Journal Title (Medline/Pubmed accepted abbreviation): J Int Soc Sports Nutr
Page numbers: N/A
Summary of Background and Research Design
Background:Dietary supplements (DS) including multivitamins, minerals, protein, and energy drinks are used by athletes to increase strength and energy and to enhance athletic performance. Two reports suggest that DS use is increasing, especially among elite athletes.
Hypothesis/purpose of study:To examine the frequency of DS use among elite Finnish Olympians between the years 2002 and 2009.
Subjects: The 2002 study included 446 Finnish Olympic athletes; the follow-up study between 2008 and 2009 examined 372 Olympic athletes.
Experimental design: Prospective, follow-up, questionnaire.
Treatments and protocol: Athletes in 4 areas of sport specialization (speed and power athletes, endurance athletes, athletes in motor skill, and team sports) completed semi-structured questionnaires inquiring into DS use within the previous year. Supplements categories were: vitamins (including beta-carotenes and antioxidants); minerals; nutritional supplements (eg, amino acids, proteins, carbohydrates, creatine, caffeine, fatty acids/oils, herbal [eg, ginseng, echinacea, or garlic] or homeopathic supplements, or other supplements [eg, fiber or conjugated linoleic acid]).
Summary of research findings:
- In 2002, 81% of athletes reported DS use (mean, 3.4 ± 3.1 DS per athlete)
- In 2009, 73% reported DS use (mean, 2.6 ± 2.7 DS per athlete)
- Overall, athletes in 2009 were 38% less likely to have supplemented than athletes in 2002; odds ratio (OR) = 0.62; 95% confidence interval (CI), 0.43-0.90
- Values adjusted for age, sex, and sport category.
- Primarily, Finnish DS users reported taking vitamin supplements (56%) or multivitamins (57%), nutritional supplements (52%), proteins (38%), and oils and fatty acids (19%)
- From 2002 to 2009, DS use decreased across all supplement types, except for the nutritional supplement subsets of amino acids (3.8% in 2002 vs 7.3% in 2009), oils and fatty acids (11 vs 19 %), homeopathic supplements (0.4 vs 1.6%), multivitamins (54 vs 57%), and antioxidants (0.7 vs 2.0 %).
- Vitamin use decreased by 38% (OR = 0.62; 95% CI, 0.45-0.85)
- Mineral use decreased by 23% (adjusted OR = 0.77; 95% CI, 0.56-1.08; P = not significant)
- Nutritional supplement overall use decreased by 23% (OR = 0.77; 95% CI, 0.56-1.04; P = not significant)
- The sport categories with the highest reported DS use in both 2002 and 2009 were speed/power events and endurance events
- Female athletes consumed fewer nutritional supplements compared with male athletes (2002: OR = 0.54; 95% CI, 0.35-0.83; 2009: OR = 0.58; 95% CI, 0.37-0.91)
- Overall, there was no difference by gender in vitamin and mineral use
- In 2009, DS use increased with athletes’ age: <21 years (63%), 21-24 years (83%), and >24 years (90%)
- In 2002, there was no difference in DS use by age
Interpretation of findings/Key practice applications:
The authors suggest that decreased DS use may be due, in part, to increased awareness of reports of low purity and lack of efficacy for many supplements. In contrast to other reports, it appears that DS use is decreasing among elite athletes, especially younger athletes. Supplement use varies among sports categories and, in Finland, is highest among endurance athletes and lowest among participants of team sports. Limitations of this follow-up study include differences between the follow-up and original sample populations (eg, younger age of subjects in the follow-up study and slightly decreased population size in the follow-up study) and the possibility of underreporting of DS use.