Clam
Clams are bivalve mollusks rich in vitamin B12, iron, and selenium. They are a low-calorie, high-protein seafood with minimal fat and low carbohydrate content.
Also known as: hardshell clam, littleneck clam, soft-shell clam, Manila clam, cherrystone clam
Scientific & Editorial Standard: This information is synthesized from peer-reviewed databases (such as PubMed, NIH, NHS, and Mayo Clinic) and validated using multi-model cross-referencing by the Plateify Editorial Team. It is intended for educational purposes and is not medical advice. If you suspect food sensitivities, consult a healthcare provider.
Clams are marine bivalve mollusks harvested worldwide and consumed in cuisines across Europe, Asia, and North America. They are commonly served steamed, in pasta dishes, chowders, or as raw preparations. Clams are available fresh, frozen, or canned. Hard clams (littleneck, cherrystone) and soft-shell clams are the most commercially available varieties. Clam consumption is concentrated in coastal regions and seafood-focused cuisines.
A 100 g serving of raw clam meat provides approximately 86 calories, 15 g protein, 1.5 g fat, and roughly 3–4 g carbohydrate (primarily glycogen). Clams are notably dense in micronutrients: vitamin B12 (values vary by species but commonly exceed 1,000% of the daily value per 100 g), iron (approximately 155–170% DV per 100 g), selenium (over 100% DV), and zinc. The protein in clams is complete, containing all nine essential amino acids. Clams are also a source of omega-3 polyunsaturated fatty acids, though in smaller quantities than fatty fish. The high iron bioavailability (enhanced by vitamin C consumed alongside) and B12 content are significant for individuals relying on seafood for these nutrients.
Histamine and Food Safety
Clams are a moderately high-histamine food due to bacterial decarboxylation during storage and processing. Individuals with histamine intolerance may experience flushing, headache, or gastrointestinal symptoms. Histamine content increases markedly in clams that are not properly refrigerated or are stored longer than 1–2 days. Proper handling—immediate refrigeration or freezing—minimizes histamine accumulation. Canned clams that have undergone high-temperature processing typically have lower histamine levels than fresh or lightly processed varieties.
Allergen Status and Tolerance
Shellfish, including clams, are recognized allergens affecting approximately 2% of the U.S. adult population. Clam allergy is mediated by tropomyosin and other heat-stable proteins; allergic reactions range from oral itching to anaphylaxis. Because these proteins are heat-stable, cooking does not eliminate the allergenic risk. Cross-reactivity with other shellfish (mussels, oysters, shrimp) occurs in a substantial proportion of shellfish-allergic individuals. Individuals with IgE-mediated shellfish allergy must avoid clams entirely and should consult an allergist for personalized guidance. Fresh raw clams are naturally low in sodium (approximately 56 mg per 100 g); however, canned or prepared clam products can be high in sodium and may not be suitable for sodium-restricted diets without label review. There is no established upper safe limit for clam consumption in non-allergic populations, though intake should remain within typical portion sizes (100–150 g) as part of a varied diet.
Frequently Asked Questions
Are clams safe for people with shellfish allergies?
No. Clams contain tropomyosin and other heat-stable allergenic proteins found in shellfish. Because these proteins are not destroyed by cooking, both raw and cooked clams pose a risk to people with IgE-mediated shellfish allergy. People with a shellfish allergy must avoid clams entirely and should consult an allergist for personalized management.
How much vitamin B12 do clams provide?
Clams are an exceptionally rich source of vitamin B12. Per 100 g of raw clam meat, B12 content commonly exceeds 1,000% of the daily value, though the exact amount varies by species. This makes clams one of the most concentrated dietary sources of B12 available.
What is histamine and why do clams contain it?
Histamine is a compound produced when bacteria degrade the amino acid histidine. Clams can develop histamine during storage and processing; levels rise rapidly if clams are not refrigerated immediately. Fresh clams refrigerated and consumed within 1–2 days have lower histamine than older or improperly stored specimens. Histamine-sensitive individuals should consume only fresh clams that have been properly handled.
How do clams compare nutritionally to other seafood?
Clams are exceptionally high in vitamin B12, iron, and selenium relative to their calorie and fat content. While fatty fish like salmon provide more omega-3s, clams offer superior micronutrient density with lower fat content, making them a lean, nutrient-dense protein option.
Sources
- Major Food Allergens — FDA
- Seafood: The Nutrition Source — Harvard T.H. Chan School of Public Health
- Shellfish Allergy — Mayo Clinic
- Clams, mixed species, raw — FoodData Central — USDA
Educational content: This page is for general informational purposes only. Individual responses to foods vary widely. If you suspect a food allergy or sensitivity, consult a licensed dietitian, allergist, or physician before making dietary changes. Full disclaimer
Some content on this site is AI-assisted. While we strive for accuracy, information may not reflect the latest research. Always verify health information with a professional.
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