HerbalEGram: Volume 16, Issue 6, June 2019

Editor’s Note: Each month, HerbalEGram highlights a conventional food and briefly explores its history, traditional uses, nutritional profile, and modern medicinal research. We also feature a nutritious recipe for an easy-to-prepare dish with each article to encourage readers to experience the extensive benefits of these whole foods. With this series, we hope our readers will gain a new appreciation for the foods they see at the supermarket and frequently include in their diets.

We would like to acknowledge ABC Chief Science Officer Stefan Gafner, PhD, for his contribution to this project.

By Jenny Perez^a and Hannah Bauman^b

^a ABC’s Education Coordinator

^b HerbalGram Associate Editor

Overview

Celery (Apium graveolens) is an herbaceous biennial in the Apiaceae family, which includes other widely cultivated vegetables and herbs with feathery, pinnate leaves and aromatic seeds, such as carrot (Daucus carota), parsley (Petroselinum crispum), coriander (Coriandrum sativum), fennel (Foeniculum vulgare), and dill (Anethum graveolens). Native to marshy, salty soils in coastal Europe and temperate Asia, wild celery (A. graveolens var. secalinum), also known as cutting celery or smallage, was originally harvested for its strong-flavored leaves, which were used as a condiment in soups and stews.^1,2

Celery thrives in cool, mild climates and requires high levels of moisture.^3,4 Growing to a height of 15-24 inches (38-61 cm), celery has long, fibrous petioles formed by conically arranged stalks joined at the base that surround the heart of the celery plant.² The stalks each produce three to five bright green, pinnate leaves at the tip of the stalk.^2,5-7 Celery’s small white or yellow flowers appear in umbels from January to August during the plant’s second year of growth. The celery fruits, or schizocarps, consist of two united carpels (mericarps), each containing a brown, ridged, ovoid-shaped, very small seed, approximately 1.3 mm in length.⁹ These fruits, known in commerce as “celery seed,” have a floral odor and slightly pungent taste, and typically ripen in August and September.^9,10

Celery is cultivated worldwide.⁴ Celery’s Latin binomial, Apium graveolens, translates to “strongly smelling” and alludes to celery’s aromatic compounds.¹ In temperate climates, including those of India, Southeast Asia, France, and Italy, celery is grown for its aromatic seeds, specifically for use in perfumes and as a flavoring.^1,2 The succulent, rigid stalk can be eaten raw or cooked, and the fleshy taproot, known as celeriac, is eaten raw, roasted, mashed, or pureed. The seeds are used in cosmetics and condiments.^1,4,10

Historical and Commercial Uses

Celery was cultivated from its wild ancestor in the 16th or 17th century in the northern Mediterranean.² During the 1700s, celery began to be cultivated as a food product and medicine throughout Europe.⁶ Cultivated celery has been bred for its elongated, thick, fleshy, ribbed, milder-tasting stalks, while wild celery is grown for its bitter leaves.² By the early 19th century, four varieties of celery were cultivated in the United States, where the plant gained popularity as a salad vegetable.^2,6 Three varieties of celery are the most commonly cultivated: Chinese celery (var. secalinum), which is used sparingly as a condiment due to its strong, bitter taste; stalk celery (var. dulce), which is eaten raw in salads or cooked; and celeriac or “turnip-rooted celery” (var. rapaceum), which is grown for its enlarged root. Celeriac is popular in European cuisine and its seeds also are used for making commercial celery salt.⁵

Celery seed is a lesser-known spice that has been used for thousands of years.¹¹ The Greeks, Romans, and Egyptians used the bitter leaves and aromatic seeds of the celery plant in rituals and as a condiment and medicine.^2,4 The use of celery was common in celebration practices as a symbol with two meanings: death and victory.⁷ Celery leaf garlands were used to adorn athletes in award ceremonies and to honor the deceased at funerals.^2,4,7 Considered a symbol of Chthonian deities (living in or beneath the earth) from ancient Greek mythology, celery’s spicy odor and dark leaf color was associated with the underworld and death.^1,4,5,7 In ancient Greece, celery leaf crowns were placed on the dead and celery wreaths were draped across graves.⁷ Celery leaves and flowers were part of the garlands found in the Egyptian Pharaoh Tutankhamun’s tomb (died ca. 1321 BCE).¹

