Low Fat Vegetarian Diet Wins

The August 2006 Diabetes Care journal reported on the impact of either a very-low-fat vegetarian (VLFV) diet or a control diet consistent with the current American Diabetes Association (ADA) diet guidelines.

The study examined 99 adults with type 2 diabetes mellitus (DM) randomly assigned to follow 2 diets for 22 weeks. Half the subjects followed a VLFV diet and the other half followed an ADA diet. Both groups of subjects were instructed to continue their current diabetes medications unless they developed low blood sugar levels during the trial. Initially all participants in both diet groups met for 1 hour with a registered dietitian experienced in the use of the assigned diet. Thereafter, the 2 groups of subjects met for one hour with a physician and a RD or cooking instructor on how to follow each diet.By all comparisons, the VLFV diet proved far superior to the ADA-style diet for the treatment of subjects with Type 2 DM. While 13 of 50 subjects on the ADA diet reduced their hypoglycemic meds, 21 of 49 subjects on the VLFV diet needed less medication because of reduced blood glucose levels.Weight loss on the ADA diet was a respectable 6.8 pounds over 22 weeks but on the VLFV diet weight loss was more than twice as great (14.3pounds). Glycosylated hemoglobin dropped about twice as much on average on the VLFV diet than on the ADA diet despite the much greater reduction in hypoglycemic meds on the vegan diet. For those subjects who did not have their diabetes meds reduced, the HbA1c fell more than 3 times as much on the VLFV diet as on the ADA diet. Serum cholesterol levels and triglyceride levels dropped significantly in both groups but the drop in LDL was about twice as great on the VLFV diet compared to the ADA diet (21.2 vs 10.7%). 

In previous trials using a VLFV diet or a very-low-fat near vegetarian diet, dramatic improvements in insulin sensitivity, blood sugar, blood lipids, blood pressure, inflammation markers, oxidative stress, and other cardiovascular disease and reduction in diabetes medication needed to control blood sugar levels have been reported in people with Type 2 DM.1 2 3 However, these clinical trials have been criticized for their short duration, accompanying exercise recommendations, and/or the lack of a control group. In this current study there were no exercise recommendations for either group and subjects were randomly assigned to each of the two diet groups and the study lasted 22 weeks.One likely factor contributing to the superior results of the low-fat vegan or near vegetarian diets may well be a reduction in AGEs and increased intake of anti-oxidant phytochemicals. Consuming a diet rich in AGEs has been shown to promote many of the complications of diabetes and restricting the amount of AGES and other pro-oxidant compounds in the diet appears to help prevent these complications of diabetes.4Bottom Line:Scientific evidence suggests the current dietary advice from the American Diabetes Association, American Heart Association, and the National Cholesterol Education Program is less effective than a very low fat, near vegetarian or vegan diet rich in whole grains, vegetables and fruits for treating those with type 2 DM or cardiovascular disease.People with type 2 diabetes or prediabetes, who want to lose more weight and improve their blood sugar and cholesterol levels can do so with the proper should be informed that greater reductions in animal products, particularly those high in fat and other high-fat foods along with increased consumption of fruits, vegetables and whole grains is likely to more dramatically cut their risk of cardiovascular disease and diabetes complications and or reduce their need for medications.By James J. Kenney, PhD, RD, FACNReferences:1. Prev Med 1999;29:87-912. Am J Med 2005;118:991-73. Diab Res and Clin Prac 2006;73:249-594. Circulation 2004;110:285-91