Onions belong to the allium family of vegetables and herbs, which includes chives and garlic. Ancient civilizations cultivated onions for their flavor and their health benefits. They were grown 5,000 years ago in parts of Iran and West Pakistan, and they were also cultivated in parts of China, India, and Egypt around 3500 B.C. Today, onions are consumed around the world. The biggest producers of onions are China and India, followed by the United States. And thank goodness for that, because onions aren’t just the ultimate flavor enhancer. They’re good for us too!
Onions vary in size, shape, color, and flavor. You’re probably most familiar with these types:
- Yellow onions: The most common type of onion with a pungent flavor and aroma.
- Sweet onions: With extra sugar and a light hue, these onions become sweeter the longer they cook.
- White onions: If you’re looking for a sweeter taste than yellow onions allow, try white onions.
- Red onions: Their magenta color and sweetly mild flavor make them a perfect salad topper.
- Shallots: Small brown-skinned onions with purple flesh, shallots add seasoning, much like garlic.
- Spring onions: Take it easy on the onion flavor with sweet and mellow spring onions.
- Green onions: Otherwise known as scallions, these are immature onions that have not yet formed a bulb.
- Leeks: They look like overgrown scallions, have a mellow flavor, and are onions through and through.
From there, each type of onion has its own varieties. Sweet onions include Walla Walla and Vidalia varieties, and then there are the Spanish yellow onions that are imbued with a sweeter pungency than most. If you’re an onion lover, it’s worth trying as many types of onions as you can get your hands on!
Onions contain plenty of antioxidants, flavonoids, and sulfur compounds. These sulfur compounds might make your eyes tear when you’re chopping an onion, but they also help protect against chronic diseases like cancer and diabetes.
A medium-sized onion is made mostly of water, with dietary fiber, carbohydrates, and protein thrown into the mix. Onions contain vitamins and minerals such as vitamin A, vitamin B6, vitamin B9, vitamin C, potassium, manganese, and folate.
Here are the onion nutrition specs for 1 cup chopped onions according to Self Nutrition Data.
- Calories: 64
- Carbs: 14.9 grams
- Protein: 1.8 grams
- Fiber: 2.7 grams
- Fat: 0.2 grams
- Vitamin C: 20% of daily value (DV)
- Vitamin B6: 10% of DV
- Manganese: 10% of DV
- Folate: 8% of (DV)
- Potassium: 7% of DV
- Phosphorus: 5% of DV
- Thiamin: 5% of DV
- Magnesium: 4% of DV
- Calcium: 4% of DV
- Copper: 3% of DV
- Riboflavin: 3% of DV
- Pantothenic acid: 2% of DV
- Zinc: 2% of DV
- Iron: 2% of DV
- Vitamin K: 1% of DV
- Niacin: 1% of DV
- Selenium: 1% of DV
Health Benefits of Onions
Eating onions…okay, maybe not eating fried onions…but eating onions is one of the healthiest dietary choices you can make. Let’s take a look at some of the proven health benefits of onion consumption.
Studies show that the sulfur compounds contained in onions can help keep the body tumor free by inhibiting cell mutation.
Using data from an integrated network of Italian and Swiss studies, researchers analyzed the relationship between frequency of onion intake and cancer. Results showed that the more allium vegetables (such as onions and garlic you eat), the lower your risk of common cancers, including stomach and colorectal cancers. In fact, researchers discovered that consuming more than seven servings of onions per week can reduce the risk of developing colorectal cancer.
Onions also contain vitamin C that helps fight the formation of free radicals, which can contribute to the development of cancer. Additional studies on prostate cancer found that men with the highest consumption of allium vegetables had the lowest risk of prostate cancer. Another team of researchers demonstrated that onions have potential protective effects on esophageal and stomach cancer.
Onions can make your bones stronger, and strong bones mean less risk for fractures.
A study on the relationship between onion intake and bone density in pre and postmenopausal non-Hispanic white women 50 years and older found that women who ate onions daily had greater bone density than those who ate onions monthly. The team of scientists concluded that eating onions regularly may decrease risk of hip fractures by more than 20%.
Onions have anti-inflammatory properties, and for this reason, they are an excellent food choice for people who suffer from inflammatory diseases like arthritis. Onions contain quercetin, a chemical compound that may be a potential natural drug for treatment of arthritis. Quercetin helps inhibit inflammatory compounds such as prostaglandins, leukotrienes, and histamines that exacerbate the pain.
A Korean study revealed that onion extract is a significant aid for diabetes management, as onions can decrease plasma glucose concentrations and body weight. They can help keep blood sugar levels in a healthy range, and they offer up chromium, an essential mineral that regulates blood glucose and may reduce the risk of developing diabetes. Studies examining the role of chromium in insulin resistance showed that people with type 2 diabetes have lower blood levels of chromium than those without the disease.