Prior to the 16th century, the celery plant was used more as a medicine than a food.¹ Celery seeds, leaves, stem, and root are used in a variety of traditional medicine systems, including the Unani tradition of ancient Persia and Arabia, Indian Ayurveda, and Chinese herbal medicine. As an herbal preparation, celery seeds were consumed fresh or as a water decoction, or the seed powder or extracts were used. The first century medical text, De Medicina, written by Roman encyclopedist Aulus Cornelius Celsus, listed the use of powdered celery seed pills for pain relief.¹ Powdered celery seeds were blended with honey to create a paste used topically as a poultice for a variety of inflammatory conditions such as boils, rheumatoid arthritis, gout, sciatica, and backache.¹²

In Unani medicine, the Arabs obtained knowledge of the use of tukhme karafs, or celery seeds, from Greek physicians including Dioscorides (first century CE) and Theophrastus (died 287 BCE).¹² The seeds of celery are rich in pungent, astringent volatile oils that are used in a variety of preparations, including teas/decoctions and pastes.¹² Celery seeds are considered a heart tonic and used to lower blood pressure.¹⁰ Other indications include hepatic and spleen disorders, brain disorders, body pain, and sleep disturbances.¹⁰ Celery seed decoctions commonly were used for breathing difficulties such as asthma, bronchitis, and pleurisy, and were considered effective for treating measles and all types of fevers.¹² Celery seed decoctions also were used to help dissolve both kidney and bladder stones and were also indicated in cases of sexual debility or low libido. However, celery seed was contraindicated in cases of venomous stings due to its ability to thin the blood and rapidly circulate the venom through the body.¹⁰

In Ayurveda, the traditional medicine system of India, celery stalk juice was used for chronic lung congestion and weight loss as well as to stimulate poor appetite.⁸ The root, leaf, and seed are used in various preparations for purifying the blood, regulating digestion and bowel movements, calming the nerves, and curing gallstones and kidney stones.⁹ Celery seed tea commonly is used to relieve indigestion, flatulence, and griping pains.¹¹ Celery seed and root are considered to have aperient (laxative), carminative (digestion-enhancing), diuretic, emmenagogue (uterine-stimulating), galactogogue (breastmilk-promoting), nervine (calming), stimulant, and tonic properties.^8,11 Celery root was used for its diuretic properties and as a remedy for colic.^3,13 Celery root tinctures are used as a diuretic in hypertension and urinary disorders.¹¹

India’s Materia Medica lists celery as a diuretic, a litholitic (breaks urinary stones), an emmenagogue, and a carminative adjunct to purgatives.¹³ Celery is a preventative treatment for rheumatism and gout and is also indicated as an antispasmodic for treating bronchitis, asthma and chronic lung congestion, and as a blood-purifying alterative for chronic skin disorders such as psoriasis.^3,8,13 Similar to Unani traditional medicine, celery seed decoctions are used as an aphrodisiac to enhance libido and as a nervine to calm anxiety and insomnia.¹¹ Celery seed extract is used similarly to improve kidney function and treat gout as well as bladder and urinary tract infections.^9,11 The typical medicinal dose for celery seed is three to five grams.¹²

Celery, specifically Chinese celery (A. graveolens var. secalinum), was independently cultivated in China where it has been used as an important food and medicine since the fifth century.² Celery is categorized as having a bitter taste and a cooling thermal nature and is used to relieve water retention and control high blood pressure. Celery’s detoxifying phytochemicals reduce blood acidity or acidosis common with tissue inflammation associated with gout and diabetes.¹⁴ Mineral-rich celery stalk juice formulations are used as a dietary therapy to renew joints, connective tissue, arteries, and veins.¹⁴

According to the German Commission E, celery is described as a natural diuretic and is noted for use for acidosis or “blood purification,” for regulating bowel movements, alleviating rheumatic complaints, gout, bladder or kidney stones, as well as for weight loss due to malnutrition, exhaustion, loss of appetite, and to calm nervousness.¹⁵ However, the Commission E listed celery as an “Unapproved Herb” due to a lack of adequate scientific or clinical evidence to support such uses at the time the commission reviewed the pertinent literature on celery (1991).

