June 7, 2017

Ontario-grown red onions are the most effective at killing colon and breast cancer cells compared to other types of onions, reports a new study. This is because of the onions' high levels of quercetin and anthocyanin. As part of this project, the researchers are also the first to develop a non-toxic way to extract quercetin from onions making it more suitable for consumption.

The next time you walk down the produce aisle of your grocery store, you may want to reach for red onions if you are looking to fight off cancer.

In the first study to examine how effective Ontario-grown onions are at killing cancer cells, U of G researchers have found that not all onions are created equal.

Engineering professor Suresh Neethirajan and PhD student Abdulmonem Murayyan tested five onion types grown in Ontario and discovered the Ruby Ring onion variety came out on top.

Onions as a superfood are still not well known. But they contain one of the highest concentrations of quercetin, a type of flavonoid, and Ontario onions boasts particularly high levels of the compound compared to some parts of the world.

The Guelph study revealed that the red onion not only has high levels of quercetin, but also high amounts of anthocyanin, which enriches the scavenging properties of quercetin molecules, said Murayyan, study's lead author.

"Anthocyanin is instrumental in providing colour to fruits and vegetables so it makes sense that the red onions, which are darkest in colour, would have the most cancer-fighting power."

Published recently in Food Research International, the study involved placing colon cancer cells in direct contact with quercetin extracted from the five different onion varieties.

"We found onions are excellent at killing cancer cells," said Murayyan. "Onions activate pathways that encourage cancer cells to undergo cell death. They promote an unfavourable environment for cancer cells and they disrupt communication between cancer cells, which inhibits growth."

The researchers have also recently determined onions are effective at killing breast cancer cells.

"The next step will be to test the vegetable's cancer-fighting powers in human trials," said Murayyan.

These findings follow a recent study by the researchers on 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, said Neethirajan.

"This new method that we tested to be effective only uses super-heated water in a pressurized container," he said. "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."

While we can currently include this superfood in salads and on burgers as a preventative measure, the researchers 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.

https://www.sciencedaily.com/releases/20...70607123928.htm

Quercetin
It is good to keep reminding ourselves of the nutritional ways we can help our bodies fight disease.
From your link: http://www.yourhealthremedy.com/nutrient...high-quercetin/

Here Is A List of Top 8 Foods With The Highest content Of Quercetin:

#1 Capers

The unique flavor of capers makes them a very desirable ingredient in the Mediterranean basin. They range in size from as small as a peppercorn to as large as a green olive. High in flavonoid compounds, capers are the highest source of quercetin (180mg per 100g).

#2 Lovage Leaves

Lovage, a member of the parsley family, is a widely-used herb in parts of Europe and southwest Asia. Contains 170mg per 100g.

#3 Red Onion

Red onions are one of the best natural sources of this flavonoid. Red onions have long been known to have many health benefits including preventing heart disease, cancer, and common colds and coughs. Contains 19.93mg per 100g.

#4 Berries

Elderberries, of all the berries, are very rich in quercetin, but blueberries, and all other berries, also contain high amounts of quercetin.

#5 Kale

One cup of kale has only 36 calories, 5 grams of dietary fiber and 0 grams of fat. It is great for aiding in digestion and elimination with its great fiber content. Contains 7,71mg per 100g.

#6 Apples

The phytochemical composition of apples varies greatly between different varieties of apples. A large red apple, for example, contains about 10 mg. Organic apples are the best since the quercetin is in the peel.

#7 Spinach

Spinach eases constipation and protects the mucus lining of the stomach so that you stay free of ulcers. It also flushes out toxins from the colon. Contains 4,86mg per 100g.

#8 Red grapes

Red grapes have a number of health benefits, mainly because they are rich in flavonoids. They are also a good source of vitamin A, vitamin C, vitamin K, carotenes, B-complex vitamins such as riboflavin, pyridoxine, and thiamine. Contains 3,54mg per 100 g.

#9 Raw Black Plums

They contain 12.5 milligrams per serving. Plums are relatives of the nectarine, peach, and almond and belong to the Prunus genus of plants. In addition to their high content of this antioxidant, they contain no saturated fats and are low in calories (46 calories per 100 g).