white onions on cutting board

15 Health Benefits of Onions (By Type of Onion)

The common onion is a staple in many people’s diets around the world, but it might not have occurred to as many people that it deserves a place in their medicine cabinets.

Onion’s are well-known for their pungent aroma and flavor, but deserve additional attention for the unique mixture of nutrients they offer the human body. Ancient Egyptians must have known this as they considered the onion to be positively divine. Clearly, onions have been around for a while. Indeed, the modern onion comes from a now extinct wild onion plant and has been used since at least 5000 BC.

It is important to note that although onions can be great for humans to eat, they are largely toxic to dogs and cats. Give them a try to improve your health, but don’t give your pets any!

In the following article, we will present the health benefits of all kinds of onions, broken down into categories. First we will speak of the general onion health benefits, under the headline reserved for yellow and white onions; and you should know that any health benefit presented in this initial part of our guide applies to virtually all onions. Red onions, silver onions, green onions, tiny bulb onions and any imported type of onion you may encounter all share these general health benefits, in somewhat varying degrees.

Then, we will move forward to take a deeper look to the health benefits of red onions, and then to those of green onions. The health effects and benefits you will see listed there aren’t the only ones carried by those two types of onions; as mentioned above, you can also expect the generic benefits of onions to be present among those of red and green onions. For the sake of not repeating the same info, only the benefits brought in addition to the generic ones will be described in those paragraphs. So, without further ado, this is what you can expect from this earthy vegetable.

white onions on cutting board

The Health Benefits of Onions (Yellow and White)

Just like their actual structure, onions have layers upon layers of amazing health benefits. These are the most common such effects, virtually present in all the onions you will find on the market, regardless of their type or color. Some of them will impress you, some of them will downright surprise you, and most will definitely motivate you to eat more onions.

1. Onions are very rich in anti-oxidants

Phytochemicals, or phytonutrients, are natural substances which are found within fresh fruit and vegetables and which make them so healthy. Some of them also have anti-oxidant effects; just like the phytonutrients in onions. You will be surprised to know, but onions are actually the most antioxidant rich food you can find. That’s right, it’s not lemons, or blueberries, or parsley, or any of the other superfoods advertised as the ultimate source of antioxidants; it was onions all along! Also, a funny fact: one of the reasons for this super-abundance of anti-oxidants is the presence of sulphuric compounds, the same which give onions their slightly unpleasant smell.

2. Onions contain powerful cancer-fighting substances

The anti-oxidants mentioned above obviously help fight cancer and all sorts of tumors, but one substance in particular has extra anti-carcinogenic properties. This compound is called quercetin, and it is a flavonoid present in onions, liked by numerous studies with plenty of healthy effects (including the prevention of cardio-vascular disease, Parkinson’s and so on). Still, the most remarkable effect of quercetin is its ability to fight cancer, and if you needed one more incentive to consume more onions, this is the best you can find. The anti-cancer properties of quercetin are among the most desirable and important of all the health benefits of onions.

3. Onions encourage the production of good cholesterol (HDL)

This wonderful effect on onions is only enjoyed if you eat them raw, so keep this in mind before adjusting your diet. An easy way to help raise your levels of good cholesterol (and thus lower your levels of the bad one) is to have them sliced on top of your dishes. If you also squeeze a little lemon juice over them to take away their potency, it’s all for the better, health-wise.

4. Onions protect your stomach from ulcers and gastritis

Few things help demolish free radicals as well as onions, and together with their healing substances (more on the healing power of onion juice below) they can protect your stomach from ulcers and wounds. Onions also prevent gastritis from developing on the long term, and help keep your stomach’s inner lining healthy and with balanced acidity levels.

5. Onions regulate blood sugar, preventing diabetes

Another precious substance present in onions – chromium – is to thank for a better and steadier regulation of blood sugar. This has a positive effect in maintaining the body’s natural sensitivity to insulin and preventing diabetes, regulating the appetite and also preventing obesity.

6. Onions reduce inflammation and fight infections

The flavonoids and compounds that make onions smell and taste pungent (when raw) are also responsible for reducing inflammation, both locally, and throughout the body in general. As you probably know, inflammation is responsible for your body developing all sorts of diseases, in time, so foods that reduce it (such as green tea, or raw almonds) are very often added to a healthy dish precisely for this purpose. The other health benefits of onions are therefore made that much more potent by their anti-inflammatory effect.

7. Onions improve the efficiency of vitamin C within your body

Onions contain high amounts of vitamin C, but, more importantly, they improve and tweak the way vitamin C gets activated and works inside your body. This makes onions helpful not only for the well-functioning of vitamin C provided by themselves there, but also for the vitamin C brought on by other foods in your diet. This is good for your entire immune system, skin and tissue elasticity, as well as your general energy levels and vitality. Studies on the health benefits of onions proved that the vitamin C present in these vegetables is much more important within the body than the vitamin C derived from other sources, theoretically richer (like citrus fruit).

