Celery is an important food source of conventional antioxidant nutrients, including vitamin C, beta-carotene, and manganese. But its "claim to fame" in terms of antioxidant nutrients may very well be its phytonutrients. Many of these phytonutrients fall into the category of phenolic antioxidants and have been shown to provide anti-inflammatory benefits as well. Below is a representative list of the phenolic antioxidants found in celery.
In animal studies, celery extracts containing the above-listed phytonutrients have been shown to decrease risk of oxidative damage to body fats and risk of oxidative damage to blood vessel walls. In addition, these celery extracts have been shown to prevent inflammatory reactions in the digestive tract and blood vessels. Interestingly, there is also some animal research showing the ability of celery extracts to help protect the digestive tract and liver following consumption of acrylamides. (Acrylamides are potentially toxic substances formed in food through a reaction of sugars and amino acids, usually through the process of frying.)
While most of the research above involves animals versus humans, we have also seen studies showing the importance of celery in diets that are considered to be high in antioxidant and anti-inflammatory health benefits. For example, we've seen one recent study showing celery to provide 7% of all flavonol and flavone antioxidants in the diet of adults in China. In addition, mechanisms of anti-inflammatory support have also been shown in human studies. For example, we've seen research showing the ability of celery juice and celery extracts to lower the activity of tumor necrosis factor alpha (TNF-alpha), as well as the activity of nuclear factor kappa B (NF-kB). Decreased levels of the pro-inflammatory cytokines interleukin 1B (IL-1B) and interleukin 8 (IL-8) have also been seen in these studies. All of these four messaging molecules play a key role in the body's inflammatory responses, and keeping them in check is an important step in the prevention of unwanted inflammation.
One interesting aspect of celery's antioxidant phytonutrients involves its furanocoumarins. Prior to harvest - when celery is still growing in the ground - it responds to stress by producing furanocoumarins in greater amounts. These substances help protect it in its natural living conditions. Even after celery has been harvested, however, and you start to chop it up on your kitchen countertop, it will still increase its production of furanocoumarins, and you will get greater amounts of these phytonutrients for this reason. (However, it is incorrect to assume that the chopping of celery makes it nutritionally "better" than it was before you chopped it. That's because other phytonutrients decrease simultaneously with the increase in furanocoumarins. The net result is basically a change in the composition of the celery phytonutrients, an interesting topic about which we hope to see more research on in the future.)
In addition to its antioxidant and anti-inflammatory nutrients that help protect the digestive tract as a whole, celery contains pectin-based polysaccharides that can provide the stomach with special benefits. We've become accustomed to thinking about polysaccharides as starchy molecules that are used by cells as a way to store up simple sugars. But there are other types of polysaccharides in plants, including the non-starch, pectin-based polysaccharides found in celery. (Pectin is a sugar-related molecule that is largely formed from a substance called glucuronic acid.) The pectin-based polysaccharides found in celery —including apiuman—appear to have special importance in producing anti-inflammatory benefits. In animal studies, celery extracts containing apiuman have been shown to improve the integrity of the stomach lining, decrease risk of stomach ulcer (gastric ulcer), and better control the levels of stomach secretions. We look forward to future research that may confirm these stomach support benefits in humans based on dietary intake of celery in its whole food form.
Given the antioxidant and anti-inflammatory properties of celery described earlier in this section, it's not surprising to see the interest of researchers in the cardiovascular benefits of celery. Oxidative stress and inflammation in the bloodstream are critical problems in the development of many cardiovascular diseases, especially atherosclerosis. Unfortunately, most of the studies we've seen in this area have involved animals. Still, we've seen promising connections between the pectin-based polysaccharides in celery and decreased risk of inflammation in the cardiovascular system. We've seen these same types of connections between celery flavonoids and decreased risk of cardiovascular inflammation.
