Celery: Benefits, Side Effects and Dosage

Celery (Apium graveolens L.) is more than a familiar crunchy snack—it's a vegetable with a long-standing reputation in both traditional and modern medicine. Whether you add it to salads, soups, or juices, celery has earned its place as a health-boosting food due to its unique profile of vitamins, antioxidants, and bioactive compounds. In this article, we will explore the scientifically supported benefits, potential side effects, and recommended dosages of celery. Drawing from a range of peer-reviewed studies and clinical reports, this comprehensive guide will help you understand how to incorporate celery safely and effectively into your wellness routine.

Benefits of Celery

Celery is celebrated for its impressive list of health-promoting properties, spanning antioxidant, anti-inflammatory, anti-obesity, and cholesterol-lowering effects. Its potential to improve cardiovascular health, manage blood sugar, and support the immune system has been documented in both animal and human studies. Let’s explore these benefits in detail and see how they might enhance your health.

Benefit	Mechanism/Compound	Effect	Sources
Antioxidant	Apigenin, luteolin, phenolics	Neutralizes free radicals, reduces oxidative stress	1 2 3 4
Cardiovascular	Phthalides, unsaturated fatty acids	Lowers blood pressure, cholesterol, lipids	2 3 4 9
Anti-inflammatory	Flavonoids, seed extracts	Reduces inflammation similarly to aspirin	2 4 10
Anti-obesity	Bioactive compounds, ECE	Reduces weight gain and fat accumulation	5
Blood sugar	Polyphenols, vitamins	Lowers blood glucose levels	2 4 5
Immunostimulant	Apigenin, ethanol extracts	Boosts phagocytosis and leukocyte count	8

Table 1: Key Health Benefits of Celery

Antioxidant Powerhouse

Celery is rich in antioxidants such as caffeic acid, p-coumaric acid, ferulic acid, apigenin, luteolin, tannins, saponins, and kaempferol. These compounds help neutralize harmful free radicals, protecting cells from oxidative damage that contributes to aging and chronic diseases. The potent antioxidant activity is found in all parts of the plant—leaves, seeds, and stems—making celery a versatile choice for boosting your body’s defense systems 1 2 3 4.

Cardiovascular Protection

Celery’s cardiovascular benefits are multi-faceted. Phthalides, especially sedanenolide found in celery seeds and oil, help relax blood vessels and improve circulation, thereby lowering blood pressure. Additionally, unsaturated fatty acids and other bioactive compounds contribute to lower cholesterol and serum lipid levels, reducing the risk of atherosclerosis and heart disease 2 3 4 9.

Anti-inflammatory Effects

Chronic inflammation is at the root of many health conditions. Celery’s flavonoids and extracts—particularly from seeds—have been shown in animal models to reduce inflammation as effectively as aspirin, making celery a natural ally against inflammatory diseases 2 4 10.

Weight Management and Anti-obesity

Emerging research suggests that enzyme-treated celery extract (ECE) can prevent weight gain and fat accumulation, especially in the context of a high-fat diet. In animal studies, ECE reduced lipid parameters, improved metabolic markers, and protected the liver from fatty changes, supporting its use as a functional food for weight management 5.

Blood Sugar Regulation

Celery’s polyphenols and vitamins A and C have been associated with lower blood glucose and improved insulin sensitivity in both animal and preliminary human studies, making it a supportive food for those at risk of type 2 diabetes 2 4 5.

Immune System Support

Apigenin, a major compound in celery leaves, has demonstrated immunostimulatory effects in animal studies. Ethanol extracts of celery leaves increased phagocytic activity and leukocyte counts, indicating a positive impact on immune function 8.

Side Effects of Celery

While celery is generally safe for most people, especially when consumed as a food, there are some documented side effects and considerations—particularly with high-dose extracts or supplements. It’s important to be aware of these potential risks to avoid adverse reactions.

Side Effect	Description	Risk Factors/Notes	Sources
Hyperthyroidism	Overactive thyroid symptoms after high-dose extract use	High intake of celery extract (8 g/day)	6
Allergic Reactions	Skin, respiratory, or systemic allergies	More common in those with celery allergy	6
Pesticide Residue	Carbendazim residues possible in conventionally grown celery	Risk mitigated with proper washing and harvest intervals	7
Drug Interactions	Possible additive effects with antihypertensive or anticoagulant drugs	Monitor if on these medications	2 3

Table 2: Notable Side Effects and Risks of Celery

Thyroid Effects and Hyperthyroidism

There is a case report of a woman developing hyperthyroidism after consuming high doses of celery extract (8 g/day) for weight loss over several weeks. Symptoms included blurred vision, palpitations, and nausea. Thyroid function normalized after discontinuing the extract and starting medication. This suggests that large amounts of celery extract may disrupt thyroid function in susceptible individuals 6.

