Crab
Crab is a nutrient-dense shellfish rich in high-quality protein, selenium, and bioactive compounds like astaxanthin, supporting cardiovascular and metabolic health with minimal caloric density.
Nutrition · per ~85 g serving · ≈ a palm-sized piece (~3 oz)
- Vitamin B128.3 mcg346% DV
- Folate43.4 mcg11% DV
- Copper0.60 mg67% DV
- Selenium33.6 mcg61% DV
- Sodium911.2 mg40% DV
- Zinc4.0 mg36% DV
- Phosphorus197.2 mg16% DV
- Omega-3 (ALA/EPA/DHA)~1.3 g
- Glutathione~13 mg
Score · 82/100
Vitamins & minerals packed in relative to calories — the single biggest driver of the score.
How much protein it delivers, by absolute grams and per calorie.
Dietary fiber for gut health, satiety and steadier blood sugar.
Fat quality — unsaturated vs saturated, and trans-fat free.
Polyphenols, flavonoids and other beneficial plant compounds for this food group.
Low sugar with a high fiber-to-carb ratio scores best — gentler on blood sugar.
- Vitamin B12408% DV
- Copper79% DV
- Selenium72% DV
- Sodium47% DV
- Zinc43% DV
Overview
Crab, harvested from oceans worldwide, has been a dietary staple across coastal civilizations for millennia. As a crustacean, crab delivers exceptional nutritional density: approximately 20g of complete protein per 100g with minimal fat, making it ideal for muscle maintenance and metabolic function. Its mineral profile is particularly notable, with exceptional selenium content (crucial for thyroid function and antioxidant defense), along with zinc, copper, and phosphorus. The reddish pigmentation in crab shells and meat contains astaxanthin, a carotenoid with potent antioxidant and anti-inflammatory properties that may protect against age-related cognitive decline and cardiovascular disease. Crab also provides vitamin B12 and omega-3 fatty acids (EPA and DHA, though in lower quantities than fatty fish), which support neurological health and reduce inflammation. The chitin in crab shells contains compounds that may benefit gut microbiota. For longevity, crab represents a lean protein source that supports healthy aging through muscle preservation, metabolic regulation, and antioxidant defense, while remaining low in mercury compared to many predatory fish.
Health Benefits (5)
- Supports cardiovascular health and endothelial functionmoderateAstaxanthin reduces oxidative stress in blood vessel walls, while selenium and omega-3 fatty acids improve cholesterol profiles and reduce arterial inflammation, promoting healthy blood flow and reducing atherosclerosis risk
- Maintains muscle mass and supports protein synthesisstrongComplete protein profile with all essential amino acids, particularly leucine, activates mTOR signaling and muscle protein synthesis, critical for preserving lean mass during aging
- Enhances thyroid function and metabolic ratestrongHigh selenium content (per serving) is essential for selenoprotein synthesis, including glutathione peroxidase and thioredoxin reductase, which regulate thyroid hormone metabolism and protect thyroid tissue from oxidative damage
- Reduces neuroinflammation and supports cognitive resiliencemoderateAstaxanthin crosses the blood-brain barrier and reduces neuroinflammatory cytokines; B12 supports myelin formation and mitochondrial function in neurons, protecting against age-related cognitive decline
- Supports immune function and wound healingmoderateZinc and copper are cofactors for immune enzymes and collagen synthesis; selenium supports T-cell function and antiviral immunity through selenoprotein expression
Food Pairings
- ·Pair with lemon or lime: Vitamin C enhances iron and zinc absorption from crab meat, while citric acid improves mineral bioavailability
- ·Pair with cruciferous vegetables (broccoli, Brussels sprouts): Synergistic antioxidant effects; sulforaphane from cruciferous vegetables and astaxanthin from crab work through complementary pathways to reduce systemic inflammation
- ·Pair with leafy greens (spinach, kale): Vitamin K from greens works with crab's minerals (calcium, phosphorus, magnesium) to support bone mineralization and vascular health
- ·Pair with olive oil: Monounsaturated fats enhance absorption of fat-soluble astaxanthin and vitamin A; polyphenols in quality olive oil add additional cardioprotective antioxidants
Practical Tips
- ·Select live crabs or those with minimal odor; freshness maximizes astaxanthin bioavailability and reduces bacterial contamination risk
