Celery

Celery (Apium graveolens)

Celery (in Hebrew “סלרי”) is a vegetable from the Apiaceae (umbellifer) family — together with carrot, parsley and dill — and it is one of the lowest-energy vegetables there is: 14 calories per 100 grams, 95% water.

In recent years it has become an internet star thanks to the “celery juice” trend, which attributes far-reaching powers to it. These claims are not supported by research, and that’s a shame — because celery has some real and interesting properties that get lost in the noise.

This page also covers two things worth knowing that nobody talks about: celery is an allergen that must be labeled by law in Europe, and it is the “natural” nitrate source used to cure processed meats that declare “no nitrates.”

Nutrition facts per 100 grams (stalks, raw)

The sodium row is unusual: 80 mg per 100 grams is one of the highest among fresh vegetables — ten times that of cucumber. This comes from the plant’s ability to concentrate sodium from the soil, and it is also the reason for its distinctive salty-bitter taste. The amount is not a problem in any reasonable diet, but it explains why celery “works” in soup without much salt.

Phthalides and blood pressure — what’s really known

Celery contains phthalides, chief among them 3-n-butylphthalide (3nB) — the compound that is also responsible for its characteristic smell. Animal studies have shown that it relaxes smooth muscle in blood vessel walls, and lab studies have identified possible mechanisms.

Where things stand today:

• Animal studies — fairly consistent, with a drop in blood pressure.
• Human studies — few, small, and most were done with concentrated celery seed extract (75-150 mg a day), not with the vegetable. Some showed a moderate drop in blood pressure.
• The vegetable itself — there is no evidence that eating celery stalks in a reasonable amount lowers blood pressure in a clinically meaningful way.

A fair conclusion: a promising mechanism, early evidence, and a big gap between a concentrated extract and a stalk in a salad. Celery is a good vegetable — not a blood pressure medication.

“Celery juice” — the trend vs. the evidence

The trend recommends 400-500 ml of celery juice on an empty stomach in the morning, and credits it with curing autoimmune diseases, “cleansing the liver” and restoring digestion.

There is no clinical research supporting these claims. What is true:

• Juicing removes the fiber — the component that makes celery beneficial in the first place.
• It concentrates nitrate and sodium — usually not a problem, but relevant for anyone medically restricting them.
• It concentrates oxalates and vitamin K — 500 ml of juice is a significant amount of vitamin K, relevant for people taking anticoagulants.
• The benefit people do report — hydration and a feeling of fullness in the morning — also comes from a glass of water and whole celery.

Nitrate — the link to “no nitrates” meat

Celery is rich in natural nitrate. The industry takes advantage of this: fermented celery powder is used as a source of nitrite in curing processed meat — making it possible to market sausages and dried meat as having “no added nitrates.”

Chemically, it’s exactly the same nitrite. The claim is correct by regulation and misleading nutritionally. Anyone who avoids processed meat because of nitrites gains nothing by switching to the version with celery powder.

Benefits

• One of the lowest energy densities there is. 14 calories per 100 grams — volume, crunch and chewing with almost no energy.
• Vitamin K: 24% of daily intake per 100 grams.
• Apigenin and luteolin: Flavonoids studied in anti-inflammatory and neurological contexts. The evidence is mainly from the lab.
• Hydration. 95% water alongside potassium and a little sodium — a convenient profile for fluid balance.
• Practically zero glycemic index and load — suitable for any diabetic diet.
• Low-FODMAP in a small serving — up to about 10 cm of stalk.
• A key flavor base. Together with onion and carrot it is the aromatic base of almost every soup and stew — and makes it possible to cut down on salt.

Downsides and considerations

• A declared allergen. Celery is on the list of allergens that must be labeled under European Union regulations. The allergy is not rare in Europe, and can be severe and even anaphylactic. It is common as part of a cross-reactive allergy syndrome with mugwort pollen (“Celery-Mugwort-Spice Syndrome”).
• Furanocoumarins and sun sensitivity. Celery contains psoralens, and their concentration rises sharply in stalks infected with pink rot fungus. Prolonged contact with celery juice followed by sun exposure may cause phytophotodermatitis — a local burn. A phenomenon known mainly among kitchen and farm workers.
• Low nutrient density. Apart from vitamin K, celery is not a significant source of any nutrient. It fills you up, it doesn’t nourish.
• Oxalates. In moderate amounts — a consideration for people prone to kidney stones, especially in concentrated juices.
• Vitamin K and anticoagulants. Consistent intake, not avoidance. Especially relevant for anyone drinking celery juice in quantity.
• Pesticide residues. Celery regularly appears on lists of vegetables with relatively high pesticide residues — the structure of the stalks makes washing difficult.
• The “negative calorie” myth. The idea that digesting celery uses more energy than it provides is not true. The thermic effect of food is about 5-10% of the calories in carbohydrate — meaning celery with 14 calories still leaves about 13. It is low in calories, not negative.

Practical use

• Eat it whole, not as juice. The fiber is the beneficial part, and juicing removes it.
• Wash between the stalks — dirt gets trapped at the base, and the stalk’s shape makes it hard.
• Don’t throw away the leaves. They are richer in flavor and antioxidants than the stalks, and excellent in soup, in pesto or chopped into salad.
• Combine with protein and fat: A celery stalk with peanut butter, tahini, hummus or cheese — that’s how an “air snack” becomes a real snack.
• As a soup base — less salt needed thanks to its sodium and natural flavor.
• Choose firm, crisp stalks that snap cleanly, with green rather than yellow leaves. A stalk that bends is old.
• Store wrapped in aluminum foil in the fridge — a method that significantly extends crispness compared with a plastic bag.
• Throw away stalks with pinkish-brown spots — a possible sign of pink rot and a high concentration of psoralens.
• People allergic to mugwort pollen — be careful, and watch for celery in spice blends and ready-made soups, where it is a common hidden ingredient.

Summary

Celery is an excellent low-calorie vegetable for filling the plate, a reasonable source of vitamin K, and a flavor base that makes it possible to cut down on salt. Its phthalides are interesting but are not a blood pressure medication, and the celery juice trend is not supported by research — it also removes the fiber, which is the beneficial thing about the vegetable. Two things worth knowing that nobody talks about: celery is an allergen that must be labeled and may cause severe reactions, and celery powder is the source of nitrite in meats marketed as “no nitrates” — a claim that is correct by regulation and misleading nutritionally.