Fish Oil? Is It Worth It?
Nearly every week I have patients ask me if a certain supplement is worth taking.
The truth? The majority aren't. But one supplement that continues to hold up to scientific scrutiny is - fish oil.
Fish oil provides certain building blocks that allow our bodies to utilize these compounds to help our brains and bodies function better in certain capacities.
So what makes fish oil different from the sea of supplements that don't deliver on their promises?
What Is Fish Oil, Really?
Fish oil contains two key omega-3 fatty acids: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These are considered "essential" fats because our bodies can't produce them efficiently – we need to get them from our diet or supplements.
Think of these omega-3s as specialized building blocks for your cells. Unlike the plant-based omega-3 (ALA) found in flaxseeds and chia, which your body must convert to EPA and DHA (a process that's surprisingly inefficient in humans), fish oil delivers these powerful compounds directly.
Once absorbed, these fatty acids become incorporated into cell membranes throughout your body, improving how cells communicate and respond to inflammation allowing multiple body systems to function better.
What's Fish Oil Good For?
Brain Health Benefits
Fish oil appears to boost levels of something called Brain-Derived Neurotrophic Factor (BDNF) – think of BDNF as fertilizer for your brain cells, helping them grow connections and stay resilient. A 2023 review of multiple studies found that omega-3 supplementation consistently increased BDNF levels in the bloodstream.
For mood disorders, particularly depression, omega-3s show promising results. EPA-rich formulations (with at least 60% EPA) demonstrate the most consistent benefits for reducing depressive symptoms. While the effect is modest compared to conventional antidepressants, it's significant enough that the American Psychiatric Association recognizes omega-3s as a reasonable add on treatment.
Do these mechanisms translate to better thinking and memory? The evidence here is mixed. While people who regularly eat fish tend to maintain better cognitive function as they age, supplement studies haven't consistently shown the same benefits – suggesting that whole food sources might offer advantages beyond isolated omega-3s.
Cardiovascular Health
When it comes to heart health, fish oil's most reliable and robust effect is lowering triglycerides, a type of fat in your blood. High-dose omega-3s (2-4 grams daily) can reduce triglycerides by 20-30% – an effect so consistent that prescription fish oil formulations are FDA-approved specifically for this purpose.
The cardiovascular benefits of fish oil demonstrate clear dose-dependency. Simply put: higher doses produce stronger effects, with minimal benefits at low doses (under 1 gram daily) and more substantial impacts at higher therapeutic doses.
Muscle Health
For older adults concerned about maintaining strength, fish oil offers intriguing benefits. Research shows that 3-4 grams daily can enhance muscle protein synthesis(this slows down as we age and is one of the factors that play a role in us losing strength as we age) – essentially making your body more efficient at building and maintaining muscle tissue, especially when combined with strength training.
Athletes may also benefit from fish oil's effects on recovery. In one study, young men taking 6 grams daily recovered their jumping ability just one hour after muscle-damaging exercise, while those on lower doses or placebo showed reduced performance for about 48 hours. They also reported significantly less muscle soreness.
The strongest evidence for muscle benefits comes from studies combining omega-3 supplementation with resistance exercise – neither approach alone produces the same magnitude of improvement seen when they're used together.
Dosage Considerations: Finding Your Sweet Spot
Effective doses vary significantly depending on your health goals:
General health maintenance: 250-500mg combined EPA+DHA daily
Mood support: 1-2 grams daily, with higher EPA ratio (at least 60% EPA)
Triglyceride reduction: 2-4 grams daily of EPA+DHA
Muscle benefits for older adults: 3-4 grams daily
Athletic recovery: Higher doses (4-6 grams daily) may be needed
When reading supplement labels, look past the "1000mg fish oil" claim and find the actual EPA and DHA content, which is typically much lower. Quality products will clearly state the specific amounts of each.
For different health goals, the EPA:DHA ratio matters. Higher EPA formulations tend to work better for mood disorders, while DHA is particularly important for brain development in children. For general health or cardiovascular benefits, a balanced ratio works well.
What to Watch For
At higher doses (above 3 grams daily), fish oil may slightly increase the risk of atrial fibrillation – an irregular heartbeat condition. The risk appears dose-dependent, with approximately 1-2 additional cases per 100 people taking high-dose omega-3s over several years. Those with existing heart conditions should discuss this with their healthcare provider.
Some fish oil formulations (particularly those containing DHA) may slightly raise LDL ("bad") cholesterol in some individuals, though this effect is usually modest (5-10%).
Quality varies enormously among over-the-counter products.
Look for supplements that:
Have been tested by third-party organizations (USP, NSF, or ConsumerLab)
Indicate the specific amounts of EPA and DHA, not just total fish oil
Use processes to minimize oxidation (which can make fish oil pro-inflammatory rather than anti-inflammatory)
Come in opaque containers and that might include an antioxidant like vitamin E
The Current State of Research
Why do results sometimes seem contradictory?
Much of the confusion stems from the difference between observational studies (which consistently show benefits from eating fish) and supplement trials (which show more variable results). This suggests that whole fish provides benefits beyond isolated omega-3s – including protein, selenium, and vitamin D – while also displacing less healthy foods in the diet.
Individual responses to omega-3 supplementation vary considerably based on genetics. Some people carry genetic variations that affect how efficiently they process and utilize these fatty acids – meaning two people taking identical supplements might experience completely different results.
Researchers continue to investigate several key questions:
What are the optimal EPA:DHA ratios for different conditions?
Which individuals are most likely to benefit based on genetic factors?
Can omega-3 supplementation slow cognitive decline when started early enough?
The Bottom Line
Fish oil isn't a miracle cure, but for specific conditions and populations, it offers evidence-based benefits when used at appropriate doses. Consider fish oil if you:
Have high triglycerides
Are looking for additional support for mood disorders
Are an older adult concerned about muscle health
Have specific risk factors for cardiovascular disease
For general health, focus first on food sources of omega-3s. Aim for two servings (3-4 oz each) of fatty fish weekly – salmon, sardines, mackerel, and herring are excellent choices. If you don't regularly eat fatty fish, a moderate-dose supplement (around 1 gram daily of combined EPA+DHA) might be a reasonable addition to your routine. My wife and I take Thorne’s Super EPA(pictured on the right) and remember if you’re a patient you get 35% off all Thorne supplements.
Remember that supplements complement rather than replace the foundations of good health: regular physical activity, plenty of vegetables and fruits, adequate protein, stress management, and sufficient sleep are key for a long healthy life.
What makes fish oil stand out in the supplement world is that it contains compounds our bodies genuinely need in forms they can readily use.