Mon. Apr 15th, 2024

Health Benefits of Onion, Uses And Its Side Effects

If you have ever cooked using recipes from your mom, grandma, Pinterest or really from anywhere, you may have noticed a common theme. Most, if not all, of these recipes will instruct you to heat your pot, pan or Dutch oven with oil then add chopped onions, which you will sauté for a few minutes until softened. Onions are a kitchen staple that appear in many dishes, and there’s a reason for that.

If you are concerned about your health, you will want to consider adding more onions to your diet. The antioxidants and anti-inflammatory properties onions contain make consuming onions great for your heart health. Not only that, but they are also highly nutritious and delicious! This article will provide you with ten health benefits of onions.

1. Have Many Antioxidants

Antioxidants may help prevent cell damage by fighting free radical molecules. Free radicals are developed when the body is exposed to radiation or tobacco smoke. These molecules can cause diabetes, heart disease, and cancer. By eating onions you can help your body fight free radicals and improve your overall health.

Loaded with antioxidants

Antioxidants are compounds that inhibit oxidation, a process that leads to cellular damage and contributes to diseases like cancer, diabetes, and heart disease (13Trusted Source).

Onions are an excellent source of antioxidants. In fact, they contain at least 17 different varieties of flavonoid antioxidants (14Trusted Source).

Red onions, in particular, contain anthocyanins, which are plant pigments in the flavonoid family that give red onions their deep color.

Multiple population studies have found that people who consume more foods rich in anthocyanins have a reduced risk of heart disease.

For example, a study in 43,880 males showed that habitual intakes as high as 613 mg per day of anthocyanins were correlated to a 14% lower risk of nonfatal heart attacks (15Trusted Source).

Similarly, a 2018 review concluded that consuming higher amounts of anthocyanin-rich foods was associated with a lower risk of heart disease and heart disease mortality (16Trusted Source).

Additionally, anthocyanins have been found to protect against certain types of cancer and diabetes (17Trusted Source, 18Trusted Source).

Red onions are rich in anthocyanins, which are powerful plant pigments that may protect against heart disease, certain types of cancer, and diabetes.

2. Help with Blood Sugar Levels

If you have diabetes, onions are an excellent way to help keep your blood sugar levels steady. The flavonoids in onions work to keep the blood glucose levels stabilized. If levels are low, you might experience symptoms such as fatigue, anxiety, headache, and many other signs.

Help control blood sugar

Eating onions may help control blood sugar, which is especially significant for people with diabetes or prediabetes.

An older study in 42 people with type 2 diabetes demonstrated that eating 3.5 ounces (oz), or 100 grams, of raw red onion significantly reduced fasting blood sugar levels after 4 hours (25Trusted Source).

Additionally, multiple animal studies have shown that onion consumption may benefit blood sugar control.

A study showed that rats with diabetes fed food containing 5% dried onion powder for 8 weeks experienced decreased fasting blood sugar levels and had lower triglyceride and cholesterol levels compared to a control group (26Trusted Source).

Specific compounds found in onions, such as quercetin and sulfur compounds, also possess antidiabetic effects.

For example, quercetin has been shown to interact with cells in the small intestine, pancreas, skeletal muscle, fat tissue, and liver to control whole-body blood sugar regulation (27Trusted Source).

Due to the many beneficial compounds found in onions, consuming them may help reduce high blood sugar.

3. Improved Digestive Health

Onions contain a high amount of prebiotics and fiber. In the body, this helps improve gut health by aiding in digestion, strengthening the immune system, and lowering inflammation.

May boost digestive health

Onions are a rich source of fiber and prebiotics, which are necessary for optimal gut health.

Prebiotics are nondigestible types of fiber that are broken down by beneficial gut bacteria.

Gut bacteria feed on prebiotics and create short-chain fatty acids — including acetate, propionate, and butyrate.

Research has shown that these short-chain fatty acids strengthen gut health, boost immunity, reduce inflammation, and enhance digestion (36Trusted Source, 37Trusted Source).

Additionally, consuming foods rich in prebiotics helps increase probiotics, such as Lactobacillus and bifidobacteria strains, which benefit digestive health (38Trusted Source).

A diet rich in prebiotics may help improve the absorption of important minerals like calcium, which may improve bone health (39Trusted Source).

Onions are particularly rich in the prebiotics inulin and fructooligosaccharides. These help increase the number of friendly bacteria in your gut and improve immune function (40Trusted Source).

Onions are a rich source of prebiotics, which help boost digestive health, improve bacterial balance in your gut, and benefit your immune system.

