3. Helps Prevent Cancer
Quercetin is a powerful compound that is available in high concentrations in all types and colors of onion. According to recent studies, such as the one conducted by the University of Guelph, onions are key players in cancer prevention. All onions help to kill colon cancer and breast cancer cells, but red onions are the most effective. Onions have massive amounts of both anthocyanin and quercetin which are two compounds that are critical in fighting cancerous cells.
The active ingredients in onions trigger the opening of certain pathways that make cancer cells turn on themselves and die. The same ingredients make it hard for the cancer cells to communicate with each other and thus slows their growth. In some cases, it can even prevent their growth completely. People who eat larger amounts of onions one a weekly basis tend to develop cancer less often than those who avoid all onions.