Is Celery Toxic?

Celery, like many natural foods, has toxic elements. If you ate pounds of it every day, it could have unpleasant or even dangerous health effects. Eating a few stuffed celery sticks on a holiday isn't going to hurt you, in most cases. Getting the juice from celery on your skin and going out in the sun, however, can cause a skin reaction.

Psoralens

Psoralens, compounds that occur naturally in a number of plants, including celery, can increase your skin's sensitivity to ultraviolet light. If you get celery juice on your skin and then go out into the sun, the skin in that area will develop a rash or other type of dermatitis within 12 to 36 hours. The rash in the area of contact lasts three to five days, but the skin remains hyperpigmented and can cause a burning pain. The hyperpigmentation can last for months, according to an October 2000 article in the "Baylor University Medical Center Proceedings."

Goitrogens

Substances that interfere with the uptake of iodine into the thyroid, called goitrogens, can cause goiter, or enlargement of the thyroid. Celery can act as a goitrogen if eaten in very large quantities, especially if it's not cooked. Cooking destroys most goitrogens. Goiters can cause the neck to swell, resulting in breathing or swallowing problems if they grow very large. A goiter can lead to hypothyroidism with symptoms such as lethargy, fatigue, dull and dry skin, and weight gain. In some cases, a goiter can become toxic and start to produce excess amounts of thyroid hormone, which leads to hyperthyroidism.

Pesticides

Pesticides can be harmful if you consume them on foods in large quantities, which is why you should always wash fruits and vegetables before eating them, even if you peel or cut off the skin. The Environmental Working Group published a list of the "dirty dozen," the fruits and vegetables found to be highest in pesticide residue. Celery appears near the top of the list, second only to apples. The EWG recommends you buy only organic celery in order to avoid pesticides. Side effects of pesticide exposure through foods have not been well proven, but could include decreased immune function and an increased risk of certain cancers, according to "Radcliffe's IPM World Textbook."

Bottom Line

Celery isn't likely to have any toxic effects as long as you take common-sense precautions such as washing your hands or any area of skin that touched the juice from celery, especially the green leafy leaves. Farmers and grocers are at particularly high risk for photosensitivity reactions from psoralens.

References

• Baylor University Medical Center Proceedings: Hyperpigmented Macules and Streaks
• Environmental Working Group: The Dirty Dozen
• MedlinePlus: Goiter
• Radcliffe's IPM World Textbook: Public Health Risks Associated with Pesticides and Natural Toxins in Foods
• Beyond Vegetarianism: Natural Toxic Constituents in Food, and Effect