Why Onions Make Us Cry

Onions have long been an integral component of cuisine and, while their pungent taste might put off some people, onions contain many essential nutrients that have numerous health benefits.

To avoid tears while chopping onions, opt for a sharp knife as this will minimize cell wall damage and volatile chemicals that irritate your eyes.

They’re an irritant

Chopping onions is an integral part of cooking – whether you’re creating Ree Drummond’s Best-Ever Baked Beans or onion rings from scratch. However, without proper care this task could leave your eyes so irritated that tears start pouring down your face! This happens due to chemical compounds and enzymes present in onions react when cut to release an irritating gas that stings your eyes and must be released by them before being cut into smaller pieces for digestion.

Onions have evolved with an effective defense mechanism to keep them alive underground. When growing underground, the bulbs are constantly under attack from critters looking to nibble. To counter this threat, onions emit gaseous substances to dissuade predators while simultaneously helping prevent too much rotting in their soil environment.

Chopping an onion releases sulfuric compounds found within its cells into the air, which then reacts with your tear fluid to produce syn-propanethial-S-oxide gas which irritates your eyes, leading to you crying to wash it away.

An onion’s irritants are to blame for its strong scent and prickly sensation when touching it, so to limit their release make sure you chop onions when they’re fully dry using a sharp knife – this way less damage to its cells occurs, less irritants are released, and you’re less likely to release toxic fumes into the atmosphere. In order to do this efficiently try keeping its root end intact as this contains the highest concentration of these chemicals.

Chemicals found in onions not only emit an unpleasant odor, but can also produce an intense burning sensation when exposed to skin. Therefore, it’s imperative that after chopping onions you thoroughly wash your hands – particularly before touching any other foods such as apples requiring cutting or peeling!

If you want to reduce the amount of syn-propanethial-S-oxide in your eyes, try selecting smaller onions that are greener in hue – these contain lower concentrations of the irritant than white or yellow ones. Chilling onions before cutting can also help decrease gas emissions.

They’re a defense mechanism

Onions are an integral component of many cuisines and add tremendous flavor. Unfortunately, onions also produce an irritating sulfur compound called propyl sulfoxide that can irritate eyes when cut or chopped. Although this chemical acts as an effective defense mechanism against predators like animals and insects that would try to consume the onion itself, its release has the effect of irritating human eyes; that’s why many tears flow when cutting or chopping onions!

As soon as an onion is cut, a chemical known as propanethial-S-oxide or lachrymatory factor is released that irritates nerves around our eyes, prompting them to tear. The chemical is released as a result of onion cells being damaged during cutting or chopping; garlic, chives and leeks all contain similar compounds.

An onion’s cells remain sealed together during normal growth due to its use of lachrymatory factor against insects, parasites, and predators such as insects or parasites. When cut open however, cells open up allowing lachrymatory factor into contact with eye of person cutting it and can then reach them as it causes irritation to their eye; their brain then triggers an anti-irritation response; in turn this causes tears to be produced to wash out chemical from onion’s chemical.

Eye stinging can be reduced by keeping some distance between onions and your face or using protective goggles to shield eyes from their chemicals. Refrigerating onions prior to cutting them also helps as molecules move more slowly when chilled.

Chopping an onion using a sharp knife will cause less cell damage and will reduce lachrymatory factor releases, while wearing contact lenses while cutting onions may also help lessen their sting by acting as a shield against its production of allyl sulfide gas.

They’re a lachrymatory agent

Onions have an inbuilt defense mechanism designed to deter animals from eating them – they produce enzymes and sulfenic acid which, when exposed to air, turns into propanethial S-oxide gas and causes tears before being converted to sulfuric acid by water in their tear ducts – this stinging is why people tend to cry when cutting onions!

Scientists have spent years deciphering what causes this strange reaction and believe they’ve finally cracked the code. After studying lachrymatory factor synthase enzyme, researchers believe they’ve discovered its source: It kickstarts a chemical process which produces propanethial S-oxide which then reacts with sulfur compounds released by onions to produce its signature irritant, which then forms tears when activated.

This discovery could help scientists develop effective new ways of reducing onion-causing vapors and may eventually lead to an eye drop that would prevent reactions altogether. Meanwhile, one method developed on TikTok in 2021 by “cerealeatingghost” that has since gone viral is using damp paper towels as eye coverings when cutting onions; according to The Almanac this trick works because its damp material captures fumes before reaching your eyes and can protect you.

Chilling onions before chopping will reduce syn-propanethial-S-oxide concentration in the air, making it less likely to irritate your eyes. Another alternative is placing it under water while you chop to trap any of its propanethial S-oxide and keep it away from your eyes.

Even though onions can be irritating, they remain one of the most nutritious vegetables available. Their nutritional profile includes plenty of vitamins and minerals – especially vitamin A which promotes skin health, immunity, cardiovascular wellbeing and blood pressure regulation. In addition, onions contain quercetin an antioxidant known to lower blood pressure while improving cardiovascular wellbeing; also providing rutin which has anticlotting capabilities by stabilizing vascular proteins.

They’re reflex tears

Reflex tears, such as those shed while chopping onions, are an emergency response that floods our eyes when they detect contaminants too large to be cleared away through blinking. They also occur when smoke gets into our eyes or we scratch nearby skin around our eyes – not necessarily providing much lubrication value but rather washing away any irritation to help restore eye comfort.

Scientists have long attempted to understand why cutting onions causes us to cry, and recent research suggests a potential explanation: when the compound syn-propanethial-S-oxide gas in onions reacts with air moisture or our own natural moisture content it forms sulfuric acid, irritating our eyes and making us tear up.

This reaction occurs because onion compounds in the eyes activate a defense mechanism known as lachrymatory factor, a type of chemical that triggers reflex tears to flow freely from them. Kat Arney from Bon Appetit offers some ways to combat onion tears when cutting onions.

First, opt for a sharp knife, as this will cause less damage and shed less tears. Contact lenses or glasses could provide another protective measure against tear-inducing compounds; kitchen goggles might not look appealing but are widely available from safety stores or sports equipment outlets.

Prevent eye burn by placing onions in the freezer before you chop them; this can halt their reaction and limit their tear-producing enzyme’s ability to escape into the air. Furthermore, should your eyes start burning from cutting onions quickly washing them is recommended to eliminate acids lingering and further irritating your eyes.

No matter your taste preference, reducing time spent tearing is something everyone can benefit from doing when cooking with onions. Other vegetables with similar flavor profiles such as garlic chives leeks or scallions could add an onion-esque taste without all the tears!