Who Should Not Eat Crabs? A Guide to Seafood Safety

October 21, 2025 •

4 min read

According to the American College of Allergy, Asthma & Immunology, shellfish allergies are among the most common food allergies and typically persist throughout a person's life. Therefore, it is critical for anyone with this condition to know who should not eat crabs to prevent potentially life-threatening allergic reactions.

Quick Summary

People with shellfish allergies, gout, compromised immune systems, or certain health conditions should avoid or limit crab consumption. Pregnant and breastfeeding women also need to be cautious due to potential contaminants. Proper cooking and handling are crucial for safety.

Key Points

Shellfish Allergies: Individuals with shellfish allergies should strictly avoid crab due to the risk of severe, life-threatening anaphylactic reactions caused by immune system overreaction to proteins like tropomyosin.
Gout Patients: Crabs are high in purines, which increase uric acid levels and can trigger painful gout attacks; sufferers should limit or avoid crab consumption, especially during flare-ups.
Pregnant and Breastfeeding Women: These individuals should only eat thoroughly cooked crab to prevent foodborne illness from bacteria and parasites, and be mindful of mercury levels by choosing low-mercury seafood varieties.
Compromised Immune Systems: Individuals with weakened immune systems, the elderly, and young children should avoid raw or undercooked crab to prevent serious infections from foodborne pathogens.
Kidney and Cardiovascular Conditions: People with hypertension or kidney issues should monitor their crab intake due to its sodium content and moderate their consumption based on their doctor's advice.
Heavy Metal Concerns: Brown crab meat contains higher levels of cadmium, so regular consumers should limit their intake to minimize heavy metal exposure, which can accumulate over time.
Proper Cooking is Key: For all consumers, ensuring crab is cooked to an internal temperature of 145°F (63°C) is essential to kill bacteria and parasites, ensuring food safety.
Be Aware of Raw Risks: Eating raw crab meat poses significant risks of bacterial contamination, parasitic infections, and biotoxins, and is not recommended.

Crab is a delicious and nutritious seafood, but for certain individuals, consuming it can pose significant health risks. From severe allergic reactions to aggravating pre-existing conditions, understanding the potential dangers is vital for safe dietary choices. This guide explores the various groups of people for whom crab meat is not recommended and why.

Shellfish Allergies: The Most Common Warning

The primary and most severe reason for avoiding crab is a shellfish allergy. This condition can manifest at any age and often lasts for life. The immune system overreacts to proteins found in crustaceans, primarily tropomyosin, triggering a defensive response.

Allergic Reactions and Anaphylaxis

For those with a shellfish allergy, symptoms can range from mild discomfort to a life-threatening anaphylactic reaction.

Mild symptoms: Hives, skin rash, itching, and swelling of the lips, face, or tongue.
Severe symptoms: Wheezing, shortness of breath, throat tightness, dizziness, and a rapid or weak pulse.

Cross-reactivity is a major concern, as individuals allergic to one type of crustacean (like shrimp) are often advised to avoid all crustaceans, including crab. In some cases, severe reactions can occur even from inhaling steam from cooking crab.

Gout Sufferers and High Purine Content

Gout is a painful form of inflammatory arthritis caused by an excess of uric acid in the blood. This condition often leads to sudden and severe joint pain, swelling, and inflammation. Crab meat, like other seafood and red meats, contains high levels of purines.

How Purines Affect Gout

During digestion, the body breaks down purines, producing uric acid. In individuals with gout, the body either produces too much uric acid or cannot excrete it efficiently, leading to uric acid crystal formation in the joints. Consuming high-purine foods like crab can trigger or worsen painful gout attacks.

Compromised Immune Systems, Pregnancy, and Foodborne Illness

Certain groups of people are at a higher risk of foodborne illness from consuming contaminated or undercooked seafood.

Risks from Bacteria and Parasites

Raw or improperly cooked crabs can harbor harmful bacteria, such as Vibrio, and parasites, such as lung flukes. Thorough cooking is essential to kill these pathogens. Vulnerable groups, including:

Pregnant and breastfeeding women: To avoid risks to the fetus or infant.
Older adults: Due to potentially weaker immune systems.
Immunocompromised individuals: Those with conditions like HIV/AIDS or undergoing chemotherapy.

These individuals should strictly avoid raw or undercooked shellfish to minimize the risk of serious infection.

People with High Cholesterol or Certain Kidney Conditions

While crab meat is often considered a healthy source of protein and omega-3 fatty acids, it contains sodium and cholesterol, which can be problematic for some. Individuals with pre-existing health conditions need to monitor their intake.

