The consumption of supplements by sportsmen: a systematic review of literature

A varied and energetically adequate diet is able to provide the appropriate amounts of all the essential nutrients. However, many sportsmen take food supplements without consulting a health professional and without the exact knowledge of its possible benefits. The purpose of this project is to present a systematic review of literature on the prevalence and main types of dietary supplements consumed by sportsmen and to understand the main sources of indication and reasons for the use of nutritional supplements. METHODS A bibliographical research was performed on the PubMed and Web of Science databases. In this context, all available publications were included between January 2007 and February 2018 that complied with the following inclusion criteria: (1) individual practitioners of any sport; (2) individuals between the age of 18 and 65 years old of both genders; (3) available studies in full text published in English, Spanish and Portuguese. Using these criteria, 14 articles of a total of 1054 were selected. RESULTS The prevalence of the use of supplements varied between 13.3% (Figueira & Cazal, 2017) and 100% (Peçanha, Navarro, & Maia, 2015), determining that the articles included in their samples merely professional athletes (n=6; 42.9%) the prevalence of the consumption of nutritional supplements varied from 46.2% (Ivković, 2016) to 90.9% (Stewart, Outram, & Smith, 2013). The most consumed supplements were protein supplements (n=9; 69.2%) (Tsitsimpikou et al., 2011; Silva & Marins, 2013; Assis, Silveira, & Barbosa, 2015; Peçanha, Navarro, & Maia, 2015; Gacek, 2016; Ivković, 2016; Korczak et al., 2016; Naves, Isizuka, Ruas, Ramada, & Nacif, 2016; Figueira & Cazal, 2017), amino acids (n=6; 46.2%) (Tsitsimpikou et al., 2011; Assis, Silveira, & Barbosa, 2015; Peçanha, Navarro, & Maia, 2015; Korczak et al., 2016; Naves, Isizuka, Ruas, Ramada, & Nacif, 2016; Figueira & Cazal, 2017), vitamins (n=5; 38.5%) (Dascombe, Karunaratna, Cartoon, Fergie, & Goodman, 2008; Tsitsimpikou et al., 2011; Stewart, Outram, & Smith, 2013; Gacek, 2016; Ivković, 2016) and minerals (n=4; 30.8%) (Dascombe, Karunaratna, Cartoon, Fergie, & Goodman, 2008; Stewart, Outram, & Smith, 2013; Ivković, 2016; Figueira & Cazal, 2017). Further, it was also found that sportsmen seek information about the consumption with nutritionists (n= 5; 62.5%) (Lima, Moraes, & Kirsten, 2010; Assis, Silveira, & Barbosa, 2015; Judge et al., 2015; Peçanha, Navarro, & Maia, 2015; Figueira & Cazal, 2017), self-prescription (n=5; 62.5%) (Lima, Moraes, & Kirsten, 2010; Tsitsimpikou et al., 2011; Silva & Marins, 2013; Ivković, 2016; Figueira & Cazal, 2017), friends (n=4; 50.0%) (Lima, Moraes, & Kirsten, 2010; Tsitsimpikou et al., 2011; Silva & Marins, 2013; Peçanha, Navarro, & Maia, 2015), coach (n=3; 37.5%) (Assis, Silveira, & Barbosa, 2015; Judge et al., 2015; Ivković, 2016) and personal trainer (n=3; 37.5%) (Lima, Moraes, & Kirsten, 2010; Tsitsimpikou et al., 2011; Silva & Marins, 2013). The main motifs for its ingestion were related to an enhanced performance in the sport (n=4; 57.1%) (Silva & Marins, 2013; Stewart, Outram, & Smith, 2013; Judge et al., 2015; Frączek, Warzecha, Tyrała, & Pięta, 2016) and maintain their health (n=3; 42.9%) (Dascombe, Karunaratna, Cartoon, Fergie, & Goodman, 2008; Stewart, Outram, & Smith, 2013; Figueira & Cazal, 2017). CONCLUSIONS The data reveals a broad range of variation is the use of supplements by sportsmen. It is considered crucial to promote nutritional education programs for sportsmen. The message about risks and benefits associated to the consumption of food supplements should be emphasized, as well as the advantages associated to a healthy and balanced diet.