An article published this week in a prominent journal on fish oil supplements has been criticized for cherry-picking data and failing to sufficiently grasp how such products are regulated.

Appearing in the journal JAMA Cardiology, the article was the work of three researchers associated with the University of Texas Southwestern Medical Center.

The article, “Health Claims and Doses of Fish Oil Supplements in the US,” used a cross-sectional approach to assess the labeling and claims associated with 2,819 products found on the National Institutes of Health Dietary Supplement Label Database. The label information was extracted from February to March 2022.

Researchers place emphasis on use of qualified health claims

The researchers noted more than 70% of the products made a claim of some sort on the label. Of those, “only” 19% used FDA-approved qualified health claim language. The rest, or 81% of the products making a claim, used standard structure/function claims language, such as “promotes heart health.”

An example of a qualified health claim for omega-3 supplements is: “Consuming EPA and DHA combined may reduce the risk of CHD (coronary heart disease) by reducing the risk of hypertension. However, FDA has concluded that the evidence is inconsistent and inconclusive. One serving of [name of the food or dietary supplement] provides [  ] gram(s) of EPA and DHA.”

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This wording and several others were approved by FDA in 2019 response to a petition submitted by the Global Organization for EPA and DHA Omega-3s (GOED). The petition was first submitted in 2014.

The researchers said almost all of the products making a qualified health claim used the wording pertaining to heart disease. Three of the products used health claims language relating to blood pressure and two products used both claims.

Qualified health claims have achieved only middling traction within the dietary supplement industry because many marketers feel their equivocal language doesn’t communicate very effectively to consumers.

Paper claims evidence doesn’t support structure/function claims

The researchers criticized the labeling of the supplements because of the wide variance in dosing and the variability of the claims being made.  Qualified health claims language is specified by regulation, whereas structure/function claims may relate to health indications for which there is insufficient evidence, in the view of the authors.

“[F]ish oil supplement labels frequently include health claims in the form of structure/function claims that imply health benefits across a wide range of organ systems, increasing potential for consumer misinformation,” the authors concluded. “Significant heterogeneity exists in the daily dose of EPA and DHA in available supplements, leading to potential variability in safety and efficacy between supplements.”

Industry reaction: Review was biased, superficial

Industry stakeholders were quick to react to what they considered a biased and superficial review of the label information.

GOED reacted to the publication in a statement emailed to members and industry stakeholders.  The organization accused the authors of cherry-picking evidence and ignoring the significant number of positive studies supporting structure/function claims.

“The authors are clearly unfamiliar with U.S. dietary supplement regulations and how to substantiate structure/function claims,” the GOED statement said.

“It's not clear why the authors believe the structure/function claims to be unsubstantiated due to a lack of trial data when there’s no evidence that they conducted a review of the scientific literature. A quick search of GOED’s Clinical Study Database (CSD) provided confirmation that trial data exists,” the statement continued.

The Council for Responsible Nutrition responded in a similar manner.

“The call for ‘additional regulation of dietary supplement labeling’ is both predictable and unsupported by the research,” Steve Mister, president and CEO of CRN, said in a statement on the organization’s website.

“Consumers should always discuss their supplement regimens with their healthcare providers, but there is nothing in this study that should persuade consumers to change their omega-3 regimens for better health,” he added. “Ultimately, this study demonstrates an amazing lack of understanding of the many different reasons why consumers choose to use supplements for better health.”