The Health Benefits of Red Onions

Red onions are a common ingredient in many cuisines around the world. They add flavor, color, and crunch to salads, sandwiches, soups, stir-fries, and more. But did you know that red onions also have many health benefits? In this article, we will explore the nutritional value and health benefits of red onions, and how to include them in your diet.

What are Red Onions?

Red onions are a type of onion that have a reddish-purple skin and white flesh with red streaks. They belong to the genus Allium, which also includes garlic, leeks, chives, and shallots. Red onions are also known as purple onions, Spanish onions, or Bermuda onions.

Red onions have a mild to sweet flavor and a crisp texture. They are usually eaten raw or lightly cooked, as they tend to lose their color and flavor when cooked for a long time. Red onions are available year-round in most grocery stores and farmers’ markets.

What is the Nutritional Value of Red Onions?

Red onions are low in calories and high in nutrients. One medium red onion (150 grams) provides:

  • Calories: 60
  • Carbohydrates: 14 grams
  • Fiber: 3 grams
  • Protein: 2 grams
  • Fat: 0 grams
  • Vitamin C: 20% of the Daily Value (DV)
  • Vitamin B6: 10% of the DV
  • Folate: 10% of the DV
  • Manganese: 10% of the DV
  • Potassium: 6% of the DV
  • Phosphorus: 4% of the DV
  • Magnesium: 4% of the DV
  • Iron: 2% of the DV

Red onions also contain small amounts of other vitamins and minerals, such as vitamin A, vitamin E, vitamin K, calcium, zinc, copper, and selenium.

What are the Health Benefits of Red Onions?

Red onions have many health benefits due to their rich content of antioxidants, phytochemicals, and fiber. Some of the main health benefits of red onions are:

  • They may lower blood pressure: Red onions contain flavonoids1, such as quercetin and anthocyanins2, that have anti-inflammatory and vasodilatory effects. These flavonoids may help lower blood pressure by relaxing the blood vessels and reducing oxidative stress. A study found that consuming red onion juice for four weeks significantly reduced systolic and diastolic blood pressure in hypertensive patients3.
  • They may protect against cancer: Red onions have anti-cancer properties due to their high levels of organosulfur compounds, such as allicin and diallyl disulfide. These compounds may inhibit the growth and spread of cancer cells by inducing apoptosis (cell death), modulating gene expression, and preventing DNA damage. A meta-analysis found that higher intake of allium vegetables, such as red onions, was associated with a lower risk of gastric cancer. Another study found that red onion extract suppressed the growth of colon cancer cells in vitro.
  • They may improve blood sugar control: Red onions may help regulate blood sugar levels by enhancing insulin sensitivity and glucose uptake. Insulin is a hormone that helps transport glucose from the blood into the cells for energy. Red onions contain chromium, a mineral that helps improve insulin action and glucose metabolism. A study found that consuming red onion juice for eight weeks improved fasting blood glucose and insulin levels in type 2 diabetic patients.
  • They may boost immunity: Red onions may help strengthen the immune system by stimulating the production and activity of white blood cells, such as macrophages and natural killer cells. These cells are responsible for fighting off infections and foreign invaders. Red onions also contain vitamin C, a powerful antioxidant that helps protect the immune cells from oxidative damage and supports wound healing.
  • They may support digestive health: Red onions may help promote digestive health by providing fiber and prebiotics. Fiber is a type of carbohydrate that helps bulk up the stool and prevent constipation. Prebiotics are substances that feed the beneficial bacteria in the gut, such as bifidobacteria and lactobacilli. These bacteria help maintain a healthy gut flora balance, produce short-chain fatty acids (SCFAs), and modulate inflammation. A study found that consuming red onion powder for six weeks increased the population of bifidobacteria in healthy volunteers.

How to Include Red Onions in Your Diet?

Red onions are versatile and easy to include in your diet. You can enjoy them raw or cooked, as a main ingredient or a garnish, in various dishes and cuisines. Here are some ideas on how to use red onions in your diet:

  • Add them to salads: Red onions add a burst of flavor and color to salads. You can slice them thinly and toss them with lettuce, tomatoes, cucumbers, cheese, nuts, and dressing of your choice. You can also pickle them in vinegar, sugar, and salt for a tangy and crunchy addition to your salads.
  • Use them in sandwiches: Red onions can enhance the taste and texture of sandwiches. You can layer them with ham, cheese, lettuce, tomato, and mayo on bread or wrap. You can also caramelize them in oil, sugar, and vinegar for a sweet and savory topping for your sandwiches.
  • Cook them in soups: Red onions can add depth and aroma to soups. You can sauté them with garlic, celery, carrots, and herbs before adding broth and other ingredients. You can also blend them with roasted tomatoes, basil, cream, and salt for a creamy and delicious tomato soup.
  • Stir-fry them with vegetables: Red onions can complement the flavors of various vegetables. You can stir-fry them with broccoli, cauliflower, zucchini, mushrooms, peppers, and soy sauce for a quick and easy side dish. You can also add some chicken, beef, tofu, or nuts for a complete meal.
  • Bake them with cheese: Red onions can make a decadent and cheesy dish. You can slice them and layer them with potatoes, cream, cheese, thyme, salt, and pepper in a baking dish. You can then bake them until golden and bubbly for a satisfying casserole.