What Is the Most Unhealthy Fish?

King mackerel, some tuna, some orange roughy, and swordfish are the unhealthiest fish due to high mercury levels. A 2003 study at the California Pacific Medical Center examined mercury levels in 123 patients consuming 30 different types of fish ( 37 ). Swordfish had the highest mercury (Hg) levels. Meanwhile, a 2023 Polish analysis found that tuna, particularly yellowfin tuna and bluefin tuna, had the highest levels of mercury ( 1 ). A Norwegian study found high mercury levels in older Atlantic orange roughy fish but lower levels among younger specimens ( 7 ). Finally, Cape Canaveral Scientific research found that Spanish and King mackerel from the Gulf Coast had high mercury levels ( 43 ).

Can I Eat Fish Every Day?

Eat healthy fish recipes 2-3 times a week. The FDA Dietary Guidelines for Americans recommend at least eight ounces of fish a week on a 2,000-calorie diet ( 9 ). Pregnant or breastfeeding women can eat 8-12 ounces of low-mercury fish each week on a 2,000-calorie diet.

Can I Eat Salmon Every Day?

Salmon is rich in omega-3 while being low in calories and having no carbs ( 23 ). You can eat salmon daily as eight ounces of fish weekly is a minimum recommendation from the FDA ( 9 ). More importantly, the Washington State Department of Health says wild-caught and farmed salmon have low mercury levels ( 14 ).

What Fish Should You Not Eat Daily?

Avoid eating any fish high in mercury daily, even if you like using the fish on occasion. King Mackerel, Yellow/Bluefin tuna, old orange roughy, and swordfish are high in mercury and should be eaten in strict moderation ( 37 , 1 , 7 , 43 ).