4. Loaded with Nutrients

Onions are considered to be nutrient-dense food. This means that they contain a small number of calories and a large number of nutrients. They are a great source of potassium and manganese. Potassium helps to increase energy and your metabolism. Manganese helps the body create connective tissue, aids in bone health, and lowers the chance of forming blood clots.

Packed with nutrients

Onions are nutrient-dense, meaning they’re low in calories but high in vitamins and minerals.

One medium onion has just 44 calories but delivers a considerable dose of vitamins, minerals, and fiber (2Trusted Source).

This vegetable is particularly high in vitamin C, a nutrient involved in regulating immune health, collagen production, tissue repair, and iron absorption.

Vitamin C also acts as a powerful antioxidant in your body, protecting your cells against damage caused by unstable molecules called free radicals (3Trusted Source).

Onions are also rich in B vitamins, including folate and vitamin B6 — which play key roles in metabolism, red blood cell production, and nerve function (4Trusted Source).

Lastly, they’re a good source of potassium, a mineral which many people are lacking.

In fact, the average potassium intake of Americans is less than half the recommended daily value (DV) of 4,700 milligrams (mg) (5Trusted Source).

Normal cellular function, fluid balance, nerve transmission, kidney function, and muscle contraction all require potassium (6Trusted Source).

Onions are low in calories yet high in nutrients, including vitamin C, B vitamins, and potassium.

5. Anti-Inflammatory Properties

Onions contain an antioxidant called quercetin. Quercetin is an anti-inflammatory and works to fight off inflammation within the body. It is great at lowering swelling, helping with arthritis, and treating bladder infections.

6. May Keep Certain Cancers at Bay

If you are concerned about your risk of developing cancer, you may want to consume more onions. Researchers found moderate consumption of onions appeared to reduce the risk of colorectal, laryngeal, and ovarian cancers.

Contain anti-cancer compounds

Eating vegetables of the Allium genus like garlic and onions has been linked to a lower risk of certain types of cancer, including stomach and colorectal cancer.

A review of 26 studies showed that people who consumed the highest amount of allium vegetables were 22% less likely to be diagnosed with stomach cancer than those who consumed the lowest amount (19Trusted Source).

Moreover, a 2014 review of 16 studies in 13,333 people demonstrated that those with the highest onion intake had a 15% reduced risk of colorectal cancer compared to those with the lowest intake (20Trusted Source).

These cancer-fighting properties have been linked to the sulfur compounds and flavonoid antioxidants found in allium vegetables.

For example, onions provide onionin A, a sulfur-containing compound that has been shown to decrease tumor development and slow the spread of ovarian and lung cancer in test-tube studies (21Trusted Source, 22Trusted Source).

Onions also contain fisetin and quercetin, which are flavonoid antioxidants that may inhibit tumor growth (23Trusted Source, 24Trusted Source).

A diet rich in allium vegetables like onions may have a protective effect against certain cancers.

7. Reduces Risks of Alzheimer’s Disease

Studies have been conducted to discover the relationship between quercetin and Alzheimer’s disease. These studies showed a significant association between consuming foods high in quercetin, such as onions, and having a lower chance of developing Alzheimer’s.

8. Great Source of Vitamin C

Did you know that onions contain a high amount of vitamin C? Vitamin C is essential for your body to function properly. It helps the formation of blood vessels, improves your immune system, and builds cartilage.

9. Supports Bone Health

Studies have proven that onions improve bone density in some people. As a result, the consumption of onions may help strengthen the bones and reduce risk of fractures for people over the age of 50.

May boost bone density

Though dairy gets much of the credit for boosting bone health, many other foods, including onions, may help support strong bones.

A study in 24 middle-aged and postmenopausal females showed that those who consumed 3.4 oz (100 milliliters) of onion juice daily for 8 weeks had improved bone mineral density and antioxidant activity compared to a control group (28Trusted Source).

Another older study in 507 perimenopausal and postmenopausal females found that those who ate onions at least once a day had a 5% greater overall bone density than individuals who ate them once a month or less (29Trusted Source).

Plus, the study demonstrated that older individuals who most frequently ate onions decreased their risk of hip fracture by more than 20% compared to those who never ate them (29Trusted Source).

It’s believed that onions help reduce oxidative stress, boost antioxidant levels, and decrease bone loss, which may prevent osteoporosis and boost bone density (30Trusted Source).

Studies show that onion consumption is associated with improved bone mineral density.

10. Antibacterial

The antibacterial properties of Allicin in onions help the colon fight off harmful bacteria. Allicin is the compound that gives off the unique strong smell of an onion. You can think of Allicin as your fighter against toxins and sicknesses. Now that’s something to cry happy tears about!

