Onion Uses, Remedies, Research, Side Effects

Onion is anti-aging, rejuvenating, aphrodisiac and improves intelligence. It improves skin complexion, useful in skin disorders. Its juice extract is useful in hair fall.

Botanical Name- Allium cepa Linn.
Family- Liliaceae (Palandu kula)

Vernacular names

Names in different languages:
Hindi name – Piyaz, Pyaz
Kannada name – Nirulli, Irulli
Bengali name – Pyanj
Malayalam name – Chuvannaulli
Telugu Name – Nirulli
Tamil name – Vengayam
Punjabi name – Ganda
Marathi name – Konda
Gujarati name – Dungali, Dungari, Kando

Sanskrit Synonyms

Yavanesta – Liked by European people
Durgandha, Mukha Dooshaka – Causes bad breath.
Palandu
Sukandaka – Bulb is beautiful

Scientific classification

Kingdom: Plantae
Phylum: Angiosperms
Class: Monocots
Order: Asparagales
Family: Amaryllidaceae
Subfamily: Allioideae
Genus: Allium
Species: A. cepa

Morphology

Onion is an annual to bi- annual shrub cultivated in the plains of India as a source of vegetable. The shrub grows up to 1 meter in height with the stem of the plant being green in colour and white coloured flower at the top. Both the stem and the bulb, which is found underground, are edible. The onion plant has been grown and selectively bred in cultivation for at least 7,000 years. Doctors were known to prescribe onions to facilitate bowel movements and erections, and to relieve headaches, coughs, snakebite, and hair loss. As a food item, they are usually served cooked, as a vegetable or part of a prepared culinary dish, but can also be eaten raw or used to make pickles or chutneys. They are pungent when chopped and contain certain chemical substances like sulfur which irritate the eyes.

Chemical constituents

Allium cepa Chemical Constituents:
Cycloallin, quercetin, Oleanolic acid, Allyl propyl disulphide (stable oil), etc.
It contains 1.2 % of protein, 11.6 % of carbohydrate.
It also contains Calcium, Iron, Vitamin E and B1.

Utpatti sthana – Distributed in all over India.

The bulb of onion contains volatile oil containing sulphurous constituents like allyl propyl disulphide, allicin and allilin. The onion bulb also contains flavonoids, phenolic acids, thiosulfinates and sterols.

Medicinal properties

Onion medicinal Properties:
Rasa (taste) – Madhura (sweet), Katu (Pungent)
Guna (qualities) – Guru (Heaviness), Snigdha (Unctuous, oily), Teekshna (strong, piercing)
Vipaka- Madhura – Undergoes sweet taste conversion after digestion.
Virya- Anushna – Not very hot in potency
Effect on Tridosha:
Because of its oiliness, sweet and hot potency, it balances Vata, Has neutral effect on Pitta, Slightly increases Kapha Dosha.

Part used, dosage

Part Used- Bulb, Seeds
Dosage- Onion Juice 10-20 ml, Onion seed powder 1-3 g.

Ayurvedic usage, remedies

Ayurvedic usage and remedies of onion:

• The paste of onion is applied over localized swelling and wounds and then covered with bandage as treatment.
• The fresh juice of onion or the oil processed with onion juice is poured into the ears to treat earache.
• The juice of Allium cepha is taken in a dose of 10-15 ml daily to improve the vision of the eyes.
• The slices of onion are fried in ghee and taken internally to treat cough with phlegm, asthma and hoarseness of the voice due to cold.
• The paste of onion is applied over black head, moles to treat them.
• The paste of the onion is slightly heated and applied over the area affected with sciatica, joint pain and pain in the nerves.
• The juice of onion is installed into the nostrils in cases of nasal bleeding.
• Onion is cut into small pieces and boiled with double the quantity of milk. This milk is consumed to treat bleeding piles and other bleeding disorders.
• The sweet variety of onions are cut into slices, fried in ghee and consumed regularly to increase the vitality and sexual vigour.
• The onion juice is consumed in doses of 10-15 ml with a pinch of rock salt to improve appetite and digestion.
• The onion seed is powdered and consumed in a dose of 3-5 g with pomegranate juice to improve sperm count.
• The fresh juice of onion is consumed in a dose of 15-20 ml to treat fever arising due to indigestion.
• The paste of onion is kept over the area affected with dental caries and inflammation of the gums.
• The fresh and cooked onion is used as a vegetable in many recipes all over the world.

