Vegetables are a crucial source of health and nutrition. There are, however, a few standout veggies and onions—a staple in many North American kitchens and cuisines worldwide—are one of them.
Onions are an antioxidant, anti-inflammatory, anticancer, and pro-heart powerhouse that come in various colors and types. They are a culinary essential that has offered people outstanding health benefits for many generations.
The type of onion may clue you in on its specific benefits. Red onions are known to be particularly rich in quercetin, a plant pigment or flavonoid present in many fruits, vegetables, and grains. Found in a great variety of foods as well as beverages like tea and wine, flavonoids have antioxidant, anti-inflammatory, and anti-carcinogenic properties, along with the ability to modulate cellular enzyme function.[i]
Other varieties such as green, brown, and white boast their own sets of health benefits. For example, green onions, also commonly known as scallions, are traditionally used to treat colds, flu, abdominal pain, headache, and heart disease.[ii] Let’s have a look at another five impressive health benefits of onions.
Onions contain antioxidants that may support healthy cholesterol levels as well as help manage blood pressure, both of which may lower the risk of heart disease.
A study involving 70 overweight individuals with high blood pressure found that quercetin-rich onion extract, 162 milligrams (mg) per day in particular, notably pushed down systolic blood pressure by 3 to 6 mmHg versus a placebo.[iii]
Another study conducted in 54 patients with polycystic ovarian syndrome (PCOS) concluded that eating about 40 to 50 grams (g) per day of raw red onions (if overweight) and 50 to 60 g a day (if obese) for an eight-week period slashed total and LDL cholesterol, compared to a control group, which ate smaller amounts of onions.[iv]
Onions are an excellent antioxidant source, and, in fact, offer more than 25 different varieties of flavonoid antioxidants.[v]
Specifically, anthocyanins, which are special plant pigments that give red onions their color, have been associated with a lower likelihood of heart attacks. This was found in a study of 93,600 women with the highest intake of anthocyanin-filled foods.[vi]Additionally, anthocyanins offer protective effects against certain kinds of cancer.[vii]
In a 2012 study, quercetin displayed a protective effect against sodium fluoride-induced oxidative stress in the heart in an animal model.[viii] Consuming onion peel itself, found to contain quercetin in abundance, may also benefit obese individuals as a way to reduce oxidative stress to help prevent the onset of chronic disease.
Skin and Hair Health
Onion extract gel may be useful for wound healing, showing promise in improving the cosmetic appearance of post-surgical scars.[x] A study showed that it significantly improved scar softness, redness, texture, as well as appearance at the site at weeks four, six, and 10 during the research.
Applied topically, crude onion juice may assist in hair regrowth compared to tap water, potentially serving as an effective topical therapy for patchy alopecia areata.