Though all vegetables are important for health, certain kinds offer unique benefits.
Onions are members of the Allium genus of flowering plants that also includes garlic, shallots, leeks and chives.
These vegetables contain various vitamins, minerals and potent plant compounds that have been shown to promote health in many ways.
Here are 9 impressive health benefits of onions.
Onions are nutrient-dense, meaning they’re low in calories but high in vitamins and minerals.
This vegetable is particularly high in vitamin C, a nutrient involved in regulating immune health, collagen production, tissue repair and iron absorption.
Lastly, they’re a good source of potassium, a mineral in which many people are lacking.
SUMMARY Onions are low in calories yet high in nutrients, including vitamin C, B vitamins and potassium.
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.
A study in 70 overweight people with 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 mmHg compared to a placebo.
Onions have also been shown to decrease cholesterol levels.
A study in 54 women with polycystic ovarian syndrome (PCOS) found that consuming large amounts of raw red onions (40–50 grams/day if overweight and 50–60 grams/day if obese) for eight weeks reduced total and “bad” LDL cholesterol compared to a control group.
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.
SUMMARY Research shows that eating onions may help reduce heart disease risk factors, such as high blood pressure, elevated triglyceride levels and inflammation.
Antioxidants are compounds that inhibit oxidation, a process that leads to cellular damage and contributes to diseases like cancer, diabetes and heart disease.
Onions are an excellent source of antioxidants. In fact, they contain over 25 different varieties of flavonoid antioxidants.
Red onions, in particular, contain anthocyanins — special 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.
SUMMARY Red onions are rich in anthocyanins, which are powerful plant pigments that may protect against heart disease, certain cancers and diabetes.
Eating vegetables of the Allium genus like garlic and onions has been linked to a lower risk of certain cancers, including stomach and colorectal.
These cancer-fighting properties have been linked to the sulfur compounds and flavonoid antioxidants found in allium vegetables.
SUMMARY A diet rich in allium vegetables like onions may have a protective effect against certain cancers.
Eating onions may help control blood sugar, which is especially significant for people with diabetes or prediabetes.
Specific compounds found in onions, such as quercetin and sulfur compounds, possess antidiabetic effects.
SUMMARY Due to the many beneficial compounds found in onions, consuming them may help reduce high blood sugar.
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 women showed that those who consumed 3.4 ounces (100 ml) of onion juice daily for eight weeks had improved bone mineral density and antioxidant activity compared to a control group.
Another study in 507 perimenopausal and postmenopausal women 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.
SUMMARYStudies show that onion consumption is associated with improved bone mineral density.
Quercetin extracted from onions seems to be a particularly powerful way to fight bacteria.
A test-tube study demonstrated that quercetin extracted from yellow onion skin successfully inhibited the growth of Helicobacter pylori (H. pylori) and Methicillin-resistant Staphylococcus aureus (MRSA) (31Trusted Source).
H. pylori is a bacteria associated with stomach ulcers and certain digestive cancers, while MRSA is an antibiotic-resistant bacteria that causes infections in different parts of the body.
SUMMARY Onions have been shown to inhibit the growth of potentially harmful bacteria like E. coli and S. aureus.
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.
Additionally, consuming foods rich in prebiotics helps increase probiotics, such as Lactobacillus and bifidobacteria strains, which benefit digestive health..
SUMMARY Onions are a rich source of prebiotics, which help boost digestive health, improve bacterial balance in your gut and benefit your immune system.
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 minerals.
Here are some tips on how to add onions to your diet:
SUMMARY Onions can easily be added to savory dishes, including eggs, guacamole, meat dishes, soups and baked goods.
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.