Phthalides are a further category of phytonutrients found in celery that seems important to mention as providing potential cardiovascular benefits. Phenolic substances found in celery, phthalides are a major contributor to the unique flavor of this vegetable. (Sedanenolide and butylphthalides are examples of phthalides found in celery.) Researchers have demonstrated that celery phthalides can act as smooth muscle relaxants, most likely through their impact on the flow of calcium and potassium inside cells and related nervous system activity involved with muscle relaxation. Of course, relaxation of smooth muscles surrounding our blood vessels allows them to expand and the result is a lowering of our blood pressure. (This overall process is called vasodilation.)
Phthalides in celery may also act as diuretics, further helping to lower the pressure inside our blood vessels. Unfortunately, most of the research we've seen in this area involves celery seeds, celery oil, or celery extracts - not the whole food itself. So it's not yet clear if these muscle-relaxant properties and blood pressure-lowering properties of celery phthalides will be provided to us if we include celery in our meal plans in everyday food amounts. But we will be surprised if future research on dietary intake of celery does not show some type of cardiovascular benefit directly related to celery phthalides.
Because chronic oxidative stress and excessive inflammation are key risk factors for the development of many cancer types, it's not surprising to see scientists interested in the potential benefits of celery intake for cancer prevention. While we've seen speculation about celery benefits for stomach cancer, colon cancer, and bladder cancer, we've been unable to find actual human research studies in any of these areas. Hopefully, future research studies will address the potential cancer-related benefits of celery much more closely.
In most U.S. markets, it's the Pascal family of greenish to pale-green celery cultivars that we've become most accustomed to finding in the produce section. Pascal celery is larger than most other celery types, with firm, solid stalks and leafy ends. Yet even within this particular scientific type of celery (Apium graveolens var. dulce), there are many other options including Matador, Red Stalk, Tango, and Sonora. Celery actually comes in a variety of colors from sheer white to vibrant gold to rich red and deep green.
In this genus/species of plant (Apium graveolens) are also found two other important types of celery. The first is celeriac (also called root celery, turnip-root celery, or knob celery). Just like the name suggests, root celery is characterized by a large root ball, which is especially prized for its unique somewhat nut-like taste. (The scientific name for celeriac is Apium graveolens var. rapaceum.) The second type of celery is leafy celery (Apium graveolens var. secalinum), which looks very similar to parsley but tastes like celery! Root and leaf celeries are valued worldwide for their unique flavors and aromas; they are often "main plate" vegetables rather than salad or soup additions.
Regardless of which celery variety you choose to buy or grow, there are nutrient benefits to be found in all parts of the plant, including the leaves, stalks, roots, and seeds. "Celery hearts" usually refers to the innermost stalks of Pascal celery. These stalks are typically the most tender.
The bigger family of plants that houses celery is what scientists call the Apiaceae or Umbelliferae family. It is also commonly known as the parsley or carrot family. (Just compare leafy carrot tops or parsley leaves with celery leaves and you'll see why.) In addition to celery, carrots, and parsley, this plant family also includes dill, fennel, cilantro/coriander, parsnip, anise, caraway, chervil, cumin, angelica, and asafetida.
Over time, many different types of plants across the world have been referred to by the common name "wild celery." Most of these plants—although not all of them—belong to the same family (Apiaceae/Umbellerifereae) as the Pascal celery found in U.S. markets. You'll find Australian celery, Vietnamese celery, Indian celery, Maori celery, and water celery all being referred to as "wild celery" in various cultures.
The direct ancestors of Pascal celery were cultivated in parts of Europe and the Mediterranean as early as 1000 BC, and we have evidence of celery being used as a medicinal plant in ancient Egypt. There's also evidence that ancient Greek athletes were awarded celery leaves to commemorate their winning.
Today over 1 billion pounds of celery are produced each year in the United States, with California, Michigan and Florida accounting for about 80% of all celery production. The average U.S. adult eats about 6 pounds of celery per year. A substantial amount of celery in the U.S. comes from Mexico, and the U.S. exports about 200 million pounds of celery to Canada each year.
On a worldwide basis, celery is often served as a "major plate vegetable" rather than an additive to salads or soups. In addition, root celery varieties of this food (chosen for their large root balls rather then their stalks) are often cultivated over the large stalk Pascal varieties that have become most popular in the U.S.
