Celery (Apium graveolens) is a plant, vegetable, with long hairy stalk, leaves, and hypocotyl from the family Apiaceae. It exists since antique times. Celery is eaten as salad or meal (stalks can be even eaten raw) or can be used in cooking as a spice. Beside kitchen, extracts of celery are used in medicine. It's not surprising that celery seed is a component in pain killers pills because it was a medical plant in ancient Egypt.
Celery flowers are yellow-white, and leaves are pinnate to bipinnate with stalk which can be separated into strings. It grows to 15-20cm in height, but wild celery can grow to 1 m tall.
The name of the plant "celery" is from French word céleri (Italian seleri, further in history Latin selinon and Greek σέλινον (selinon)). Celery grows on fertile, moisture-rich soil, so historically celery has been used for a long time, from Europe (mostly Sweden), Africa (Algeria, Egypt) and (Asia the Caucasus Mountains of India). Although archeological find of celery dating to the 9th century BC at Kastanas, there is the literary evidence for ancient Greece in Homer's Iliad and in Odyssey, where wild celery is mentioned. Because of spicy odor and dark colored leaves, celery was associated with the cult of death in Greece. Romans later dedicated celery to Pluto, god of hell. It also has a reputation as an aphrodisiac, and French King Louis XV’s official chief mistress - Madame de Pompadour, swore by celery and truffle soup washed down with hot chocolate. In the English kitchen, celery didn't come until the 17th century - until plant didn't get high sweetness. In the USA for a long time celery was known only as one class of parsley; there it was popularized in the 19th century.
In North America the most popular cultivar is "Pascal" celery with firm, solid stalks and leafy ends, so stalk is most used and eaten there. In Europe is popular cultivar "celeriac", or blanched celery, which is often incorrectly named celery root (because of large white hypocotyl which is most eaten there). In Asia is for example mostly popular celery leaf. Wild form of celery - "smallage", is also in use, which has an original smell and because of that is mostly used as a spice. Taste of wild celery is coarse, but thanks to cultivation, it becomes sweeter. Leaves of celery are most used as a flavor, even if the herb is dried. There is so called "holy trinity" in Louisiana Creole and Cajun cuisine, which consists of celery, onions, and bell peppers. In France, French mirepoix, the base for sauces, is made of celery, onions, and carrots. You can't imagine soup anywhere in the world without celery.
There is also celery salt made by celery seeds (or extract of roots and dried leaves) and salt which is used in cocktails such as Bloody Mary.
Celery seed is mostly used for getting volatile oil for perfume and pharmaceutical industries. Seed is important because contains an organic compound called apiole. It can be used as a spice in meals. Celery plant’s essential oils are popular and usually used as a soothing remedy for osteoarthritis, anxiety and gouty-arthritis conditions.
It's interesting that restaurants used to keep celery in a container of water with sulfites, but in 1986 it was banned due to allergic reactions caused by sulfites.
Although is thought that celery is "negative-calorie food," (meaning that burns more calories than the body can obtain), truth is different - it provides low-calorie dietary fiber which boosts digestion and weight loss, so it's used in weight loss diets. It's important that because of a high percentage of water and electrolytes, it can also prevent dehydration.
Celery is a source of antioxidant nutrients, vitamins like C, K and B6, beta-carotene, and manganese, but scientists have also identified a dozen types of antioxidant nutrients including dihydrostilbenoids such as lunularin as well as furanocoumarins like bergapten. Antioxidants fight free-radical damage so that celery can prevent inflammation of any kind, especially urinary tract infections, or bacterial infections of the digestive tract and reproductive organs. These antioxidants, however, can be lost if the meal is prepared by boiling, so it's best that celery is eaten row or steamed.
There is also a celery study from 2010 published in the Journal of Pharmaceutical Biology, which hypotheses is that celery’s ethanol extract can protect the lining of the digestive tract from ulcers.
Studies from the University of Missouri and the University of Illinois also found that the apignen in celery can inhibit breast and pancreatic cancer, and the luteolin, a nutrient in celery, can boost cognitive function.
It could be that it also significantly reduced hypertension because of 3-n-butylphthalide which has lipid-lowering action (in an experiment published in the Journal of Medicinal Food it was demonstrated on lowering blood pressure in rats, but 14 of 16 tested people also confirmed that). Celery phthalides can act as smooth muscle relaxants, so it's most likely that it improve the potassium and calcium flow from and in the cells. Further, its allow our blood vessels to expand and contract, improving blood flow, so the result is a lower blood pressure. Therefore eating celery regularly helps us to avoid many diseases like it's shown in many studies: high blood pressure, acidosis, neuritis, tuberculosis, catarrh, mental exhaustion, anemia, obesity, asthma, constipation and it also protects kidney, pancreas and helps us improving the overall health.
But, we should keep in mind that celery can cause allergy, even anaphylactic shock. It's important that we know that allergen can't be destroyed at cooking temperatures. Celery root contains more allergen than the stalk, but seeds contain the highest levels of allergen content. There are risks of eating large amounts of celery like malnutrition and gastrointestinal problems, and because it is low-calorie food, it could lead to malnutrition. Seeds have bergapten which increases photosensitivity (because of that, external use of essential oil in bright sunshine should be avoided). There are also chemicals called psoralens, which, if are on your skin, make it temporarily highly sensitive to ultraviolet light: if you get celery juice on your skin and go into the sun, you could get a rash which is the main problem of workers in celery fields.
The United States are a big manufacturer of celery, yearly over 1 billion pounds are produced, and the average adult consumes about 6 pounds of celery per year.