Onion.Medicinal properties and health effects of onions

Wide-ranging claims have been made for the effectiveness of

onions against conditions ranging from the common cold to

heart disease, diabetes, osteoporosis, and other diseases.

They contain chemical compounds believed to have

anti-inflammatory, anticholesterol, anticancer, and antioxidant

properties, such as quercetin. Preliminary studies have shown

increased consumption of onions reduces the risk of head and

neck cancers.
Among all varieties, Asian white onions have the most eye

irritating chemical reaction.
In India some sects do not eat onions as they believe them to

be an aphrodisiac;various schools of Buddhism also advise

against eating onions and other vegetables of the Allium
family.
In many parts of the undeveloped world, onions are used to heal

blisters and boils. A traditional Maltese remedy for sea urchin

wounds is to tie half a baked onion to the afflicted area

overnight. A similar traditional cure is known in Bulgaria.

Half-baked onion with sugar is placed over the finger and

fingernail in case of inflammation.
An application of raw onion is also said to be helpful in reducing

swelling from bee stings. In the United States, products that

contain onion extract are used in the treatment of topical scars;

some studies have found their action to be

ineffective, while others found that they may act as

an anti-inflammatory or bacteriostatic and can improve

collagen organisation in rabbits.
Onions may be beneficial for women, who are at increased

risk for osteoporosis as they go through menopause, by

destroying osteoclasts so they do not break down bone.
An American chemist has stated the pleiomeric chemicals in

onions have the potential to alleviate or prevent sore throat.

Onion in combination with jaggery has been widely used as a

traditional household remedy for sore throat in India.
Shallots have the most phenols, six times the amount found in

Vidalia onion, the variety with the lowest phenolic content.

Shallots also have the most antioxidant activity, followed by

Western Yellow, pungent yellow (New York Bold) Northern

Red, Mexico, Empire Sweet, Western White, Peruvian Sweet,

Texas 1015, Imperial Valley Sweet, and Vidalia. Western Yellow

onions have the most flavonoids, eleven times the amount

found in Western White, the variety with the lowest flavonoid

content.
For all varieties of onions, the more phenols and flavonoids they

contain, the more reputed antioxidant and anticancer activity they

provide. When tested against liver and colon cancer cells in

laboratory studies, 'Western Yellow', pungent yellow (New York

Bold) and shallots were most effective in inhibiting their

growth. The milder-tasting cultivars (i.e., 'Western White,'

'Peruvian Sweet,' 'Empire Sweet,' 'Mexico,' 'Texas 1015,'

'Imperial Valley Sweet' and 'Vidalia') showed little

cancer-fighting ability.
Shallots and ten other onion (Allium cepa L.) varieties commonly

available in the United States were evaluated: Western Yellow,

Northern Red, pungent yellow (New York Bold), Western White,

Peruvian Sweet, Empire Sweet, Mexico, Texas 1015, Imperial

Valley Sweet, and Vidalia. In general, the most pungent onions

delivered many times the effects of their milder cousins.
The 3-mercapto-2-methylpentan-1-ol in onion was found to
inhibit peroxynitrite-induced mechanisms in vitro.
While members of the onion family appear to have medicinal
properties for humans, they can be deadly for dogs, cats, and
guinea pigs.

 

Raw Onions

Nutritional value per 100 g (3.5 oz)

Energy 166 kJ (40 kcal)

Carbohydrates 9.34 g

- Sugars 4.24 g

- Dietary fiber 1.7 g

Fat 0.1 g

- saturated 0.042 g

- monounsaturated 0.013 g

- polyunsaturated 0.017 g

Protein 1.1 g

Water 89.11 g

Vitamin A equiv. 0 μg (0%)

Thiamine (vit. B1) 0.046 mg (4%)

Riboflavin (vit. B2) 0.027 mg (2%)

Niacin (vit. B3) 0.116 mg (1%)

Vitamin B6 0.12 mg (9%)

Folate (vit. B9) 19 μg (5%)

Vitamin B12 0 μg (0%)

Vitamin C 7.4 mg (9%)

Vitamin E 0.02 mg (0%)

Vitamin K 0.4 μg (0%)

Calcium 23 mg (2%)

Iron 0.21 mg (2%)

Magnesium 0.129 mg (0%)

Phosphorus 29 mg (4%)

Potassium 146 mg (3%)

Sodium 4 mg (0%)

Zinc 0.17 mg (2%)

Percentages are relative to

US recommendations for adults.

Source: USDA Nutrient Database