Tuna is one of the most popular fish consumed worldwide. It’s a lean protein packed with healthy fats, vitamins and minerals. However some people experience stomach discomfort after eating tuna.
If you’ve ever wondered “why does tuna make my stomach hurt?” you’re not alone. In this comprehensive guide we’ll explore the various reasons tuna can cause stomach pain and how to enjoy this fish without the unpleasant side effects.
What Causes Tuna to Upset Your Stomach?
There are a few potential culprits behind tuna’s tendency to cause stomach discomfort
High Levels of Histamine
One of the most common causes of stomach pain after eating tuna is histamine toxicity. Tuna contains high levels of the amino acid histidine. When tuna isn’t stored at proper cold temperatures, bacteria generate histamine from the histidine.
The symptoms of histamine poisoning include:
- Hives or rash
- Flushing
- Headache
- Abdominal cramps
- Diarrhea
- Vomiting
To avoid histamine toxicity, consume tuna immediately after opening or store it below 4°C. Cooking doesn’t destroy histamine.
Excess Zinc
The zinc added to the interior lining of tuna cans can leach into the fish. Consuming high amounts of zinc over time can impact your body’s ability to absorb nutrients properly.
Studies show tuna can contain up to 100 times the recommended dietary allowance of zinc. Too much zinc can lead to:
- Digestive issues
- Nutrient malabsorption
- Inflammation
Eat tuna in moderation and get zinc from other sources like meat, seafood, dairy, etc.
Pathogenic Bacteria
Tuna can contain bacteria like Salmonella, E. coli, and Clostridium botulinum. These can lead to vomiting, diarrhea, and severe illness. Always check expiration dates and proper storage/handling.
High Sodium Content
Canned tuna often contains very high amounts of sodium. Consuming too much sodium regularly has been linked to high blood pressure, heart disease, and stroke.
Check labels and opt for low-sodium versions when possible. Balance tuna with other lean proteins and limit portions to control sodium intake.
Allergic Reactions
Some people are allergic to tuna and experience digestive upset after consuming it. Symptoms range from mild nausea to severe anaphylaxis.
People with tuna allergy need to avoid it entirely, including canned varieties which can still trigger reactions.
Why Tuna Causes Stomach Pain: The Science
Now that we’ve covered the main culprits, let’s dive deeper into the science behind tuna’s association with stomach discomfort.
Histamine Toxicity
Histamine toxicity is one of the most frequently implicated causes of stomach issues after eating tuna.
Tuna contains high levels of the amino acid histidine. When tuna isn’t handled properly after catching, bacteria present in the flesh generate histamine from the histidine through the enzyme histidine decarboxylase.
Histamine is highly stable and not destroyed by freezing, cooking, or canning. Consuming high amounts causes an allergic-like reaction, leading to the digestive symptoms.
According to the FDA, histamine toxicity accounts for 40% of all seafood-related food poisoning cases.
Excess Zinc
Tuna contains concerningly high levels of zinc. Studies show that zinc oxide nanoparticles from the can lining accumulate in the digestive tract.
Researchers believe this alters gene expression and protein synthesis in intestinal cells. The zinc causes inflammation, increasing intestinal permeability.
This “leaky gut” allows compounds to pass into the bloodstream that normally wouldn’t. Over time, excess zinc can impact digestion and nutrient absorption.
Sodium Overload
While tuna itself doesn’t contain excess sodium, canned varieties are often packed in salty brines.
Per the CDC, most people should keep sodium intake under 2,300 mg daily. However, just one serving of high-sodium tuna can provide 320 mg.
Consuming high-sodium foods regularly can cause your total sodium intake to skyrocket. Over time, this distracts fluid balance and circulation, leading to high blood pressure and other issues.
Tuna Allergy: Symptoms and Treatment
If tuna makes you feel sick every time you eat it, you may have a fish allergy. Let’s explore the symptoms and how it’s treated.
Signs of Tuna Allergy
Symptoms of tuna allergy include:
- Hives, rash, or itching
- Swelling of lips, face, tongue
- Vomiting, diarrhea, stomach pain
- Stuffy or runny nose
- Shortness of breath, wheezing
- Dizziness
- Anaphylaxis (difficulty breathing, low blood pressure)
Reactions can occur after eating tuna or inhaling vapors from cooking or processing. Even touching tuna may provoke a response in highly sensitive people.