Choose celery that looks crisp and snaps easily when pulled apart. It should be relatively tight and compact and not have stalks that splay out. The leaves should be pale to bright green in color and free from yellow or brown patches. Sometimes celery can have a condition called "blackheart" that is caused by insects. To check for damage, separate the stalks and look for brown or black discoloration. In addition, evaluate the celery to ensure that it does not have a seed stem, the presence of a round stem in the place of the smaller tender stalks that should reside in the center of the celery. Celery with seed stems are often more bitter in flavor.
At WHFoods, we encourage the purchase of certified organically grown foods, and celery is no exception. Repeated research studies on organic foods as a group show that your likelihood of exposure to contaminants such as pesticides and heavy metals can be greatly reduced through the purchased of certified organic foods, including celery. In many cases, you may be able to find a local organic grower who sells celery but has not applied for formal organic certification either through the U.S. Department of Agriculture (USDA) or through a state agency. (Examples of states offering state-certified organic foods include California, New York, Oregon, Vermont, and Washington.) However, if you are shopping in a large supermarket, your most reliable source of organically grown celery is very likely to be celery that displays the USDA organic logo.
Most people use plastic produce bags to bring celery (and other fresh vegetables) home from the market. If this method is the one you use, you can leave your celery in the plastic produce bag, squeeze out any extra air, and close the bag securely for storage in your refrigerator. While food storage in plastic bags can create health risks under certain circumstances, 5-7 days of refrigerator storage for an uncut head of celery is not one of them. The refrigerator temperature is too cold (about 40°F/4°C), the time period too short, and the celery-to-plastic surface contact too moderate to create a substantial health risk from this use of a plastic produce bag. If possible, please recycle the plastic bag after using.
We recommend a period of 5-7 days as a window of time for refrigeration of fresh celery. While some nutrients appear to be stable in whole, refrigerated celery for longer periods of time, several studies show greater losses of phenolic antioxidants in celery after this week-long period. In addition, based on changes in flavonoid content, we also recommend that you wait to chop up your celery just before you are adding it to a salad or cooked dish (rather than chopping it up the night before and leaving it stored in the refrigerator overnight). If you find yourself needing to cut up celery far ahead of time, in a way that requires overnight storage in your refrigerator, we recommend that you place the cut celery into a hard plastic or glass container instead of a soft plastic bag. Since the cutting of celery will expose more of its surface area, you can avoid increased contact of more celery surfaces to the less stable materials that are found in soft plastic bags by using more sturdy containers for your cut celery. Loss of some nutrients in celery—for example, its vitamin C content—is likely to be slowed down through refrigeration.
Here is some background on why we recommend refrigerating celery. Whenever food is stored, four basic factors affect its nutrient composition: exposure to air, exposure to light, exposure to heat, and length of time in storage. Vitamin C, vitamin B6, and carotenoids are good examples of nutrients highly susceptible to heat, and for this reason, their loss from food is very likely to be slowed down through refrigeration.
Freezing will make celery wilt and should be avoided unless you will be using it in a future cooked recipe.
For some of our favorite recipes, click Recipes.
If you'd like even more recipes and ways to prepare celery the Nutrient-Rich Way, you may want to explore The World's Healthiest Foods book.
Celery, diced, raw
GI: very low
|vitamin K||29.59 mcg||33||36.6||excellent|
|folate||36.36 mcg||9||10.1||very good|
|potassium||262.60 mg||6||6.2||very good|
|pantothenic acid||0.25 mg||5||5.6||very good|
|fiber||1.40 g||5||5.6||very good|
|vitamin B2||0.06 mg||5||5.1||good|
|vitamin C||3.13 mg||4||4.6||good|
|vitamin B6||0.07 mg||4||4.6||good|
|vitamin A||22.67 mcg RAE||3||2.8||good|
Density>=7.6 AND DRI/DV>=10%
Density>=3.4 AND DRI/DV>=5%
Density>=1.5 AND DRI/DV>=2.5%