Research Indicates that Health Benefits of Fish Oil Supplements Might Be Overstated

 

• A recent study has evaluated the scope of claims associated with heart health in fish oil supplements.
• According to the scientists, the majority of these products make assertions, although numerous ones lack substantiating experimental evidence.
• Although certain investigations have determined that fish oil supplements don't influence cardiovascular health, alternative findings suggest that supplementation can be advantageous.
• Further examination is necessary to better understand the connection between fish oil and heart health.

Dietary supplements constitute a substantial industry in the United States, with a market valuation exceeding $50 million, and approximately 60% of adults regularly incorporating supplements into their routines to enhance their health and well-being.

A significant segment of this industry centers around fish oil supplements, many of which make assertions regarding their positive effects on heart health.

However, the scientific basis for these claims raises questions. Researchers from the University of Texas Southwestern Medical Center delved into this matter in a recently published analysis on August 23rd, available on the JAMA Cardiology website.

Their investigation revealed that the majority of labels on fish oil supplements include claims about heart health benefits, as well as benefits for other bodily organs. Intriguingly, these claims are often not substantiated by trial data showcasing their effectiveness.

Furthermore, their research brought to light the variability in the levels of crucial compounds such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) across different products.

Components of the Analysis

The researchers analyzed information extracted from currently available fish oil and non-fish omega-3 fatty acid supplement labels, which were sourced from the National Institutes of Health Dietary Supplement Label Database.

They specifically examined the prevalence of two types of assertions regarding cardiovascular disease: qualified health claims (QHCs) and structure/function claims.

Qualified health claims are statements made by the US Food and Drug Administration (FDA) that pertain to a supplement's potential to assist in the treatment or prevention of diseases. These claims are authorized after the FDA evaluates the available evidence.

The investigation unveiled the existence of two qualified health claims related to cardiovascular matters for fish oil. One is associated with coronary heart disease, while the other pertains to blood pressure. For instance, an example of such a claim is: "Supportive but not conclusive research shows that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease."

Conversely, the FDA defines a structure/function claim as one that "describes the role of a nutrient or dietary ingredient intended to affect the structure or function in humans." These assertions cannot state that a supplement prevents, treats, or cures any disease.

The research paper provided various examples of structure/function claims, such as "Promotes heart health," "Supports heart, mind, and mood," and "Omega-3 fatty acids are important for cardiovascular, immune, and nervous system health."

Among the 2,819 distinct fish oil supplements evaluated, a considerable number (73.9%) featured at least one health claim, predominantly in the form of structure/function claims.

A mere 399 supplements (19.2%) utilized qualified health claims, with 394 relating to coronary heart disease, three concerning blood pressure, and two covering both conditions.

Of all the health claims associated with fish oil supplements, a substantial majority (62%) were linked to heart health.

The researchers expressed concern over this, highlighting that "Numerous randomized clinical trials have demonstrated no cardiovascular benefit from fish oil supplements."

Furthermore, they pointed out that the prevalence of structure/function claims could potentially mislead consumers by conveying inaccurate information.

Constraints of the Study

The researchers acknowledged a number of limitations in the study:

• Labels were submitted to the National Institutes of Health Dietary Supplement Label Database on a voluntary basis, potentially leading to the exclusion of certain fish oil supplements.
• Despite variations in market share, all supplement labels were treated equally in terms of assessment.
• The analysis focused solely on health claims present on product labels, without considering claims found in advertisements or other promotional content.
• Evaluation was limited to supplements from the 16 most prominent potential brands.

External experts not associated with the study have highlighted additional potential limitations.

The Council for Responsible Nutrition (CRN), a trade organization representing dietary supplements, released a statement critiquing the study.

The CRN remarked, "The report seems to overlook the fact that [structure/function] claims and Qualified Health Claims (QHCs) serve different purposes – one offers general health information not specific to diseases for consumers, while the latter are allowed [by the FDA] to discuss the connection between a nutrient and disease risk."

The CRN continued by stating, "Although [structure/function] claims might not demand the same level of scientific substantiation as qualified health claims, they still necessitate evidence to support their accuracy and furnish consumers with valuable health-related details."

Moreover, the CRN emphasized that "Current labeling, as highlighted by the authors, feature suitable legal disclaimers outlining the constraints of these claims."

Do fish oil supplements have a positive impact on heart health?