Celery’s crunchy texture and mildly salty flavor is versatile whether cooked or eaten raw as a salad vegetable.^2,6 Celery is an integral ingredient in many cuisines. It is one of three vegetables in the “holy trinity” of Louisiana’s Creole and Cajun cuisine along with green bell pepper (Capsicum annuum, Solanaceae) and onion (Allium cepa, Amaryllidaceae) and the French mirepoix along with onion and carrot. When selecting celery in the grocery store, consumers should look for vegetables that are light green, with fresh-looking leaves and firm, crisp stalks.⁶

Although the stalks of celery may be most familiar to consumers, its leaves, roots, and seeds are used as food and as seasoning.⁶ Celery leaves can be used similarly to parsley and contain more calcium, potassium, and vitamin C than other parts of the celery plant. Celery root can be prepared like other root vegetables.

Celery leaves, stalks, and seeds are used to flavor canned soups, sauces, pickles, sauerkraut, tomato products, and meats.⁹ Celery seeds can also be used in baked products.^2,9

Phytochemicals and Constituents

Celery is a nutrient-dense, mineral-rich vegetable. A 100-g serving of celery stalks (about one cup, chopped) contains only 14 calories, 95% water, and 1.6 g fiber.⁶ One cup of celery stalks provides 24% of the recommended daily allowance (RDA) of vitamin K, moderate amounts of vitamins A and C, folate, potassium, and manganese, significant amounts of all other B vitamins, vitamin E, calcium, copper, iron, magnesium, phosphorus, silicon and zinc.^6-7,9,11 Celery’s salty flavor is indicative of a higher sodium content than most vegetables, which is offset by its high potassium content as well as celery’s 3-n-butylphthalide (3nB), which relax smooth muscles, including blood vessels.^6,9 The amount of sodium in celery is insignificant even for the most salt-sensitive individuals. One celery stalk contains 32 mg of sodium and 104 mg of potassium while delivering only 20 calories as a carbohydrate.⁶ Due to the 3:1 ratio balance of potassium to sodium, consuming celery-based juices after exercise can replace lost electrolytes.^6,9

Celery seeds and oleoresin contain linoleic acid, a monounsaturated fatty acid (MUFA) which provides cardiovascular benefits.⁹ Celery oleoresin is commonly used in perfume making and consists of volatile oils, fixed oils, wax, and resin obtained from repeated steam distillation of coarsely ground celery flakes/powder. Celery seeds contain approximately 2% essential oil that is used in the flavor and fragrance industries.⁹ Volatile oils present in celery seed, predominately d-limonene and myrcene, decrease free radical production, while the sesquiterpenes eugenol and piperitone are associated with pain relief.^9,12 Celery essential oil also contains approximately 20% phthalides, including 3nB. When used for its aromatic properties, celery seed oil has a calming effect on the central nervous system and has antispasmodic, sedative, and anticonvulsant properties.⁸ Celery’s essential oil has antifungal activity and inhibits bacteria including Escherichia coli, Staphylococcus aureus, Shigella dysenteriae, Streptococcus faecalis, and Salmonella typhi.^9,10 In one study, celery seed oil (with 5% vanillin) was found to repel mosquitos better than commercially used repellent.¹⁰

Bioactive compounds known as phthalides (compounds that contain a chemical moiety known as lactone) are abundant throughout celery and other Apiaceae plants, such as lovage (Levisticum officinale), and appear to protect against cancer, high blood pressure, and cholesterol based on evidence from in vitro and animal studies.^9,11 The 3nB from celery seed extract has been evaluated for its ability to both treat and prevent inflammation and gastrointestinal irritation while promoting smooth muscle relaxation.⁹ Phthalides are responsible for celery’s flavor.¹¹ Research indicates that 3nB lowers uric acid production by inhibiting xanthine oxidase.^6,9 Sedanolide has been found to reduce tumor growth in vivo.⁹ Sedanolide and 3nB isolated from celery seed oil have demonstrated the ability to induce high amounts of glutathione S-transferase (GST), an important detoxification enzyme. Additionally, 3nB and sedanolide from celery stalk and seed have been linked to its traditional and aromatic uses to calm and mildly sedate the central nervous system.^9,12