- ·Boil or steam rather than frying to preserve heat-sensitive B vitamins and avoid oxidizing the omega-3 content; steaming for 15-20 minutes is optimal
- ·Consume the hepatopancreas (soft yellow organ) which concentrates selenium and astaxanthin, though source quality matters—only from pristine waters
- ·Store live crabs at 4°C (39°F) in a humid environment; consume within 1-2 days of purchase for maximum nutrient retention
- ·Aim for 100-150g portions (one crab serving) 2-3 times weekly as part of a rotated seafood strategy to optimize selenium intake while managing mercury and iodine balance
Optimal Timing
Protein-rich midday meals optimize muscle protein synthesis in response to morning movement and prepare for afternoon metabolic demands; timing provides extended amino acid availability for circadian protein turnover
While crab can be consumed anytime, midday consumption maximizes the anabolic window for protein synthesis and distributes selenium intake across the day for optimal thyroid hormone cycling
Systems supported
body systems this food feedsPathways supported
biochemical reactions enabled by this foodCompared to other seafood
Per 100 g of the default form. Bars show how much higher or lower crab is than the average across 13 peer foods in this category. Green means a favorable direction; amber means the opposite.
What people ask about crab
What is crab?
Crab is classified as a seafood. Crab is a nutrient-dense shellfish rich in high-quality protein, selenium, and bioactive compounds like astaxanthin, supporting cardiovascular and metabolic health with minimal caloric density.
Is crab healthy?
Crab scores 82/100 in Formulate, making it a great choice. Its strongest contributions come from Vitamin B12, Copper, Selenium. The score blends nutrient density, fiber, healthy fats, protein quality, bioactive compounds, and glycemic impact.
Is crab high in protein?
Yes — it's a high-protein food. A 85 g serving provides about 16.4 g of protein (~33% of the 50 g daily value).
Is crab high in fiber?
Not really. A 85 g serving provides about 0 g of fiber (~0% of the 28 g daily value).
What vitamins and minerals are in crab?
In a 85 g serving, crab is highest in Vitamin B12 (~346% DV), Copper (~67% DV), Selenium (~61% DV), Sodium (~40% DV), Zinc (~36% DV).
Is crab keto-friendly?
Yes — it fits comfortably in most keto plans. A 85 g serving has about 0 g of net carbs (0 g total minus 0 g fiber).
When is the best time to eat crab?
Best in the midday. Protein-rich midday meals optimize muscle protein synthesis in response to morning movement and prepare for afternoon metabolic demands; timing provides extended amino acid availability for circadian protein turnover
How much crab should I eat?
A typical serving is around 85 g (~82 kcal), based on the FDA's Reference Amount Customarily Consumed for this food category. There's no fixed daily target — most adults benefit from rotating crab alongside several other seafood sources.
Is crab an allergen?
Crab falls into the fish or shellfish group, which is a common allergen. If you have a known allergy or sensitivity in this category, avoid it and consult a clinician before adding it back.
What pairs well with crab?
Crab pairs nicely with: Pair with lemon or lime: Vitamin C enhances iron and zinc absorption from crab meat, while citric acid improves mineral bioavailability; Pair with cruciferous vegetables (broccoli, Brussels sprouts): Synergistic antioxidant effects; sulforaphane from cruciferous vegetables and astaxanthin from crab work through complementary pathways to reduce systemic inflammation; Pair with leafy greens (spinach, kale): Vitamin K from greens works with crab's minerals (calcium, phosphorus, magnesium) to support bone mineralization and vascular health; Pair with olive oil: Monounsaturated fats enhance absorption of fat-soluble astaxanthin and vitamin A; polyphenols in quality olive oil add additional cardioprotective antioxidants.
Supplements that mirror Crab's nutrient profile
Encyclopedia entries that supply the same signature nutrients crab contributes. Click through to see clinical dose ranges, evidence quality, and bioavailable forms.
Signature nutrients in Crab
These are the nutrients crabcontributes meaningfully toward (≥10% DV per 100 g serving). Click one to see what it does in the body, which supplements concentrate it, and which other foods are top sources.