Red onion also called Spanish onion or purple onion, is a vegetable, one sort of the onion. It has red, almost purple skin and white meat with red strings. It is considered that it is the most widely cultivated species of the genus Allium. Red onion is very mild and has a sweet taste.
There are famous varieties: red onion of Turda and red onion of Tropea. Red onion of Turda is a particular variety from Turda, Central Romania, and has a particular aroma. Red onion of Tropea is from Italy and has a strong and sweet taste. It is juicier than others red onions, actually, so much juicer that jam can be made with it. In the United States, the most popular variety is Wethersfield red onion, red onion from Connecticut.
Red onions are most popular type of onions in India, the Mediterranean, and the Middle East, but in Britain white onion is the most common type.
Although both onions, red and white, are so-called "superfood" due to beneficial nutrients, red has more health benefits. Both onions provide about 10% of the daily value for vitamin C, but red contains a higher amount of antioxidant compounds. White onion has 0.5 g more of fiber and a higher amount of sulfur, but red has a higher amount of flavonols and anthocyanins. Red onion contains at least 25 different anthocyanins. Red onions are also more effective natural blood thinner than white onions because they are richer in flavonoids, which help thin the blood. Both onions meet 2% of daily value for calcium, but the red onion meets 2% of the daily value for iron.
Red onion is mostly popular because of phytochemicals, which are important because they boost our immune system. Red onion is also a rich source of vitamin K, B6, and C, but at the same time, the phytochemicals act as a stimulant to vitamin C within the body. Fiber from red onion helps in functioning of the digestive tract, and it helps prevent constipation. Red onion is rich in minerals, too: it has folate, thiamine, calcium, magnesium, potassium, and manganese.
Among others health benefits, red onions contain antioxidants, flavonoids. Antioxidants are important because they are fighting the free radicals. Free radicals (toxic organic waste) are considered dangerous because they can cause cancer by mutating the DNA. Because of that, quercetin, antioxidant from red onion, is most valued - some studies showed that it can even reduce spreading of cancer through the body. Studies showed that one-half of onion on a daily basis could reduce the risk of stomach cancer by 50%. For example, in the USA, in Georgia where red onion is grown, the number of stomach cancer is a half the average for the rest of cancer and in China, where is red onion mostly used, the risk of stomach cancer is 40% lower than average.
Quercetin is also significant for those with high blood pressure. According to a study by the University of Utah, this antioxidant can reduce the risk of coronary heart disease and stroke. Although the study didn't show results on people who don't have high blood pressure, the ones who have hypertension did have benefits. Allicin, also compound, helps in reducing high blood pressure. Quercetin is also good due to anti-inflammatory effect, so it's beneficial for people with allergies, asthma, and arthritis. Short-term inflammation in the human body should raise the natural defense of the body, so it's not dangerous, but on the other hand, long-term inflammation can cause serious problems like heart disease, cancer or Alzheimer’s disease. Quercetin can help with that. Beside of anti-bacterial effect, it has anti-fungal properties, too. It can help with psoriasis and can inhibit many viruses, such as herpes simplex.
Anti-inflammatory effects of red onion are best shown in people with acne. When you apply red onion on face together with honey or olive oil, it reduces redness and swelling. Also, when you put red onion on area injured by a bee, you will feel immediate pain relief - burning sensation will stop.
Because of mineral chromium, red onion is especially good for people with diabetes - chromium has an impact on sugar level in the body and helps in slowing and controlling the release of sugar into the body. As an essential for insulin activities, lack of chromium can cause a gain of weight, so if you want weight loss, make sure to eat red onion. Also, red onion is low glycemic food (glycemic index GI is 10) which means that it's ideal for diet. One ounce of onions contains only 11 calories and has zero fat. Raw red onion is ideal for overweight women, in particular for ones with PCOS, because it significantly lowers level of cholesterol (high cholesterol is an indication of PCOS).
If you have the ringing sound in the ear or earaches, just put few drops in the ear. Tinnitus can also be cured this way.
It is important to know that many people have an onion allergy. That includes itchy eyes, redness, and rashes if an onion only comes into contact with skin, but also vomiting and gastric problems.