Who should not eat celery?

November 29, 2025 •

4 min read

In parts of Europe, celery is one of the most frequent triggers for food-related allergies, with one study reporting that 42% of food-allergic adults in Switzerland reacted to it. It is vital to understand who should not eat celery, as this seemingly harmless vegetable can pose health risks for certain groups of people.

Quick Summary

Certain individuals should avoid or limit celery due to potential health risks, including those with celery allergies, people on specific medications like blood thinners or lithium, pregnant women avoiding seeds and extracts, and those with sensitive digestive systems.

Key Points

Allergy Warning: Individuals with celery or related plant allergies, including pollen food syndrome, should avoid celery to prevent reactions ranging from mild oral itching to life-threatening anaphylaxis.
Drug Interactions: Patients on blood thinners, blood pressure medication, lithium, or thyroid medication should consult a doctor, as celery can interfere with these drugs and cause adverse effects.
Pregnancy Precaution: Pregnant women should avoid celery seed and oil extracts, as they can cause uterine stimulation, though food amounts of properly washed celery stalks are generally safe.
Digestive Sensitivity: Those with IBS or sensitive stomachs should be cautious, as celery is high in fermentable FODMAPs (mannitol) and insoluble fiber, which can cause bloating and gas.
Photosensitivity Risk: High intake of celery can increase skin sensitivity to sunlight due to psoralens, leading to severe sunburn or skin rashes, a risk amplified when combined with other photosensitizing drugs.
Risk with Low Blood Pressure: People with existing low blood pressure should avoid large or medicinal amounts of celery, as its hypotensive properties could cause blood pressure to drop dangerously low.
Supplements vs. Food: The risk profile of celery can differ significantly between regular food consumption and high-dose supplements or juices, with the latter carrying higher risks of adverse effects.

Understanding Celery: More Than Just a Crunch

Celery (Apium graveolens) is a popular vegetable known for its crisp texture and high water content. It is a versatile ingredient, used raw in salads or cooked in soups and stews. While it offers numerous nutritional benefits, including vitamins K and C, potassium, and antioxidants, it also contains compounds that can be problematic for some individuals. Understanding these risks is crucial for safe consumption.

Medical Conditions Requiring Caution

Celery Allergies and Oral Allergy Syndrome (OAS)

Celery is a known food allergen that can cause reactions ranging from mild to severe anaphylaxis.

Symptoms: Reactions can include oral itching, swelling of the lips or throat, hives, abdominal pain, and in serious cases, breathing difficulties or a drop in blood pressure.
Pollen Food Syndrome: Many celery allergies are linked to pollen from birch or mugwort, known as Oral Allergy Syndrome. For these individuals, symptoms may only occur when eating raw celery, as cooking can break down the allergenic proteins.
Serious Reactions: For those with a primary celery allergy not linked to pollen, cooking may not prevent a reaction. Even tiny traces of celery or its derivatives, like celery salt or seeds, can trigger symptoms.

People with Low Blood Pressure

Celery is known to have diuretic and blood pressure-lowering properties, thanks to compounds like phthalides.

While this can be beneficial for people with high blood pressure, those with naturally low blood pressure (hypotension) should exercise caution.
Consuming large or medicinal amounts of celery, such as through juicing, could cause blood pressure to drop to an unsafe level, leading to dizziness or fainting.

Those with Bleeding Disorders

Celery root in medicinal or supplemental amounts may slow blood clotting. Individuals with existing bleeding disorders should avoid celery root to prevent an increased risk of bruising and bleeding.

Digestive Sensitivities and IBS

Celery can cause significant digestive discomfort for individuals with Irritable Bowel Syndrome (IBS) or sensitive digestive systems.

High in FODMAPs: Celery contains mannitol, a polyol, which is a type of FODMAP (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols). These can be poorly absorbed and fermented by gut bacteria, leading to bloating, gas, and diarrhea.
High Insoluble Fiber: For those not used to a high-fiber diet, an increase in celery can cause gas, bloating, and stomach pain. Celery's insoluble fiber can also be particularly irritating for those with an inflamed gut.

Drug Interactions and High-Dose Extracts

Anticoagulants (Blood Thinners)

Celery contains vitamin K, which plays a role in blood clotting. Large amounts of celery, especially in juice form, can interfere with anticoagulant medications like warfarin, potentially altering their effectiveness and increasing the risk of bleeding.

