Green Onion Nutrition Facts and Health Benefits

Green onion, annotated

Verywell / Alexandra Shytsman 

The term green onion is usually used interchangeably with spring onion and scallion. All are onions that don't have a large bulb, either because they don't grow that way or because they are harvested before the bulb forms. Green onions deliver a lot of the flavor of mature bulb onions, with a little less of the bite. And the green leaves are edible, which offers some different nutrients from bulb onions.

Green Onion Nutrition Facts

The following nutrition information is provided by the USDA for 1 medium (15g) raw green onion.

  • Calories: 4.8
  • Fat: 0g
  • Sodium: 2.4mg
  • Carbohydrates: 1.1g
  • Fiber: 0.4g
  • Sugar: 0.4g
  • Protein: 0.3g

Carbs

One raw green onion contains just over 1 gram of carbohydrate, about half of which is from fiber and the other half from sugar.

As with most non-starchy vegetables, green onions are not measured by the glycemic index. Because they have so little carbohydrate, they can't be tested for glycemic index and are assumed to have a low GI. The glycemic load, which takes into account the amount that may be eaten, is also assumed to be very low; consuming them does not raise blood sugar.

Fat

Like most vegetables, green onions have virtually no fat.

Protein

Green onions also contain very little protein.

Vitamins and Minerals

Nutritionally, green onions have a combination of the benefits of onions and leafy greens like spinach or chard. They are an excellent source of vitamin K (one medium green onion provides 34% of adequate intake for women) as well as a good source of vitamin A, vitamin C, and folate.

Calories

Green onions are a low-calorie food, containing just 32 calories per cup when chopped. This makes them a great vegetable to use as a garnish in dips, soups, or salads. They can also be used in salsas or as a topping to not only add flavor, but also color. Their low-calorie and nutrient-dense qualities make them a healthy food choice. 

Summary

Green onions are a vegetable that are an excellent source of vitamin K, vitamin A, Vitamin C, and folate. They are a low-calorie and low fat food, however are they are not a good source of protein or fiber.

Health Benefits

The humble onion packs a surprising punch when it comes to disease fighting and health promoting. If you use green onions as a garnish, you won't get as much of their nutrition, so try upping the serving size.

Supports Bone Health

Eat three medium-sized green onions and you've gotten your daily dose of vitamin K. This vitamin is important for blood clotting and also for bone health, and research specifically links onions with decreased risk of osteoporosis.

May Decrease Risk of Cancer

Green onions are part of the Allium family, along with garlic, leeks, and chives. Scientists have identified certain compounds in these vegetables that seem to protect against cancer. Studies show a correlation between the consumption of these vegetables and reduced risk for myeloma, gastric, colorectal, endometrial, lung, and prostate cancer.

Reduces Obesity and Related Diseases

Researchers are investigating the many antioxidants and bioactive compounds in onions and finding that they may be effective against obesity and related diseases such as high blood pressure and diabetes. One study noted that the heart-healthy Mediterranean diet is rich in onions and related vegetables.

Boosts Immunity

Green onions are a great source of vitamin A, which helps boost your immunity. Just one cup of green onions is a great source of this important nutrient. They also contain other immunity-boosting nutrients like vitamin C and magnesium.  In addition, onions contain antioxidants called phytonutrients while also help protect your cells against damage.

Low in FODMAPs

If you follow a low-FODMAP diet to relieve symptoms of irritable bowel syndrome, you may have to avoid onions. However, the green parts of green onions are low in FODMAPs and usually safe to consume.

May Lower Cholesterol

According to research, green onions contain flavonoids, which helps reduce the “bad cholesterol”(LDL) and improve the “good” cholesterol (HDL). Many of these studies were done using raw onions, so either consume them raw or, if you cook them, make sure you consume the juice they are cooked in as well. 

Allergies

Onion allergy appears to be rare, but a few cases have been reported in the medical literature. If you are concerned about an allergy to green onions or any other food, discuss your symptoms with your doctor for diagnosis and advice on managing your condition.

Oral allergy syndrome, in which consuming raw fruits and vegetables can cause symptoms such as itching and swelling around the mouth, can also happen in people with seasonal mugwort pollen allergies. Other vegetables, including garlic, parsley, peppers, and cabbage, may also cause a reaction.

Adverse Effects

If you take the blood thinner Coumadin (warfarin), you need to consume a consistent amount of vitamin K. That may mean limiting your intake of green onions and other leafy greens. Discuss your diet with your doctor or a registered dietitian.

Varieties

There are dozens (if not hundreds!) of onion varieties, and any of them can be harvested early enough to be used as green onions. It's just a matter of timing.

When They're Best

Green onions are available year-round. They have bright green tops with a firm white base that includes small shoots of roots. The entire green onion is edible, although you may want to trim off the tiny roots. The bulb portion of a green onion is mild-tasting, relative to large bulb onions. You can even re-grow your green onion by placing the base in a small container of water.

Storage and Food Safety

Remove any packaging, such as rubber bands, and discard leaves that have been damaged. Wrap green onions in a plastic bag and store them in the vegetable crisper drawer of your refrigerator.

They should not be stored for more than five days and may wilt or lose their crispness in as little as two to three days, depending on how fresh they were when you bought them. Store green onions separately from foods that tend to absorb onion odors, such as mushrooms or corn.

How to Prepare

Green onions are often eaten raw, but can also be roasted, grilled, or sauteed, whole or chopped. Use to garnish soups, salads, or dips, or to spice up tuna or chicken salad. You can also use a food processor and combine green onions, garlic, ginger, and olive oil to make a pesto-like sauce or spread that can be added to meat dishes or used on top of other vegetables.

8 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Laura Dolson
Laura Dolson is a health and food writer who develops low-carb and gluten-free recipes for home cooks.