After reading about the ten health benefits that onions provide, you may be wondering how you can add more onions to your daily diet. A simple and quick way to start consuming more onions is using Spice World Easy Onion! You no longer have to deal with the hassle of peeling and chopping onions as your eyes well up with tears. All you need to do is squeeze the bottle for minced onions in an instant. It doesn’t get easier than that!

If you would like to learn more about Spice World’s new onion product and reap the benefits of incorporating more onions in your meals, visit us online for recipes and tips on how to add onion to your weekly meals.

Have antibacterial properties

Onions can fight potentially dangerous bacteria, such as Escherichia coli (E. coli), Pseudomonas aeruginosaStaphylococcus aureus (S. aureus), and Bacillus cereus (31Trusted Source).

Furthermore, onion extract has been shown to inhibit the growth of Vibrio cholerae, a bacteria that is a major public health concern in some parts of the world (32Trusted Source).

Quercetin extracted from onions seems to be a particularly powerful way to reduce the growth of bacteria.

Some test-tube studies suggest that quercetin could inhibit the growth of several strains of bacteria, including Helicobacter pylori (H. pylori), a type of bacteria associated with stomach ulcers and certain digestive cancers (33Trusted Source, 34Trusted Source).

Another test-tube study found that quercetin damaged the cell walls and membranes of E. coli and S. aureus (35Trusted Source).

Onions have been shown to inhibit the growth of potentially harmful bacteria like E. coli and S. aureus.

11. May benefit heart health

Onions contain antioxidants and compounds that fight inflammation, decrease triglycerides, and reduce cholesterol levels — all of which may lower heart disease risk.

Their potent anti-inflammatory properties may also help reduce high blood pressure and protect against blood clots.

Quercetin is a flavonoid antioxidant that’s highly concentrated in onions. Since it’s a potent anti-inflammatory, it may help decrease heart disease risk factors, such as high blood pressure (7Trusted Source).

A study in 70 people with overweight and high blood pressure found that a dose of 162 mg per day of quercetin-rich onion extract significantly reduced systolic blood pressure by 3–6 millimeters of mercury (mmHg), compared to a placebo (8Trusted Source).

Onions have also been shown to decrease cholesterol levels.

A 2014 study in 54 females with polycystic ovarian syndrome (PCOS) found that consuming large amounts of raw red onions (80–120 grams per day) for 8 weeks reduced total and LDL (bad) cholesterol compared to a control group (9Trusted Source).

Additionally, evidence from animal studies supports that onion consumption may reduce risk factors for heart disease, including inflammation, high triglyceride levels, and blood clot formation (10Trusted Source, 11Trusted Source, 12Trusted Source).

Research shows that eating onions may help reduce heart disease risk factors, such as high blood pressure, elevated triglyceride levels, and inflammation.

12. Easy to add to your diet

Onions are a staple in kitchens around the world.

They give flavor to savory dishes and can be enjoyed either raw or cooked.

Not to mention, they can boost your intake of fiber, vitamins, and minefrals.

Here are some tips on how to add onions to your diet:

  • Use raw onions to add a kick of flavor to your guacamole recipe.
  • Add caramelized onions to savory baked goods.
  • Combine cooked onions with other vegetables for a healthy side dish.
  • Try adding cooked onions to egg dishes, such as omelets, frittatas, or quiches.
  • Top meat, chicken, or tofu with sautéed onions.
  • Add thinly sliced red onions to your favorite salad.
  • Make a fiber-rich salad with chickpeas, chopped onions, and red peppers.
  • Use onion and garlic as a base for stocks and soups.
  • Throw onions into stir-fry dishes.
  • Top tacos, fajitas, and other Mexican dishes with chopped raw onions.
  • Make a homemade salsa with onions, tomatoes, and fresh cilantro.
  • Prepare a hearty onion and vegetable soup.
  • Add onions to chili recipes for a flavor boost.
  • Blend raw onions with fresh herbs, vinegar, and olive oil for a tasty homemade salad dressing.

Onions can easily be added to savory dishes, including eggs, guacamole, meat dishes, soups, and baked goods.

The bottom line

The health benefits related to onions are quite impressive.

These nutrient-packed vegetables contain powerful compounds that may decrease your risk of heart disease and certain cancers.

Onions have antibacterial properties and promote digestive health, which may improve immune function.

What’s more, they’re versatile and can be used to heighten the flavor of any savory dish.

Adding more onions to your diet is an easy way to benefit your overall health.