All parts of the celery plant contain phenolic acids such as caffeic acid, chlorogenic acid, chrysoeriol, p-coumaric acid, coumarolyquinic acid, and ferulic acid.^3,16 Additionally, celery stalk, seed, and root are rich in antioxidant flavonoids including apigenin, apiin, luteolin, and kaempferol. Animal studies have demonstrated that apigenin improves blood glucose levels and antioxidant status, possesses antiplatelet activity, and stimulates adult neurogenesis.^10,16 The anti-inflammatory effects may be partly due to the presence of apiin, a glycoside of apigenin.¹⁷ Apiin increases the activity of detoxification enzymes, including superoxide dismutase (SOD), GSH peroxidase, and catalase, in vitro.³ Celery also contains coumarins, including furanocoumarins such as bergaptene, isopimpinellin, and psoralene, which are known to be phototoxic. However, furanocoumarin concentrations in stalks and root are below the threshold to cause any phototoxic reactions when consumed as part of typical diet.^8,10,18

The polyphenol content of celery coupled with its vitamin C content enhances celery’s ability to strengthen the immune system and reduce the severity of inflammatory conditions by enhancing detoxification processes in the body.^8,9 Like vitamin C, celery’s flavonoids reduce reactive oxygen species (ROS) and increases SOD enzymes.³ Celery seed also contains the phenylpropanoid apiol, which is a mild diuretic and urinary antiseptic, making it particularly useful in treating genitourinary conditions, including urinary tract infections.^3,8 Celery seed stimulates the kidneys, promotes urine flow, and assists in the breakdown of uric acid and other metabolic wastes.¹¹

Modern Research and Potential Health Benefits

There is limited human research that explores the therapeutic properties of celery. Animal studies have shown celery’s ability to reduce blood glucose, cholesterol, and blood pressure, which benefits cardiovascular health.³ Studies focused on the nutrients and phytochemicals found in celery leaf, seed, and root have demonstrated a wide range of potential health benefits including improved male fertility by increasing spermatogenesis, and protection against cardiovascular disease, diabetes, liver diseases, urinary tract obstruction, gout, gastric ulcers, rheumatic conditions, and neurodegenerative diseases.⁸ Further clinical research is needed to validate these potential uses and to determine the effective individual dose of celery in order to obtain maximum health benefits.⁹

Anti-Hypertensive Activity

High blood pressure or hypertension is one of the biggest risk factors for heart attack or stroke. More than 60 million people in the United States have hypertension.¹⁹ Coumarins that naturally occur in plants (as opposed to concentrated coumarins commonly prescribed as blood thinners, such as Coumadin^®) gently tone the vascular system, lower blood pressure, and may be useful in treating migraines.^6,9 The 3nB content in celery is correlated with lower blood pressure by acting as both a diuretic and a vasodilator via increasing prostaglandin synthesis and by blocking calcium channels.^9,20 In animal studies, daily consumption of 3nB (an equivalent dose of approximately four celery ribs) lowered blood pressure by 12 to 14% and cholesterol by 7%.^6,19 Animal studies have also confirmed that 3nB lowers blood cholesterol and reduces arterial plaque formation, which may increase the elasticity of blood vessels.¹⁹

Results from a pilot clinical trial that evaluated the blood pressure-lowering effects of celery seed extract in hypertensive patients found a statistically significant decrease in both systolic blood pressure (SBP) and diastolic blood pressure.¹⁹ Following a seven-day wash-out period, 30 mildly to moderately hypertensive patients were given 75 mg of celery seed extract standardized to contain 85% 3nB (no other information given) dosed twice daily, one capsule in the morning and one capsule in the evening for a total of six weeks. At week three and week six, there was a statistically significant decrease in SBP and DBP compared to baseline. The results indicate clinically relevant blood pressure-lowering effects that warrant larger, more conclusive double-blind studies.

Unlike conventional antihypertensive medications, such as beta-blockers, angiotensin converting enzyme (ACE) inhibitors, and calcium channel blockers that often leave patients feeling tired or forgetful, celery seed extract does not lower cerebral blood circulation.¹⁹ In fact, in animal models of stroke, recovery of neurological and brain function improved significantly after the use of celery seed extract. For stroke prevention and recovery, celery seed extract may offer significant benefits due to its ability to improve blood flow, protect the brain, and enhance energy production.

Detoxification Activity

Celery provides a wide variety of flavonoids and phenolic acids that play a vital role in neutralizing free radicals and preventing damage to pancreatic β-cells.¹⁶ Celery contains abundant phytonutrients that improve the elimination of metabolic wastes and lower blood pH. Chronic inflammatory conditions like arthritis traditionally have been treated with phytonutrients like those found in celery.

