastrointestinal effects of a snack before an intense effort, has an even more tenuous link with drowning after a meal.

The most recent study which focused directly on the link between eating and swimming is Japanese and was published in 2011 in the journal Science, Medicine and the Law. Based on 85 drownings, she concluded that 79 % of accidental drownings occurred shortly after a meal, compared to 43 % of suicides by drowning. The suicides by drowning constituted the control group, an astonishing choice which was however validated by the acceptance of the study by this review with reading committee (peer review).

But the authors cited some weaknesses of their own study. In particular, 5 of the 34 drownings had occurred in a bathtub and 35 % of accidental drownings also involved alcohol.

Then, the drowned by accident were also older, 61 years old against 53 years on average, than drowned by suicide. All these factors left the authors of the study hesitant to conclude that digestion makes swimming more dangerous. For example, if we omitted the drowned having consumed alcohol, there was no longer any difference between suicides and accidental drownings, compared to a recent meal.

The D^re Plotnick believes that the Japanese study has too few subjects to be valid.

Another study on the gastric content of the drowned, published last November in the journal Forensic Science Internationalsimply did not evaluate the presence or not of a partially digested meal in the stomach. The objective of the study was to determine whether certain characteristics of the content of various organs made it possible to conclude that drowning was the cause of death, or if the victim had died before finding himself in the water – or had died of a heart attack while swimming, notes her main author, Brita Zilg, of the Karolinska Institute in Stockholm. In the case of the stomach, only the presence of foam created by the massive ingestion of water was measured.

Settlement

According to the Montreal pediatrician, the new Quebec regulation forcing to have a fence separating the pools from houses, and not just neighbors, is a big step forward.

In the decade preceding the last tightening of standards on swimming pool fences in 2010, there were 61 to 97 drownings per year in Quebec. Since (with the exception of the years of pandemic, where travel restrictions have altered statistics), the balance sheet varies between 52 and 84. The record of drownings in the last 35 years is 152, in 1996.

The urgentologist does not believe that there are unanswered questions with regard to research on drowning, or other desirable tightening of the regulations.

Could lakes and rivers be restricted by fences? “It is certain that you must make sure that children cannot get out of the house to go to the lake without being aware of it,” said the D^re Plotnick. You should never swim alone. »»

Some adult swimmers drag behind an inflatable cushion with a whistle, in case they have discomfort. But that makes no less dangerous the solo swim, according to the D^re Plotnick. “If we have discomfort, there must be someone who answers the call of the whistle and come to save us. »»

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