Onions

Health Benefits of Onions.

  • Onions are very low in calories and fats. 100 grams carry just 40 calories. However, they are rich in soluble dietary fiber.
  • Phyto-chemical compounds allium and Allyl disulphide in the onions convert into allicin by enzymatic reaction when its modified leaves are distorted (crushing, cutting, etc). Studies have shown that these compounds have anti-mutagenic (protects from cancers) and anti-diabetic properties (helps lower blood sugar levels in diabetics).
  • Laboratory studies show that allicin reduces cholesterol production by inhibiting HMG-CoA reductase enzyme in the liver cells. Further, it also found to have anti-bacterial, anti-viral, and anti-fungal activities.
  • Additionally, Allicin also decreases blood vessel stiffness by facilitating release of nitric oxide (NO) and thereby bring a reduction in the total blood pressure. Further, it blocks platelet-clot formation, and has fibrinolytic action in the blood vessels. Altogether, it helps decrease in overall risk of coronary artery disease (CAD), peripheral vascular diseases (PVD), and stroke.
  • Onions are rich source of chromium, a trace mineral that helps tissue cells respond appropriately to insulin levels in the blood. It thus helps facilitate insulin action and control sugar levels in diabetes.
  • They are also good source of antioxidant flavonoid quercetin, which is found to have anti-carcinogenic, anti-inflammatory, and anti-diabetic functions.
  • They are also good in antioxidant vitamin, vitamin-C and mineral manganese. Manganese is required as a co-factor for anti-oxidant enzyme, superoxide dismutase. In addition, isothiocyanate anti-oxidants in them help provide relief from cold and flu by exerting anti-inflammatory actions.
  • Onions are also good in B-complex group of vitamins like pantothenic acid, pyridoxine, folates and thiamin. Pyridoxine or vitamin B-6 helps keep up GABA levels in the brain, which works against neurotic conditions.

 

See the table below for in depth analysis of nutrients:
Onion (Allium cepa), raw Nutrition value per 100 g.(Source: USDA National Nutrient data base)
Principle Nutrient Value Percentage of RDA
Energy 40 Kcal 2%
Carbohydrates 9.34 g 7%
Protein 1.10 g 2%
Total Fat 0.10 g 0.5%
Cholesterol 0 mg 0%
Dietary Fiber 1.7 g 4.5%
Vitamins
Folates 19 µg 5%
Niacin 0.116 mg 1%
Pantothenic acid 0.123 mg 2.5%
Pyridoxine 0.120 mg 9%
Riboflavin 0.027 mg 2%
Thiamin 0.046 mg 4%
Vitamin A 2 IU 0%
Vitamin C 7.4 mg 12%
Vitamin E 0.02 mg 0%
Electrolytes
Sodium 4 mg 0%
Potassium 146 mg 3%
Minerals
Calcium 23 mg 2%
Copper 0.039 mg 4%
Iron 0.0.21 mg 3%
Magnesium 10 mg 2.5%
Manganese 0.129 mg 5.5%
Phosphorus 29 mg 4%
Zinc 0.17 mg 1.5%
Phyto-nutrients
Carotene-beta 1 µg
Cryptoxanthin-beta 0 µg
Lutein-zeaxanthin 4 µg

Why do onions make you cry?

When you cut into an onion, the cell walls are damaged releasing a sulfur compound called propanethial-S-oxide which floats into the air. This compound is converted to sulfuric acid when it comes in contact with water which is why it stings your eyes. Chilling inactivates the propanethial-S-oxide so it does not float into the air. Thus, no tears.

To keep eyes dry when chopping onions, try chilling peeled onions in the refrigerator before chopping. To get the onion smell off your hands, rub with lemon juice or vinegar. To freshen onion breath, chew a little parsley or a coffee bean.