In a clinical trial evaluating the efficacy of an unnamed celery seed extract, participants who had chronic osteoarthritis and gout (a type of arthritis characterized by a buildup of uric acid crystals from excess purine intake in the joints) were given 34 mg of celery seed extract twice daily. Despite the small dose, after three weeks of use, the participants experienced statistically significant pain relief, with average pain reduction scores of 68%, though some participants reported 100% relief from pain.⁶ Maximum pain-relieving benefits were achieved after six weeks of using the standardized extract. In patients suffering from gout, it was noted that 3nB lowered uric acid production.

Another clinical study on a smaller group of patients with chronic arthritis-related pain reported on the effects of 75 mg of celery seed extract twice daily for three weeks.⁶ This higher dose produced even more clinically relevant and more highly statistically-significant results in pain relief scores, physical mobility, and quality of life. No adverse side effects were reported, but there was a predictable diuretic effect. Celery extracts standardized to contain 85% 3nB are considered by some authors an effective treatment for rheumatism, or arthritic and muscular aches and pains.^6,9

Celery seed extracts have demonstrated antioxidant activity in vivo with similar hepatoprotective activity to that of silymarin from milk thistle (Silybum marianum, Asteraceae) seed.¹⁰ Histopathological studies showed the reversal of structural changes of the liver induced by acetaminophen. Oral administration of celery seed extract (300 mg/kg) for six weeks prevented an increase in oxidative stress and hepatic enzyme and bilirubin levels.⁹ An infusion of celery root increased GSH and total antioxidant capacity, and celery leaf water extract increased GSH but had no effect on total antioxidant capacity.³

Cancer Preventive Activity

Celery has been studied for its ability to prevent cancer though improving detoxification processes in the body.⁶ Coumarins support immune function and may prevent cancer not only by protecting cells from becoming damaged by free radicals, but also enhancing white blood cell activity in targeting and eliminating potentially harmful cells, including cancer cells.^6,9 Researchers have investigated the antioxidant activity of celery in rats treated with doxorubicin, a potent chemotherapeutic drug commonly used to treat acute leukemias, lymphomas, and solid tumors.²⁰

The flavonoid apiin from celery leaves has shown to increase the activity of detoxification enzymes including SOD, GSH peroxidase, and catalase.³ In an animal study, celery leaf juice provided protection from drug-induced free radical damage while not interfering with the therapeutic effects of drugs like doxorubicin.²⁰ Clinical trials are needed to confirm these effects in humans.

Celery and other Apiaceae plants contain bitter-tasting polyacetylenes, potent antifungal and antibacterial compounds that are cytotoxic against several solid and leukemic cancer cell lines and also potentiate the cytotoxicity of other anti-cancer drugs.²¹ Pure polyacetylenes cannot be used in medicinal preparations due to their chemical instability and potential allergenicity when concentrated. To access the protective benefits of bioactive polyacetylenes, it is best to consume foods with high amounts of these compounds, such as celery, parsnips (Pastinaca sativa, Apiaceae), and parsley.

Insulin Regulation Activity

Insulin is a hormone produced by the β-cells of the pancreas, which regulates carbohydrate metabolism.¹⁶ Hyperglycemia, an indication of pre-diabetes, and diabetes occurs when insulin secretion or insulin regulation are abnormal. Chronic hyperglycemia and uncontrolled diabetes are the major causes of diabetes mellitus (DM). Long-term use of anti-diabetic medication is costly and is associated with weight gain, bone loss, and cardiovascular disease. Celery leaf extract has the potential as an adjuvant anti-diabetic medicine with fewer side effects. Unlike most anti-diabetic medications, celery’s phytonutrients affect the absorption of glucose in the intestine rather than stimulating the pancreas to produce more insulin and also decrease gluconeogenesis in the liver. It is believed that celery’s essential oils, phenolic acids, and flavonoids contribute to its hypoglycemic effects.

In a small randomized, placebo-controlled study, 16 elderly pre-diabetic participants were divided into two groups to study celery’s effects on hyperglycemia.¹⁶ The control group received 250 mg placebo capsules containing magnesium stearate and aerosol while the treatment group received a 250 mg dose of encapsulated celery leaf extract three times daily, 30 minutes prior to meals, for 12 days. Pre-and post-prandial blood glucose levels as well as insulin levels were obtained twice: before and after treatment. In the celery group, pre-prandial blood glucose levels decreased by 9.8% and post-prandial blood glucose levels decreased by 19.5% after treatment, but it slightly increased plasma insulin levels in elderly patients who were pre-diabetic.

