A dietary intervention for chronic diabetic neuropathy pain: a randomized controlled pilot study

Randomized controlled pilot trial with two groups in adults aged 18-65 with type 2 diabetes and painful diabetic neuropathy for at least 6 months (N=35). Intervention: low-fat, plant-based diet plus vitamin B12; Control: vitamin B12 alone. Assessments at baseline, 10 weeks, and 20 weeks; independent blinded clinician performed select neuropathy assessments; participants were not blinded to group; recruitment from Washington, DC area.

Vitamin B12 (methylcobalamin) 1000 mcg daily, taken as a daily tablet, for 20 weeks.

Over 20 weeks, the intervention led to meaningful weight loss and improvements in several neuropathy-related outcomes. Weight loss averaged 6.4 kg greater than control (P<0.001). Foot sudomotor function improved by about 12.4 microSiemens versus control (P=0.03). Pain decreased more in the intervention group on the SF-MPQ (between-group difference −8.2 points; P=0.04). Neuropathy symptoms (MNSI-Q) improved by −1.6 points (P=0.03). Quality of life improved within the intervention group, but between-group differences were not significant. Authors conclude that a low-fat, plant-based diet with weekly support shows potential for treating painful diabetic neuropathy and warrants larger trials.

Small sample size; 20-week duration; not blinded to group; concomitant changes in diabetes medications; adherence to the low-fat diet was variable; cannot separate effects of diet vs weekly classes; possible influence of vitamin B12 supplementation on outcomes; reliance on self-reported pain measures.