Shark meat is high in protein and low in fat, but the health risks outweigh the benefits for most people. With nearly 1 part per million of mercury on average, shark is one of the most mercury-contaminated fish you can eat. It also carries other heavy metals and a neurotoxin linked to brain disease. While a single serving won’t harm a healthy adult, regular consumption poses genuine long-term risks.
Nutritional Profile of Shark Meat
On paper, shark looks like an excellent protein source. A 100-gram serving of raw shark fillet contains about 24.6 grams of protein and only 0.4 grams of fat, putting it in the same league as chicken breast for lean protein. It delivers roughly 104 calories per serving.
Shark also provides meaningful amounts of key micronutrients. That same serving covers about 62% of your daily selenium needs, 50% of your vitamin B12, and 10% of your magnesium. Selenium supports thyroid function and acts as an antioxidant, while B12 is essential for nerve health and red blood cell production.
The omega-3 content is respectable too. Shark muscle contains around 2.4 milligrams of EPA and DHA (the two omega-3 fats that matter most for heart and brain health) per gram of tissue. That’s higher than many white fish species like snapper, which contain roughly 1.0 milligram per gram. But you can get the same omega-3s from salmon, sardines, or mackerel without the contamination risks that come with shark.
The Mercury Problem
Mercury is the biggest concern with shark meat. FDA testing data shows shark averages 0.979 parts per million of mercury, making it one of the highest-mercury fish on the market. For comparison, canned albacore tuna averages 0.350 ppm, halibut sits at 0.241 ppm, and snapper comes in at 0.166 ppm. Only tilefish from the Gulf of Mexico (1.123 ppm) and swordfish (0.995 ppm) consistently test higher.
Mercury accumulates in your body over time. It’s a potent neurotoxin that can damage the brain, kidneys, and nervous system with chronic exposure. The body does clear mercury, but slowly, with a half-life of about 70 to 80 days. If you eat shark regularly, mercury builds up faster than your body can eliminate it.
The FDA, EPA, and Mayo Clinic all specifically name shark as a fish to avoid during pregnancy and breastfeeding. Their joint guidance recommends pregnant people eat 8 to 12 ounces of lower-mercury seafood per week, and explicitly lists shark, swordfish, king mackerel, and tilefish as fish to skip entirely. Children are similarly vulnerable because their developing brains are more sensitive to mercury’s effects.
Other Contaminants Beyond Mercury
Mercury isn’t the only toxic metal in shark tissue. A study of two commercial shark species in Trinidad and Tobago found arsenic levels ranging from 144 to over 6,000 micrograms per kilogram, and lead levels ranging from 0.14 to nearly 460 milligrams per kilogram depending on the species. The researchers calculated that consuming these sharks could be a major source of lead, cadmium, arsenic, and mercury exposure, with potential health risks from long-term eating.
Sharks also contain a neurotoxin called BMAA, a compound produced by cyanobacteria that accumulates up the food chain. BMAA has been linked to neurodegenerative diseases, including ALS and Alzheimer’s. A study published in Toxins tested fins and muscle tissue from ten shark species across the Atlantic and Pacific Oceans and detected BMAA in nearly all samples. Only 12% of shark fins tested fell below detection limits. Concentrations ranged widely, from 34 to over 2,000 nanograms per milligram, with bonnethead sharks showing the highest average levels. This is particularly relevant for shark fin soup, but BMAA appears in the muscle tissue people eat as steaks and fillets as well.
The Ammonia Issue
Shark meat has a unique quirk that affects both safety and taste. Sharks regulate their body chemistry using high concentrations of urea in their tissues. After the animal dies, that urea breaks down into ammonia, giving the meat a harsh, unpleasant smell and flavor if it’s not handled properly.
This is why many traditional preparations involve soaking shark meat in milk, citrus juice, or saltwater for several hours before cooking. The soaking draws out urea and ammonia, improving both the taste and digestibility. If you buy shark from a fishmonger who didn’t handle it quickly after catch, the ammonia flavor can be overwhelming. Commercial processors sometimes use ozone immersion for 15 to 20 minutes to reduce urea content, but home cooks typically rely on acidic marinades or milk soaks lasting one to four hours.
Who Should Avoid Shark Meat
Pregnant and breastfeeding women should not eat shark at all. Children under 12 should also avoid it. For healthy adults who aren’t in these groups, an occasional serving is unlikely to cause measurable harm, but making it a regular part of your diet is a different story. The combination of mercury, other heavy metals, and BMAA creates a cumulative risk profile that’s hard to justify when so many safer fish offer the same nutritional benefits.
If you enjoy shark for its firm, meaty texture, mahi-mahi and swordfish-style tuna steaks offer a similar eating experience with lower contamination. If you’re after the omega-3s, wild salmon and sardines deliver more per serving without the baggage. The protein and selenium in shark are easy to find in dozens of other seafood options that don’t come with a FDA warning attached.