Allergic Reactions

Celery is a known allergen for some people, and reactions can range from mild skin irritation to severe anaphylaxis. Individuals with a history of food allergies—especially to plants in the Apiaceae family (e.g., carrots, parsley)—should exercise caution 6.

Pesticide Residues

Celery is often treated with fungicides such as carbendazim, which can leave residues on the plant. While recommended agricultural practices and washing can reduce this risk, it’s still a consideration, particularly when consuming large quantities or juicing celery 7.

Potential Drug Interactions

Celery’s naturally occurring compounds may have additive effects with certain medications, such as those for lowering blood pressure or preventing blood clots. If you are taking such medications, consult your healthcare provider before increasing your celery intake or using supplements 2 3.

Dosage of Celery

The health benefits and side effects of celery are often dose-dependent. While eating fresh celery as a vegetable is generally safe, extracts and supplements can contain much higher concentrations of active compounds. Determining the right dosage depends on your goals and health status.

Form/Preparation	Effective Dose	Notes/Usage Context	Sources
Fresh celery	1–2 stalks per day (approx. 80–100g)	Common dietary intake; safe for most	2 3
Celery juice	100–250 mL/day	Popular for detox/health routines	2 9
Leaf extract	125–500 mg/kg body weight (animal studies)	Immunostimulant effects in mice	8
Seed extract	25–100 mg/kg (animal studies)	Anti-inflammatory; 100 mg/kg optimal	10
Powdered extract	≤ 1–2 g/day (human estimate)	Higher doses (e.g., 8 g) linked to side effects	6

Table 3: Typical Dosages and Preparations of Celery

Eating Fresh Celery

Including 1–2 stalks of fresh celery in your daily diet is a safe and effective way to access its nutrients and health benefits. This amount fits easily into salads, snacks, or cooked dishes and is unlikely to cause adverse effects for most people 2 3.

Celery Juice

Drinking 100–250 mL of fresh celery juice daily is a common wellness practice. While some claims are anecdotal, this amount is generally considered safe and provides a concentrated dose of vitamins and antioxidants 2 9.

Extracts and Supplements

• Leaf Extracts: Animal studies show immunostimulant benefits at doses of 125–500 mg/kg body weight. Human equivalent doses are not well established, so supplements should be used cautiously and according to product instructions 8.
• Seed Extracts: Anti-inflammatory effects were seen at 25–100 mg/kg in animal models, with 100 mg/kg performing similarly to aspirin. Again, human dosing should be more conservative 10.
• Powdered Extracts: While small supplemental doses (1–2 g/day) may be safe for most, high doses (e.g., 8 g/day) have been linked to adverse effects, including hyperthyroidism 6.

Practical Recommendations

• Always start with food sources before considering supplements.
• If using extracts, choose standardized products and start with the lowest effective dose.
• Consult a healthcare provider, especially if you have thyroid issues, allergies, or take medications.

Conclusion

Celery is a versatile vegetable with scientifically supported health benefits, but it’s important to approach supplementation and extracts with caution. Here’s a summary of the key points from this article:

• Rich in Antioxidants: Celery contains unique compounds that fight oxidative stress and may help protect against chronic diseases 1 2 3 4.
• Heart and Metabolic Health: Regular celery consumption may lower blood pressure, cholesterol, and blood sugar, and support weight management 2 3 4 5 9.
• Supports Immunity and Reduces Inflammation: Celery extracts can boost immune function and act as a natural anti-inflammatory agent 2 4 8 10.
• Watch for Side Effects: Large amounts of celery extract may cause thyroid disturbances or trigger allergies, and pesticide residues can be a concern with non-organic produce 6 7.
• Dosage Matters: Typical dietary amounts are safe, but be cautious with supplements and extracts; consult a healthcare provider for guidance 2 3 6 8 10.

Whether you enjoy celery as a snack, juice, or herbal supplement, incorporating it thoughtfully into your diet can contribute to a healthier lifestyle. As always, balance and moderation are key to maximizing benefits while minimizing risks.