Celery is mostly fiber and water—by weight, celery is 1.6 percent dietary fiber and 95 percent water. It is an excellent source of vitamin C. Celery also provides the minerals potassium, calcium, molybdenum, manganese, magnesium, phosphorus, and iron, as well as the B vitamins thiamine, niacin, folate, and B6.
Celery also provides some trace nutrients, including the male hormone androstenone and apiol, a substance that appears to affect the female hormonal system and was at one time used to induce miscarriage of unwanted pregnancies. The phthalides in celery help it to enhance flavor and richness in other foods, even when its own taste is overpowered. These compounds may also help arteries to dilate, reducing blood pressure.
Celery contains coumarins, the best known of which is the anti-coagulant warfarin.
Others, such as auraptene, have been shown in animal studies to help prevent cancers of the skin, tongue, esophagus, liver, and colon. Ensaculin is being investigated for its potential in treating dementia. It has not yet been proven effective for this purpose in humans, but its main side effect—low blood pressure—could be a health advantage in the long run. These compounds may also help reduce the risk of blood clots and stroke. In the laboratory, other compounds appear to reduce the growth and proliferation of cancer cells.
The one drawback in celery’s nutritional package is that because so much of this vegetable is water and fiber, there’s just not a lot of room for these other nutrients— so you may have to eat a lot of celery to see its benefits.
Celery seed has an even longer medical history. It was at one time used as an analgesic, though modern testing has found no such effect.
A word of warning: For a small number of people, celery can cause a severe allergic reaction—including anaphylactic shock. There appears to be more of the allergen in celery root than in the stalks that are more commonly eaten in this country, with seeds containing the most. Cooking does not appear to destroy the allergen.Nutritional Facts
One raw stalk (7.5 inches long) of celery provides 6 calories, 1.5 g carbohydrate, 0.3 g protein, 0.1 g fat, 0.7 g dietary fiber, 54 IU vitamin A, 3 mg vitamin C, 11 mcg folic acid, 115 mg potassium, 35 mg sodium, 10 mg phosphorus, 16 mg calcium, and 4 mg magnesium.