Are onions vegetables?

In this brief blog, we will answer the question,”Are onions vegetables?” We will also answer if onions are fruits. We will look at the nutritional profile of onions as well as the health benefits of onions. We will also discuss some potential risks associated with onions.

Are onions vegetables?

Yes, onions are definitely vegetables and this can be based on some factors, one being in a culinary sense because they are used in the preparation of various dishes to add a savory flavor. 

Botanically, onions are also a vegetable because they have a bulb that grows underground which also contains roots and forms leaves with the plant being edible. These characteristics fit the basic profile of what a vegetable is.

Are onions fruits?

Onions are not fruits, botanically fruits are edible parts that form from the flower of a plant. There are some fruits that are commonly mistaken as vegetables mostly because of the culinary uses such as cucumbers, tomatoes and squash.

Fruits also contain seeds and for that simple reason onions are not botanically fruits.

What is the nutritional value of onions?

Raw onions are a low- calorie food only providing 40 calories in 100 grams. By fresh weight they are water dense containing 89 percent water, 1.7 percent of dietary fiber and 9 percent of carbohydrates. 

Onions have very low amounts of fat as well as protein.

100 grams of raw onions can typically provide the below nutrients:

  • Calories: 40
  • Water: 89 percent
  • Protein: 1.1 g
  • Carbohydrates: 9.3 g
  • Sugar: 4.2 g
  • Dietary fiber: 1.7 g
  • Fat: 0.1 g

What are the health benefits of onions?

They can help lower the risk of cancer

Many types of onions have a tonne of chemicals that can help reduce the risk of cancer. Onions are an excellent source of a compound known as quercetin. Quercetin has been shown by studies to help lower the activity of elements that cause cancer.

Consumption of a diet that is rich in quercetin has been linked with a reduced risk of developing lung cancer.

They can help lower the risk of heart disease and stroke

Onions are a good source of organic sulfur compounds. The intense sharp, strong taste and smell that is in onions is actually as a result of the sulfur compounds. 

Organic sulfur compounds are known to help lower the level of cholesterol in the body and also aid in the breaking down of blood clots both of which aid in reducing the risk of heart diseases and also stroke.

To benefit from this you are required to consume onions raw instead of cooked so as to get in as much sulfur compounds as possible.

They can help in the management of diabetes

The quercetin and also the organic sulfur compounds in onions have been shown by studies to help in promoting the production of insulin. This makes onions an excellent veggie for people that have diabetes.

They can help lower the risk of Alzeheimer’s disease

Onions also contain plenty of flavonoids. Studies have shown that people who consume a diet that is high in flavonoids for long periods of time can lower the risk of developing Alzeheimer’s disease.

What are some potential risks of consuming onions?

Onion allergy and intolerance

Onion allergy is a very rare condition but there are people that have intolerance to raw varieties of onions.

Such people may experience side effects which are mainly gastrointestinal problems such as stomach upset, heartburn and gas.

Other people can also have allergic reactions from just coming into contact with onions whether they are allergic to them or not.


Onions also contain fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) which are carbs that are poorly absorbed by the small intestines.

They can result in digestive distress after consuming them with some of the symptoms being gas, bloating, cramping and diarrhea.

People that have Irritable Bowel Syndrome (IBS) are usually intolerant to FODMAPs and should therefore steer clear of onions.

Eye and mouth irritation

Most people usually experience eye irritation and tear up when they are chopping up onions. This is because onion’s cells  usually produce a gas known as lachrymatory factor.

The gas usually triggers neurons in the eyes that bring a sting in the eyes and tears are produced so as to flush out the irritant.

Lachrymatory factor is also the cause of the burning sensation in the mouth when you eat raw onions. This can however be alleviated by cooking the onions.


In this brief blog, we have answered the question,”Are onions vegetables?” We have also answered if onions are fruits. We have looked at the nutritional profile of onions as well as the health benefits of onions. We have also discussed some potential risks associated with onions.


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