During the current doom and gloom we need to be cheered up with some positive news. And should you read this when a vaccine has disarmed the coronavirus causing the COVID-19 pandemic in 2020 and governments around the world have taken the necessary actions to limit global warming to 1.5ºC, well, you might still appreciate some good news.
So here goes.
Multiple health benefits
The next time you go shopping you might reach for red onions. Onions belong to the Allium family of plants, which also includes chives, garlic, and leeks. Farmers have cultivated Allium vegetables for millennia. These vegetables have characteristic pungent flavours and some beneficial medicinal properties. The benefits among many include a reduction of the risk of several types of cancer, improving mood, and maintaining skin and hair health.
Looking back in time, ancient medical texts from Egypt, Greece, Rome, China, and India all cite therapeutic applications for Allium vegetables.
Contemporary studies confirm the early findings. One review from 2015 found a general relationship between an increased consumption of Allium vegetables and a reduced risk of cancer, especially cancers of the stomach and gastrointestinal tract.
Such a relationship was further supported by a 2019 Chinese study that compared 833 people with colorectal cancer with 833 people who did not have the disease. The researchers found that the risk of colorectal cancer was 79% lower in those who regularly consumed Allium vegetables, such as onions.
Experts do not fully understand the exact mechanism by which some compounds in onions inhibit cancer. There are compounds called organosulfurs in onions, some of which have been shown to suppress aspects of tumour growth. However, further research is necessary to confirm which compounds in onion have protective effects against cancer.
But there is more
A wide range of further beneficial effects have also been proven. Different biological properties, such as antioxidant, antimicrobial and anti-diabetic activities, have been reported.
Not surprising as onions are nutrient-dense. One medium onion has just 44 calories but delivers a considerable dose of vitamins, minerals and fibre.
As a good source of vitamin C, onions may support the building and maintenance of collagen. Collagen provides structure to skin and hair.
A 2014 review found that among various activities of Allium vegetables, regulation of hypoglycaemic activity is considered important in helping to control diabetes. Sulfur compounds including S-methylcysteine and flavonoids such as quercetin are mainly responsible for the hypoglycaemic activity. S-methylcysteine and flavonoids help to decrease the levels of blood glucose, serum lipids, oxidative stress and lipid peroxidation, as well as increasing antioxidant enzyme activity and insulin secretion.
A 2019 review found that quercetin, a compound in onion skin, had links to lower blood pressure when the researchers extracted it and administered it as a supplement.
Somewhat surprisingly onions have been shown to be able to fight potentially dangerous bacteria, such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus cereus.
Onions are also rich in B vitamins, including folate (B9) and pyridoxine (B6) playing key roles in metabolism, red blood cell production and nerve function.
Lastly, they’re a good source of potassium, a mineral in which many people are lacking.
I hope you’re convinced by now.
So why red onions?
Any Allium vegetable would do but there is something special with the red colour of red onions.
A Canadian 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. 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.
There are plenty more benefits associated with Allium vegetables, but this is it for now as I’m off to buy some red onions.