Medications for Blood Pressure

Due to its natural blood pressure-lowering properties, celery and its extracts can interact with antihypertensive drugs. This combination could cause a patient's blood pressure to drop too low. People on these medications should monitor their blood pressure closely and consult their doctor before increasing their celery intake.

Other Drug Interactions

Lithium: Celery may interfere with the body's ability to excrete lithium, potentially increasing lithium levels and causing serious side effects.
Sedatives: Celery contains compounds that can cause sleepiness. Combining celery with sedatives could lead to excessive drowsiness.
Photosensitizing Drugs: Celery contains psoralens, which increase skin's sensitivity to sunlight. Combining celery with other photosensitizing medications can heighten the risk of sunburn or skin inflammation.

Special Considerations for Specific Groups

Pregnancy and Breastfeeding

While small, food-level amounts of properly washed celery stalks are generally considered safe during pregnancy, certain forms should be strictly avoided.

Celery Seed/Oil: Large or medicinal amounts of celery seeds or oil are considered unsafe, as they may stimulate the uterus and could induce a miscarriage.
Breastfeeding: There is insufficient reliable information on the safety of medicinal amounts of celery for breastfeeding mothers, so it's best to stick to food quantities.

Sun Sensitivity (Psoralens)

Celery contains psoralen compounds, which increase skin sensitivity to UV light. This condition, known as phytophotodermatitis, can lead to severe sunburn, rashes, and blistering upon sun exposure. This risk is heightened with high intake (e.g., celery juicing) or contact with celery affected by pink rot fungus.

Risks of Celery vs. Celery Seed or Extract


Feature	Celery Stalks	Celery Seeds & Extracts
Allergens	Contains allergens; can trigger reactions.	Can contain a higher concentration of allergens, increasing risk.
Medication Interaction	Minimal risk with food amounts.	High risk, especially with blood pressure and blood-thinning medications.
Pregnancy Safety	Safe in moderate food amounts. Must be washed thoroughly.	Unsafe due to risk of uterine stimulation and miscarriage.
Sun Sensitivity	Present, but typically requires high intake for severe effects.	Can significantly increase skin's sensitivity to sunlight.
Fiber Content	High in fiber, potentially causing digestive upset in large amounts.	Negligible to none, depending on processing.

When to Consult a Healthcare Professional

If you fall into any of the high-risk categories, you should consult with a healthcare professional before making significant changes to your celery intake. This is particularly important for individuals on medication for blood pressure, blood thinning, or thyroid conditions, as well as pregnant women. Your doctor can provide personalized guidance based on your medical history.

Conclusion: The Bottom Line on Celery Intake

While a nutritional powerhouse for most, celery is not for everyone. Key groups who should not eat celery in medicinal quantities, or at all in some cases, include those with diagnosed celery allergies, individuals on specific medications, and pregnant women. Additionally, people with digestive issues or low blood pressure should consume celery with caution. For those in doubt, especially concerning supplements or high-dose juicing, seeking medical advice is the safest approach to prevent potential health complications. Anaphylaxis UK offers additional resources for those with food allergies.

Frequently Asked Questions

If you have a diagnosed celery allergy, you should avoid celery completely, including all parts of the plant and celery-derived products like seeds or spices. Consult an allergist for proper diagnosis and management.

Celery contains vitamin K, which can interfere with the effectiveness of blood-thinning medication like warfarin. Patients should discuss their celery intake with their doctor to ensure proper monitoring and dosage adjustments if necessary.

Pregnant women should avoid celery seeds and seed extract due to the risk of uterine stimulation and miscarriage. Moderate, food-level consumption of fresh, well-washed celery stalks is generally considered safe.

Yes, celery contains mannitol, a FODMAP that can cause bloating, gas, and diarrhea in sensitive individuals, including those with IBS. Its high insoluble fiber content can also be problematic in large quantities.

Celery contains natural compounds called psoralens. When exposed to UV light, psoralens can cause a reaction on the skin that leads to increased sensitivity, rashes, and burns, a condition known as phytophotodermatitis.

In medicinal amounts, such as with celery seed extracts or heavy juicing, celery can lower blood pressure. This can be risky for individuals already dealing with hypotension and may cause blood pressure to drop too low.

Besides blood thinners and blood pressure medication, celery can interact with drugs like lithium, thyroid medications (e.g., Levothyroxine), and sedatives. Always consult your doctor if you are on medication and plan to consume large quantities of celery.