New research published in January 2013 reports that aerobic exercise paired with a high-fat diet prevents the rise in total cholesterol and low-density lipoprotein (LDL) cholesterol. An estimated 71 million Americans have elevated LDL, and only one in three have the condition under control. Individuals with elevated cholesterol have twice the risk of heart disease compared to individuals with normal levels.
Researchers assigned 14 overweight healthy subjects with an average age of 24.8 years to a high-saturated-fat diet or a high-saturated-fat diet plus exercise. The subjects increased dietary saturated fatty acids from an average of 31 grams per day to 52 grams per day without changing total fat intake for 14 consecutive days.
The subjects in the exercise group completed 11 cycle-ergometer sessions of 55 minutes each at 60 percent peak oxygen uptake. The investigators assessed insulin sensitivity, body composition, blood lipids, resting blood pressure and VO2 peak (oxygen uptake attained) at the beginning of the study and again after the intervention period.
The researchers found that, in the high-saturated-fat diet group, average total cholesterol increased from 147 to 161 mg/dL and average LDL-cholesterol increased from 71 to 82 mg/dL. In the high-saturated-fat diet plus exercise group, total cholesterol and LDL-cholesterol remained unchanged. The investigators also showed that in the high-saturated-fat diet plus exercise group, systolic blood pressure decreased and VO2 peak increased. Neither group showed changes in body weight and composition, plasma free fatty acids composition and concentration or insulin sensitivity.
The researchers concluded, “Increases in total cholesterol and LDL-cholesterol concentration induced by 14 days of high-saturated-fatty-acid diet can be prevented by concurrent aerobic exercise training, which, in addition, improves cardiorespiratory fitness.”
Ortega JF, et al. Appl Physiol Nutr Metab. 2013;1:42-8.