Blue crab is one of the healthier proteins you can eat. A one-cup serving of cooked blue crab meat delivers 24 grams of protein and only 112 calories, with less than a gram of fat and zero carbohydrates. It’s packed with minerals and omega-3 fatty acids, and it’s low in mercury compared to many other seafood options. There are a few things worth knowing about sodium, cholesterol, and one part of the crab you should skip entirely.
Protein and Calorie Breakdown
Blue crab is remarkably lean. That 112-calorie, 24-gram protein punch per cup of cooked meat puts it on par with chicken breast, but with a fraction of the fat. For anyone trying to increase protein intake while keeping calories low, blue crab is hard to beat. The near-zero fat and carbohydrate content also makes it a straightforward fit for low-carb or ketogenic eating patterns.
Omega-3s for Heart and Brain Health
Blue crab contains roughly 400 milligrams of omega-3 fatty acids (split evenly between EPA and DHA) per 100 grams of meat. These are the same heart-protective fats found in salmon and sardines, though in smaller amounts. EPA and DHA help reduce inflammation, lower triglycerides, and support brain function. You won’t get as much per serving as you would from fatty fish, but blue crab still makes a meaningful contribution, especially if you eat it regularly as part of a varied seafood diet.
Sodium and Cholesterol Worth Watching
One cup of cooked blue crab contains about 466 milligrams of sodium and 115 milligrams of cholesterol. The sodium is naturally occurring in the meat, not added during processing, but it can add up quickly if you’re eating multiple servings or dipping in melted butter with salt. If you’re managing blood pressure, it’s worth factoring in.
The cholesterol number looks moderate on its own. Current dietary guidelines no longer set a strict daily cholesterol cap, and for most people, dietary cholesterol has a smaller effect on blood cholesterol than saturated fat does. Since blue crab is extremely low in saturated fat, the cholesterol here is less of a concern than it might be in, say, a cheese omelet.
Mercury Levels Are Low
Crab, including blue crab, has a mean mercury concentration of just 0.065 parts per million, according to FDA testing. That’s well below the levels found in tuna, swordfish, or shark, which can range from 0.3 to over 1.0 ppm. Blue crab falls firmly in the “good choices” category for mercury, meaning you can safely eat two to three servings per week without concern. This makes it a solid option for pregnant women and young children who need to be more cautious about mercury exposure.
Don’t Eat the “Mustard”
The yellow-green paste inside a blue crab’s body cavity is the hepatopancreas, commonly called the “mustard” or “tomalley.” Many people consider it a delicacy, but health agencies strongly advise against eating it. The hepatopancreas functions like a combined liver and pancreas, and it concentrates environmental contaminants at levels far higher than the surrounding muscle meat.
Testing by the New York State Department of Environmental Conservation found that the hepatopancreas consistently contained cadmium at concentrations 10 to 100 times greater than leg or body meat. PCBs were detected in every hepatopancreas sample tested, while they were rarely found in the muscle meat at all. Chlorinated dioxins and furans also accumulate there. The official guidance is simple: don’t eat it, and discard any cooking liquid that may have come in contact with it.
The crab meat itself, from both the legs and body, tested clean in comparison. So the risk is specific to the hepatopancreas, not the crab as a whole. As long as you pick the meat and leave the mustard behind, you’re avoiding the vast majority of contaminant exposure.
Key Vitamins and Minerals
Beyond protein and omega-3s, blue crab is a notable source of several micronutrients. It’s rich in vitamin B12, which supports nerve function and red blood cell production. A single serving can provide well over your daily B12 needs. Blue crab also delivers zinc, which plays a role in immune function and wound healing, along with selenium, a mineral that acts as an antioxidant and supports thyroid health. Copper and phosphorus round out the mineral profile.
These nutrients are especially valuable because they come in highly bioavailable forms, meaning your body absorbs them more efficiently from animal sources like crab than from plant-based alternatives or supplements.
How Preparation Changes the Picture
Steamed blue crab with Old Bay seasoning is a Chesapeake Bay tradition, and steaming is one of the healthiest ways to prepare it. The meat stays lean, and you control the seasoning. Where things shift is in preparation style. Crab cakes, for instance, often include breadcrumbs, mayonnaise, and are pan-fried or deep-fried, which can double or triple the calorie and fat content per serving. Crab dips made with cream cheese follow the same pattern.
If you’re eating blue crab for its nutritional benefits, steaming or boiling keeps the profile intact. Picking the meat and adding it to salads, grain bowls, or light pasta dishes preserves the high-protein, low-calorie advantage. Just be mindful of the sodium that seasoning blends add on top of the crab’s naturally occurring salt content.