Antioxidant Intake is Associated with Paraoxonase Activity

Clement Furlong
University of Washington
R01ES09883

Background: Paraoxonase (PON1) is an enzyme involved in preventing vascular disease. It is physically associated with high density lipoprotein (HDL), the so-called "good" cholesterol, and may have its protective effects by preventing oxidation of low density lipoproteins (LDL) also known as the "bad" cholesterol. The enzyme is also active in chemical metabolism in that it inactivates the toxic metabolites of some insecticides as well as the nerve agents sarin and soman. This multi-purpose enzyme is usually present in lower serum concentrations in patients with coronary artery disease, coronary heart disease, and myocardial infarction. Vascular disease risk factors such as tobacco consumption are also known to depress the concentration of PON1. Free radical oxygen species are products of metabolic activity and are known to depress PON1 activity. Since the antioxidant vitamins C and E destroy free radicals, these investigators wanted to determine if the consumption of antioxidants would have an effect on PON1 activity.

Advance: In an epidemiologic study of 189 subjects, dietary intakes of vitamin C and of vitamin E were significant predictors of PON1 activity. The higher the intake of the vitamins, the higher the concentration of PON1. Current smoking predicted a decrease in PON1 activity. Current statin drug use was also associated with increased PON1 activity.

Implication: Although the effects of PON1 on LDL oxidation appear to be independent of the function of the antioxidant vitamins, vitamins C and E have been shown to inhibit LDL oxidation as well. Therefore any reduction in oxidative stress related to the intake of vitamins C and E may help to maintain PON1 levels and therefore reduce the risk of cardiovascular disease. PON1 activity appears to be a good predictor of the risk of vascular disease; therefore, further studies of other environmental influences on PON1 activity are warranted.

Citation: Jarvik GP, Tsai NT, McKinstry LA, Wani R, Brophy VH, Richter RJ, Schellenberg GD, Heagerty PJ, Hatsukami TS, Furlong CE. Vitamin C and e intake is associated with increased paraoxonase activity. Arterioscler Thromb Vasc Biol. 2002 Aug 1;22(8):1329-33.