Quercetin—a water-soluble plant pigment known as a flavonoid that is found in onions, apples, tea, and other vegetables and legumes—may help prevent the chronic inflammation that leads to cardiovascular disease. The scientists found that a low dose of quercetin reduced the inflammatory molecules that can lead to cardiovascular disease, noting that “We tested compounds that are actually found in the blood, rather than the flavonoid in food before it is eaten, as only these compounds will actually come into contact with human tissues and have an effect on arterial health.”