Abstract P164: Effect of a Low-Carbohydrate Diet on Risk of Cardiovascular Disease: A Randomized Controlled Trial
The effect of a long-term low-carbohydrate diet versus a low-fat diet on 10-year risk of cardiovascular disease is still unknown.
We recruited 148 study participants with a body mass index of 30-45 kg/m2, who were free of diabetes, cardiovascular disease and kidney disease at baseline, and randomly assigned them to either a low-carbohydrate diet (<40 g /day; N=75) or a low fat (<30% energy from fat, <10% from saturated fat; N=73) diet. Participants met with a study dietitian weekly for the first month followed by group settings bi-weekly for 5 months and monthly for the subsequent 6 months. Each group was provided the same behavioral curriculum related to diet emphasizing portion control and eating habits. Clinic visits for data collection were conducted at 3, 6 and 12 months of intervention. The Framingham risk score (FRS), ARIC risk score (ARS), and Reynolds risk score (RRS) were used to estimate risk of cardiovascular disease in the next 10 years. Mixed-effect regression models including group, time and their interaction were used to analyze the data.
The mean age of participants was 46.8 years, mean body mass index was 35.4 kg/m2; 11.5% were men, and 51% were African-Americans. The baseline FRS, RRS, and ARS were 4.2%, 2.1% and 2.6% in the low-fat group, and 3.9%, 1.5%, and 2.0% in the low-carbohydrate group, respectively. There was no significant difference in these risk scores between the two diets at baseline. Of the study participants, 60 in the low-fat group (81.1%) and 59 in the low-carbohydrate group (79.7%) completed the entire intervention. Compared to the low-fat diet group, the low-carbohydrate group had greater reductions in FRS (net changes: -0.9%, -1.0%, and -1.5% at 3, 6, and 12 months, respectively; overall P<0.001) and RRS (-0.2%, -0.2%, and -0.1% at 3, 6, and 12 months, respectively; overall P=0.08). Changes in ARS were not significantly different between the two diets.
Our findings suggest that a long-term low-carbohydrate diet is at least as effective as a low-fat diet at decreasing the 10-year risk of cardiovascular disease.
- © 2013 by American Heart Association, Inc.