Though all vegetables are important for health, a lot of people do not like eating onions for one reason or the other. 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 man.
In fact, the medicinal properties of onions have been recognized since ancient times, when they were used to treat ailments like headaches, heart disease and mouth sores. Here are some impressive health benefits of onions.
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. 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. Onions are also rich in B vitamins, including folate (B9) and pyridoxine (B6) — which play key roles in metabolism, red blood cell production and nerve function.
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. 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.
Help Control Blood Sugar
Eating onions may help control blood sugar, which is especially significant for people with diabetes or prediabetes. A study in 42 people with type 2 diabetes demonstrated that eating 3.5 ounces (100 grams) of fresh red onion reduced fasting blood sugar levels by about 40 mg/dl after four hours.
Additionally, multiple animal studies have shown that onion consumption may benefit blood sugar control. A study showed that diabetic rats fed food containing 5% onion extract for 28 days experienced decreased fasting blood sugar and had substantially lower body fat than the control group.
Contain Cancer-Fighting Compounds
Eating vegetables of the Allium genus like garlic and onions has been linked to a lower risk of certain cancers, including stomach and colorectal. 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 least amount.
Moreover, a review of 16 studies in 13,333 people demonstrated that participants with the highest onion intake had a 15% reduced risk of colorectal cancer compared to those with the lowest intake. These cancer-fighting properties have been linked to the sulfur compounds and flavonoid antioxidants found in allium vegetables.