Celeriac

What is Celeriac?

Celeriac is the swollen root of a celery plant, Apium graveolens var. rapaceum.

It is a vegetable first and foremost. People roast it, mash it, grate it raw into salad, or add it to soup.

It tastes like celery stalk, but milder and nuttier. Shops sell it as a knobbly brown root, sometimes called celery root. It is close kin to celery stalk and celery seed, which are the forms used in herbal medicine.

Older European kitchen and herb lore linked celery plants to gout, swollen joints and water retention. Long use is not proof that a thing works, and it is not proof that it is safe. Both have to be checked on their own.

Here is the honest verdict. Celeriac is a useful, low-starch vegetable with fibre, potassium and vitamin C. As a remedy for any named illness, the human evidence is thin to absent.

How does Celeriac work?

Most of what celeriac does is ordinary nutrition. It gives fibre, potassium, vitamin C and vitamin K, with few calories and a lot of water.

Celery plants also hold phthalides, a group of oily aroma compounds. In animal studies, one of these relaxed the walls of blood vessels. Whether eating celeriac does that in people has not been shown.

The root contains flavonoids such as apigenin and apiin. In cell studies, apigenin quiets some signals tied to swelling. That is laboratory work, and it does not tell you what a plate of celeriac will do.

Celery crops take up nitrate from soil. In the body, some nitrate turns into nitric oxide, which widens blood vessels. Most of that research used beetroot juice, not celeriac, so the link is a guess here.

The traditional "water pill" idea has a simple possible cause. Celeriac is mostly water and potassium, so a big serving may nudge urine output. No good human trial has tested this for the root.

What forms does Celeriac come in?

Celeriac is sold as food far more often than as a supplement.

- Fresh whole root, sold loose or waxed. - Pre-cut cubes or batons, chilled or frozen. - Celeriac remoulade: grated raw root in a mayonnaise dressing.

- Mash, purée and oven chips. - Dried celery root powder, used as a seasoning. - Celeriac juice, usually blended with other vegetables.

Two near relatives are often confused with it. Celery salt is ground celery seed mixed with salt. Celery seed extract capsules are a different product, with their own stronger claims and their own cautions.

If a product promises blood pressure or gout benefits, check the label. It is almost certainly celery seed, not celeriac root.

Where it comes from:

Wild celery grew in salt marshes around the Mediterranean and the Near East. Ancient Greek and Roman writers mentioned it as a strong-smelling herb. It was used in wreaths and in funeral rites as much as in cooking.

Old herbals placed celery plants in the "opening" group. Writers of the period claimed they moved urine, eased wind and helped stiff joints. Those texts describe what people believed then, not what has been tested since.

The swollen-root form was described in Europe in the 1600s. Gardeners in Italy and Germany bred it up as a winter vegetable. By the 1700s it was common in German, Polish, French and Dutch kitchens.

From then on its story is mostly culinary. It became a soup base, a mash and the French salad remoulade. Medicinal claims stayed attached to the seed, not to the root.

What does Celeriac help with?

• Everyday nutrition and fibre: This is the one clear use. Celeriac adds fibre, potassium, vitamin C and vitamin K to a meal. A diet with plenty of vegetables is linked to better heart and bowel health. That credit belongs to the whole pattern of eating, not to celeriac alone.
• A lower-starch swap for potato: Celeriac mash holds far less starch than potato mash. People managing weight or blood sugar sometimes use it this way. No trial has tested celeriac itself for blood sugar. It is a sensible swap, not a treatment.
• Traditional use for gout and joint pain: Old European herb books recommended celery plants for gout. The modern version of that claim is sold as celery seed extract, not root. Human trials are few, small and weak. There is no good evidence that eating celeriac lowers uric acid or prevents gout attacks.
• Traditional use as a water pill (diuretic): Celery was long classed as a plant that increased urine. Celeriac is mostly water and potassium, so a large serving may raise urine output a little. This has not been measured in a proper human study. It is not a substitute for a prescribed water pill (diuretic).
• Blood pressure support (unproven for celeriac): Small studies on celery seed extract have hinted at a drop in blood pressure. They were short, small and not strong enough to rely on. None of them used celeriac root. Treat any blood pressure claim on a celeriac product as unproven.

Which foods are rich in Celeriac?

1. Celeriac remoulade
2. Celeriac mash or purée
3. Root vegetable soups and winter stews
4. Roast vegetable trays
5. Celeriac oven chips
6. Mixed vegetable juices

Practical Tips:

Celeriac is itself a food, so this list is simply where you meet it. It is a winter root, best from autumn to early spring.

Peel it thickly, since the skin is tough and often gritty. Cut surfaces brown fast, so drop them in water with lemon juice.

If you must limit potassium, boiling in plenty of water and draining lowers the amount.

What are the side effects of Celeriac?

• Itchy or tingling mouth and lips in people allergic to celery
• Hives, swelling or trouble breathing in severe celery allergy
• Burning, blistering rash if juice is left on skin before sun exposure
• Wind and bloating from the fibre, mostly from raw servings
• More urine after a large portion
• Loose stools if you suddenly eat a lot more fibre

Good to know:

For most people celeriac causes nothing worse than a bit of wind. It is an everyday vegetable and is eaten safely by millions.

The one serious risk is allergy. Celery is a well-known cause of severe allergic reactions in Europe, including anaphylaxis. Celeriac can trigger it, and cooking does not always remove the risk.

The second real risk is skin. The juice holds furanocoumarins, which can make skin burn badly in sunlight. This mostly affects people who handle large amounts, such as cooks and pickers.

How much Celeriac should you take?

• Recommended daily: Celeriac is a food, so there is no dose to take. A normal serving is roughly 100 to 150 g, about a cupful once diced. That figure describes a plate of food, not a plan for you. Supplement labels you may see are usually celery seed, a different product with stronger claims. If you want to try one, ask a pharmacist or your doctor first.
• Best time of day: Timing does not matter. Eat it whenever it suits the meal. One small point: a very large serving is high in water. Some people find that means an extra trip to the toilet at night.
• With or without food: Celeriac is food, so this does not really apply. Eating it with some fat, such as olive oil, helps you absorb its fat-soluble vitamins. Raw grated celeriac keeps more vitamin C. Boiling pulls some potassium out into the water, which can help if you have been told to limit potassium.
• Time to effect: As food, there is nothing to wait for. Fibre effects on bowel habit show up within a few days. For gout, swelling or blood pressure, it may do nothing at all. No reliable human evidence says otherwise. Do not delay proper treatment while you wait.
• How long to take it: You can eat celeriac as often as you like a vegetable, year after year. There is no course to finish and no break to take. If you are using it hoping for gout or blood pressure benefits, set a limit. A few weeks is enough to see that nothing is happening.