Despite the benefits companies tout and the billions of dollars spent, experts warn Americans to be wary of fish oil supplements: they’re not as great as you may think.
Most fish oil supplements, which have long been touted for boosting heart, joint, eye, and skin health, make health claims that science doesn’t back up, a study suggests.
Researchers at the University of Texas Southwestern Medical Center (UTSMC) in Dallas looked at nearly 3,000 fish oil supplements, three-quarters of which made at least one health claim.
They found about 80 percent made broad claims like ‘support heart health’ that scientific evidence cannot prove true, making them misleading to customers.
The researchers even suggested taking too much fish oil, an industry worth $2.3 billion globally, could actually increase the risk of heart issues like atrial fibrillation, or an irregular heartbeat, which could lead to stroke and heart failure.
Experts told DailyMail.com that not all fish oil supplements ‘are created equal,’ and the lack of a scientific foundation to their claims creates a ‘confusing’ landscape for consumers.
Researchers at the University of Texas Southwestern Medical Center (UTSMC) found about 80 percent of fish oil supplements made broad claims like ‘support heart health’ that scientific evidence does not support, making them misleading to customers
About 80 percent of the supplements that made a health claim used structure/function claims, which broadly describe a health effect, such as ‘boosts heart health.’ These can’t be proven by studies or regulated by authorities like the Food and Drug Administration (FDA)
Dr Ann Marie Navr, a cardiologist at UTSMC and lead study author, said: ‘About one in five Americans over the age of 60 take fish oil supplements, often because they think it is helping their heart.
‘But extensive research has shown that for most people, there is no cardiovascular benefit in taking over-the-counter fish oil supplements, and at high doses, they can even increase the risk of atrial fibrillation.’
The study analyzed 2,819 fish oil supplement labels obtained from the National Institutes of Health Dietary Supplement Database, which catalogs all information printed on labels of dietary supplements sold in the US. Of those studied, 2,082 made at least one health claim.
About 80 percent of the supplements that made a health claim used structure/function claims, which broadly describe a health effect, such as ‘boosts heart health.’ These can’t be proven by studies or regulated by authorities like the Food and Drug Administration (FDA).
A structure/function claim simply refers to how a substance impacts the structure and/or function of the body, such as ‘calcium helps create strong bones.’ It is required to have a disclaimer stating the substance is not intended to diagnose, treat, cure, or prevent any disease. These claims are not regulated, monitored or scientifically sound.
However, a health claim refers specifically to how a nutrient or ingredient impacts a disease or health condition. These types of claims are ‘authorized’ and ‘qualified,’ meaning they have significant scientific agreement based on health information or are supported by substantial amounts of evidence.
Carolyn Williams, a registered dietitian in Alabama, told DailyMail.com that structure/function claims made by fish oil supplement labels are ‘very confusing’
‘Structure/function claims are allowed by the FDA, but they can be vague and misleading,’ Dr Navar said. ‘And they are being made for fish oil for many organ systems, including the heart, brain, joints, eyes, and immune system.
‘We feel that this type of language can be very confusing to consumers who may be unaware these statements do not require support from randomized trials.’
Carolyn Williams, a registered dietitian in Alabama who was not involved in the study, called structure/function claims ‘the wild, wild west’ and said they are misleading to consumers.
‘It’s very confusing,’ she told DailyMail.com.
‘You can say, “boosts immunity,” “improves brain health,” “boosts heart health.” They’re all things that really are impossible to measure. And for some reason, you can say pretty much whatever you want if you’re a manufacturer and you’ve worded it as a structure/function claim.’
In addition to identifying these claims, researchers also compared the amount of two key omega-3 fatty acids in 255 of the supplements: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
These have been shown to lower levels of fats called triglycerides in some patients, which could lower blood pressure. They have also been shown to support immune function and proper fetal development.
EPA and DHA can primarily be found in fatty fish like salmon, herring, sardines, mackerel, trout, some oysters, shrimp, tuna, and lobster, as well as algae.
The recommended daily amount to lower blood pressure is 2,000 to 3,000 milligrams.
However, only one in 10 of the studied supplements met those EPA and DHA levels.
‘Not all fish oils are created equal,’ Ms Williams said.
‘You really want the majority of that [dosage] to be EPA and DHA.
‘The fish oil supplements that really have little to no EPA or DHA really can’t live up to these claims they’re putting on them.’
Ms Williams added the ideal fish oil supplement should contain 60 percent EPA and 40 percent DHA.
‘The majority of Americans are just not getting enough EPA and DHA,’ she said.
Joanna Assadourian, the study’s co-author and fourth-year medical student at UT Southwestern, said: ‘Supplement labels can be confusing even for the savviest consumers.’
‘Patients should talk to their doctor about what supplements they are taking and why they are taking them – they may be surprised to learn they are not getting the health benefits they think they are.’
The study was published last month in the journal JAMA Cardiology.