Absence of attenuation in oxidative stress response with repeated lipid-rich feedings

Abstract

Innocence I. Harvey, Sang-Rok Lee, Trint A. Gunnels, JohnHenry M. Schriefer, Richard J. Bloomer

Background: The study of postprandial oxidative stress has received considerable attention in recent years. Excess production of reactive oxygen and nitrogen species (RONS) in response to high fat feeding can lead to oxidative stress. However, repeated exposure to the same stressor may lead to attenuation in the oxidative stress response, possibly via an up-regulation in antioxidant enzyme activity. Objective: To determine if repeated exposure to lipid-rich meal ingestion leads to a lower oxidative stress response over time, possibly due to an increase in antioxidant enzyme activity. Methods: Sixteen healthy men consumed 10 high fat milkshakes over a 3+ week period. Blood was taken from subjects on the first day of each week (before and for 4 hours after milkshake ingestion) and analyzed for oxidative stress and antioxidant biomarkers. Results: The oxidative stress response to repeated lipid-rich feeding was not different over time, as indicated by similar changes in plasma malondialdehyde and hydrogen peroxide, as well as superoxide dismutase, catalase and glutathione peroxidase activity. Conclusion: These data indicate that RONS production is likely similar with repeated exposure to lipid-rich meals and does not induce an adaptive response within the blood antioxidant defense system in a way that is protective to cells.