Allium cepa medicinal uses:

It aggravates Kapha and alleviates Vata, but it does not alleviate Pitta. It is useful as a food.
It is heavy and aphrodisiac. It promotes strength and appetite.

Red onion qualities are quite similar to garlic.
Balakara – improves strength and immunity
Veeryakara – improves quality and quantity of sperm and semen
Agnivardhana – improves digestions strength
Sthira Dhatukara – improves body strength and stability
Medhada – improves intelligence
Psuhtida – nourishing

It is widely used in treating neurological pains, sciatica and osteoarthritis.
The white variety of onion is:
Swadu – sweet in taste
Guru – slightly heavy to digest
Picchila – sticky
shonitapitta shasta – useful in bleeding disorders such as nasal bleeding, bleeding piles, etc.

Sanskrit verse

Onion seed benefits

Vrushya – aphrodisiac, improves vigour
Dantakeetajit – useful in dental caries
Pramehajit  – Useful in urinary tract disorders, diabetes

Onion juice benefits

Snigdhangatva – makes body lustrous
Gaurata – imparts heaviness
Kantimata – improves skin complexion
Vahnerdeepti – improves digestion strength
Charma shuddhi – Detoxifies skin
Vrushatva – acts as aphrodisiac
Deerghamayu – anti aging
Balakara – improves strength and immunity
Varnakara – Improves skin tone and complexion
Ojaskara – improves immunity
Swarakara – improves voice tone and quality
Saumanyasya – Brings calmness to mind
Badhira – useful in hearing problems

Onion Juice helps to expel the worms from the stomach and intestines. In case of viral infections affecting stomach and intestines, such as Foot Hand and Mouth Disease, onion juice is administered mixed with honey in a dose of 1-2 spoons in children. Crush the onion. Extract juice. Take 2 teaspoons of onion juice. Mix it with a teaspoon of honey. Give this twice a day, after food.

Onion juice for hair
Applying onion juice – 10 minutes before hair wash, is known to improve hair shine and hair growth. It also reduces hair fall.

How to consume onions?

Regular intake of onion in diet in the form of Onion chutney, onion pakoda, Pyaz Ki Kachori, Liver and onions (English food) or simple one or two slices of onion would deliver all the health benefits listed above.

Onion a Tamas food

Are onions good for you? Onion a Tamas food –
Onion has Rasayana properties – It means, if you take it for a long period of time, it has anti aging effects on your health. But it is also a Tamasik food. Tamas means darkness. It means that it is not suitable for those seeking celibacy and spiritual success.
However, if you have any disease, the concept of Tamasik food does not apply to you.
The benefits of onion outweigh its Tamasik side effects. Unless you are a very serious spiritual seeker, you may continue enjoying its immense health benefits.

Ayurvedic medicines

Ayurvedic medicine with onion ingredient:
Murivenna Oil – a renowned oil for non healing wounds, fractures and sprains.
Crackot ointment: This is a proprietary ayurvedic medicine useful in treating cases of cracked heel, removing the dead cells of the local area and softens the skin.

Pilocid ointment: This is a proprietary ayurvedic medicine useful in the treatment of external bleeding piles and has anti-inflammatory, styptic and anti-bacterial properties.

External application

In cases of neurological pains, local inflammation, onion paste is heated, tied in a cloth and the poultice is applied over the affected area.

Onion side effects

Bad breath, burning sensation and excess hotness are some of its side effects. It is not preferred by spiritual speakers and the Jain community.
It is safe to use during pregnancy, lactation and in children.
Onion should always be cut afresh and used immediately. Its refrigeration is not recommended. It gets spoiled very easily.

Interaction with medicines, supplements

Can this be used while taking Homeopathic medicine?
Yes. This product does not react with homeopathic medicine.

