Superfoods Series

Health Benefits of Eating Red Onions


This versatile culinary plant can provide a real health boost to anyone. But exactly why are red onions good for you? This article sheds light on the health benefits of onions, particularly red onions, and explains how the nutrients in onions — including quercetin, allicin and chromium — can protect against cancer, fight fungi and bacteria, promote cardiovascular health, reduce high blood pressure and insulin resistance, and aid in weight loss. Nutrition facts for red onions (GI rating, vitamin and mineral content, etc) are provided at the end of the article.


Red onions are packed with quercetin

red onions
Quercetin in red onions provides wide ranging health benefits.

Red and yellow onions are one of the best natural sources of quercetin, a bioflavonoid that is particularly well suited for scavenging free radicals. Aside from its antioxidant properties, quercetin has been found to possess cancer fighting, anti-fungal, anti-bacterial, and anti-inflammatory properties. It has shown promising potential for preventing and controlling the formation of intestinal polyps, suppressing the rhinoviruses that are the underlying cause of common cold, treating psoriasis, and inhibiting the replication of viruses including the herpes simplex virus that can cause cold sores. It has also been shown to reduce the risk of stomach cancer: according to one study, half an onion a day could reduce the risk of stomach cancer by 50%.


Allicin in onions fights regenerative diseases and fungi

In addition to quercetin, red onions provide allicin, a potent health-promoting compound that is found in onions and other members of the Allium family when the plant is crushed or chopped. Allicin has been shown to promote cardiovascular health, prevent and treat cancer, and reduce high blood pressure. It has also been suggested that allicin could be helpful for people with dandruff due to its anti-fungal properties.


Chromium makes onions a great food to tackle insulin resistance

Onions are a rich source of chromium, a trace mineral that can help control glucose levels. This is great news for those who suffer from insulin resistance as chromium is an essential for insulin activity in carbohydrate, fat and protein metabolism. A lack of chromium-rich foods, such as onions, in diet may lead to insulin resistance and impaired blood sugar control and may increase the risk of cardiovascular disease and type 2 diabetes. Furthermore, there is some evidence suggesting that severe chromium deficiency may make weight loss more difficult or even cause weight gain.


Additional health benefits associated with red onions' low GI rating

With a glycemic index (GI) rating of 10, onions are considered a low glycemic food. The glycemic index ranks carbohydrate containing foods based on how quickly they raise blood sugar levels. Foods are rated between 0 and 100, and the higher the rating, the quicker the food will release energy and cause blood glucose levels to rise. The glycemic index was initially created to help diabetics decide what foods are best for them, but now also many weight conscious people are using the concept of glycemic index to help them lose weight and improve their health. By choosing low GI foods — such as red onions — over high GI carbs, you can regulate blood sugar and insulin levels, which in turn causes the body to store less fat. Studies also suggest that stable insulin levels can contribute to slower aging, lower blood pressure and improved cholesterol levels.


Red Onion Nutrition Facts

Glycemic Index (GI) Rating / Glycemic Load: Red onions have a very low Glycemic Index rating (10).
Calories: Red onions are very low in calories, with 1 ounce of onions (28 grams) containing only 11 calories.
Macronutrients: Red onions are mainly made of carbohydrates and water. They contain zero fat.
Vitamins & Minerals: Red onions provide significant amounts of vitamin C and vitamin B6. They are also one of the best food sources of chromium.