Yahoo Life – For years, fish oil supplements were promoted as an important way to boost health and particularly heart health.
But recent research has shown mixed results on their impact, despite some supplement companies continuing to promote their products as having a big influence on health.
Still, nearly 10% of U.S. adults take fish oil supplements. Now, a new study finds that many fish oil companies make claims that are untested, and that a wide variety of amounts of omega-3 fatty acids — the core healthy fats in fish oil — are in their supplements.
The study finds that the majority of fish oil supplements on the market make health claims that aren’t backed up by clinical trial data.
For the study, researchers analyzed the labels of more than 2,800 fish oil supplements and found that 2,082 (or nearly 74%) made at least one health claim.
Of those, only 399 (19.2%) used a qualified health claim that was approved by the Food and Drug Administration (FDA). (A qualified health claim means that the statements are supported by scientific evidence.)
But nearly 81% of those supplements made claims about the structure or function of what the supplements could do, such as saying that they “promote heart health,” with cardiovascular claims being the most common.
The researchers also found “substantial variability” in the supplements’ daily dose of omega-3s EPA and DHA — two major compounds in fish oil.
The researchers noted in the study’s conclusion that most fish oil supplement labels make health claims “that imply a health benefit across a variety of organ systems, despite a lack of trial data showing efficacy.” There is also “significant” diversity and quality in the daily dose of EPA and DHA in supplements, “leading to potential variability in safety and efficacy” between them.
Joanna Assadourian, lead study author and a fourth-year medical student at University of Texas Southwestern Medical Center, tells Yahoo Life that “based on what I’ve seen personally in the grocery store and pharmacy, I was not surprised … ”