Risks of food supplements and fortified foods for athletes
Food supplements and foods fortified with proteins, amino acids or plant extracts are taken by athletes, both professional and amateur, to build muscle mass or reduce body fat. Following an initial alert issued in 2016, the Agency is once again warning athletes, coaches and healthcare professionals of the risks of consuming these products, both to the health of the athlete and in the event of a drug test.
Products used by amateur and professional athletes alike
While seeking to improve their performance, some athletes turn to food supplements and fortified foods to build muscle mass or reduce body fat.
Although these products have traditionally been used by bodybuilders, their popularity is spreading, particularly in sports where performance is based on muscle strength and power or reduced body weight. This practice is encouraged by an unfounded belief that a regular diet is not enough to achieve the performance targets set.
Some of these food supplements and fortified foods are sold on the internet, in sports halls or pharmacies, and may be consumed when training, before, during or after a competition, or simply when practising a leisure activity.
Since 2016, 20% of the reported adverse effects have been very serious
Between 2009 and 2016, 49 reports of adverse effects potentially associated with the consumption of food supplements for athletes were reported to the nutrivigilance scheme.
Since then, ANSES has continued its health monitoring. Between 2016 and February 2024, it was notified of 154 new cases of adverse effects following consumption of these products, 18 of which were considered very serious. Two deaths occurred and four people suffered life-threatening symptoms.
Among the many adverse effects reported, cardiovascular effects were the most common, with the occurrence of tachycardia, palpitations and even cardiac arrest. General symptoms such as faintness, fatigue, fever, dizziness, digestive effects and neurological effects (stroke) were also recorded.
Watch out for banned substances!
Use of certain ingredients – such as anabolic steroids, clenbuterol and ephedrine – is prohibited, mainly because of their numerous serious adverse effects on cardiovascular function. Their presence in food supplements therefore constitutes fraud and, besides the health risks, any athlete consuming them stands a chance of failing a drug test (i.e. testing positive).
Furthermore, even if it meets French regulatory requirements, an ingredient may not be authorised by the World Anti-Doping Agency (WADA).
Athletes therefore need to be able to identify these substances, which are banned by WADA in competition or in any other circumstances, and should pay close attention to the composition of the products they consume, opting in particular for products that comply with European standard EN 17444:2021.
Report any adverse effects to nutrivigilance
These new cases prompted ANSES to initiate a new expert appraisal to supplement its risk assessment work published in 2016. The number and diversity of cases are crucial to the quality of the expert appraisal. ANSES therefore reminds healthcare professionals and consumers of the importance of reporting to its nutrivigilance scheme any adverse effect likely to be associated with the consumption of a food supplement or fortified food.
Products for athletes: what are the recommendations?
- Avoid consuming several food supplements or fortified foods at the same time, or combining them with medicines;
- Before taking them, seek the advice of a healthcare professional, doctor or sports dietician;
- Choose products that comply with European standard EN 17444:2021 and avoid purchases on the internet.