Onions (Allium cepa L) are a member of the Liliaceae plant family, which also includes other flavorful allium vegetables like garlic and leeks. Allium vegetables contain therapeutic oils that hold sulfur compounds (cysteine sulfoxides), which are partially responsible for their signature smell and taste.
Onions are the pungent allium vegetables that are packed with numerous health benefits in addition to their very obvious flavor. They come in many types or colors as you must have seen while grocery shopping: white, red, yellow etc. Rich in nutrients and antioxidants including flavonoids and polyphenols — onion can help you maintain better blood sugar levels, facilitate in building stronger bones, alongside their anti-inflammatory properties.
Studies have shown that onions are linked to cancer and heart disease prevention, plus lower risks of developing arthritis, asthma, diabetes and neurodegenerative disorders.
Quercetin, in onions, is considered an antihistamine phytonutrient that’s often found in allergy products because it can lower the effects of histamines on the immune system. And anthocyanins, the same type of antioxidants found in red berries, are responsible for giving red onions their deep color.
While chopping an onion, your eyes tend to water because cutting onions punctures their cell membranes that store ‘ACSOs’, which are alkenyl cysteine sulphoxides (ACSOs). These are sulfur compounds that have been reported to have a range of health benefits, including anti-carcinogenic properties, anti-platelet activity, anti-thrombotic activity, anti-asthmatic and antibiotic effects.
One cup of raw, chopped onions has about 64 calories, 2 grams protein, 2 grams fiber, 7 grams of sugar, 8 milligrams vitamin C, 0.2 milligrams vitamin B6, 0.2 milligrams manganese, 22 milligrams folate, 234 milligrams potassium, 46 mg phosphorus and 0.07 mg vitamin B1 thiamine.
Here are some of its health benefits:
Onions help reduce the risk of developing colon, ovarian and mouth cancers through their rich supply of antioxidants that prevent cell damage. Onion’s sulfur compounds have been found to prevent the growth of tumors and cancer development by protecting cells from mutation and inducing apoptosis.
Even consuming onions just several times per week has been linked to cancer protective benefits. But, of course, the more you consume onions, the more cancer protection you receive.
Studies from southern European populations published in the American Journal of Clinical Nutrition show an inverse association between the frequency of consuming onions and other allium vegetables and the risk of several common cancers.
Onions have fibrinolytic benefits: they provide cardiovascular protection by reducing the risk of blood clot formation. Moreover, they can protect against “bad” LDL cholesterol. They do this by limiting the activity of harmful free radicals within blood vessels, therefore lowering oxidative stress and improving blood circulation and blood pressure levels.
Onions can help achieve greater bone mineral density, which lowers the risk for fractures. A study done by the Department of Family Medicine at the University of South Carolina found that bone density increased in women as onion consumption increased.
Women who consumed onions once a day or more had an overall bone density that was 5 percent greater than individuals who consumed onions once a month or less. Researchers concluded that women who consume onions most frequently may decrease their risk of hip fractures by more than 20 percent as compared to those who never consume onions.
One possible mechanism responsible for the bone-building benefits of onion nutrition might be onions’ GPCS substances (gamma-L-glutamyl-trans-S-1-propenyl-L-cysteine sulfoxides), which help inhibit the breakdown of bone and prevent osteoporosis and reverse corticosteroid-induced bone loss.
The Plant Resources Research Institute in Korea found that onion extract can help fight diabetes because onion intake may be effective for lowering plasma glucose concentrations and body weight. Onions are an effective, natural way to control the level of blood sugar released into the bloodstream and prevent insulin resistance.
Onion nutrition research also shows that onions supply chromium, which is beneficial for controlling blood glucose and may be beneficial for preventing diabetes.
Because onions as a great anti-inflammatory food, they’re one of the best vegetables if you suffer from painful inflammatory diseases like arthritis or asthma. According to the National Arthritis Foundation, quercetin found in onions may be especially beneficial for arthritis patients because it inhibits inflammation-causing leukotrienes, prostaglandins and histamines that make the pain and swelling worse.
If you’re suffering from a cold or respiratory illness, try including more onions in your diet as a natural way to treat it. Experts believe that certain onion nutrition phytonutrients can increase immune defense; fight inflammation, and clear mucus from the nasal passages, lungs and respiratory system quicker.
Antioxidants in Onion have a positive impact on sperm health parameters, which may be a natural way to improve fertility. Researchers in Iran investigated the effects of onions on fertility of rats, and found that total testosterone levels significantly increased, as did sperm concentration, viability and mobility in the rats who received high levels of onions over the course of 20 days.