Purple onion tea is actually an herbal infusion made from soaking finely chopped up purple onion in hot water. The process of cutting the onion, and maybe even the taste of the tea, will bring a tear to your eye, but there are many potential health benefits to be had. All types of onions contain compounds that are biologically active, but the purple varieties are especially rich in anthocyanins, a type of phytonutrient renowned for its cardiovascular benefits.
General Benefits of Onion
Onion's health promoting abilities have long been recognized, and worldwide, it is one of the plants most consumed by people. According to the book “Advanced Human Nutrition,” onions are a major source of two types of phytonutrients that play significant roles in human health: flavonoids and sulfur-containing compounds. The two flavonoid subgroups found in onions are anthocyanins, which are found in greater abundance in red and purple-colored varieties, and flavanols such as quercetin. According to David Bender, author of “A Dictionary of Food and Nutrition,” numerous studies have found quercetin and sulfur compounds in onions to be beneficial for the treatment of asthma, sinus congestion, high blood pressure, arteriosclerosis, high blood cholesterol and high blood sugar levels. Quercetin levels are highest in red and purple onions. In terms of essential nutrients, onions are a reasonable source of phosphorous, zinc, potassium, calcium and vitamin C.
Benefits of Anthocyanins
Purple color within vegetables and fruits is almost always a clue to their nutritional power. Purplish tones within onions are caused primarily by the presence of anthocyanins, powerful antioxidants also found within dark colored grapes and red wine. Anthocyanins are able to eliminate harmful free-radicals from your blood vessels and other tissues, but they also demonstrate anti-cancer activity, as cited in Tonia Reinhard’s “Superfoods: The Healthiest Foods on the Planet.” Purple onions are not the richest source of anthocyanins, as purple, blue and red berries and grapes contain more. Other vegetable sources of anthcyanins include eggplant and purple cabbage and kale.
Why Drink It?
Cutting and soaking purple onions in hot water allows the beneficial compounds within the onion’s cell walls to escape. Thoroughly chewing raw onion has similar effects, but it is less efficient and your stomach might be sensitive to digesting raw onion. In some people, raw onion causes stomach upset, bloating and flatulence. Drinking purple onion tea is likely better absorbed by your body and causes fewer gastrointestinal symptoms. It may also be a more concentrated source of beneficial nutrients, depending on how you prepare it.
To get the most health benefits from your purple onions, chop them finely and let them sit for five to 10 minutes before steeping them in hot water, according to Phyllis Balch in “Prescription for Nutritional Healing.” She explains that using water that has not quite boiled is better because intense heat deactivates some of the sulfur-based compounds in onion. Let the raw onion steep in the hot water for a further five minutes before filtering and consuming. To reduce the risk of stomach upset, consume the purple onion tea on an empty stomach and see how you feel. Although purple onions are not recognized as cures for any diseases, the nutrients within them are a welcome addition to any healthy diet.
- “Advanced Human Nutrition”; Robert Wildman and Denis Medeiros; 2000
- “A Dictionary of Food and Nutrition: 3rd Edition; David A. Bender; 2009
- “Superfoods: The Healthiest Foods on the Planet”; Tonia Reinhard; 2010
- “Prescription for Nutritional Healing”; Phyllis Balch; 2010