Can this medicine be continued while taking supplements like multivitamin tablets, Omega 3 fatty acids etc?
Yes. Generally, this product goes well with most dietary supplements. However, if you are taking more than one product per day, please consult your doctor for an opinion.

With western medicines
Seek your doctor’s advice if you are taking this product along with other western (allopathic / modern) medicines. Some Ayurvedic herbs can interact with modern medicine.
If both Ayurvedic and allopathic medicines are advised together, then it is best to take Allopathic medicine first, wait for 30 minutes and then take the Ayurvedic medicine.

How to use Onions for skincare?

Usage in different conditions

Addition by – 

Dr M S Krishnamurthy MD(Ayu) PhD

1. Regular intake of one onion relieves dysuria and scanty urination.
2. Administration of onion with few black pepper, morning and night helps to promote the health benefits in fever.
3. Instillation of lukewarm onion juice 1-2 drops into the ear relieves ear related problems like earache, discharge from ear, tinnitus etc.
4. Regular intake of 1 teaspoon of onion juice, 2 buds of garlic and 1 teaspoon of Aloe Vera juice mixture in the morning up to 1 month controls Asthma.
5. To control high cholesterol- fine paste of onion is mixed with 1 cup of buttermilk and ¼ teaspoon of black pepper powder and is taken.
6. Paste prepared out of onion and turmeric if applied on the wound helps in fastening the healing process.
7. Onion consumed along with dinner followed by intake of 1 glass of hot water helps to reduce excess fat in the body.
8. Intake of onion paste mixed with buttermilk relieves headache.
9. Consumption of raw onion regularly acts as a good nervine tonic.
10. Regular intake of onion with jaggery helps to gain weight.
11. Application of onion juice to the site of scorpion bite reduces the pain markedly.
12. Regular consumption of onion increases the sperm count, motility and viscosity.
13. Intake of onion flower increases digestive capacity.
14. Onion being a rich source of iron increases the Haemoglobin percentage, body stamina and vital capacity.
15. Application of onion juice on bleeding gum immediately arrests the bleeding.
16. Regular intake of raw onion increases body resistance.
17. Intake of raw onion with meals particularly with dinner induces good sleep.
18. Intake of onion flower juice with the addition of buttermilk helps to cure dysentery.
19. 1 teaspoon each of onion juice and ginger juice along with honey reduces productive cough and it facilitates expectoration.
20. Administration of onion juice along with breast milk cures hiccough in children.
21. Intake of onion along with butter milk and salt instantly relieves fatigue.
22. Intake of fried onion relieves constipation.
23. Intake of onion reduces the severity of cholera.
24. Application of onion juice relieves skin disorders and promotes luster of the face.
25. Intake of 1 teaspoons of onion juice and equal amount of ginger juice mixed with ½ glass of hot water at bed time relieves cough, cold and
26. Peeled onion soaked in honey for 45 days if taken (one onion regularly) corrects the hormonal imbalance.
27. Oil prepared with onion juice, coconut oil and turmeric powder is useful in wounds.
28. Oil prepared with onion juice and mustard oil relieves joint pain.
29. Regular intake of buttermilk mixed with smashed onion and little rock salt reduces the excess fat in the body.
30. Application of paste of onion seeds on white patches decreases the patches.
31. Place some chopped onions in a vessel, cover with salt and leave overnight. The resulting juice, if applied twice daily, helps to cure warts.
32. Intake of onion juice 2 teaspoons along with honey cures foot corn.
33. Application of onion juice or poultice on heels helps in crack healing.
34. Oil prepared out of 100 ml of onion juice and 50 ml of coconut oil if instilled as ear drops, reduces the pus discharge from the ear.
35. Administration of onion juice along with Holy basil flowers, ginger juice and honey helps to reduce phlegm.
36. White onion juice applied with turmeric powder cures scabies.
37. Instillation of 3-4 drops of onion juice along with 3-4 black pepper seed powder helps to cure half sided headache.
38. Massage with smashed onion on gums relieves toothache.
40. Chewing raw onion regularly prevents tooth decay.
41. Intake of onion juice with ghee and sugar candy cures Hemorrhoids.
42. Application of onion juice relieves Acne.
43. In bleeding from the nostrils caused during summer (due to heat stroke), few drops of onion are instilled to the nostrils. This relieves the complaint.
44. Onion fried with ghee is given to a delivered woman to relieve constipation.
45. Instillation of small onion juice with the juice of holy basil into eyes relieves fever in children.
46. Application of onion paste with salt on the forehead relieves headache.
