“Research indicates that omega-3 supplements don’t reduce the risk of heart disease.”

💡 The federal government’s health authority directly contradicts Costco’s front-label claim that its fish oil supports heart health

“Results of this cross-sectional study suggest that fish 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.”

💡 A major medical journal study identifies systematic misinformation across the fish oil industry, including products like Costco’s

“Heart disease along with stroke, which is the fifth leading cause of death, claimed more lives in 2021 in the U.S. than all forms of cancer and chronic lower respiratory disease combined.”

💡 The severity of heart disease makes consumers desperate for solutions and vulnerable to misleading marketing claims

“These findings, together with results of earlier randomized trials involving patients with and those without diabetes, do not support the current recommendations for routine dietary supplementation with n-3 fatty acids to prevent vascular events.”

💡 A study of over 15,000 patients found no cardiovascular benefit from omega-3 supplementation, contradicting Costco’s marketing

“Consumers have been told so many times that dietary fish oil supplements promote heart health that it seems to be accepted as factual. But this conventional thinking is not supported by the science. After decades of promises that fish oil may work, the lack of demonstrated benefit leads me to conclude that consumers are wasting their money on supplements in an effort to reduce cardiovascular risk.”

💡 A Harvard Medical School researcher directly states that the widespread belief in fish oil’s heart benefits is not supported by science

“With regard to prespecified tertiary end points, an increased rate of investigator-reported new-onset atrial fibrillation was observed in the omega-3 CA group.”

💡 A major clinical trial found omega-3 supplements increased the risk of a dangerous heart arrhythmia, a risk Costco never disclosed

“Patients who choose to take omega-3 fatty acids, especially in high doses, should be informed of the risk of atrial fibrillation and followed up for the possible development of this common and potentially hazardous arrhythmia.”

💡 A medical expert states consumers should be warned about atrial fibrillation risk, but Costco’s labels contain no such warning

“There have now been a large number of well-conducted studies which have not shown a cardiac benefit to taking over-the-counter fish oil supplements. In fact, Jacobson said, taking fish oil could even have adverse effects for some people. There is data these supplements may increase the risk of atrial fibrillation.”

💡 A chief cardiologist confirms both the lack of heart benefits and the potential for harm from fish oil supplements

“As a preventive cardiologist, I see patients in clinic all the time taking fish oil with the belief it is helping their heart. They are often surprised when I tell them that randomized trials have shown no benefit for fish oil supplements on heart attacks or strokes.”

💡 Medical professionals routinely encounter patients misled by fish oil marketing into believing they are protecting their hearts

“At all relevant times, Defendant has known or reasonably should have known that the Heart Health Representation on the front label of the Products is false and deceptive, and that Plaintiff and other members of the California Consumer Subclass would reasonably and justifiably rely on this representation when purchasing the Products.”

💡 The lawsuit alleges Costco knowingly made false claims, not that it made an innocent mistake

“Plaintiff and other consumers purchased the Products and paid a price premium relying on the false and deceptive labeling, advertising, and marketing of the Products.”

💡 Consumers paid more money than they should have based on heart health claims that were scientifically unsupported

“Had Plaintiff and other consumers been aware that the Products do not support heart health, they would not have purchased the Products or would have paid significantly less for them.”

💡 The lawsuit establishes that consumers made purchasing decisions based specifically on the false heart health claims

“One in 5 US adults older than 60 years takes fish oil supplements often for heart health despite multiple randomized clinical trials showing no data for cardiovascular benefit for supplement-range doses. Statements on the supplement labels may influence consumer beliefs about health benefits.”

💡 The problem extends beyond Costco to an entire industry making unsupported heart health claims that mislead millions of consumers

“For people with a healthy cardiovascular profile, regular use of fish oil supplements was associated with an increased risk of atrial fibrillation.”

💡 A 2024 study found fish oil supplements may actually harm heart health by increasing arrhythmia risk, the opposite of what Costco claims

“The supplement industry, anecdotal evidence and earlier studies have often promoted these benefits. Once a narrative becomes deeply embedded in popular culture, it can be difficult to change, even when new evidence emerges.”

💡 Corporate marketing has created a false cultural belief about fish oil that persists despite scientific evidence to the contrary