Impact of a high-monounsaturated-fat diet on lipid profile in subjects with type 1 diabetes.

OBJECTIVE

Controversy persists regarding the use of a high-monounsaturated-fat diet in people with type 1 diabetes. The purpose of this study was to compare the effects of a high-monounsaturated-fat diet containing 43% to 46% carbohydrates and 37% to 40% fat (17% to 20% monounsaturated fat) with those of a high-carbohydrate diet containing 54% to 57% carbohydrates and 27% to 30% fat (10% to 13% monounsaturated fat) on the quantitative and qualitative lipoprotein profile in type 1 diabetes.

DESIGN

A randomized crossover study was conducted. Two months before the dietary trial, subjects were monitored on their intensive insulin regimen to normalize glycemic and lipid levels.

SUBJECTS

Twenty-six individuals followed each diet for 2 months. Eight subjects lost or gained >2 kg, and three had the same dietary intakes during the two diets. For the remaining 15, seven adhered to the two diet prescriptions and eight followed one of the two diets.

STATISTICAL ANALYSIS

Analysis of variance for crossover design (intent-to-treat group of 26) and Wilcoxon signed rank test (group of seven) were used to assess differences between the two diets.

RESULTS

For the intent-to-treat group (n=26), low-density lipoprotein cholesterol, although within normal range, was lower by 7% (P=.034) at the end of the high-monounsaturated-fat diet. The other 17 lipid parameters tested were not statistically significant. For those who adhered to the two diets (n= 7), lower plasma total triglycerides by 18% (P=.027), lower very low-density lipoprotein triglycerides by 26% (P=.043), lower very low-density lipoprotein cholesterol by 48% (P=.043), higher apolipoprotein A1 by 7% (P=.018), smaller low-density lipoprotein particle size by 1% (P=.043), and longer low-density lipoprotein oxidation lag time by 25% (P=.043) were found after the high-monounsaturated-fat diet.

APPLICATIONS/CONCLUSIONS: A high-monounsaturated-fat diet seemed to have a favorable effect on fasting lipoprotein profile in people with type 1 diabetes. Further research is needed with a larger sample to recommend a high-monounsaturated-fat diet as an alternative diet therapy in type 1 diabetes.