Who Should Not Consume Celery? A Guide to Health Risks and Precautions

November 6, 2025 •

4 min read

An estimated 0.45% of European adults have a celery allergy, and for some, it can trigger severe reactions. While a nutritious vegetable for many, individuals with certain health conditions or those taking specific medications should be cautious about who should not consume celery.

Quick Summary

Individuals with celery allergies, bleeding disorders, kidney problems, low blood pressure, or thyroid conditions should limit or avoid celery consumption. Pregnant women should avoid concentrated celery supplements, and people on certain medications like blood thinners or sedatives should consult a doctor due to potential interactions. Understanding these risks is crucial for personal health safety.

Key Points

Allergy Risks: Individuals with celery or related plant allergies (e.g., mugwort, birch) may experience allergic reactions, which can be severe and life-threatening.
Bleeding Disorders: People with bleeding disorders or taking blood-thinning medication should avoid medicinal amounts of celery due to its potential to slow blood clotting.
Pregnancy Concerns: Pregnant women should avoid concentrated celery supplements (seeds, oil) as they can stimulate uterine contractions.
Kidney Health: Those with kidney problems, especially kidney inflammation, should be cautious with high concentrations of celery and consult a doctor, particularly regarding celery juice cleanses due to high potassium.
Medication Interactions: Celery can interact with sedatives, thyroid medication, and lithium, potentially intensifying side effects or interfering with effectiveness.
Low Blood Pressure: Because celery can lower blood pressure, it should be consumed cautiously by individuals with low blood pressure or those on blood pressure medication.
Pesticide Exposure: Non-organic celery is often high in pesticide residues, making it crucial to wash thoroughly or opt for organic versions.

Who Is at Risk? Understanding Celery Contraindications

While a common and healthy vegetable for most people, certain individuals and specific health situations warrant avoiding or limiting celery. A comprehensive understanding of the potential contraindications is crucial for personal safety and well-being.

Allergy Sufferers

Celery is a major food allergen, with allergic reactions ranging from mild oral symptoms to severe, life-threatening anaphylaxis. A specific issue is the 'celery-carrot-mugwort-spice syndrome,' where individuals allergic to mugwort pollen can experience cross-reactive reactions to celery. The allergens are stable and can remain active even after cooking, meaning reactions are possible from both raw and cooked celery. Symptoms can include itching or swelling of the mouth, tongue, and lips, hives, or breathing difficulties. If you have a known allergy to celery, or related plants like parsley, fennel, or carrots, complete avoidance is the safest course.

People with Bleeding Disorders

Celery root, especially in medicinal or concentrated amounts, might slow blood clotting. This poses a risk for individuals with bleeding disorders or those taking anticoagulant or antiplatelet drugs, such as warfarin, aspirin, or clopidogrel. Combining these can increase the risk of bruising and bleeding. If you have a bleeding disorder, or are on such medication, consult a healthcare provider before consuming celery in large quantities or as a supplement.

Pregnant and Breastfeeding Women

While moderate amounts of celery in food are generally considered safe during pregnancy, concentrated forms are not. Celery seed and celery oil in medicinal amounts are considered unsafe for pregnant women as they may stimulate the uterus and increase the risk of miscarriage. For breastfeeding women, there isn't enough reliable information on the safety of concentrated celery products, so it is best to stick to food amounts as a precaution.

Individuals with Kidney Problems

For most, celery is a kidney-friendly food. However, individuals with existing kidney problems, especially inflammation or kidney disease, should avoid excessive, medicinal amounts of celery or celery seed supplements. Celery juice cleanses, in particular, can be dangerously high in potassium for those on a low-potassium diet due to kidney disease. Any such regimen should be discussed with a doctor or renal dietitian.

Those with Low Blood Pressure

Celery is known to have a blood pressure-lowering effect due to compounds like phthalides. While beneficial for some, it can be problematic for individuals already on blood pressure medication or those with naturally low blood pressure. Consuming large amounts of celery in these cases could cause blood pressure to drop too low, leading to dizziness or fainting.