8. Onions improve bone density for post-menopausal women

This beneficial effect comes not only through the onions’ own calcium content, but also due to their flavonoids which help the calcium you take find its way to the places in the body where it’s needed most. The health benefits of onions therefore include ostheoporosis prevention.

red onions on a cutting board

The Health Benefits of Red Onions

As mentioned above, red onions share all the wonderful health benefits and nutritional value of the yellow (and white) onions presented above, with a few extra perks. These extra perks are:

9. Red onions further reduce bad cholesterol

The flavonoids which give red onions their red pigmentation are also extremely valuable to your health by its wonderful effects on reducing bad cholesterol and stimulating the production of the good one. Studies have shown that increasing the consumption of quercetin (the main flavonoid compound in onions) will also relive blood pressure, reducing the risk of stroke and coronary heart disease.

10. Red onions are a rich source of iron, calcium and other precious minerals

The humble red onion may be one of nature’s richest sources of calcium, iron, manganese, magnesium, potassium, along with vitamins C, K, and B-6. These precious substances are rarely found together in nature, so take advantage of red onions’ nutritious components as often as you can. No list of the health benefits of onions could be complete without mentioning this powerful vitamin cocktail which is essential for a healthy bone density and a healthy cycle of blood formation and circulation.

11. Red onions alleviate asthma, allergies and arthritis

One health effect particular to red onions (which isn’t noticeably present in yellow onions) is their ability to improve the state of people troubled by asthma, arthritis and allergies. This is due to their general anti-inflammatory properties (shred with other types of onions as well), but also due to onionin A, a compound which suppresses the activity of the immune cells which trigger the above mentioned diseases.

green onions in gardening basket

The Health Benefits of Green Onions

Spring onions, with their lovely green and white parts, are carriers of the same health benefits present in other types of onions, and also a few extras. Here are the main 3 health benefits of onions which are reserved for the green ones in particular.

12. The green parts of spring onions are loaded with vitamin A

A green onion stalk contains about 24 micrograms of vitamin A, which is the equivalent of 2.6 percent of a man’s daily need of vitamin A and 3.4 percent of a woman’s daily need of this vitamin. That’s a huge amount for just one little stalk. Next time you feel like you should add more vitamin A to your diet, just remember that carrots aren’t the only option.

13. Green onions are a rich source of fiber

Fiber has plenty of health benefits for your overall digestive system, and for regulating the blood sugar levels and thus maintaining your cardiovascular health as well. The health benefits of onions include the benefits of fiber-rich vegetables in general, therefore.

14. Green onions are also a rich source of copper

Copper is a rare and precious mineral, which you won’t be able to find in many other vegetable sources. Take advantage of spring onions when they’re in season to load up on copper. Your capillaries and several of your organs (pancreas, liver) will have nothing than to benefit from it.

15. Their particular vitamin cocktail can prevent DNA and cell damage

The substances present in green onions have been proven to inhibit the production of xanthine oxidase, an enzyme that produces the free radicals which end up harming cells and their DNA. Eating green onions regularly can help keep your body healthier and younger, by maintaining the cells in their original state for longer. That is one of the most amazing health benefits of onions, present especially in their green form.

Healthy Ways to Consume Onions

If you’re wondering how you should consume onions in order to make the most out of their health benefits, we have a few suggestions popular among various nutrition hubs. We won’t actually reproduce here a bunch of recipes, since you can find those on the multitude of culinary websites out there, but provide you with a few tips instead:

  • Raw onions do have a higher concentration of beneficial substances than cooked ones, obviously. But the difference becomes significant more in the matter of antioxidants, and it’s safe to say that all the other health benefits presented above will be available for cooked onions as well.
  • A simple way to add more onions to almost every dish, without fretting about recipes and such, is to do this: slice the onions, put them in a bowl with a squeeze of lemon juice and let them marinate for 5-10 minutes. Also add salt and perhaps also pepper or fresh herbs (to taste). The lemon juice will take away some of their pungent taste and smell, while keeping the antioxidant properties of the flavonoids intact. After they marinated for a bit, feel free to just add them on top of any savory dish you may be having. Do this at least once a day and your health will visibly improve.
  • For a cup of immunity boosting, anti-inflammatory goodness, try onion juice. It sounds as if it may not taste very good, but with the right additions and extra ingredients, it can be quite yummy. Look for onion juice recipes online and you will discover a pleasant variety of suggestions. Traditional wisdom prescribed onion and honey juice as a cure for the flu, but based on all the health benefits of onions described above, you should know that its restorative powers go way beyond a simple flu cure.
  • Add ingredients which complement and boost the nutritional substances present in onions. The best choices would be garlic (for its similar properties), as well as onion seeds (they’re black and tiny, about the size of sesame, and can be found in health food stores).

Image sources: 1, 2, 3, 4.

Add comment

As a participant in the Amazon Services LLC Associates Program, this site may earn from qualifying purchases. We may also earn commissions on purchases from other retail websites.