47. Rubbing of smashed onion bulb on the affected area of hair loss, in Alopecia areata facilitates hair growth.
48. Application of onion juice with turmeric powder removes dark patches.
49. Onion juice rubbed over the affected area reduces the complaint of itching.
50. Onion juice rubbed over scalp kills lice.
51. Intake of white onion with jaggery and turmeric is useful in obstructive jaundice.
52. Onion juice with jaggery cures sore throat.
53. Intake of onion juice eliminates worms in children.
54. Daily consumption of raw onion with sugar helps children to gain weight.
55. 1-2 teaspoons of onion juice with honey twice or thrice a day relieves chest congestion.
56. One teaspoon of onion juice with equal amount of honey if taken lowers the blood pressure.
57. Intake of 2 teaspoons of onion juice with ginger juice controls vomiting.
58. Application of onion paste on feet reduces heat stroke.
59. Onion juice diluted with rose water applied as eye drops. It helps in improving eyesight.
60. Onion piece soaked in vinegar or lemon juice if taken with salt and black pepper twice a day helps to cure jaundice.
61. Onion juice mixed with hot water acts as diuretic.
62. Massage with sesame oil mixed with onion juice relieves arthritic pain.
63. After removing the bee stings from the site, application of crushed onion to the bee stung site reduces the inflammation
64. Rubbing of raw onion on mosquito bites relieves itching.
65. Application of onion juice reduces age spots/marks.
66. Rinsing the face with refrigerated onion juice diluted with water reduces the oily skin.
67. Application of the mixture of onion juice, apple cider and vinegar helps to get rid of Melasma.
68. Chopped onion is added to the shampoo bottle; kept for 2 weeks and used to wash the hair. This facilitates hair growth.
69. Place onion slices on the area as soon as possible to facilitate the healing process in bruises.
70. Eating fried onion helps in preventing and dissolving the blood clots.
71. Onion juice mixed with little salt is applied as eye drops. It helps in night blindness.
72. Regular intake of a few slices of onion reduces the menstrual problems.
73. Rubbing onion and garlic paste together reduces the toxic effects produced in the localized area in insect bites.
74. Few drops of white onion juice, if used as nasal drops, effectively cures nasal blockage.
75. Onion juice mixed with honey is rubbed on the dog bite site to reduce its poisonous effect.
76. Keeping the slices of white onion on the forehead reduces the temperature in case of fever.
77. Application of onion juice on burn wounds facilitates wound healing.
78. Regular consumption of onion reduces the incidence of osteoporosis.
79. Onions are effective in treatment of diabetes as it increases the insulin production.
80. Red onion helps to preserve and maintain the normalcy of cholesterol in the body.
81. Daily intake of red onion reduces the incidence of coronary heart diseases.
82. Application of onion juice on moles helps to reduce the markings.
83. Application of onion juice on the scalp reduces hair fall.
84. Eating onion twice a day helps to clear stuffy nostrils and alleviates Asthma, bronchial and nasal catarrh.
85. Onion juice mixed with half the quantity of honey if taken daily on an empty stomach for 1-2 months will help to develop resistance against cold, fever, respiratory infection and worm infestation.
86. A tablespoon of lime juice and onion juice (equal quantity) if taken before the journey will avoid motion sickness.
87. Drinking onion juice mixed with ghee or sugar for a fortnight helps in recovery from bleeding piles.
88. Outer peeling of onion is boiled with a cup of water and used as a hair conditioner; particularly in dry areas where only hard water is available.
89. Fine paste of smashed potato and white onion is applied to cure the burn lesions.
90. Turmeric powder mixed with bishop’s weed and onion juice helps in all types of skin infections and rashes.
91. 30 grams of juice of white onion, 5 ml of ginger juice and ghee, 10 grams of honey are mixed well and eaten in the morning for 4 months. This helps in rejuvenation and promotes body strength.
92. Regular consumption of onion reduces the incidence of cancer.
93. Onion juice helps to counter fluid retention and can provide relief from arthritis and gout.
94. Intake of raw onion boiled with water facilitates expulsion of renal stones.
95. Steam of red onion used for washing wounds facilitates faster healing in chronic wounds.
96. Red onion boiled with olive oil can be applied on cracked nipples to effectively manage the complaint.
97. Inhalation of red onion aroma helps in dizziness and fainting.
98. Chewing red onions for a few minutes kills microbes present in the oral cavity.
99. Salads prepared with onion and other raw vegetables act as antioxidants and revitalize.
100. Regular consumption of onions is good for memory and the nervous system.
101. Application of red onion boiled with olive oil cures

