Sitting down for dinner? Extra red onions, please.
This may become a new mantra for those wanting to stave off cancer, according to a new study from Canadian researchers.
Five types of Ontario-grown onions were tested for their effectiveness at destroying cancer cells, and researchers from the University of Guelph found that one variety beat out the rest: the Ruby ring onion.
Onions contain one of the highest concentrations of the flavonoid quercetin, and Ontario onions contain especially high levels, compared to other regions around the globe. Flavonoids are found in almost all fruits and vegetables and are one of the reasons for their vibrant colors. Flavonoids, which are strong antioxidants and have anti-inflammatory and immune system benefits, have been singled out by scientists as a potential explanation for some of the health benefits linked to fruit and vegetable-rich diets.
For the study, published in Food Research International, the scientists extracted quercetin from five different onion types and put them in direct contact with colon cancer cells.
“We found onions are excellent at killing cancer cells,” Abulmonem Murayyan, a Ph.D., student and lead study author, said in a prepared statement. “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.”
In addition, the team discovered the red onion also contains high amounts of anthocyanin, “which enriches the scavenging properties of quercetin molecules,” Murayyan said.
The onions also had cancer-fighting properties against breast cancer cells, the researchers found.
A new extraction technique was used that removes the need for chemicals, making the quercetin better for consumption. Other methods involved solvents that can leave toxic residue that is not good to ingest.
“This new method that we tested to be effective only uses super-heated water in a pressurized container,” Suresh Neethirajan, engineering professor, said in a statement. “Developing a chemical-free extraction method is important because it means we can use onion’s cancer-fighting properties in nutraceuticals and in pill form.”