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. 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.
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. 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. 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.
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. As noted in the worlds healthiest foods.