Benefits, health dangers, placebo effect… Food supplements, a fine line between performance improvement and doping

Taking food supplements among high-level athletes has become common in recent years, but is not without risk for athletes.

Food supplements at the heart of several doping cases? In the space of a few weeks, footballer Paul Pogba, tennis player Simona Halep and sprinter Mouhamadou Fall have been flagged for positive results for products banned by the World Anti-Doping Agency (WADA). In each of these cases, the athletes mentioned food supplements to exonerate themselves from a doping practice. Among these three situations, Simona Halep is the one who most strongly questions these products. On September 12, the former world number one received a four-year suspension for two anti-doping rule violations: a positive urine test for roxadustat (an anti-anemic drug) during the 2022 US Open, as well as irregularities noted on her passport. biological in that same year.

The winner of Roland-Garros 2018 and Wimbledon 2019 defends herself by mentioning taking collagen, a food supplement, purchased in Canada. “At least two ingredients contained in this food supplement come from China, justified to franceinfo: sport Jean-Claude Alvarez, director of the toxicology laboratory at Garches University Hospital, and who carried out a new analysis of the player’s hair, at her request. “Roxadustat is very rare in Europe and the United States, but is very common in China. It is likely that the same production line was used both to manufacture drugs based on roxadustat and for the production of collagen, which was therefore contaminated. Contaminated products in China, unfortunately, there are a lot of them”, continues the professor who also works at the University of Paris-Saclay, whose laboratory is at the forefront of doping issues. The player has announced her intention to appeal to the Court of Arbitration for Sport (CAS).

Athletes, solely responsible for their food intake

Although food supplements are not prohibited in sport, and are not on the list of substances banned by WADA, caution must nevertheless be exercised. Beyond possible side effects, “as the food supplement industry is not regulated, the products could contain prohibited substances which are not indicated on the label or packaging”, alerts the French Anti-Doping Agency (AFLD) on its website. Some manufacturers even state on their labeling that “their food supplements are ‘certified’ or ‘tested’ or even ‘certified’ by independent organizations”, what “does not certify that these products do not contain a prohibited substance”, further specifies the AFLD website. The AMA does not certify any food supplement.

If the “zero risk does not exist, it is however very low when we take standardized products, that is to say we know what is in them and we know their origin”, underlines Véronique Rousseau, dietitian sports nutritionist at Insep (National Institute of Sport, Expertise and Performance). At Insep, it therefore prescribes to athletes products referenced on a “safe supplements list”, which meets a European standard.

Because for any high-level athlete, one rule prevails: whether the contamination is voluntary or accidental, he remains responsible. “In When it comes to anti-doping, the principle of strict liability applies, meaning that it is the duty of every athlete to ensure that no banned substances enter their body. Athletes are responsible for any prohibited substance, its metabolites or its markers present in their body samples. reminds franceinfo: sport of the International Testing Agency (ITA), which, like the World Anti-Doping Agency, did not wish to comment further.

A rising market

In 2022, the food supplement market increased by 3% in France compared to 2021 with a turnover of 2.6 billion euros, according to a study by the National Union of Food Supplements (Synadiet). Still according to this study, 59% of French people consume it, including 44% on a regular basis (several times a year), a percentage up 7% over the past two years. All this within a market that is difficult to understand about the origins of the products and added ingredients. “The food supplement market has exploded over the past twenty years. The range is very wide, with very strong associated marketing,” notes Véronique Rousseau. This trend has not escaped the middle of the high level. Although no figures give the exact proportion of athletes consuming these products, specialists confirm the craze among this population.

“Top athletes will use these supplements in the hope that they will improve their performance or recovery, explains Raphaël Faiss, anti-doping researcher at the University of Lausanne (Switzerland). They also make it possible to supplement a food intake that we would not necessarily have effectively with the normal diet. In this case, we find some use for the complements. assures the researcher. Food supplements are also used for muscle building purposes, with isolated proteins, devoid of associated fats.

“If a Tour de France rider had to compensate for the amount of sugar energy he burns during a mountain stage, he would have to consume about 400 grams of sugar, or about eight or nine plates of pasta, which is complicated to achieve with a normal diet.”

Raphaël Faiss, anti-doping researcher at the University of Lausanne

at franceinfo: sport

Another interest for athletes: practicality. “Sometimes, post-workout, if the athlete does not eat within an hour, because he is not able to have a real meal immediately, we will resort to protein powders which assimilate quickly, and which we will associate with carbohydrates. While we must not neglect the practical side, we always put a priority on the plate before the food supplement”, nuance Véronique Rousseau.

If the traditional meal is to be prioritized according to the dietitian nutritionist at Insep, the prescription of certain food supplements, such as “exercise drink and protein powder, however, is quite common and supervised”, she assures. Although it is difficult to control everything that athletes ingest. “We are not every day with them, and those around them can also recommend certain products. Besides, when we ask them what they take, how much and why they take it, they often don’t know how to answer“, observes this dietitian nutritionist.

An efficiency that divides

However, their use is not unanimous among professionals. “There are a lot of beliefs in nutrition. Often, among athletes there is an overestimation of the perception of these supplements, without really verifying their need, which nevertheless depends on individual monitoring. The priority should be diet natural, but for them, the cursor is often a little shifted, and more focused on a preoccupation with taking supplements”, observes Véronique Rousseau, who calls for caution.

“There is sometimes a placebo effect, researcher Raphaël Faiss decides. Some will say to themselves that ‘if I take it, it may not have a positive effect, but not taking it will have a negative effect’.” Above all, their effectiveness has not always been demonstrated. “The IOC has published a consensus to list the supplements and foods for which there is a scientific interest in having supplementation, those for which we have very little scientific evidence and those for which we have absolutely no evidence,” notes Raphaël Faiss, who regrets a lack of information among athletes. But “if we have any doubt, if we have an unclear list of ingredients, he concludes, the athletes must then simply move on.”


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