The study examined the differences in perceptions and usages of dietary supplements among so-called ‘active and passive users’.
They surveyed 1031 high school students (276 male, 755 female) between the ages of 15 to 18. Findings suggest 30.8% of males use dietary supplements compared to 26.7% in females.
Among the group of students who used supplements, 42.4% of males and 43.8% of females were defined as active users, meaning they purchased the supplements themselves.
Sports and exercise
Among the active users, males used supplements mainly for health maintenance, stamina and athletic performance enhancements.
Researchers found, “Sports and exercise habits were significantly associated with the use of dietary supplements.”
“For active users, the purpose of using supplements was the maintenance of health, the enhancement of stamina, and the enhancement of athletic performance. Therefore, they used proteins/amino acids and individual minerals such as zinc, calcium, and iron.”
Female high schools students were more likely to use supplements for health and weight-loss purposes rather than sports purposes.
Among the active female users, approximately 20% used supplements for weight loss.
Previous studies found a prevalence of 41% to 68.8% in dieting behaviours among Japanese females which could explain the high usage of weight loss supplements.
Researchers said, “A desire to lose weight quickly without making an effort to change dietary and exercise habits may drive females to want to use weight-loss supplements while completely believing in their safety and having no knowledge of their potential dangers.”
However, they warned, “These marketed weight-loss supplements may be adulterated with undeclared illegal drug ingredients, resulting in negative adverse effects.”
“Compared to passive users and non-users, more active users believed that dietary supplements were safe and that word of mouth from other users was trustworthy,” said researchers.
“There seems to be a trend towards overly trusting the safety of dietary supplements, obtaining information primarily from the internet and television, and purchasing supplements of choice by active users.”
Similarly in adults, weight-loss supplements are popular among women while performance-related supplements are popular among men. This could stem from usage as adolescents.
The study had some limitations. One, the response rate was very low, and was not representative of Japanese high school students.
Another limitation is the usage of unintentional supplements, especially in passive users. They may not have paid attention to what supplements they were given, and hence not reported in the study. It is also possible that the use of supplements that resemble conventional foods was not declared by the students.
However, researchers believed the present study, “is the first to report dietary supplement use that is focused on the level of activity of the user.”
They suggest, “Since supplement users, and particularly active users, are vulnerable to convincing words on the internet and television and overlook the safety of supplements, dietary education, including healthy eating and the appropriate use of dietary supplements, needs to be provided.”
A Nationwide Survey of the Attitudes toward the Use of Dietary Supplements among Japanese High-School Students
Authors: Chiharu Nishijima, et al.