The New Complete Book of Food
Adverse Effects Associated with This Food
Contact dermatitis. Celery contains limonene, an essential oil known to cause contact der-
matitis in sensitive individuals. (Limonene is also found in dill, caraway seeds, and the peel
of lemon and limes.)
Photosensitivity. The furocoumarins (psoralens) released by damaged or moldy celery are
photosensitizers as well as potential mutagens and carcinogens. Constant contact with these
chemicals can make skin very sensitive to light, a problem most common among food work-
ers who handle large amounts of celery without wearing gloves.
Nitrate/nitrite poisoning. Like beets, eggplant, lettuce, radish, spinach, and collard and
turnip greens, celery contains nitrates that convert naturally into nitrites in your stomach
and then react with the amino acids in proteins to form nitrosamines. Although some nitro-
samines are known or suspected carcinogens, this natural chemical conversion presents
no known problems for a healthy adult. However, when these nitrate-rich vegetables are
cooked and left to stand at room temperature, bacterial enzyme action (and perhaps some
enzymes in the plants) convert the nitrates to nitrites at a much faster rate than normal.
These higher-nitrite foods may be hazardous for infants; several cases of “spinach poison-
ing” have been reported among children who ate cooked spinach that had been left standing
at room temperature.Food/Drug Interactions
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