Vegetarian diet outperforms Conventional Diabetes Diet


A 2010 study provides compelling evidence that a vegetarian diet is superior in many ways compared to the standard recommended diet, for the treatment of type 2 diabetes. 

Study: Kahleova, H et al. Vegetarian diet improves insulin resistance and oxidative stress markers more than a conventional diet in subjects with type 2 diabetes. Diabet. Med. 28, 549 - 559 (2011) 


What was the purpose of the study? 

Researchers divided up subjects to receive a vegetarian diet or a conventional diabetes diet and assessed the effects on  insulin sensitivity, weight, HbA1c, fat reduction, adipokines, and other markers like oxidative stress, over 24 weeks (approximately 6 months). Exercise was added in both groups after week 12. 


How did the diets differ? 

The vegetarian diet (60% carbohydrates, 15% protein, 25% fat) consisted of: vegetables, grains, legumes, fruits and nuts. Low-fat yogurt was permitted once per day (one portion serving size) 

The control group was asked to follow the standard dietary guidelines of the Diabetes and Nutrition Study Group  which recommends a diet of: 50% carbohydrates, 20% protein, less than 30% fat (less than 7% saturated fat, and less than 200 mg of cholesterol per day). The control group was still permitted to consume meat. Both study groups had a caloric deficit of 500 kcal.


What did the researchers find? 

  •  43% of participants in VEG group reduced diabetes medications. Only 5% in the CONVENTIONAL group reduced medications
  • Body weight decreased 6.2 kg (~13 lbs) in VEG group vs 3.2 kg (7 lbs) in CONVENTIONAL group
  • 30% increase in insulin sensitivity in VEG group vs 20% in CONVENTIONAL group
  • Reduction in visceral and subcutaneous fat greater in VEG group
  • Plasma adiponectin and leptin decreased in VEG group. No change in control group
  • plasma vitamin C increased 16%, whereas no change in CONVENTIONAL group
  • superoxide dismutase increased by 49% in the VEG group but decreased by 30% in the CONVENTIONAL group. 
  • Reduced glutathione increased 27% in VEG group, but decreased by 11% in CONVENTIONAL group
  • Glutathione reductase decreased by 42% in VEG group vs increased by 20% in CONVENTIONAL group
  • Total Adiponectin increased by 19% in VEG group, while the CONVENTIONAL group had no change
  • LDL cholesterol decreased by 8% in the VEG group,  whereas there was no change in CONVENTIONAL group


What did the researchers conclude? 

"In conclusion, our results indicate that a vegetarian diet alone or in combination with exercise is more effective in increasing insulin sensitivity, reducing volume of visceral fat and improving plasma concentrations of adipokines and oxidative stress markers than a conventional diabetic diet with or without the addition of exercise. Vegetarian diets may provide a beneficial alternative for nutritional therapy in Type 2 diabetes, especially in combination with aerobic exercise." 


To read the full study, click here

George Cho