Flavonoids play an important role in managing pre-diabetes or metabolic syndrome. Flavonoids reduce hyperglycemia, increase insulin resistance, control the intestinal absorption of glucose and glucose metabolism in the liver, as well as the digestion of carbohydrates, regulate cell-signaling AMP-activated protein kinase pathways, and even improves glucose uptake and reduce oxidative stress in skeletal muscle cells.¹⁶ High levels of sorbitol in diabetic patients are linked to cataracts, retinopathy, and neuropathy. Apigenin, a predominant flavonoid in celery, inhibits the aldose reductase, which is a key enzyme in converting glucose to sorbitol. Both apigenin and luteolin are being studied for their potential as sodium-glucose cotransporter-2 (SGLT-2) inhibitors in neuropathic diabetes. Kaempferol reduces hyperglycemia by increasing glucose uptake through the phosphatidylinositol-3-kinase (PI3K) and protein kinase C (PKC) pathways in muscle. Kaempferol also decreases fasting blood glucose and HbA1c levels and increases insulin resistance.

Consumer Considerations

Currently, California produces 75% of the stalk celery crop in the United States, followed by Florida, Texas, and Michigan.⁹ Celery is cultivated extensively in India, France, and the United States for its seed. In India, 40,000 tons of celery is grown annually, much of it for seed, which is exported to American and European markets.^3,9 For seed production, large-scale cultivation of celery is required. When seed heads are ripe, celery plants are cut and left to dry in the field for two to three days before threshed for seeds. Average yield of celery seed cultivation is approximately one ton per hectare.¹²

Celery generally is safe for common consumption. However, type 1 (IgE-mediated) allergic reactions to celery upon ingestion are common among those allergic to birch (Betula spp., Betulaceae) pollen as well as in central European populations.^8,10 Celery root which contains xanthotoxin (methoxsalen, 8-methoxypsoralen) and 5-methoxypsoralen and the allergen profilin (Api g 1), which shows strong similarities to birch pollen profiling.⁸ Additionally, those that are allergic to mugwort (Artemisia spp., Asteraceae) pollen frequently have allergic reactions to celery and other Apiaceae plants. This is known as “celery-mugwort-spice-syndrome” which was documented in 31 patients (27 females and four males) between 1978 and 1982.²² Subsequent skin and radioallergosorbent tests (RAST) revealed that 87% of patients that were allergic to celery had pollinosis in the form of mugwort pollen sensitization.²³ In sensitive individuals, allergic reactions may include anaphylaxis.^8,23 Celery may cause cross-reactivity (cross-allergenicity) between cucumber (Cucumis sativus, Cucurbitaceae), carrot, watermelon (Citrullus lanatus, Cucurbitaceae), and possibly apples (Malus spp., Rosaceae).⁸

Celery roots, stems, and seeds also contain a class of phototoxic phenolic compounds known as furanocoumarins, including psoralen, xanthotoxin, and bergapten (see above).⁸ Phototoxicity has primarily been reported by those handling fresh plants or consuming large quantities of celery root followed by exposure to high-intensity UV radiation, such as UVA photochemotherapy or tanning salons.²³ Phototoxic reactions are not associated with consuming celery seeds. Occasionally, furanocoumarins can cause sensitization in those experiencing phototoxic reactions although there is no allergic mechanism involved.²⁴ Besides the Apiaceae, furanocoumarins are only found in plants belonging to the mulberry (Moraceae), rose (Rosaceae), pea (Fabaceae), and citrus (Rutaceae) families.

