Reactions to onion
Onion (Allium cepa L.) is the most widely cultivated species of the genus Allium. Its close relatives include garlic, scallion, leek, shallot and chive. Onions come in white, yellow, brown, purple and red varieties. Onions have been grown and selectively bred in cultivation for at least 7,000 years, and are used around the world for both culinary and medicinal purposes. As a food they are usually served raw, as a vegetable or part of a prepared savoury dish, but can also be eaten cooked or used to make pickles or chutneys. They are pungent when chopped and emit vapours that may irritate the eyes.
Onions are toxic to cats, dogs, guinea pigs and many other animals.
Onion oil is used in Europe as a pesticide against carrot fly. However, onions are prone to attack by a number of pests and diseases, particularly the onion fly, the onion eelworm, and various fungi which can cause rotting. This means that conventionally farmed onions tend to be heavily sprayed.
- Quercetin - onions are one of the richest food sources of this flavonoid. Quercetin gives onion many of its health and healing properties. Yellow onions have the highest total flavonoid content, an amount 11 times higher than in white onions. (5)
- Sulphur - onions are a good food source of organosulphur compounds and sulphur-based phytonutrients.
- Raw if you can. Many of the health benefits of onions come from using raw onions rather than cooked onions. Some, but not all benefits are lost by cooking them. For full benefits, use raw onions in small quantities in salads, salsa, guacamole, and various dips and sauces. You can also try adding a little raw onion to a dish that is cooking just a couple of minutes before serving.
- Onion boosts the body's production of luteinising hormone, and this hormone stimulates the production of testosterone, particularly in men. Onion is a good way of boosting natural testosterone production, benefiting both men and women.
- Nitric oxide. Onion helps produce nitric oxide, dilating blood vessels and promoting cardiovascular health. It is also an antioxidant.
- Antiseptic. Helps prevent infections and is an excellent remedy for a variety of infections.
- Anti-inflammatory, reduces inflammation.
- Carminative prevents gas / flatulence.
- Diuretic, reducing the level of salt and water in the body.
- Expectorant which reduces congestion. Treats bronchial and pulmonary (lung) secretions.
- Digestive disorders. Helps prevent stomach upsets, gas and other gastrointestinal disorders. Helps with digestion, acts as an anti-flatulent, carminative and diaphoretic.
- Hypoglycaemic. Onion lowers insulin and improves insulin resistance.
- Cancer preventative. Regular use of onion is associated with lower rates of cancer. (1)
- Cardiovascular health. Onion reduces the accumulation of cholesterol on the vascular walls, reducing the risk of atherosclerosis, angina, heart attack and stroke. Onions help lower blood pressure.
- Cataracts - helps prevent.
Grate a medium size onion and squeeze the pulp through a cloth or juice bag and into a bowl. One onion will make about one tablespoon of onion juice. Keep it in the fridge, and try to use it the same day.
Onion tea recipe. Put one tablespoon of onion juice in a mug, and then fill it with lukewarm water. Add a pinch of sea salt if required.
If the above onion tea with nearly raw onion juice is too strong, use boiling water instead of lukewarm water.
Sip the warm tea slowly. It is a good way to take onion for all the benefits listed in the Properties above. Onion tea is one of those traditional remedies which may be used almost every day and will do no harm, only good. Onion tea is particularly effective as a cough remedy and for problems around the throat.
Onion oil. Make it by mixing onion juice with warmed animal or coconut oil, or olive, avocado or macadamia oil. Use it to rub on the skin, or to treat areas under the skin. It will smell but try to leave it on for an hour, or overnight!
Reactions to onion
Onions cause uncontrollable tears for nearly everyone who is close to their cutting and chopping, and this is normal. You can avoid the sharp vapour by cutting them under running water or submerged in a basin of water.
Some people suffer from an allergic reaction after handling raw onions or being nearby when they are cut. Symptoms can include itching, conjunctivitis, contact dermatitis, blurred vision, bronchial asthma, sweating and anaphylaxis. Often these allergic reactions only occur when eating or handling raw onions, with cooked onions causing no problems. This is because some of the allergen proteins are denatured by cooking.
Onions are high in FODMAPS. Fructose and some other plant sugars cause digestive malabsorption in some susceptible people, with the main symptom being diarrhoea. You can download the free Grow Youthful FODMAP brochure here, and read about fructose malabsorption here.
1. Teuscher E. Medicinal Spices. 2005 Stuttgart: Medpharm.
2. Banihani SA.. Testosterone in Males as Enhanced by Onion (Allium Cepa L.). Biomolecules. 2019 Feb 21;9(2):75. doi: 10.3390/biom9020075. PMID: 30795630; PMCID: PMC6406961.
3. K P Sampath Kumar, Debjit Bhowmik, Chiranjib Biswajit, Pankaj Tiwari. Allium cepa: A traditional medicinal herb and its health benefits. Journal of Chemical and Pharmaceutical Research, retrieved online February 2023.
4. Nakayama Y, Makita M, Nozaki S, Kikuchi Y.. Effects of onion extract containing concentrated cysteine sulfoxides on sleep quality: a randomized, double-blind, placebo-controlled, crossover study. Food Sci Biotechnol. 2020 Oct 6;29(12):1755-1762. doi: 10.1007/s10068-020-00829-0. PMID: 33282442; PMCID: PMC7708608.
5. Slimestad R, Fossen T, Vagen IM. Onions: A source of unique dietary flavonoids. (2007). Journal of Agricultural and Food Chemistry. 55 (25): 10067-80. doi:10.1021/jf0712503.