Male Fertility Enhancer
The antioxidants contained in onions can have a beneficial influence on sperm health, at least according to animal studies. A study investigating the androgenic activity of onions on spermatogenesis in rats found that the total testosterone and sperm concentration increased in the rats that received high doses of onions for 20 days. Now, we don’t know how this plays out in humans, but it’s another reason to add some onions to your salad!
Onions also contain folate, which helps to reduce depression. Researchers concluded that individuals with depression have lower serum levels of folate than individuals without depression. Folate also prevents an excess of homocysteine from forming in the body. Homocysteine is associated with cerebral diseases, depression of mood, and also interferes with the production of serotonin, dopamine, and norepinephrine, neurotransmitters that regulate mood, sleep, and appetite.
Onions are versatile vegetables. With flavors that range from pungent to sweet, onions can be roasted, grilled, caramelized, chopped, added to salads or used as garnish for tacos, and sweetly cooked in French onion soup.
Yellow onions are the most common type, and they can be prepared in a variety of ways. If a recipe does not specify which type of onion to use, you can assume that a yellow onion will do the job.
Sweet onions are great for caramelizing, while white onions are perfect for fresh salsa and guacamole. Red onions and green onions can be added to salads and sandwiches.
Onions can offer health benefits whether raw or cooked, but raw onions have higher levels of sulfur compounds, which, as we’ve seen, can help the body in numerous ways.
Ready to start cooking with onions? Check out two of our favorite recipes!
Israeli Couscous Greek Salad
This salad is rich in flavor and nutritional value, but light and easy to digest. It is a fast recipe—perfect for weeknights.
Ready In: 30 minutes
- 1 cup Israeli couscous
- 1 Roma tomato
- 1 cucumber
- 1/4 cup minced onion
- 1/2 cup Kalamata olives
- 4 tablespoons extra virgin olive oil for the dressing
- 3 tablespoons extra virgin olive oil to cook the couscous
- 2 tablespoons apple cider vinegar
- 2 tablespoons honey
- Black pepper
- Mince the onion.
- Dice the tomato and cucumber.
- Chop the olives.
- Put all the veggies in a big bowl and set aside.
- Cook the couscous in extra virgin olive oil for 5 minutes until it gets golden.
- Add 2 cups of water to the couscous and cook for around 12 minutes.
- Dressing: whisk extra virgin olive oil, apple cider vinegar, honey, salt, and pepper.
- When the couscous absorbs the water, turn off the heat, pour the couscous in the bowl with veggies, and add the dressing.
- Couscous: made with whole-wheat or white flour. Like pasta, it fuels brain and muscles.
- Tomato: contains antioxidants, which reduce the risk of heart disease and cancer. It is also an excellent source of vitamin C.
- Cucumber: helps you stay hydrated and improves digestion.
- Olives: offer up antioxidants that can help prevent cancer and heart disease.
- Onion: contains sulfur compounds and minerals that can help protect against cancer and reduce the risk of diabetes.
- Extra virgin olive oil: lowers high blood pressure and supports brain health.
- Apple cider vinegar: helps lower cholesterol and blood pressure.
- Honey: contains antioxidants and is an excellent alternative to sugar.
- Black pepper: helps digestion and reduces high blood pressure.
Guacamole is an excellent snack and a great way to entertain guests. The mayonnaise makes it creamy and even more delicious.
Ready In: 15 minutes
- 1 avocado
- 1/2 cup diced tomato
- 1/2 cup minced onion
- 1/4 cup lime juice
- 1 teaspoon mayonnaise
- 2 cloves garlic
- A few stems of cilantro
- A dash of cayenne pepper
- Black pepper
- Cut the avocado and mash it with a fork in a small bowl.
- Add mayonnaise and mix.
- Dice tomato and onion, and mince the garlic.
- Add the veggies to the bowl and mix.
- Add salt, pepper, and cayenne pepper.
- Add the stems of cilantro.
- Serve with tortilla chips.
- Avocado: high in heart-healthy monounsaturated fatty acids and helps lower bad cholesterol and promote weight loss.
- Tomato: packed with antioxidants, which help reduce the risk of heart disease and cancer. It is also an excellent source of vitamin C.
- Onion: full of sulfur compounds and minerals that may just help put you in a better mood.
- Garlic: loaded with compounds that help fight diseases, from common colds and infections to diabetes and cancer.
- Lime: improves heart health and boosts immunity.
- Cilantro: protects against oxidative stress and helps lower blood sugar levels.
- Black pepper: helps digestion and reduces high blood pressure.
- Cayenne pepper: lowers blood pressure and supports digestion.
- Mayonnaise: contains amino acid-rich eggs, but also a lot of fat. Experts recommend consuming mayonnaise in moderation because it is high in calories. Make sure you buy a good quality mayonnaise, possibly organic, without added flavors and made with a healthy oil like avocado oil.