Veronica Hackethal, MD
June 05, 2019
Supplements sold for colon cleansing and sexual functioning were tied to approximately a twofold increase in risk for severe medical problems.
The authors, led by Flora Or, ScD, from the Department of Social and Behavioral Sciences, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, call for better regulation and decreased access to these supplements by adolescents and young adults.
"How can we continue to let the manufacturers of these products and the retailers who profit from them play Russian roulette with America's youth? It is well past time for policymakers and retailers to take meaningful action to protect children and consumers of all ages," senior author S. Bryn Austin, ScD, said in a press release. Austin is also affiliated with the Harvard T. H. Chan School of Public Health and Boston Children's Hospital.
She added that reputable physicians do not recommend these types of supplements. Many of these products have misleading labels and may be contaminated with prescription drugs, steroids, heavy metals, pesticides, and other substances that could damage health. Contaminants in supplements have been linked to liver damage, renal failure, cardiac arrythmias, seizures, other neurologic adverse events, and other severe adverse events, including death.
Dietary supplements are a big market in the United States — about 52% of Americans consume them, according to data quoted in the article.
Despite their popularity, supplements are subject to very little safety regulation. The Dietary Supplement Health and Education Act (DSHEA) of 1994 prohibits the FDA from screening supplements for safety and efficacy. As a result, the FDA relies on an honor system that defers to manufacturers to ensure the safety of dietary supplements.
"The FDA has issued countless warnings about supplements sold for weight loss, muscle building or sport performance, sexual function, and energy, and we know these products are widely marketed to and used by young people. So what are the consequences for their health? That's the question we wanted to answer," first author Or said in a press release.
In the retrospective cohort study, the researchers analyzed adverse event data for dietary supplements reported between January 2004 and April 2015 to the US Food and Drug Administration Adverse Event Reporting System (FAERS).
They assessed the relative risk for severe medical events linked to dietary supplements in comparison with vitamins in persons aged 0 to 25 years. They included supplements sold for weight loss, colon cleansing, muscle building, sexual function, energy, or other reasons. Severe medical events were defined as death, disability, life-threatening events, hospitalization, emergency department visits, or interventions to prevent permanent disability.
Overall, they identified 1392 adverse events associated with dietary supplements, of which 977 involved consumption of a single supplement.
Among single-supplement adverse events, 40% involved severe medical outcomes, including 22 deaths and 39 life-threatening events.
Compared with vitamins, the relative risk for severe adverse events was 2.7 (95% confidence interval [CI], 1.9 – 4.0) for muscle building supplements, 2.6 (95% CI, 1.9 – 3.6) for energy supplements, and 2.6 (95% CI, 1.9 – 3.4) for weight loss supplements.
The relative risk (RR) was also significantly elevated for supplements sold for sexual function (RR, 2.4; 95% CI, 1.3 – 4.3), colon cleansing (RR, 1.7; 95% CI, 1.0 – 2.8), and other reasons (RR, 1.5; 95% CI, 1.1 – 2.1).
The highest frequency of adverse events were for individuals aged 18 to 25 years. In this age group, adverse events were highest with respect to weight loss supplements.
"Our findings support the American Academy of Pediatrics' recommendation that dietary supplements are dangerous and should not be used for weight loss and muscle building purposes," the authors write.
They call for measures to decrease supplement use in youth, such as taxation, the use of childproof caps, and revision or repeal of the 1994 DSHEA law, which prevents the FDA from regulating the safety of supplements.
"As the dietary supplement industry continues to grow, efforts aiming at reducing access and consumption, implementing proactive enforcement of regulations, and providing clear warning at the point of purchase are paramount in preventing severe medical outcomes among children, adolescents, and young adults and consumers in general," they conclude.
The authors note several study limitations, including that the analysis was limited to those adverse events reported to FAERS and thus may underestimate the number of adverse events associated with dietary supplements.
They also note that vitamins were used as a reference group, but they have also been associated with adverse events.
The study was funded by the Ellen Feldberg Gordon Fund for Eating Disorders Prevention Research and the Strategic Training Initiative for the Prevention of Eating Disorders. The authors have disclosed no relevant financial relationships.