Asparagus comes first among fifteen plants in terms of its concentration of two forms of thiols, glutathione and acetylcysteine. These substances are thought to have varying levels of antioxidant activity. Glutathione, among other things, may increase the clearance of oxidized cholesterol, which is extremely harmful to the arteries. Consuming glutathione-rich foods may help reduce the incidence of upper digestive tract cancer. Because these findings are unrelated to the particular intake of asparagus, additional research will be required to determine the impact of this vegetable's thiol consumption.