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Why Do Onions Make You Cry?

Posted: June 23, 2017

This article was written by Sharon Driedger, a 2016 Penn State Extension Summer Assistant in Montgomery County. Sharon is a senior Nutrition major at West Chester University. Most people know that onions can make you cry when you cut into them. But, do you know why? Onions also provide important vitamins to the diet.
photo: pixby.com/stevepb

photo: pixby.com/stevepb

“Why do onions make you cry?” the somewhat pitiful yet common question was asked by the camper at the 2016 4-H Chef Camp, as she and others shared the tear-jerking experience of chopping onions. The well-known fact that onions cause eyes to bring forth tears begs the question of “why?”. The answer to this question, according to the University of Nebraska’s Institute of Agriculture and Natural Resources, is simply because of the compound in onions, called propanethial-s-oxide, which is released to the air after cutting onions and subsequently contacts the eye. Sulfuric acid is formed at that point and the eye’s nerves stimulate tears to be shed. The shorter answer I gave to the camper was that onions contain chemicals that irritate the eyes.

Not only do onions provide sulfuric acid to irritate the eyes, sulfur is a chemical that provides the strong smell experienced by the onion chopper according to the University of Georgia. So if you chop onions, your eyes will be irritated and you’ll enjoy a strong smell. Although sulfur in onions can give a negative experience for the onion cutter, these same chemicals provide powerful health benefits for the onion consumer. Research, according to the University of Nebraska, has suggested that these sulfur compounds, along with a phytochemical found in abundance in onions called Allicin, could lower cholesterol levels and blood pressure. Sulfur compounds have been attributed to preventing heart disease according to Utah State University. Research with the University of Georgia has also suggested that onions can reduce the risk of cancer and provide many other nutrients such as vitamin C, the B vitamins and fiber. If you find you don’t particularly care for onions, you can still gain the nutrients and health benefits onions boast from eating a variety of other fruits and vegetables.

As with other fruits and vegetables, proper selection, storage and uses of onions are important. The Penn State Extension provides a brochure called Pennsylvania Produce: A Guide to Quality Produce Grown in Pennsylvania, which includes information about that. When selecting a good onion, look for one that is firm with even-colored, paper-dry skin. Onions should be stored in a dark and dry place that is well-ventilated. Avoid storing onions in the refrigerator, unless they have been cut. Do not store onions in places with exposure to moisture, specifically near potatoes, because onions can rot quicker when they absorb the potatoes’ moisture and gas. Uses for onions are versatile. They can be eaten raw, grilled or sautéed and added to a variety of dishes.

            The University of Georgia provides a recipe for a dish that includes onions and many other nutritious vegetables which is as follows:

Avocado Salsa

1 medium avocado

1 large, ripe tomato

¼ cup finely chopped red onion

2 Tbsp fresh chopped cilantro or 2 tsp dried cilantro

2 cloves garlic, minced

½ tsp ground cumin

½ tsp ground black pepper

½ tsp salt, optional

Juice of 1 large lime (about 2-3 Tbsp juice)

1.      Combine all ingredients in medium-mixing bowl. Stir well, but careful not to break up vegetable chunks.

2.      Chill well before serving to allow flavors to blend. Serve with tortilla chips, cut vegetables or as a topping for salad or other vegetables. Makes 12 servings.

About 2 Tbsp. of this salsa provides a total of 30 calories, 2 grams of fat and 2 grams of fiber.

Chopping onions can be unenjoyable due to sulfur compounds, however, when these sulfur compounds and other nutrients are inside your body, they can give protection from heart disease and cancer. There are ways you can reduce irritation to the eyes according to the University of Nebraska’s Institute of Agriculture and Natural Resources. Chilling onions for 30 minutes before cutting and cutting onions under water, reduces tears. Avoid cutting the root of the onion because that is where most of the sulfur chemicals are. By following these tips, you can receive sulfur compounds without crying to get them.

References

1.      food.unl.edu/cooking-onions-without-crying

2.      http://extension.usu.edu/fscreate/files/uploads/FS_Vegetables/FVegetablesOnion.pdf

3.      http://spock.fcs.uga.edu/noahnet/lp/fv/fv6garlicandonions.pdf

4.      http://extension.psu.edu/health/nutrition-links/pennsylvania-produce/produce-buying-guide/onions

Contact Information

Mandel Smith
  • Educator
Email:
Phone: 610-489-4315