Onion plays a vital role in our traditional health care system. Onion is the most widely cultivated species of the Allium family. It also has other relatives such as garlic, leeks, shallots, and chives. This humble vegetable is stable for all dishes and almost found in every kitchen. Onions vary in color, shape, size, and flavor; their taste ranges from sweet and juicy to sharp, pungent, and spicy depending on the season they are grown. Both small onions and Bellary onions are rich in various medicinal properties (1). Thus, onions are used medicinally in many countries.
These bulbs are an excellent source of nutrients such as Vitamin C and B, flavonoids, sulphuric compounds, and phytochemicals. However, the sulfur content of raw onions is not compatible with some people, so they should use cooked onions. Onion bulbs are famous for making you cry, but its powerful antioxidants and anti-inflammatory properties shield the body from few wild disorders. It also acts as the main ingredient in most of the dishes, and it can be in any form such as raw, boiled, baked, steamed, or sautéed. Likewise, it would be challenging to prepare a dish without them (2).
Types of Onions
- Yellow onions – Ivory white flesh covered by heavy brown skin, have a strong flavor and pungent aroma.
- Sweet onions – Sweet and mild, have less-opaque skin.
- White onions – Have papery white skin; the flavor is sweeter and milder than yellow onions.
- Red onions – Have white flesh with a red outer layer, pungent and spicy.
- Shallots – Brown-skinned and have purple flesh, pungent with mild sweetness.
- Green onions - Also known as spring onions, salad onions, or scallions, have tiny white bulbs and green top.
|Nutritional value per 100 g|
|Energy||166 kJ (40 kcal)|
|Thiamine (B1)||0.046 mg|
|Riboflavin (B2)||0.027 mg|
|Niacin (B3)||0.116 mg|
|Pantothenic acid (B5)||0.123 mg|
|Vitamin B6||0.12 mg|
|Folate (B9)||19 μg|
|Vitamin C||7.4 mg|
Here are a few Health Benefits of Onion:
1. Hair Care
Sulfur in onion is good for hair growth as it stimulates collagen production. Amino acids and Keratin, which are essential proteins for strong hair, are also rich in sulfur. Applying onion juice directly to the scalp increases blood supply to hair follicles, improving hair growth. Similarly, it also maintains hair follicles nutrients absorption that prevents hair damage and hair loss. Onion’s antibacterial properties assist in preserving hair color, keep dandruff and lice away from your scalp.
2. Improves Heart Health
Onions, particularly red onions, contain flavonoids that help decrease the bad cholesterol (LDL), which in turn reduces the risk of heart attack and stroke. Hence, eating raw onions every day promotes good cholesterol (HDL) production in your body. Organosulfur and thiosulfate in onions help to prevent heart disease. The sulfur acts as a natural blood thinner, and it prevents blood clotting, which helps to lower blood pressure and risk of cardiovascular disease (3).
3. Skin Care
Onions are filled with Vitamin A, C, B6, and E that helps in enhancing skin health and beauty. Allicin, the Sulphur compound, is a powerful antiseptic that shields the skin from bacteria and treats acne. The vitamins in onions protect the skin from premature aging caused by free radicals. The antibacterial, antimicrobial, and anti-inflammatory properties of onions shield the skin from bacteria that cause acne, pimple, and other skin infections. Vitamin C in onion helps to impart a glow to the skin.
4. Enhances Good Vision
Sulfur in onion improves eye health by stimulating glutathione production, which is a protein that acts as an antioxidant. Higher levels of glutathione in the eye reduce the risk of macular degeneration, glaucoma, and cataracts. Onion extracts prevent corneal haze development. Also, onion contains selenium that helps in vitamin E production, protecting the cells in the eye. Besides, mix an equal amount of onion juice with honey and apply one drop to the eyelid to get rid of cataracts and eye strain.
5. Promotes Digestion
Inulin, a fiber present in onion, is a food source for the beneficial microbes in the intestines. Consuming onions helps maintain good levels of beneficial bacteria in the gut, and enhance digestive health, reducing inflammation in the stomach (4, 5). It also prevents constipation and boosts nutrient absorption. Foods that are rich in prebiotics make digestive health better.
6. Oral Health
The sulfur compounds of onions help to prevent tooth decay and oral infections. Vitamin C in onion helps to keep the teeth healthy. Chewing raw onions for 2 or 3 minutes kills all the germs present in the mouth area. Few people avoid eating raw onions because that causes bad breath in the mouth. However, it is good oral hygiene. Hence, it is better to wash your mouth after the consumption of onions.
7. Bone Health
Vitamin C in onions plays a vital role in enhancing bone strength. They are super-rich in antioxidants, anti-inflammatory flavonoids that prevents the bone from breaking down. It also secures the bone against damages caused by free radicals. A compound in onion reduces bone loss; it also prevents age-related osteoporosis. Onions contain Quercetin that inhibits osteoarthritis and rheumatoid arthritis (6). The Sulphur compounds in onion strengthen the collagen in the bone. Hence, regular consumption of onions can improve bone mineral density and decreases the risk of hip fractures for women (7, 8).
8. Boosts Immunity
Applying onion extract helps to promote the pain, appearance, and itching of different types of scars. This extract helps with hypertrophic scars, keloids, and scars from surgery or tattoo removal. Selenium in onions stimulates immune function. Vitamin C, a powerful anti-inflammatory agent, is high in onions that help to improve immunity (9). Onions boost the production of interferons that enhances the natural immunity against infectious agents. Thus, regular consumption of onions develops a healthy immune system.
Onions are super rich in nutrients, and their health benefits are awe-inspiring. It contains powerful compounds that increase bone density and reduces heart diseases.
It also promotes good oral health and develops immunity. Adding more onions to your diet will provide numerous benefits to your overall health.