Onions: Important Facts, Health Benefits, and Recipes

Onion is a pungent and flavorful bulb vegetable widely used in cooking, known for its potential health benefits such as anti-inflammatory properties.

What is a Onion?

An onion is an edible bulb from the Allium family with a pungent taste and smell, made of several concentric layers and used in cooking. Its close relatives include garlic, scallion (green onion), leek, chive, and Chinese onion. Onions are rich in phytochemicals, fiber, and may help keep our heart, lungs, and digestive system healthy.

Are Onions Good For You?

Yes! Onions are rich in phytochemicals, fiber, and may help keep our heart, lungs, and digestive system healthy.

9 Health Benefits Of Onions

1. Onions are rich in phytochemicals: naturally occurring compounds in fruits and vegetables that have health benefits. The particular phytochemical in onions, a flavanoid called quercetin, is an antioxidant that may help the heart and blood pressure.

  • Yellow onions have the highest total flavonoid content

  • Red onions have anthocyanin pigments, which can be anti-inflammatory and antioxidants. 

2. The polyphenols in onions act as a natural blood thinner and prevents blood platelets from clustering. 

3. Onions may help reduce heart disease risk

  • The quercetin has been found to help lower blood pressure and inflammation

4.Quercetin in onions has been found to relax the airway muscles and may help with asthma symptoms 

5. Quercetin in onions acts as antioxidants, protecting the body against free radicals, which can help build a strong immune system. 

  • The quercetin in onions also reduces allergic reactions by stopping your body from producing histamines, which are what make you sneeze, cry and itch if you're having an allergic reaction.

6. Onions may be anti-cancer agents

  • A study found that intake of allium vegetables, including onions, were associated with reduced gastric cancer risk. 

  • According to World’s Healthiest Foods, eating between one and seven servings of onions per week may help reduce the risk of some cancers. 

  • Eating several servings of onions a day may help decrease the risk of oral and esophageal cancer.

7. Onions are a good source of fiber, which is good for digestion.

  • Onions have a special type of soluble fiber called oligofructose, which promotes good bacteria growth in the intestines. 

8. Onions may help with blood sugar. 

  • The chromium in onions may help in regulating blood sugar. 

  • The sulfur in onions helps lower blood sugar by triggering increased insulin production.  

9. Onions may help with bone density in post-menopausal women

  • A 2009 study in the journal Menopause found that daily consumption of onions improves bone density in women who are going through or have finished menopause.

  • Women who ate onions frequently had a 20 percent lower risk of hip fracture than those who never ate onions.

History, Background, and General Facts about Onions

  • Many historians believe onions originated in central Asia and are one of the oldest cultivated vegetables. Other research suggests onions were first grown in Iran and West Pakistan. 
  • It is presumed our ancestors discovered and started eating wild onions very early (before farming or writing were around).
  • Most researchers agree that onions have been cultivated for at least 5000 years.
  • Onions prevented thirst and could be dried and preserved for later consumption when food might be scarce in earlier times.
  • Onions were easy to grow on any kind of soil, any type of weather, and were easy to store, dry, and preserve during winters. 
  • Onions were symbols of eternity and endless life and were part of burial and mummification ceremonies in Egypt. 
  • Egyptians painted onions on the walls of their structures, pyramids, tombs, and were present in both ordinary meals, celebratory feasts, and offerings to the gods.
  • Onions were celebrated by the traditional Indian medical system as one of the most important remedies for heart, joint, and digestive illnesses. 
  • Onions were used in Ancient Greece by physicians, soldiers, and athletes who believed onions gave them strength from gods.

What Are The Cuisines That Regularly Include Onions?

  • French - French onion soup, onion tart
  • Mexican - taco garnish, salsa, pickled jalapeños
  • Indian - onion paratha, South Indian Vengaya Bajji
  • Vietnamese - pho
  • Chinese - scallion pancake
  • Korean - bulgogi, green onion salad
  • American - onion rings, Mel Gibson cocktail
  • Thai - thai basil chicken, thai curry
  • Russian - kasha, piroshkis
  • Japanese - Sweet Onion Takikomi Gohan
  • Dutch - Hutspot (Dutch Carrots, Potatoes and Onions)

What Is The Best Way To Store Onions?

  • The best way to store whole yellow, white, or red onions is in a single layer in a bowl on the kitchen counter away from heat or direct sunlight. The best way to store cut yellow, white, or red onions in a sealable container in the refrigerator.
  • The best way to store green onions is in a breathable bag (e.g. mesh or bag with holes) in a drawer in the refrigerator.

What Are The Different Types Of Onions?

  • Yellow or brown onions
    • These onions are sweet and are the onions of choice for everyday use in European cuisine
    • Vidalia, Walla Walla, Cévennes, and Bermuda are some varieties
    • Yellow onions turn a rich, dark brown when caramelized and are used in French onion soup
  • Red or purple onions 
    • These onions are known for their pungent flavor and are the onions of choice for everyday use in Asian cuisine
    • They are also used raw in salads and in grilling or pickled.
  • White onions 
    • These onions are milder in flavor and turn a golden color when cooked and turn sweet with sautéed
    • Found in classic Mexican cuisine
  • Spring Onions/scallions/green onions
    • These onions are young plants that are harvested before bulbing occurs and used whole as spring onions or scallions.

Toxicity and Side Effects Of Onions

Onions are generally considered safe to eat. The carbohydrates in onions may cause gas and bloating, according to the National Digestive Diseases Information Clearinghouse.  Raw onions may make heartburn in people who suffer from chronic heartburn or gastric reflux disease.

What Is The Best Substitute For Onions If I Don't Have Any?

Onions have a distinct flavor and aroma, so finding an exact substitute can be challenging. However, if you don't have onions available or need a substitute for them in a recipe, here are a few alternatives you can consider:

  1. Shallots: Shallots have a flavor profile that is similar to onions but milder and slightly sweeter. They can be used as a substitute in many recipes. Use shallots in the same quantity as onions called for in the recipe.

  2. Leeks: Leeks have a mild and slightly sweet flavor and can be used as a substitute for onions in certain dishes. They work particularly well in soups, stews, and braised dishes. Use the white and light green parts of leeks as a substitute for onions.

  3. Celery: While celery doesn't have the same flavor as onions, it can provide a similar texture and contribute to the overall savory profile of a dish. Finely chop celery and use it as a substitute for onions, particularly in soups, stews, and stir-fries.

  4. Onion Powder or Onion Flakes: If you have onion powder or onion flakes available, you can use them as a substitute for fresh onions. Keep in mind that these substitutes won't provide the same texture, but they will add the characteristic onion flavor to your dish. Use about 1 teaspoon of onion powder or 1 tablespoon of onion flakes for every medium-sized onion.

Nutritional Facts
1 medium
Amount per serving
10.3 g
0.1 g
1.2 g
Saturated Fat
0 g
4.4 mg
1.9 g
4.7 g