京葱含有蒜素，是一種抗氧化物質，它有殺菌及抑制細菌生長的功效，同時亦有助血管擴張，令血液流動更暢順；另外也有助減少脂肪積聚在血管壁上，預防血管硬化和收窄，有助降低患上心血管疾病的機會。 京葱葱白的部分含維他命C，同樣具有抗氧化功效，有助提高身體的免疫力，減少細菌入侵的機會。
Peking onion contains allicin, an antioxidant which is effective in sterilising and inhibiting the growth of bacteria. It also helps to dilate blood vessels, resulting in a smoother blood flow; it also helps to reduce the accumulation of fats on the walls of blood vessels, preventing hardening and narrowing of blood vessels, which helps to reduce the chances of developing cardiovascular diseases. The white part of the green onion contains vitamin C, which also has antioxidant properties, helping to improve the body's immunity and reduce the chance of bacterial invasion.