Research

Research articles about Allium cepa:

Anti- bacterial activity: Research was carried out on antibacterial activity of Allium cepa. Two different extracts were made from Allium cepa (onion) using distilled water. The extracts include fresh onion extract and cold water extract. The antibacterial activity of the onion was tested on four bacteria isolates associated with various ocular infections. The bacterial isolates include: Escherichia coli, Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumonia. Among the two extracts, fresh onion extracts exhibited antagonistic effects on the test organisms ranging from observed zone of inhibition (average value) of 15mm for Escherichia coli, 17mm for Staphylococcus aureus, 20mm for Streptococcus pyogenes, and 8mm for Streptococcus pneumoniae.

Anti- diabetic action: The hypoglycemica and hypolipidemic activity of Allium cepa aqueous extracts was studied on Rattus novergicus (rats). The extract produced a dose dependent significant result in blood glucose level at the end of six weeks.

Enhancing immune function: Researchers evaluated and compared the effect(s) of single and combined oral administration of fresh aqueous onion (Allium cepa) and garlic (Allium sativum) extracts at different concentrations on some immunological determinants in rats. CD₄ cells of the rats were estimated using Partec flow cytometric technique, while total and differential white blood cell (WBC) counts were estimated using the Sysmsex® automated hematology analyzing technique. Our findings revealed that, CD4 and total WBC counts were significantly increased (P?0.05) in a dose-dependent manner in both onion (250 mg/Kg/d: 349±11cell/ul and 2.75±0.15X10³cell/l; 500 mg/Kg/d: 389±10cells/µl and 3.05±0.05 X10³cell/l; 750mg/Kg/d: 600±11cell/µl and 3.25±0.05X10³cells/l) and garlic (250mg/Kg/d: 410±10cell/ul and 2.85±0.15X10³cell/l; 500mg/Kg/d: 494±32cells/µl and 3.30±0.10 X10³cell/l; 750mg/Kg/d: 684±11cell/µl and 3.55±0.05X10³cells/l) treated rats when compared to the zero control (200±11cells/µl and 1.55±0.05X10³cells/l, respectively)

The antibacterial activity of fresh red and white Allium cepa (Onion) and Zingiber officinale (Ginger), garlic (Allium Sativum) juices against multi-drug resistant bacteria viz: Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi, Aerobacter aerogenes, Proteus vulgaricus pure cultures were investigated using agar well diffusion and agar dilution methods. All the bacteria were susceptible to the fresh garlic and white onion juice with the diameter of zones of inhibition ranging from 1.3cm-5.5cm while the test bacteria were not sensitive to the fresh ginger juice.

Author: Dr.B.K.Prashanth M.D (Ayu), Ph.D
E mail: drprashanthbk@gmail.com

Properties of onion as per Bhojana Kutuhalam

According to Bhojana Kutuhalam eleventh chapter, Onion(palandu) is pungent in taste and strengthening in nature, alleviates kapha and pitta and is heavy for digestion.It acts as a aphrodisiac, imparts taste, it is unctuous and treats vomiting.