Individuals Taking Specific Medications

Several common medications can interact negatively with concentrated celery products.

Blood Thinners: As noted, the vitamin K in celery can interfere with blood-thinning medications like warfarin.
Sedatives: Psoralens in celery can cause sleepiness. Combining celery with sedatives, such as benzodiazepines or barbiturates, can lead to excessive drowsiness.
Thyroid Medications: Celery might interfere with thyroid function and reduce the effectiveness of thyroid medication like levothyroxine.
Lithium: Celery has a diuretic effect, which can affect how the body eliminates lithium. This could cause lithium levels to build up to dangerous concentrations.

Food Safety Concerns

Beyond individual health concerns, there are broader food safety considerations when handling celery.

Pesticides: Conventionally grown celery consistently ranks high on the Environmental Working Group's (EWG) list for pesticide residues. It is highly recommended to choose organic celery or wash conventional celery thoroughly before consumption to reduce exposure.
Photo-sensitivity: Compounds called psoralens in celery can make the skin more sensitive to sunlight, increasing the risk of sunburn or rashes. This risk is higher for those who handle celery extensively, like farmers, or who get celery juice on their skin and are then exposed to sun.

Raw vs. Cooked Celery: Understanding the Differences


Feature	Raw Celery	Cooked Celery
Allergens	Allergenic proteins are intact, posing a higher risk of oral allergy syndrome (OAS) in sensitive individuals.	Cooking may break down some allergenic proteins, making it safer for some with mild OAS. However, severe celery allergies can still be triggered by cooked forms.
Nutrient Content	Contains the highest levels of vitamins, minerals, and antioxidants.	Some nutrients, including certain antioxidants, can be reduced by cooking, especially boiling.
Digestibility	Can be more difficult to digest due to its fibrous nature, potentially causing gas and bloating in sensitive people.	Cooking can make the fibers softer and easier to digest for some individuals.
Drug Interactions	Potential interactions with medications are primarily associated with the concentration of components found in celery and its supplements, which is generally higher in uncooked or juiced forms.	Medicinal amounts of celery root or seeds, rather than small quantities of cooked stalks, are the main concern for drug interactions.

Conclusion: Prioritize Safety Before Consumption

While celery is a hydrating and nutrient-rich addition to many diets, it is not universally safe for everyone. Individuals with celery allergies, bleeding disorders, low blood pressure, kidney issues, and pregnant or breastfeeding women should exercise caution. Furthermore, those on specific medications should consult a healthcare provider to avoid dangerous interactions. By being aware of these risks and taking the necessary precautions, you can ensure that you are consuming celery safely and responsibly.

Authoritative Source

For more information on food allergies and related concerns, consult the Anaphylaxis UK fact sheet on celery allergy.

Frequently Asked Questions

If you have a mugwort pollen allergy, you should be cautious with celery. The proteins are similar and can cause a cross-reaction known as 'celery-mugwort-birch-spice syndrome,' triggering allergic symptoms.

Yes, celery has properties that can lower blood pressure. Individuals who already have low blood pressure or are taking medication for high blood pressure should be careful, as large amounts could cause an unsafe drop.

While small, moderate amounts of celery in food are safe for pregnant women, concentrated forms like celery seed extract or oil should be avoided. These can stimulate the uterus and increase the risk of complications.

Yes, celery can interfere with blood-thinning medications like warfarin. The vitamin K content can affect blood clotting, increasing the risk of bleeding.

For those with kidney disease, particularly on low-potassium diets, excessive consumption or juice cleanses should be avoided. Consult a doctor, as high levels of potassium in celery juice can be dangerous.

Celery contains psoralens, which are compounds that can make skin more sensitive to ultraviolet light. This is a particular risk for those who handle celery extensively and are then exposed to sunlight.

For those with mild oral allergy syndrome, cooked celery might be safe as heat can break down some allergens. However, individuals with severe celery allergies, especially from mugwort cross-reactivity, should avoid all forms, as some allergens are heat-stable.