Why Do Onions Make Us Cry?

We’ve all experienced it: the burning feeling and tears in our eyes when we chop, dice, or mince our favorite bulb to add to our meal. Why do onions make us cry?

The cells of the onion’s bulb have a chemical called propanethial S-oxide, or otherwise known as Lachrymatory Factor (LF). When the onion is whole, the chemical is safely tucked inside the cell walls. When we start cutting into the onion, we slice open the cells releasing allinase, starting a chemical chain reaction which leads to the production of LF. When the LF comes into contact with our eye, our brain gets signalled that an irritant is present and blinking and tears are initiated.

This phenomenon may seem like a cruel trick, but it’s actually the onion’s way of protecting its energy-storing bulb from predatory insects or creatures. This advanced chemistry is an onion’s self defense.

Should we heed the onion’s warning and stay away? No! Just be prepared for the coming tears or turn your head away to help reduce them. Onions have vitamin C and chemicals linked to growth inhibition of cancer cells. Plus, onions give our food tons of flavor and add very little calories (only 4 calories in a tablespoon). That is a major benefit to assist with weight loss, especially for gastric sleeve, gastric bypass, and lap band patients.

Dr. Shillingford, MD, PA, encourages his gastric sleeve, gastric bypass, and lap band patients to choose healthy foods, and onions are a great choice for their flavor as well as their small caloric content. Dr. Shillingford’s bariatric patients come from all over Florida, including Boca Raton, Miami, Orlando, Tampa, and Jacksonville, for his reputation as a Center of Excellence Surgeon and his compassionate bedside manner. To schedule a surgical evaluation with Dr. Shillingford or to attend one of his free informational sessions, please call his Boca Raton office at (561) 483-8840.