Pilot randomized controlled trial of a Mediterranean diet or diet supplemented with fish oil, walnuts, and grape juice in overweight or obese US adults

Year Published: 2018

BMC Nutrition

Lindsay M. Jaacks, Salman Sher, Christine De Staercke, Markus Porkert, Wayne R. Alexander, Dean P. Jones, Viola Vaccarino, Thomas R. Ziegler and Arshed A. Quyyumi

This study was a randomized controlled trial (RCT) that examined the efficacy of consumption of either a Mediterranean diet or diet supplemented with fish oil, walnuts, and grape juice vs a control diet (unaltered). Group 1 received the Mediterranean diet; Group 2 received an habitual high fat Amerian diet supplemented with fish oil, walnuts and grape juice; Group 3 consumed an unaltered, habitual high-fat American diet. The Mediterranean diet included an abundance of plant foods (fruits, vegetables, whole grains, nuts, and legumes).

Key Findings: Mediterranean diet participants (n=11) had significantly greater weight loss than participants on the control diet (n=9), despite no significant changes in total caloric intake. Mediterranean diet participants also had lower plasma cysteine levels (a marker for oxidative stress) than the control group (n=9), and lower cholesterol and LDL. The supplement arm (group 2, n=10) had lower adiponectin levels compared to the control group (adiponectin is a protein associated with increased risk for atherosclerosis). In conclusion, "eight weeks of substitution of an American-type diet with a Mediterranean diet was found to reduce cardiovascular disease risk factors (weight and cholesterol levels)."