Bethesda, MD Mental stress is known to induce heart problems in at-risk individuals, but why? Recent research published in the American Journal of Clinical Nutrition suggests that prolonged mental stress - - such as job-related stress - - causes higher levels of lipids and lipoproteins in the blood.
Previous studies have measured lipid levels in the blood after an overnight fast; however, this study focuses on lipid levels during the postprandial period (immediately following a meal). Study participants consumed a meal that was 16% protein, 34% fat, and 50% carbohydrate, composed of bread, butter, ham or cheese, apple marmalade, and cottage cheese. Following the meal, individuals in the test group were subjected to a computerized reaction-response test for 10 minutes, every half-hour, for 5 hours, imitating the real-life stress many people experience at work. Control subjects ate the same meal, but did not participate in the test. Blood samples were drawn prior to the meal and every hour for seven hours. Results showed that, throughout the study period, individuals subjected to prolonged mental stress had significantly higher levels of fats in the blood than "stress-free" control subjects.
According to Jean Dallongeville, PhD, senior author of the study, "Our study shows that mental stress increases the levels of atherogenic lipoproteins and decreases the rate at which fats are cleared from the blood after a meal. The longer fats reside in the body, the greater the risk of cardiovascular consequences."
Contact: Jean Dallongeville, MD, PhD
American Society for Clinical Nutrition/American Society for Nutritional Sciences