Red onions help fight cancer, study says

When it comes to fighting off cancer, your diet plays a large role. You’ve probably heard all about antioxidants and their ability to prevent cell damage by fighting off free radicals. Plant-based foods in particular contain these compounds. This makes it important to eat your fair share of fruits and vegetables, and recent research has found that there is one vegetable that is especially effective when it comes to fighting off cancer: the red onion.

Onions are generally regarded as a cancer-fighting food, but it turns out the type of onion you choose matters. Research out of the University of Guelph found that Ontario-grown red onions are the most effective at killing colon and breast cancer cells compared to other types of onions.

Red onions in particular have high levels of quercetin and anthocyanin, two types of antioxidants. The flavanoid quercetin is especially the most effective at killing cancer cells, but anthocyanin acts as a booster, “enrich[ing] the scavenging properties of quercetin molecules,” says the study’s lead author, Ph.D. student Abdulmonem Murayyan.

To test which onions out of the five types they looked at were most effective at fighting off cancer, the researchers placed colon cancer cells in direct contact with quercetin extracted from the different varieties. All five were effective at killing the cancer cells, but the “Ruby Ring onion variety” came out on top when it came to its cancer-fighting power.

They also found that the onion cells were just as capable of killing breast cancer cells. “Onions activate pathways that encourage cancer cells to undergo cell death. They promote an unfavorable environment for cancer cells and they disrupt communication between cancer cells, which inhibits growth,” said Murayyan.

The study, which was published in the journal Food Research International, happened to look at Ontario-grown onions in particular, so the researchers can’t say for certain that these findings apply to onions grown in other parts of the world, although they say the similarities are likely.

The next step in utilizing the power of quercetin will be to test onions’ cancer-fighting powers in human trials, the researchers said. They also hope to eventually utilize onion extract, adding it to other food products or being able to sell it in pill form as a type of natural cancer treatment.

For now, your best bet is to opt for red over white when it comes to adding onion to your salads or sandwiches if you want to help decrease your risk of getting cancer down the line.