Health Benefits of Onion, Uses And Its Side Effects

Onion is one of the common vegetables used in hundreds of dishes all over the world to enhance the taste. Eating raw onion daily offers lots of health benefits. Vitamin C and other nutrients in onion help to check cancer and also enhance skin and hair. The blood sugar levels are largely controlled by onion extracts and it also boosts immunity, sex drive and anemia control.


Onions are vegetables, which have the scientific classification of Allium cepa. They are rich in antioxidant compounds that are very effective in neutralizing the free radicals present in the human body. They have been used for decades by human beings for medicinal purposes.

Nutritional Value of Onion

Onions have many valuable medicinal applications because it acts as a rich source of nutrients, vitamins, minerals, and organic compounds. These include the presence of sulfuric compounds and quercetin which are essential for health.

Onion also contain mineral components such as calcium, magnesium, sodium, potassium, selenium, and phosphorus and they are a good source of vitamin C, vitamin B6, and dietary fiber.

Nutritional facts Per 100 Grams

40 Calories
0.1 g Total Fat
4 mg Sodium
146 mg Potassium
9 g Total Carbohydrate
1.1 g Protein

Vitamins and Minerals

0.02 Calcium
12 % Vitamin C
1 % Iron
5 % Vitamin B-6
2 % Magnesium

Health Benefits of Onion

After getting onion nutrition facts, let check amazing Health Benefits of eating onions, you can onion in a different way, you can use raw onion in cooking for hundreds of dishes. Onion juice is also used for hair growth and skin care. According to the season, you find various onions such as red onion, green onion, white onion, etc. Onion offers medicinal properties and is used to treat mouth sores, headaches, and heart problems.

Onion Fight Against Cancer

Red onions are the most effective in destroying breast and colon cancer cells. Onions have a powerful compound called quercetin that plays a significant role in preventing cancer.

Onion Lower Blood Sugar Levels

One of the sulfur compounds present in onions (S-methylcysteine) and quercetin can have beneficial effects on controlling the blood sugar level in the body. Chromium, also present in this root vegetable, may help regulate blood sugar.

Onion Prevent Inflammation And Other Allergies

Quercetin (and other flavonoids) in onions helps in preventing inflammation. Onion also helps the treatment of allergies by preventing the cells from releasing histamine.Antihistamine properties of quercetin can also aid in reducing nasal congestion. The antibiotic effects of onion accelerate wound healing.

Onion Promote Respiratory Health

Patients with respiratory issues like asthma and allergic rhinitis can benefit from onion extracts. The prebiotics present in onion can help removing nasal congesion and thus aiding peaceful sleep.

Onion Juice Benefits for Eyes Health

The sulfur in onions improves the health of the lens of the eye thus aiding in vision. It stimulates the greater production of a protein named glutathione, which acts as an antioxidant and reduces risk of glaucoma, macular degeneration, and cataracts.

The selenium in onions supports the vitamin E in the eye (which protects the cells in the eye).Onion extracts can also aid in preventing the development of corneal haze and onion juice can also be used as eye-drops.

Onion Good for Oral Thrush

Onions contain a rich source of thiosulfinates and thiosulfonates (the sulfur compounds) that help scale down bacteria that cause tooth decay.The vegetable is also enriched in vitamin C that keeps the teeth healthy.Onions can relieve tooth pain.

Onion Juice for Hair Fall & Hair Regrowth

Rich in antibacterial and antifungal properties, onions help to nurture hair and proliferates its growth. The rich sulfur content and antioxidants prevent thinning and breakage and premature greying. They fight dandruff and assist in blood circulation that helps in hair growth.

Onion Benefits for Brain Health

Antioxidant rich onions bind with the harmful toxins in the brain and flush them out of the body.The extracts of onions have been found to maintain the hippocampus.

Another sulfur-compound in onions, named di-n-propyl trisulfide, improves memory impairment and lower down age-related memory loss. Onions are also believed to treat dizziness, epilepsy, and vertigo.

10 Benefits of Red Onions and How To Use Them

10 Benefits of Red Onions and How to Use 

Onions are one of the most popular vegetables worldwide.  While most children dislike their pungent and bity flavor, most adults embrace and use them regularly.   Red onions contain twice as many antioxidants as any other form of onion making them a powerful part of an anti-inflammatory diet and lifestyle.  This article will go over 10 benefits of red onions and how to use them to get the best results.

Red onions get their bite from the many sulfur groups they contain.   These sulfur groups include the diallyl sulfides:  DMS, DDS, DTS & DTTS.   These sulfur groups help produce cysteine within the body that aids in weight loss, detoxification and cancer prevention (1, 2).  Additional research has shown that sulfur compounds have a strong antioxidant capacity that inhibits blood cell clumping (3).