The use of celery seed in concentrated herbal preparations is not recommended for pregnant women due to its uterine stimulating properties.^{8,10,12,23,25} Celery seed should be avoided if there is a history of nephritis or acute kidney inflammation due to potential irritation caused by excretion of celery’s phthalide and other essential oil components.^23,25 Celery seed may interact with individuals taking thyroid medications, diuretics, lithium, sedatives, or blood-thinning medications, including aspirin, clopidogrel (Plavix^®) and warfarin (Coumadin) as drug excretion may be enhanced by celery’s diuretic properties, reducing the effectiveness of medications.²⁵

Celery is listed among the top 10 fruits and vegetables that frequently have the highest pesticide residue. According to the Environmental Working Group’s annually published research on detectable pesticide residues on fresh produce, more than 95% of samples of conventionally grown celery tested positive for pesticides.²⁶ For children, the elderly, or those with compromised immune systems, it is recommended to choose celery that has been organically grown.⁶ If the celery is not organically grown, recent study indicate that rinsing produce in a 10% salt water solution was significantly more effective at removing pesticides than plain water. However, mixing one ounce of baking soda with 100 ounces of water was most effective at removing pesticide residues on the surface of crops.²⁷

Nutrient Profile²⁸

Macronutrient Profile: (Per 100 grams raw celery [approx. 1 cup, chopped])

14 calories
0.7 g protein
3 g carbohydrate
0.2 g fat

Secondary Metabolites: (Per 100 grams raw celery [approx. 1 cup, chopped])

Very good source of:

Vitamin K: 29.3 mcg (24.4% DV)

Good source of:

Folate: 36 mcg (9% DV)
Vitamin A: 449 IU (9% DV)
Potassium: 260 mg (5.5% DV)
Dietary Fiber: 1.6 g (5.3% DV)

Also provides:

Manganese: 0.1 mg (4.3% DV)
Vitamin B₆: 0.07 mg (4.1% DV)
Riboflavin: 0.05 mg (3.8% DV)
Vitamin C: 3.1 mg (3.4% DV)
Calcium: 40 mg (3.1% DV)
Magnesium: 11 mg (2.6% DV)
Phosphorus: 24 mg (2% DV)
Niacin: 0.3 mg (1.7% DV)
Thiamin: 0.02 mg (1.7% DV)
Iron: 0.2 mg (1.1% DV)

DV = Daily Value as established by the US Food and Drug Administration, based on a 2,000-calorie diet.

Image credits:

All photos ©2019 Steven Foster.
Illustration is from Prof. Dr. Otto Wilhelm Thomé, Flora von Deutschland, Österreich und der Schweiz. 1885.

