ecent research has greatly bolstered our knowledge about celery's anti-inflammatory health benefits, including its protection against inflammation in the digestive tract itself. Some of the unique non-starch polysaccharides in celery—including apiuman—appear especially important in producing these anti-inflammatory benefits. (Unlike starchy polysaccharides that provide plants with a way to store simple sugars, these non-starch polysaccharides in celery help provide this vegetable with its unique structure and are not made from simple sugars but rather from pectins.)
In addition to well-known antioxidants like vitamin C and flavonoids, scientists have now identified at least a dozen other types of antioxidant nutrients in celery. These antioxidants include dihydrostilbenoids like lunularin as well as furanocoumarins like bergapten and psoralen. The antioxidant support we get from celery is largely due to its phenolic nutrients that have been shown to help protect us against unwanted oxygen damage to our cells, blood vessels, and organ systems.
If you are planning to steam vegetables as part of your meal, you can include celery without having to worry about excessive loss of its phenol-based antioxidants. In a recent study, researchers compared the impact of steaming (10 minutes) versus boiling (10 minutes) versus blanching (3 minute submersion in boiling water) on the total phenolic antioxidant nutrients in celery. Both boiling and blanching resulted in substantial loss of these antioxidants, in the range of 38-41%. With steaming, however, 83-99% of these antioxidants were retained in the celery even after 10 minutes. While we encourage the practice of steaming as a cooking method of choice for many of our WHFoods vegetables, it's great to see how nutrient-preserving steaming can be in the case of celery.
Based on multiple recent studies involving nutrient changes in stored, refrigerated celery, we recommend a period of 5-7 days as a window of time for consuming 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). This will help to preserve its maximum nutrient potential.