Swordfish contains a moderate amount of purines, not a high amount. Fresh swordfish has about 132 mg of total purines per 100 grams, according to USDA data from 2025. That places it well below the high-purine fish like anchovies, sardines, and mackerel, which can exceed 300 mg per 100 grams, but above low-purine foods like eggs and most vegetables.
How Swordfish Compares to Other Seafood
Purine content in fish varies dramatically. Organ meats and small oily fish sit at the top, often ranging from 200 to over 400 mg per 100 grams. Swordfish, at 132 mg, falls into a moderate range similar to many other large, lean fish. For context, a typical serving of swordfish is around 150 grams (about 5 ounces), which would deliver roughly 200 mg of total purines.
Most of the purines in swordfish come from a single compound called hypoxanthine, which accounts for 111 mg of that 132 mg total. Hypoxanthine is the dominant purine in most fish and is efficiently converted to uric acid in the body. The remaining purines in swordfish are split between two other bases at much lower levels (about 10 mg each).
For comparison, high-purine seafood typically includes anchovies, sardines, herring, mussels, and scallops. Lower-purine options include salmon, sole, and crab. Swordfish lands in the middle of the pack.
What “High Purine” Actually Means
There is no single universally agreed-upon cutoff, but most dietary references use a three-tier system. Foods under roughly 50 mg of purines per 100 grams are considered low. Those between 50 and 150 mg are moderate. Foods above 150 to 200 mg are considered high. By this standard, swordfish sits comfortably in the moderate category.
That distinction matters if you have gout or elevated uric acid levels. Your body breaks purines down into uric acid, and when uric acid builds up in the blood, it can form sharp crystals in joints. People with gout are often told to limit high-purine foods, but the picture is more nuanced than simply avoiding all seafood.
Swordfish and Gout Risk
Current guidelines from the American College of Rheumatology offer only a conditional recommendation to limit purine intake for people with gout, reflecting low certainty of evidence that strict purine restriction alone makes a meaningful difference. This is a shift from older advice that encouraged avoiding all moderate and high-purine foods. Diet still plays a role, but medications that lower uric acid production are far more effective at preventing flares than food avoidance alone.
That said, large servings of moderate-purine fish can add up quickly. Eating a 200-gram portion of swordfish delivers about 264 mg of purines in a single meal, which could nudge your uric acid levels upward if you’re already prone to gout. Keeping portions reasonable and avoiding pairing swordfish with other purine-rich foods (like beer or organ meats) in the same meal is a practical approach. Alcohol, particularly beer, is more strongly and consistently linked to gout flares than moderate-purine fish.
Mercury Is the Bigger Concern With Swordfish
If you’re weighing how often to eat swordfish, purines may not be the main limiting factor. Swordfish is one of the highest-mercury fish available commercially. Mercury levels in swordfish have been recorded as high as 4.27 mg/kg, which is well above regulatory limits in most countries. Because swordfish are large, long-lived predators, mercury accumulates in their flesh over time.
Health agencies in the UK advise the general population to eat no more than one portion of swordfish per week, and pregnant women are advised to avoid it entirely. The FDA in the United States similarly categorizes swordfish as a “choices to avoid” fish for pregnant and breastfeeding women and young children. For the general adult population, keeping swordfish to one serving per week or less is a reasonable guideline that also happens to keep purine intake from swordfish in check.
Practical Takeaways for Purine-Conscious Eaters
Swordfish is a moderate-purine food, not one you need to eliminate. A standard serving once a week is unlikely to cause problems for most people with gout, especially if they are managing their condition with medication and limiting alcohol. If you’re trying to keep purines as low as possible, lower-purine fish like salmon or tilapia are better everyday choices, with swordfish reserved for occasional meals. The mercury content of swordfish is a stronger reason to limit frequency than its purine content.