The US National Onion Association reports that studies have shown that quercetin protects against cataracts, cardiovascular disease, and cancer.
"In addition, onions contain a variety of other naturally occurring chemicals known as organosulfur compounds that have been linked to lowering blood pressure and cholesterol levels."Also, as the British Onions site tells us, new scientific research "has discovered the humble onion could be just what the doctor ordered to give our brains a boost. The research findings could prove valuable in the fight against aging and neurodegenerative diseases such as Alzheimer's and Parkinson's, while also providing protection from the effects of modern life." (The fantastic pictures in this post are taken from their image gallery)
Apart from all that we know that onions are low in calories but pack a punch in the flavour stakes and can be added to almost any savoury meal, someone once said that every meal began with peeling an onion. They are also sodium, fat, and cholesterol free, and provide dietary fibre, plus vitamins C and B6, potassium, and other key nutrients. Try raw onion on it's own with olive oil (and vinegar) and a pinch of salt as dressing - that plus a sliced apple plus maybe a chunk of strong, hard cheese and a glass or two of red wine and you can feel the benefit: a meal fit for a king!! If you're not keen on the strong flavour then try sweet onions: they still taste like an onion, but be much sweeter and milder. If however you're not keen on that either then you can just read about them: Ode to the Onion.