Eating plenty of red onions could prevent cancer, according to new research. A compound which gives the vegetable its distinctive color destroys tumor cells, say scientists.
The discovery may soon lead to an anti-cancer pill based on the humble food’s magical properties, express.co.uk reported.
It is known people with the highest consumption of onions have a lower risk of many types of the disease, including ovarian, bowel and breast cancer.
They contain several anti-cancer compounds including quercetin and anthocyanins — which, crucially, give the red variety their color.
Abdulmonem Murayyan of the University of Guelph in Canada, said: “Anthocyanin is instrumental in providing color to fruits and vegetables.
“So it makes sense the red onions, which are darkest in color, would have the most cancer fighting power.”
In the first study of its kind Murayyan and Professor Suresh Neethirajan found red onions have the strongest cancer fighting power.
The humble vegetable has been a key ingredient in Mediterranean cooking for thousands of years, which could help explain lower rates of the disease in southern Europe.
Diced in a side salad, sprinkled as a garnish or chopped through a pasta dish, they may just be one of the best raw ingredients you can eat.
Red onions have also been linked with protecting against diabetes and heart disease.
The researchers said all onions contain high concentrations of quercetin, a type of flavonoid.
But the red variety not only has high levels of this but also large amounts of anthocyanin, which boosts the properties of quercetin, said Murayyan.
Along with Professor Neethirajan, he tested five onion types grown in Ontario and discovered the Ruby Ring red came out on top.
In lab experiments reported in Food Research International, colon cancer cells were placed in direct contact with quercetin extracted from the five different onion varieties.
Murayyan said: “We found onions are excellent at killing 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.”
The researchers have also recently found onions are effective at killing breast cancer cells.
Murayyan said: “The next step will be to test the vegetable’s cancer-fighting powers in human trials.”
The findings follow a previous study by the researchers on a new extraction technique that eliminates the use of chemicals, making the quercetin found in onions more suitable for consumption.
Other extraction methods use solvents that can leave a toxic residue which is then ingested in food.
Professor Neethirajan said: “This new method that we tested to be effective only uses super-heated water in a pressurized container.
“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.”
The researchers said we can currently include the superfood in salads and on burgers as a preventative measure.
But they expect onion extract will eventually be added to food products such as juice or baked goods and be sold in pill form as a type of natural cancer treatment.
Experts say it is best, where possible, to eat red onions in their raw state as cooking them in any manner can kill off the goodness.
If you are diabetic, you should eat raw red onions as these help increase insulin levels.
In Europe and Asia, red onions and raw garlic are often encouraged amongst diabetics.
Red onions each contain roughly 1.5grams of fiber, which helps your digestive track move things along.
Flavonoid compounds — the same compounds that give the onions their striking pigmentation — reduce the low-density lipoprotein (LDL), or ‘bad’ cholesterol in obese people at risk of heart disease.
The compounds also have anti-inflammatory abilities and can be useful in the treatment of arthritis and other such conditions.
Not only do red onions lower cholesterol, they can also fend off heart disease and discourage clot formation. They can also help to maintain blood flow and reduce inflammation to the blood vessels.
Publish Date: Fri, 09 Jun 2017