6 min read
- Fish oil supplements were once celebrated for various health benefits, from enhancing hair thickness to promoting heart health.
- However, some research has raised concerns about the validity of these findings, particularly comparing dietary intake of oily fish to supplementation.
- Recent studies indicate that fish oil supplements might negatively affect brain health and increase stroke risk.
- Nutritional experts recommend that supplementation may not be necessary for those who consume fatty fish twice a week.
ONCE UPON A TIME, it seemed that fish oil supplements were our miracle solution. Numerous studies consistently highlighted their health benefits, touting advantages such as reduced heart disease risk, enhanced intelligence, and relief from dry eyes and arthritis. Additionally, claims emerged that fish oil promoted thicker hair and healthier nails. If you weren’t taking fish oil in the 2000s, the question was—what were you doing?
While alternative “wonder” products might have quickly been dismissed as dubious, fish oil was backed by science. Advocates had clinical trial data and robust studies to support their assertions.
However, just like other once-favored products, fish oil’s credibility has taken a hit.
As it turns out, the research that originally supported fish oil supplementation has proven to be less reliable than previously thought. Many supplement companies blurred the lines between data on the health benefits of eating oily fish versus that of their fish oil capsules. There is a clear distinction, which we will explore further.
Despite the shift in nutritional guidance, fish oil supplements continue to occupy a prominent place in countless medicine cabinets. Let’s take a closer look at what science currently says about fish oil supplements and their purported benefits.
What Exactly Is Fish Oil?
SIMPLY PUT, it is oil derived from fish. Specifically, fish oil contains omega-3 fatty acids like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are present in higher concentrations in certain fish species. Fatty fish varieties like salmon and mackerel are rich in omega-3s, while cod and tilapia contain less. Shellfish also contribute omega-3s to our diets.
In supplement form, fish oil is extracted from fishes and shellfish high in omega-3s, often using anchovies or krill as sources. (Yes, the anchovies that some Americans love to scorn.)
What Is Fish Oil Good For?
FIRST, IT’S IMPORTANT TO NOTE that we are referring to omega-3 fatty acids sourced from whole seafood—not supplements at this point.
Fish oil—from seafood—offers a multitude of well-researched advantages.
“There’s significant evidence suggesting that adequate omega-3 intake is crucial for heart, brain, eye, and joint health—all of these areas benefit from sufficient omega-3s in the diet,” states Brian St. Pierre, MS, RD, CSCS, director of nutrition at Precision Nutrition.
What Are Fish Oil Supplements Good For?
THERE’S AN ABUNDANCE of research surrounding fish oil and its supplements, which is favorable for understanding its effects. While a full scientific consensus is still developing, findings in certain areas are becoming clearer.
Here’s the current state of research.
Fish Oil Supplements and Heart Health
One of the most extensively studied aspects of fish oil supplementation is its impact on heart health. Many studies indicate that fish oil supplements may offer cardiovascular protection. According to a study published in JAMA Cardiology, cardiovascular health claims were the most common in a review of 255 fish oil supplements. High-dose fish oil supplements available by prescription are intended to lower elevated triglycerides, which are fats that raise the risk of heart disease and stroke.
Nevertheless, ongoing research raises new questions.
A study published in BMJ Medicine found an association between fish oil supplements and increased risks of stroke and atrial fibrillation in healthy individuals. Conversely, those with preexisting heart issues experienced a reduced risk of serious complications when taking fish oil.
Another study published in the journal Nutrition indicated that individuals who incorporated fish or fish oil supplements into their diet over a year demonstrated lower pro-inflammatory blood markers. Notably, the greatest benefits were seen in those who had previously consumed fish less than once a month.
Are these changes likely to lower disease risk or prevent new conditions? That remains unclear.
It’s essential to remember that fish oil supplements should never replace statins for high cholesterol. According to research published in the Journal of the American College of Cardiology, statins are more effective than fish oil or other common supplements in reducing cholesterol levels.
Fish Oil Supplements and Arthritis
A review published in the Journal of Orthopaedic Surgery and Research found that omega-3 supplementation alleviated arthritis pain and enhanced joint function compared to placebo groups. Researchers hypothesize that the anti-inflammatory properties of fatty acids may contribute to the preservation of cartilage.
However, conflicting studies exist.
Another study concludes that evidence regarding dietary interventions through omega-3 supplementation in arthritis patients is “limited,” making it difficult to draw definitive conclusions from existing research.
Are you noticing a trend?
Fish Oil Supplements and Eye Health
Research in this area is sparse. A review published in Acta Opthalmologica found that individuals with dry eyes taking fish oil reported symptom improvement, although clinical trials did not corroborate these findings.
The American Academy of Ophthalmology cautions that the recommendation of fish oil supplements in this context is “outdated advice” and lacks substantial evidence. Additionally, variations in dosage and quality across fish oil brands make assessing benefits challenging.
Fish Oil Supplements and Brain Health
Previously, fish oil was heralded as a simple solution for cognitive enhancement. While research indicates potential benefits for brain health, experts are hesitant to term it neuroprotective.
A review in Cureus suggests that fish oil supplementation may enhance learning, memory, cognitive performance, and blood flow to the brain. Another article published in GeroScience found a minor (7 percent) reduction in dementia risk among those taking fish oil. Alarmingly, a study from 2026 revealed fish oil might actually slow brain recovery following mild head injuries.
The notion that fish oil promotes mental health remains unestablished.
Research in JAMA suggests that individuals who took omega-3 supplements for an average of 5.3 years had a slightly higher likelihood of developing depression compared to those on placebos.
According to LesLee Funderburk, PhD, RD, CSSD, CSCS, an associate professor at Baylor University, “The science isn’t adequate if you’re seeking improvements in mood or managing serious mental health disorders like major depression.” In other words, fish oil should not serve as a replacement for mental health medication.
Experts Say This Is The Only Time to Take A Fish Supplement
DO YOU EAT fatty fish at least twice a week? If so, you likely do not need a fish oil supplement, according to St. Pierre. Each time you consume fatty fish, consider skipping the supplement for that day and the next few days.
A daily intake of one to two grams of EPA and DHA is generally considered safe and beneficial without requiring excessive doses, as explained by St. Pierre.
When selecting a product, choose one verified by organizations like NSF, USP, ConsumerLab, or Informed Choice for purity and quality. Additionally, it’s vital to read labels carefully—some products contain combination ingredients like vitamin D or vitamin K, which could lead to overdoses if you’re also taking other supplements containing these nutrients.
Before starting any new supplement, consult with your doctor or pharmacist. This is especially crucial if you take blood thinners, as fish oil can exhibit anticoagulant properties, particularly at high doses. For those with fish allergies, alternatives like krill or algae oil can be considered.
Lastly, avoid products like eggs or milk fortified with DHA or EPA; the additional cost isn’t justified by their negligible benefits. “The amounts in such products are insufficient for any therapeutic impact,” emphasizes Dr. Funderburk. “Using those products throughout the week won’t result in any substantial effects.”
Julie Stewart is a writer and content strategist whose work has also appeared in Health, Women’s Health, Everyday Health, Vice, and Shape.