Cross-Reactivity with Other Fish
The parvalbumin protein responsible for tuna allergy can also trigger reactions to other fish like salmon and cod. This is called cross-reactivity.
There’s also potential for cross-reactivity with shellfish, as the protein is similar to that found in crustaceans.
Treating Tuna Allergy
The only way to prevent a reaction is strict avoidance. Check labels carefully for tuna ingredients.
Antihistamines can relieve mild symptoms, while epinephrine pens are prescribed for severe reactions like anaphylaxis.
See an allergist to test for specific fish/shellfish allergens and develop a management plan. Desensitization immunotherapy may be an option to reduce sensitivity over time.
Tips to Enjoy Tuna Without Stomach Discomfort
If you don’t have a tuna allergy but still struggle with stomach upset, these tips can help you enjoy tuna without the nasty side effects:
- Choose fresh over canned – Less risk of high histamine, zinc, and bacteria
- Cook thoroughly – Kill any potentially harmful bacteria
- Limit portion size – Avoid excessive zinc and sodium
- Read labels – Pick low-sodium canned varieties
- Add probiotics – Can improve digestion of proteins
- Take antihistamines – If histamine is the culprit
- Avoid fatty dressings – Like mayo, which can be harder to digest
- Eat with carbs – Pairing with crackers or rice makes it more digestible
The key is moderation. While tuna does offer some excellent nutritional benefits, be mindful of portion size, preparation method, and how your body reacts.
When to See a Doctor
In most cases, tuna-related stomach discomfort is mild and can be managed with diet and lifestyle measures. However, contact your doctor if you experience:
- Difficulty breathing or swallowing
- Significant vomiting/diarrhea
- Chest pain
- Swelling of the lips, tongue or throat
- Rapid heartbeat, dizziness or fainting
These can signal a severe allergic reaction that requires prompt medical treatment. Antihistamines and epinephrine may be needed to control symptoms and prevent progression to anaphylaxis.
See an allergist if you suspect tuna allergy so they can confirm it through medical history review and testing. They will also provide emergency management instructions and guidance on avoiding tuna going forward.
The Bottom Line
Tuna is a healthy, affordable protein source that’s popular worldwide. However, it does come with some potential downsides – namely stomach discomfort after eating.
Histamine toxicity, excess zinc, high sodium, and allergies seem to be the main culprits behind tuna’s tendency to cause stomach issues. Pay close attention to how your body reacts and limit intake if needed. Check canned tuna labels and opt for fresh when possible.
With the proper precautions, you can still incorporate tuna into your diet and take advantage of its great nutritional profile. But if pain persists, see a doctor to explore whether an underlying condition may be to blame.
If You Eat Tuna Every Day For A Week This Will Happen To Your Body
FAQ
Why does my stomach hurt after eating tuna?
Is canned tuna hard on the stomach?
Why does canned tuna make me feel sick?
Does tuna trigger gastritis?
Why does canned tuna make you bloated?
So salt is still a crucial part of a healthy diet. But why does canned tuna make you feel bloated? The reason, states Medical News Today, is because it causes water retention in the body, which makes you feel puffy and uncomfortable. So, next time you crack open a can of tuna, keep good old salt in mind.
Can pineapple cause a stomach ache?
Moderate pineapple consumption had no negative effects on the body. For those with GERD/gastritis, this fruit should be consumed with caution, as it contains a moderate amount of acid that may alleviate pain. However, it is fine to consume in moderation, as part of a balanced diet, and at the appropriate time.
How does eating to much tuna affect your health?
Eating too much tuna can have negative effects on your health. Tuna is a species of fish that is often consumed by people, but it is also a common source of mercury in the diet . Mercury is a chemical
Why does tuna make you feel Puffy?
The reason, states Medical News Today, is because it causes water retention in the body, which makes you feel puffy and uncomfortable. So, next time you crack open a can of tuna, keep good old salt in mind. A healthy diet is all about balance, pairing your tuna salad with whole wheat bread, carrots, or low-salt crackers is a good way to make it.