Cancer, red onions kill cancer cells: the effect of antioxidants

Red onions contain high concentrations of substances that block communication between tumor cells and push them to ‘committ suicide'. Quercetin antioxidant is particularly effective when it acts in synergy with the anthocyanins.
A research team at the University of Guelph in Ontario (Canada) found that red onions can be invaluable allies in the fight against cancer, especially the breast one and colon one, two of the most widespread and lethal neoplasias. The substances contained in these vegetables, in particular the quercetin antioxidant and the anthocyanins, are in fact able to kill the diseased cells, preventing the growth and proliferation of the tumor mass.

The researchers, coordinated by the engineering professor Suresh Neethirajan and the graduate student Abdulmonem Murayyan, were already aware of the virtuous antioxidant and anticancer properties of onions (Allium cepa); so they decided to test some variations to determine which ones were the most effective against cancer.

From the analyses conducted on five onions normally grown in Ontario, the most populous Canadian province, it emerged that the tasty and bulbous ‘Ruby ring onion', a very popular red onion, turned out to be the first in the class for anti-cancer properties. The reason lies in the higher concentration of useful substances, such as the flavonoid quercetin, an antioxidant that has the ability to naturally inhibit various intracellular enzymes and therefore for a long time kept in mind by oncologists. Other particularly valuable compounds are the so-called anthocyanins, pigments that, in addition to giving the color to the onion, catalyze the anticancer action of quercetin.

The team of Neethirajan to test the effectiveness of the onions has contacted cancer cells extracted from human colon with a solution of quercetin, discovering that the latter not only pushes the tumor cells to the so-called apoptosis (the cell ‘suicide'), but it also prevents communication, further complicating their process of development and proliferation. In short, it would be a veritable deadly weapon against cancer, which scholars have managed to extract from the vegetable without using chemical agents, but only through superheated water inside a pressurized container. The process thus preserves its natural effectiveness without any contamination. The idea is to create pills or simple solutions to associate with fruit juices and bakery products with preventive action against cancer. The details of the study were published in the specialized scientific journal Food Research International.