Why Does Shrimp Make Me Nauseous? Getting to the Bottom of Shrimp Sensitivity

Shrimp is one of the most popular seafoods prized for its sweet briny flavor and versatility. But if you’ve ever felt sick to your stomach after eating it, you’re not alone. Many people experience nausea or vomiting after consuming shrimp.

If you find yourself wondering “why does shrimp make me nauseous?” this comprehensive guide will explore the science behind shrimp sensitivities. We’ll also provide tips to enjoy shrimp without an upset stomach.

Common Causes of Shrimp Nausea

There are several potential reasons shrimp can trigger nausea or vomiting in sensitive individuals

• Allergies – Shellfish allergies, and shrimp allergies in particular, are a common cause of adverse reactions to shrimp. Allergies provoke the immune system, leading to nausea, stomach cramps, and other symptoms.

• Toxins – Natural toxins found in shrimp can stimulate nausea in some people. These include glutamate, sulfur compounds, and histamine which can be liberated during cooking.

• Bacterial Contamination – Spoiled shrimp harbors pathogenic bacteria which release toxins that can induce vomiting when ingested. Proper cooking typically neutralizes the bacteria but not necessarily the toxins.

• Medication Interactions – Certain medications like monoamine oxidase inhibitors (MAOIs) block the breakdown of histamine in shrimp, increasing nausea and vomiting risk.

• Digestive Issues – Some people may have sensitivities to chitin, a fibrous protein in shrimp shells, making it difficult to digest. This can cause stomach discomfort, bloating, and nausea.

Allergic Reactions to Shrimp

Shellfish allergies are one of the most common food allergies. The prevalence is estimated to be 0.5-2.5% of American adults.

With shrimp, the allergy is typically caused by proteins found in the shrimp flesh called tropomyosins. When someone with the allergy consumes shrimp, their immune system flags these proteins as foreign invaders.

As part of the allergic reaction, the body releases chemical messengers like histamine that irritate and inflame the digestive system. This causes nausea, cramping, diarrhea and vomiting.

Shrimp allergy symptoms usually start suddenly within minutes to hours after eating. In severe cases, it can potentially lead to life-threatening anaphylaxis. Those with known shellfish allergies must avoid shrimp entirely.

Natural Toxins in Shrimp

In some individuals, naturally occurring compounds in shrimp may irritate the stomach and cause feelings of nausea. A few of these problematic compounds include:

Glutamate – An amino acid that acts as a neurotransmitter. In excess, it signals nausea neurons in the brain. Cooking and storage increases glutamate levels in shrimp.

Sulfur Compounds – Shrimp contain sulfur-containing amino acids. Cooking breaks these down into volatile, pungent compounds that can induce nausea.

Histamine – High concentrations of histamine develop as shrimp decomposes. Histamine stimulates vomiting. Cooking helps reduce histamine levels.

Iodine – Shrimp and other shellfish are rich in iodine, which can cause gastric distress in those sensitive to excessive iodine intake.

So while not true allergies, these naturally present compounds may irritate the digestive system and provoke feelings of nausea in those prone to it.

Bacterial Contamination

Like any seafood, shrimp is prone to spoilage by pathogenic bacteria. Eating undercooked or spoiled shrimp can therefore lead to food poisoning and symptoms like nausea, vomiting, and diarrhea.

Bacteria of concern include Salmonella, Vibrio parahaemolyticus, Vibrio vulnificus, and Listeria monocytogenes. These release toxins that can continue to cause illness even after proper cooking eliminates the bacteria themselves.

Only consuming fresh, properly handled shrimp helps avoid bacterial contamination. Proper storage and thorough cooking to an internal temperature of at least 145°F kills bacteria and makes shrimp safe to eat.

Medication Interactions

Certain medications are known to increase the likelihood of nausea and vomiting from foods containing biogenic amines like histamine and tyramine.

Monoamine oxidase inhibitors (MAOIs) are a class of antidepressants that interfere with the breakdown of these compounds. People taking MAOIs need to avoid aged, fermented, or spoiled foods with high amine levels.

This interaction makes those using MAOIs more prone to nausea when consuming foods like shrimp. Cooking shrimp thoroughly to reduce amine content can help limit this reaction.

Digestive Discomfort from Chitin

The shell of shrimp contains a fibrous, indigestible polysaccharide called chitin. For some individuals, chitin can be difficult to digest and may cause irritation, bloating, and nausea symptoms.

People with digestive conditions like irritable bowel syndrome (IBS) and Crohn’s disease seem especially prone to chitin intolerance. This is likely due to both the indigestibility of chitin and the potential for shellfish allergies being more common among those with these conditions.

Tips to Prevent Nausea from Shrimp

If you’re sensitive to shrimp, try these preparation and serving tips to help avoid nausea:

• Buy high-quality, fresh shrimp and use promptly or freeze for later use. Avoid old, spoiled shrimp.

• Cook shrimp thoroughly until opaque and flaky to deactivate bacteria and toxins. An internal temperature of 145°F is recommended.

• Peel shrimp to remove chitin-containing shells. The chitin may be hard for some people to digest.

• Limit additional histamine-releasing foods like aged cheese, cured meats, wine, and beer that are served alongside shrimp.

• Cook shrimp gently. Aggressive high-heat cooking can increase nausea-inducing compounds like glutamate.

• Marinate shrimp in ginger, fennel, mint, or other anti-nausea herbs and spices.

• Those with shellfish allergies must avoid shrimp entirely to prevent severe reactions.

When to See a Doctor

If shrimp frequently causes nausea or vomiting, see your doctor. They can help determine if there is an underlying food allergy, medication interaction, or chronic digestive issue at play.

Testing for food allergies may be recommended. Shellfish allergy testing involves a simple skin prick test. Blood tests looking for elevated antibodies can also help diagnose shellfish allergies.

Treatment will focus on avoiding trigger foods and managing symptoms. For severe life-threatening allergies, an epinephrine auto-injector prescription and allergy management education are vital.

The Bottom Line

While shrimp is a coveted delicacy for many, it can prompt nausea in those prone to shellfish sensitivities. Several factors, ranging from toxins to allergies, can turn shrimp from a tasty treat into a stomach churning experience.

Luckily, being an informed shopper and cook can help prevent adverse reactions. Those highly sensitive should avoid shrimp, but for others, small preparation tweaks can allow enjoyment of this popular crustacean. Though if symptoms persist, having an allergy evaluation is advised.

Understanding the root cause of shrimp nausea provides peace of mind and strategies to savor shrimp safely. With knowledge and care in handling, most seafood lovers can continue indulging in shrimp without stomach upset!