The sulfur compounds in red onions also lower LDL cholesterol & triglycerides while boosting HDL levels (4).  They are associated with improving cell membrane function in red blood cells and improving oxygen utilization.  This improves cardiovascular function as well as fat metabolism.

Rich in Antioxidant PhytoNutrients

Red onions are also a rich source of the flavonoid antioxidant quercetin and the polyphenol antioxidant anthocyanin.  These antioxidants prevent the oxidation of dietary and cellular fatty acids.  They are very powerful free radical scavengers that neutralize cancer cell growth and dramatically reduce whole body inflammation (5, 6).

Many believe that consuming quercetin from onions is more effective than taking quercetin extracts in supplement form.  The body is able to better recognize the nutrient when it is in a natural form and has other synergistic components associated with it.

Red Onions are Rich in Chromium:

Red onions are also a fantastic source of chromium which lowers blood sugar and enhances cellular insulin sensitivity.    Nearly 50% of the US population is deficient in chromium which is greater than any other developed nation (7).  This is due to over cropping that has stripped the land of chromium and processed food consumption.  Chromium deficiencies lead to diabetes and heart disease.

The antioxidant flavonoids are extremely rich in the outer layers of the onion.  Many people will peel off the first few layers and lose much of these critical nutrients.  Be sure to utilize the outer, fleshy edible portions as much as possible.  Over peeling, by taking off the outer 2 layers of flesh will cost one about 20% of its quercetin and over 75% of its anthocyanins.

How Many Red Onions to Eat?

Simmering onions in a soup or broth will damage some of the anthocyanins but not the quercetin.  The quercetin moves into the soup or broth.  The lower the heat the more nutrients will be contained in the soup or broth.  Studies have shown that 4-7 servings of red onions each week (equivalent to about 2-3 onions) has been associated with the greatest benefit in reducing colorectal, oral, laryngeal, esophageal & ovarian cancer (8).

Red onions should be stored in a cool, dry area with good airflow.  Until they are opened they should not be stored in a refrigerator or plastic bag as both of these have been shown to speed up spoilage.  Once opened, it is best to store in refrigeration.  Avoid any onions that are wet, soft, bruised or have dark spots or mold on them.

Frequently Asked Questions With Onions:

1.  Do I Need to Purchase Organic Onions?  

Because onions are covered in a thin skin and are very sharp and pungent they repel pests.  They are not highly sprayed with toxic herbicides and pesticides and therefore can be purchased non-organic without significant risk for toxic chemical exposure.

2.  How Do I Reduce the Effect Onions Have on My Breath?

You can reduce the negative effects onions and other sulfur rich foods (garlic, shallots, radishes) have on your breath by consuming green veggies, bitter herbs such as dandelion, parsley or cilantro and herbs such as rosemary, fennel and peppermint.

I often advise my clients to consume parsley or make a green drink on days when you are consuming a lot of raw onion.

3.  Do I Get the Same Benefits from Cooked Onions as I Do with Raw Onions?

No, you will certainly lose much of the nutrient content but you will still get some of the benefits so it is better to consume cooked onions than no onions at all.

4.  What if Onions Give Me Gas When I Eat Them?

Onions have very healthy polyphenols (quercetin) that help to improve the make up of our gut microflora.  For most individuals, they are extremely good for the gut microbiome.  However, they also contain fructan sugars that are part of the FODMAP group.  Some individuals with small intestinal bacterial overgrowth (SIBO) and other digestive issues can struggle to digest these sugars.  This can lead to gas and bloating.

If you notice gas, bloating, cramping when consuming onions than take them out of your diet and follow a low FODMAP diet for a period of time while you work to heal your gut.

5.  Do Vidalia Onions and White Onions Have the Same Benefits as Red Onions?

The vidalia and white onions are very healthy as they do contain the sulfur compounds, quercetin and chromium.  However, red onions are the only onions that have anthocyanins and therefore they are more nutrient dense than any other form of onion.



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5. Sak K. Site-specific anticancer effects of dietary flavonoid quercetin. Nutr Cancer. 2014;66(2):177-93. PMID: 24377461

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7. Cefalu WT, Hu FB. Role of chromium in human health and in diabetes. Diabetes Care. 2004 Nov;27(11):2741-51. Erratum in: Diabetes Care. 2013 Sep;36(9):2872. PMID: 1550501

8. Galeone C, Pelucchi C, Levi F, Negri E, Franceschi S, Talamini R, Giacosa A, La Vecchia C. Onion and garlic use and human cancer. Am J Clin Nutr. 2006 Nov;84(5):1027-32. PMID: 17093154