A new study from the University of Texas Southwestern Medical Center and Duke University Medical Center reveals that many people interpret common supplement label phrases as promises of disease prevention or treatment.
The United States leads the world in dietary supplement use, with about 56% of adults taking at least one.
Although the FDA requires accurate labeling and holds companies responsible for product safety, it does not review most supplements for safety or effectiveness before they hit the market.
Labels can include ‘nutrient claims’, ‘health claims’, or ‘structure/function claims’—the latter meant to describe normal body functions without implying disease treatment.
But phrases like ‘heart health’ or ‘supports cognitive function’ are vague and may mislead consumers.
Fish oil supplements are one example. Around 75% of them feature health-related claims, even though major clinical trials have shown that fish oil does not prevent heart attacks.
Yet, many people with heart disease still take fish oil for ‘heart health’, and the industry earns over $1 billion annually.
Published in JAMA Network Open, the study surveyed more than 4,300 U.S. adults who reviewed either a real fish oil label or a hypothetical supplement called Viadin H. Participants were randomly assigned one of four different labels and asked whether they believed the product could prevent or treat specific diseases.
‘Supports Heart Health’ made 62.5% believe fish oil could prevent heart attacks, compared to 53.9% with no label. ‘Supports Cognitive Function’ led 47.4% to believe the supplement could reduce dementia risk.
Even official FDA-qualified claims with disclaimers still made people believe the product was effective. For Viadin H, phrases like ‘Heart Health’ and ‘Brain Health’ doubled the number of people who believed in their disease-prevention benefits.
The study shows that even vague language on supplement labels influences how consumers view their effectiveness. Researchers suggest that it’s time to reevaluate labeling rules to reduce confusion and protect public health.
Consumers should remain cautious and seek medical advice before using supplements for disease prevention or treatment.
The study is published in JAMA Network Open.
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