Onions contain antioxidants and compounds that fight inflammation, decrease triglycerides and reduce cholesterol levels — all of which may lower heart disease risk. Their potent anti-inflammatory properties may also help reduce high blood pressure and protect against blood clots.

Turns out, there's one variety of onions that's better for you than the others. A 2021 study published in Food Research International found that red onions were most effective at killing human cancer cells compared with other onions thanks to their higher levels of the antioxidants quercetin and anthocyanin.