Polluted Oceans Mean Toxic Fish
Oceans today are increasingly contaminated with mercury, heavy metals, and chemicals, primarily due to industrial activities like manufacturing, chemical farming, and industrial animal agriculture. These pollutants make their way into marine ecosystems, accumulating in fish, which poses health risks to consumers. However, fish remain one of the few natural sources of the essential Omega-3 fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), as fish obtain these nutrients by consuming algae—the only true source of EPA and DHA.
Benefits of EPA and DHA
These Omega-3 fatty acids (specifically EPA and DHA) are critical for brain health, reducing inflammation, and supporting the structural integrity of cell membranes. EPA and DHA play an essential role in brain function and development, with deficiencies linked to conditions such as Multiple Sclerosis and cognitive decline. Research shows that higher levels of EPA and DHA can significantly improve cognitive function, particularly in older adults. DHA is especially crucial for fetal brain development, and babies born to mothers who supplemented with DHA during pregnancy tend to have better brain function.
Wild-Caught Versus Farm-Raised
While fish are an excellent source of EPA and DHA, it’s essential to select wild-caught species rather than farm-raised ones. Farmed fish often lack these vital nutrients due to unnatural diets that exclude algae, the primary source of EPA and DHA. The crowded conditions in fish farms also make the fish more susceptible to parasites and diseases, leading to the use of antibiotics and chemicals, which further reduce their nutritional value and pose health risks. In some cases, farmed fish even have different appearances; for example, farmed salmon have a greyish color, while wild salmon’s natural pink or red hue comes from eating krill. Farm-raised salmon are fed colorants to mimic the natural color of their wild counterparts.
Certain wild-caught fish species not only have higher levels of EPA and DHA but also lower mercury content, arsenic, and microplastics, making them a safer and more nutrient-rich choice for those looking to boost their Omega-3 intake. Opting for wild-caught fish from cleaner waters also helps avoid the nutrient deficiencies and contaminants commonly found in farm-raised fish.
Best and Worst Fish
These are sorted from fish with the highest EPA and DHA and lowest mercury at the top, to fish with the lowest EPA and DHA and highest mercury at the bottom. If you are supplementing with EPA and DHA, you can enjoy any of the fish with low mercury content and continue to supplement. If you are trying to get your EPA and DHA from fish, select options closer to the top to maximize EPA/DHA and minimize mercury exposure.
Remember to always get wild-caught fish, and do not undercook. Do not eat old fish or fish that smells bad.
| Fish | Mg of Omega-3 | Mcg of Mercury |
|---|---|---|
| Salmon: Atlantic, Chinook, Coho | 1200 | 2 |
| Sardines: Atlantic and Pacific | 1100 | 2 |
| Salmon: Pink and Sockeye | 700 | 2 |
| Anchovies, Herring and Shad | 2300 | 10 |
| Mackerel: Atlantic and Pacific (not King) | 1350 | 13 |
| Pollock: Atlantic and Walleye | 600 | 6 |
| Trout: Freshwater | 1000 | 11 |
| Tilapia | 150 | 2 |
| Flounder, Plaice and Sole (Flatfish) | 350 | 7 |
| Haddock and Hake | 200 | 5 |
| Tuna: Bluefin and Albacore | 1700 | 58 |
| Tuna: White (Albacore), Canned | 1000 | 40 |
| Marlin, Striped | 1030 | 69 |
| Cod: Atlantic and Pacific | 200 | 14 |
| Catfish | 100 | 7 |
| Tuna: Light canned | 150 | 13 |
| Shark | 1250 | 151 |
| Swordfish | 1000 | 147 |
| Tilefish from the Gulf of Mexico | 1000 | 219 |
| Mackerel: King | 450 | 110 |
| Marlin, Blue | 250 | 69 |
| Tuna: Skipjack and Yellowfin | 150 | 49 |
| Orange Roughy (aka Deep Sea Perch) | 42 | 80 |