Back to Annual Meeting Page		American Public Health Association 133rd Annual Meeting & Exposition December 10-14, 2005 Philadelphia, PA

Abstract #108376

Neal D. Barnard, MD¹, Ernest P. Noble, PhD, MD², Terry Ritchie, PhD², Joshua Cohen, MD³, David J. A. Jenkins, MD, PhD⁴, Gabrielle Turner-McGrievy, MS, RD⁵, and Brent J. Jaster, MD¹. (1) Washington Center for Clinical Research, 5100 Wisconsin Avenue, NW, Suite 400, Washington, DC 20016, 202-686-2210 x.303, nbarnard@pcrm.org, (2) Dept of Psychiatry/Biobehavioral Sciences, Neuropsychiatric Institute, University of California, Los Angeles, 760 Westwood Blvd, Room 38-154, Los Angeles, CA 90024, (3) Division of Endocrinology, George Washington University School of Medicine, 2150 Pennsylvania Avenue, NW, Washington, DC 20037, (4) Dept of Nutritional Sciences, University of Toronto Faculty of Medicine, 150 College Street, Room 339, Toronto, ON M5S 3E2, Canada, (5) University of North Carolina, 1007A South Columbia St, Chapel Hill, NC 27514

Preliminary evidence suggests that a low-fat vegetarian diet significantly improves glycemic control in type 2 diabetes. However, dietary behavior may be influenced by genetic factors. The D2 dopamine receptor (DRD2) gene A1 allele is associated with a reduced number of brain DRD2 receptors and with elevated risk of substance abuse, including disordered eating habits. We hypothesized that a low-fat vegan diet is more effective than a diet based on current American Diabetes Association (ADA) dietary guidelines, but that the presence of the A1 allele is associated with poorer response to dietary treatment.

Ninety-nine adults with type 2 diabetes were DRD2 genotyped and randomly assigned to either a low-fat vegan diet or a diet following ADA guidelines. Glycosylated hemoglobin (A1c) was measured at baseline and 22 weeks.

The DRD2 A1 allele was present in 49% of participants. Among participants whose diabetes medications remained constant, A1c fell 1.2 ± 1.4 percentage points in the vegan group and 0.4 ± 1.1 points in the ADA group (P = 0.014). Those without the A1 allele experienced a mean A1c reduction of 1.5 ± 1.3 in the vegan group, compared to 0.2 ± 1.2 for the ADA group (P = 0.0074). Among A1+ individuals, these reductions were 0.9 ± 1.4 and 0.6 ± 1.0, respectively (P = 0.50).

These results suggest that a low-fat vegan diet improves glycemic control in type 2 diabetes. Furthermore, the DRD2 A1 allele is common among individuals with type 2 diabetes and may influence the effectiveness of dietary interventions.

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