Background: The aim of the study was to describe the prevalence, trends and associated factors of dietary supplements (DS) and anabolic-androgenic steroids (AAS) use among Finnish adolescents.
Methods: The sample comprised 30 511 adolescents aged 12-18 years, of which 22 519 (74%) answered a questionnaire. We also studied associations between 14 socioeconomic, health and health behavioural variables and DS and AAS use by logistic regression.
Results: The proportion of respondents using DS was 45% during the past year and it increased linearly by age. Vitamins (37%) and herbal products (13%) were the most common DSs. In 1991, 9% of the boys aged 16-18 years reported protein use, while the frequency in 2005 was 17% (P < 0.001). AAS use was uncommon; only 53 boys (0.5%) and 20 girls (0.2%) reported AAS use. The strongest factors associated with DS use in multivariate model were physical exercise outside sports clubs (OR 1.9; 95% CI: 1.6-2.2), and in sports clubs (OR 1.7; 95% CI: 1.5-1.9). Recurrent drunkenness (OR 5.8; 95% CI: 1.5-21.6) and peer drug use in boys (OR 2.1; 95% CI: 1.2-3.7) were the risk factors for AAS use, whereas physical exercise outside sports clubs (OR 0.3; 95% CI: 0.1-0.5) was a protecting factor.
Conclusions: Although the overall use of DS remained at the same level during the study period, there was a slight trend towards increasing use of vitamin and protein supplements. DS use is associated with frequent sports participation and poorer than average health, while AAS use is associated with health-compromising behaviours.