Regrettably, a conclusive answer remains elusive. Why? The research findings are somewhat conflicting. "Fish oil supplements have always sparked debate, particularly concerning their role in promoting heart health," remarked Miranda Galati, MHSc, RD, a registered dietitian and the founder of Real Life Nutritionist. In the recent analysis, the researchers highlighted three distinct randomized trials, none of which yielded definitive cardiovascular advantages from the consumption of fish oil supplements. They did acknowledge that several other studies indicated that higher doses of EPA and/or DHA (exceeding 2 g per day) could contribute to heart health benefits, encompassing reductions in cardiovascular events and lowered levels of triglycerides (blood fats). However, one study linked higher doses to an increased risk of atrial fibrillation. Yet, there is also research supporting the use of fish oil supplementation to mitigate the risk of cardiovascular disease. For example, a meta-analysis of 13 trials revealed that marine omega-3 supplementation "reduces the risk of myocardial infarction [heart attack], death due to [coronary heart disease], total [coronary heart disease], death due to [cardiovascular disease], and total [cardiovascular disease]." The majority of reviewed trials involved a daily dosage of approximately 850 mg. Another meta-analysis demonstrated that specific marine fatty acids contributed to lowering heart rate, while a double-blind, randomized crossover study found that fish oil supplements reduced triglyceride levels by about 14%. However, "Conducting nutritional studies in a precise manner is notoriously challenging," stated Megan Lyons, a certified clinical nutritionist, board-certified holistic nutritionist, and the founder of The Lyons’ Share Wellness. "Humans are influenced by numerous variables: varying health conditions, diverse dietary intake, different physical activity patterns, and unique sleep and stress profiles — all of which impact our overall health," she conveyed to Healthline. Lyons elucidated that to accurately isolate the specific benefits or detriments of a singular nutrient or supplement, study participants would need to be rigorously controlled and monitored for extended periods — a feat that's not feasible. "As a result, many of these studies... often rely on what researchers can control and isolate," she added.

Understanding EPA and DHA

EPA and DHA: What You Need to Understand Both EPA and DHA are classified as omega-3 fatty acids. "The most noteworthy distinction lies in their chemical composition due to variations in the number of carbon atoms and double bonds they contain," noted Allie Echeverria, a registered dietitian and the founder of Eaton Broshar. The research team uncovered "considerable variability" in the quantities of daily dose EPA, DHA, and the combined EPA and DHA across 255 diverse fish oil supplements from leading brands and manufacturers. They highlighted that this "significant diversity" in the daily dosage of EPA and DHA could potentially lead to differences in safety and effectiveness among supplements. The median EPA amount found in the analyzed supplements was 340 mg/day, DHA was 270 mg/day, and the combined EPA and DHA dosage was 600 mg/day. However, there isn't an officially recommended daily intake for EPA or DHA, just as "there's no established upper limit for omega-3 fats," as explained by Galati. Generally, Galati advised aiming for a daily dosage of 250 mg of combined EPA and DHA. She also mentioned that doses up to 1 g might be suggested for individuals with heart health concerns. Excessive consumption "can result in gastrointestinal discomfort, including gas, burping, and diarrhea," Echeverria elucidated. She further added that fish oil might interact with medications for blood pressure, anticoagulation, and contraception. The appropriate amount of fish oil varies based on factors like dietary habits and underlying health conditions. If uncertain, consulting a doctor or a healthcare professional, such as a dietitian, is recommended. EPA and DHA are believed to contribute to distinct aspects of health. According to Echeverria, "EPA is thought to be more beneficial in reducing inflammation and pain," whereas "DHA is recognized for its support in maintaining brain health." Fundamentally, neither is superior nor more essential. Lyons emphasized, "Our bodies require a balance of both EPA and DHA. Without this balance, our body cannot function optimally."

Navigating the Landscape of Dietary Supplements and Regulations

In the United States, the regulation of dietary supplements by the FDA differs from the regulation of drugs, but it's important to note that supplements are not completely unregulated. The Dietary Supplement Health and Education Act of 1994 outlines a range of standards that supplement manufacturers must adhere to, encompassing aspects like manufacturing procedures, labeling, and ingredients. Non-compliance with these standards can result in FDA intervention, as the agency possesses the authority to take action against dietary supplement products that are found to be adulterated or misbranded once they are on the market. However, challenges can still emerge with dietary supplements, according to Lyons. For instance, they might contain lesser amounts of the active ingredients than advertised or could include additional additives, fillers, or potentially harmful substances that aren't listed on the label. Fortunately, consumers can adopt measures to ensure their safety when purchasing and using supplements. "I always recommend seeking supplements that have undergone third-party testing," advised Galati. "This indicates that a company has taken the extra step of having their products tested for accuracy and safety by an unbiased third party." Information about third-party testing is typically found on a product's label or website. Additionally, you might consider conducting your own research, as Lyons suggested. This could involve consulting a practitioner who can offer tailored advice about suitable supplements based on your individual needs.