We all shed tears for onions, not over sentiment, but because they are stealthy, stalwart troopers in the battle for optimal health. They bring flavor to your food, sure, but they also hold the fort against free radicals, bolster immune defenses, and may even have cancer-bottling properties.

"But, oh, the bacteria!", you gasp. Don't worry, onions have that covered too. Quercetin-a flavonoid found in onions-isn't just hard to pronounce; it's also a certified bacteria buster.

And about that Big C – clutching onions could reduce the risk of certain cancers; specifically, those lethargic travelers down your digestive tract. The same quercetin also stretches its anti-cancer tentacles to a bacteria known as Helicobacter pylori – a nasty little piece that whispers sweet nothings to gastric cancer.

Besides being witty bacteria exterminators, onions are inflammation's worst nightmares. They're packed with flavonoids, such as quercetin, that prevent free radicals from throwing destructive parties in your body. The benefits of dialing up your quercetin intake are well-backed by studies.

Onions have Allium relatives such as garlic, leeks, and shallots, which also contribute to antioxidant properties. Onion bulb extract, Allium cepa if you're feeling scientific, has demonstrated potential in lowering high blood glucose levels in animal studies.

There's more to onions than just bacteria fighting and inflammation tackling. If your bones could talk, they would thank onions for a compound named GPCS that prevents bone loss and reduces the risk of fractures.

Good gut health revolves around fiber, and onions, along with other probiotic foods like leeks, celery, apples, and beans, can safeguard your gut lining. They contain inulin-a prebiotic compound that tucks in gut bacteria for a healthy growth party.

Onions are beneficial, raw or cooked. But for all you keen kitchen warriors, beware, certain cooking methods can reduce their health-giving properties. Boiling and frying are the chief villains whittling down the nutritional value. However, crushed before cooking, onions can clinch onto their health benefits. Baking is the superior way, increasing their flavonoid content.

So, bear these tips in mind when making your onion choice: Kill bacteria, reduce inflammation, prevent bone loss-all in a day’s work for the humble onion.