References

1. Celery. New World Encyclopedia website. Available at: www.newworldencyclopedia.org/entry/Celery. Accessed March 13, 2019.
2. National Geographic Society. Edible: An Illustrated Guide to the World’s Food Plants. Lane Cove, Australia: Global Book Publishing; 2008.
3. Kooti W, Daraei N. A review of the antioxidant activity of celery (Apium graveolens). J. Evid-Based Complementary Altern. Med. 2017;22(4),1029-1034.
4. Megaloudi F. Wild and Cultivated Vegetables, Herbs and Spices in Greek Antiquity (900 B.C. to 400 B.C.). Environmental Archaeology. 2005;10(1):73-82.
5. Van Wyk B-E. Food Plants of the World. Portland, OR: Timber Press; 2006.
6. Murray M. The Encyclopedia of Healing Foods. New York, NY: Atria Books; 2005.
7. Ewbank A. Ancient Greek funerals were decked out in celery. Atlas Obscura website. Available at: www.atlasobscura.com/articles/history-of-funeral-wreaths. Accessed June 3, 2019.
8. Tyagi S, Chirag J, Dhruv M, et al. Medical benefits of Apium graveolens (celery herb). Journal of Drug Discovery and Therapeutics. 2013;1(5):36-38.
9. Sowbhagya HB. Chemistry, technology, and nutraceutical functions of celery (Apium graveolens): an overview. Critical Reviews in Food Science and Nutrition. 2012;54(3):389-398.
10. Al-Asmari AK, Athar MT, Kadasah SG. An updated phytopharmacological review on medicinal plant of Arab region: Apium graveolens. Pharmacognosy Reviews. 2017;11(21):13-18.
11. Fazal SS, Singla RK. Review of the pharmacognostical and pharmacological characterization of Apium graveolens. Indo Global Journal of Pharmaceutical Sciences. 2012;2(1):36-42.
12. Hussain IMT, Ahmed G, Jahan N, et al. Unani description of Tukhme Karafs (seeds of Apium graveolens). International Research Journal of Biological Sciences, 2013;2(11):88-93.
13. Nadkarni AK. Apium graveolens. Volume one. Indian Materia Medica. Bombay, India. Popular Prakashan Private Ltd.;1976.
14. Pitchford P. Healing with Whole Foods: Ancient Traditions and Modern Nutrition. Berkeley, CA: North Atlantic Books; 2002.
15. Blumenthal M, Busse WR, Goldberg A, Gruenwald J, Hall T, Riggins CW, Rister RS, eds. Klein S, Rister RS, trans. The Complete German Commission E Monographs¾Therapeutic Guide to Herbal Medicines. Austin, TX: American Botanical Council; Boston, MA: Integrative Medicine Communication; 1998.
16. Yusni Y, Zufry H, Meutia F, et al. The effects of celery leaf (Apium graveolens) treatment on blood glucose and insulin levels in elderly pre-diabetics. Saudi Medical Journal. 2018;39(2):154-160.
17. Mencherini T, Cau A, Bianco G, Della Loggia R, Aquino RP, Autore G. An extract of Apium graveolens var. dulce leaves: structure of the major constituent, apiin, and its anti-inflammatory properties. J Pharm Pharmacol. 2007;59(6): 891-897.
18. Schlatter J, Zimmerli B, Dick R, Panizzon R, Schlatter C. Dietary intake and risk assessment of phototoxic furocoumarins in humans. Food Chem Toxicol. 1991;29(8):523-520.
19. Madhavi D, Kagan D, Rao V, et al. A pilot study to evaluate the antihypertensive effect of a celery extract in mild to moderate hypertensive patients. Natural Medicine Journal. 2013;4(4):1-3.
20. Kolarovic J, Popovic M, Mikov M, et al. Protective effects of celery juice in treatments with Doxorubicin. Molecules. 2009;14:1627-1638.
21. Zidorn C, Johrer K, Ganzera M, et al. Polyacetylenes from the Apiaceae vegetables carrot, celery, fennel, parsley, and parsnip and their cytotoxic activities. Journal of Agricultural and Food Chemistry. 2005(53):2518-2523.
22. Wüthrich, Brunello & Hofer, T. (1984). Food allergy: The 'celery-mugwort-spice syndrome' - associated with mango allergy?. Deutsche medizinische Wochenschrift. 1984 Jun 22;109(25):981-986.
23. Gardner Z, McGuffin M. American Herbal Products Association’s Botanical Safety Handbook. 2nd ed. Boca Raton, FL: CRC Press; 2013.
24. Christensen LP. Polyphenols and Polyphenol-Derived Compounds and Contact Dermatitis. Chapter 62 in Polyphenols in Human Health and Disease. 2014;793-815. https://doi.org/10.1016/B978-0-12-398456-2.00062-1
25. Brinker F. Herbal Contraindications and Drug Interactions Plus Herbal Adjuncts with Medicines. Expanded 4th ed. Sandy, OR: Eclectic Medical Publications; 2010.
26. The Dirty Dozen. Environmental Working Group website. Available at: www.ewg.org/foodnews/dirty-dozen.php. Accessed on March 12, 2019.
27. How to Wash Vegetables and Fruits to Remove Pesticides. Food Revolution Network. https://foodrevolution.org/blog/how-to-wash-vegetables-fruits/. Accessed on 6-5-3019.
28. Basic Report: 11143, Celery, raw. United States Department of Agriculture website. National Nutrient Database for Standard Reference Legacy Release. April 2018. Available at: https://ndb.nal.usda.gov/ndb/foods/show/11143. Accessed June 7, 2019.
29. López-Alt JK. Warm Spanish-Style Giant-Bean Salad with Smoked Paprika and Celery Recipe. Serious Eats website. August 29, 2018. Available at: www.seriouseats.com/recipes/2015/02/warm-spanish-style-giat-bean-salad-recipe.html. Accessed June 7, 2019.
30. Bauman H, Valdes G, Charles C. Food as Medicine: Tomato (Solanum lycopersicum, Solanceae). HerbalEGram. 2016;13(7). Available at: http://cms.herbalgram.org/heg/volume13/07July/FoodAsMedicine_Tomato.html. Accessed June 10, 2019.
31. Bauman H, Applegate C. Food as Medicine: Shallot (Allium cepa var. aggregatum, Amaryllidaceae). HerbalEGram. 2017;14(2). Available at: http://cms.herbalgram.org/heg/volume14/02February/FAMShallot.html. Accessed June 10, 2019.