There is another variety of onion called rajapalandu, yavanesta and nrupahvaya. This type of palandu(onion) are cold in potency, alleviates pitta and kapha, stimulates the digestive fire and imparts excessive sleep.

The rajapalandu is alkaline, penetrating, sweet and imparts taste. Treats dryness of throat, does excessive dipana( i.e causes burning sensation). Alleviates kapha and pitta and stimulates digestive fire.

Onions, cooked, boiled, drained, without salt

Taste – sweet, pungent
Properties – not very heavy, unctuous, sharp, piercing
Potency – not very hot
After digestion taste transformation ( Vipaka )  – sweet
Effect on Doshas
Vata balancing
Pitta neutral
Kapha nourishing (due to reduced heaviness it does not increase Kapha but nourishes it)

Onions, dehydrated flakes

Taste – sweet, pungent
Properties – heavy, sharp, piercing (not unctuous as it is dehydrated)
Potency – not very hot
After digestion taste transformation ( Vipaka )  – sweet
Effect on Doshas
Vata balancing
Pitta neutral
Kapha nourishing (due to decreased unctuousness)
Pharmacological actions – Stimulant, Expectorant, Diuretic, Rubefacient Aphrodisiac

Onions, canned, solids and liquids

Taste – sweet, pungent
Properties – not very heavy (as it is boiled in water before canning), unctuous, sharp, piercing
Potency – not very hot
After digestion taste transformation ( Vipaka )  – sweet
Effect on Doshas
Vata balancing
Pitta neutral
Kapha nourishing (as it is boiled, it does not increase Kapha but nourishes it)

Onions, yellow, sautéed

Yellow onions are slightly more sweeter and delicate in flavour (more kapha increasing than white onions)
Sautéing involves use of fat.
Taste – sweet, mildly pungent
Properties – heavy, unctuous, sharp, piercing
Potency – not very hot
After digestion taste transformation ( Vipaka )  – sweet
Effect on Doshas
Vata balancing
Pitta neutral
Kapha increasing (more Kapha increasing as it is sautéed)

Onions, frozen, whole/chopped , unprepared

Taste – sweet, pungent
Properties – heavy, unctuous, sharp, piercing
Potency – not very hot
After digestion taste transformation ( Vipaka )  – sweet
Effect on Doshas
Vata balancing
Pitta neutral
Kapha increasing

Onions, frozen, chopped/whole , cooked, boiled, drained, without salt

Taste – sweet, pungent
Properties – not very heavy, unctuous, sharp, piercing
Potency – not very hot
After digestion taste transformation ( Vipaka )  – sweet
Effect on Doshas
Vata balancing
Pitta neutral
Kapha nourishing (due to reduced heaviness it does not increase Kapha but nourishes it)

Onions, spring or scallions, raw

(includes tops and bulb)

Taste – sweet, mildly pungent
Properties – heavy, unctuous
Potency – not very hot
After digestion taste transformation ( Vipaka )  – sweet
Effect on Doshas
Vata balancing
Pitta neutral
Kapha increasing

Onions, young green, tops only

Taste – sweet, mildly pungent
Properties – not very heavy, unctuous
Potency – not very hot
After digestion taste transformation ( Vipaka )  – sweet
Effect on Doshas
Vata balancing
Pitta neutral
Kapha increasing (slightly less Kapha increasing when compared to Onions, spring or scallions (includes tops and bulb), raw as it does not contain bulbs)

Onions, sweet, raw

A sweet onion is a variety of onion that is not pungent. Their mildness is attributable to their low sulfur content and high water content when compared to other onion varieties.
Taste – sweet
Properties – heavy, unctuous
Potency – cold
After digestion taste transformation ( Vipaka )  – sweet
Effect on Doshas
Vata balancing
Pitta balancing
Kapha increasing