High Cholesterol and Hypertension Concerns

For people managing high cholesterol or hypertension, excessive consumption of crab should be monitored. While the omega-3s in crab are beneficial for heart health, the sodium content can be a concern for those with high blood pressure.

Heavy Metal Accumulation in Crabs

Crabs, being bottom-dwellers and scavengers, can accumulate heavy metals from their environment, particularly in certain parts of their body. Cadmium is a specific concern, especially in brown crab meat.

The Danger of Cadmium

High levels of cadmium can build up in the body over time, causing health issues. The European Food Safety Authority has noted that cadmium intake from brown crab meat can be a concern, especially for regular consumers. It is advisable for everyone, but particularly sensitive individuals, to limit their intake of brown crab meat.

Comparison Table: Crab Safety by Health Profile


Health Condition	Primary Risk Factor	Recommended Action
Shellfish Allergy	Allergic reaction to tropomyosin protein	Strict avoidance of all crustaceans and cross-contaminated items.
Gout	High purine content, increases uric acid	Strictly limit intake, especially during flare-ups.
Pregnancy/Breastfeeding	Foodborne illness, parasites, and mercury	Avoid raw/undercooked shellfish; opt for thoroughly cooked crab in moderation.
Compromised Immune System	Foodborne pathogens (bacteria, parasites)	Avoid raw/undercooked shellfish entirely.
High Blood Pressure	High sodium content	Consume in moderation; be mindful of preparation methods (e.g., steamed vs. heavily seasoned).
Kidney Disease	High sodium, potassium, and phosphorus	Consult a doctor; may need to limit intake depending on condition severity.

Safe Alternatives and Cooking Practices

For those who must avoid crab, there are many delicious and safe alternatives. These include options like chicken, tofu, or low-mercury fish that are safe for most people. For everyone else, proper food preparation is key to minimize risk.

Source from reputable suppliers: Ensure crabs are fresh and from clean waters.
Cook thoroughly: Heat crab to an internal temperature of at least 145°F (63°C) to kill bacteria and parasites.
Avoid cross-contamination: Use separate utensils and cutting boards for raw and cooked seafood.
Limit brown meat intake: If consuming European brown crab, moderate your intake of the hepatopancreas (brown meat) to minimize cadmium exposure.

Conclusion: Prioritizing Health Over Craving

While crab can be a delightful and healthy addition to many diets, it is not suitable for everyone. Individuals with shellfish allergies face the most immediate and serious threat, with the risk of life-threatening anaphylaxis. Gout sufferers must also be cautious due to the high purine content that can trigger painful attacks. Furthermore, pregnant women, older adults, and those with compromised immunity must prioritize thoroughly cooked crab to avoid foodborne illness. By understanding these specific risks and making informed choices, everyone can enjoy a safe and healthy diet. When in doubt, it is always best to consult a healthcare provider or a registered dietitian for personalized dietary advice.

For more information on food allergies, consult the Food Allergy Research & Education (FARE) website [https://www.foodallergy.org/].

Frequently Asked Questions

No, if you have a known shellfish allergy, you must strictly avoid crab. Shellfish allergies can cause severe and life-threatening anaphylactic reactions, and cross-reactivity with crab is common for those allergic to other crustaceans like shrimp.

Crab meat is high in purines, which the body breaks down into uric acid. High levels of uric acid can cause painful gout attacks, so people with this condition should limit or avoid crab, especially during flare-ups.

Pregnant women can eat thoroughly cooked crab in moderation, but should avoid all raw or undercooked seafood to prevent foodborne illness. It is best to choose low-mercury seafood varieties as part of a balanced diet.

You should be most cautious with the hepatopancreas, or brown meat, especially in brown crabs, as it can accumulate higher levels of heavy metals like cadmium. Limiting consumption of this part is a good safety measure for everyone.

Older adults, especially those with compromised immune systems or underlying health issues like high blood pressure or kidney problems, should be cautious with crab consumption. It is recommended to eat it in moderation and ensure it is always thoroughly cooked.

Eating raw or undercooked crab can lead to foodborne illnesses caused by bacteria like Vibrio or parasites like lung flukes. Symptoms can include severe gastrointestinal distress, and infections can be particularly dangerous for vulnerable populations.

Crab does contain cholesterol and sodium, so individuals managing high cholesterol or hypertension should be mindful of their intake. While it also provides beneficial omega-3 fatty acids, moderation is key for those with heart-related conditions.

Yes, it is possible to develop a shellfish allergy as an adult, even if you have safely consumed it in the past. Symptoms can range from mild itching to severe anaphylaxis, and it's often a lifelong allergy.