Onions, cooked, boiled, drained, with salt

Taste – sweet, pungent, slightly salty
Properties – not very heavy, unctuous, sharp, piercing
Potency – hot (onion is not very hot in potency, but salt makes it further hot)
After digestion taste transformation ( Vipaka ) – sweet
Effect on Doshas
Vata balancing
Pitta nourishing (onion is Pitta neutral but salt is Pittakara)
Kapha nourishing (due to reduced heaviness it does not increase Kapha but nourishes it)

Onions, frozen, chopped/whole, cooked, boiled, drained, with salt

Taste – sweet, pungent, slightly salty
Properties – not very heavy, unctuous, sharp, piercing
Potency – hot (onion is not very hot in potency, but salt makes it further hot)
After digestion taste transformation ( Vipaka ) – sweet
Effect on Doshas
Vata balancing
Pitta nourishing (onion is Pitta neutral but salt is Pittakara)
Kapha nourishing (due to reduced heaviness it does not increase Kapha but nourishes it)

Onion rings, breaded, par fried, frozen, unprepared

Taste – sweet
Properties – heavy, unctuous (as it is fried, bread is also heavy and unctuous)
Potency – not very hot
After digestion taste transformation ( Vipaka )  – sweet
Effect on Doshas
Vata balancing
Pitta neutral
Kapha increasing

Onion rings, breaded, par fried, frozen, prepared, heated in oven

Taste – sweet
Properties – heavy, unctuous (as it is fried, bread is also heavy and unctuous)
Potency – not very hot
After digestion taste transformation ( Vipaka )  – sweet
Effect on Doshas
Vata balancing
Pitta neutral
Kapha increasing (slightly less kapha increasing when compared to unprepared onion rings as oven heating reduces unctuousness which slightly decreases Kapha) Shallots / Wild onion

 Shallots, freeze-dried

Rasa – pungent, sweet
Guna – heavy (as it is dried)
Veerya – not very hot
Vipaka – sweet
Effect on Doshas
Vata balancing
Pitta neutral
Kapha increasing (more Kapha increasing due to increased heaviness)

Shallots, raw

Rasa – pungent, sweet
Guna – light
Veerya – not very hot
Vipaka – sweet
Effect on Doshas
Vata balancing
Pitta neutral
Kapha nourishing

Varieties

Dh. Ni and Ka. Ni – Palandu and Ksira palandu
Ra. Ni – Palandu and Raja Palandu

Sthanika Karma (Systemic Action)

External – External application of its paste relieves inflammation.. It has scraping action. Indicated swelling associated with wounds, skin problems. Its juice is good for eyesight, and ear pain. In wound associated swelling, skin disorders like vyanga, Nyacha (discoloration on face), Kilasa (Viiligo) , its juice or paste can be applied. In diminished vision Its juice with honey can be administered as Anjana, also its juice can be applied in the ear in case of ear pain.

Nervous System – It has pain relieving action. Not good for the brain as it increases raja, and Tamo dosha. Indicated in Neurological pain, Sciatica, Joint pain, Hysteria, Rabbis, Convulsions.

Digestive System – stimulate liver, act as appetizer, promote taste. indicated in loss of appetite, constipation, hemorrhoids, Jaundice, rectal prolapse.

Circulatory System – Being hot and unctuous it stimulates heart, reduces oedema, Red variety of onion has styptic action.

Respiratory System – Indicated in Cough, indicated for weak patients. Helps to expel the phlegm

Skin – As it contains Sulphur, it is indicated in skin disorders.
Satmikarana – It promote body strength, and increase ojas

Onion increases Rajas and Tamas

Why some spiritual leaders consistently criticize/malign onion and garlic?
Dr JV Hebbar
If one is highly desirous of leading purely Satvik life, then better to avoid onion and garlic. But for a common family man, who aspires to be healthy and spiritual, having them once a while is not very bad. At the end of the day, like DivinePark.Org says, what eats our mind is more important that what we eat.
Read: 
Satvik Nature Influencing Disease Manifestation: Case Study
 Are there any problems consuming onion and garlic? Who should refrain from eating them?
There are no specific adverse effects of onion and garlic on health. Excess garlic can increase Pitta dosha and can cause gastritis, high blood pressure, improving bleeding tendency etc.