Issue 117 Item 10 Animal Versus Plant Protein in Individuals With Type 2 Diabete

There is no clear advantage for the recommendation of diets containing only plant protein. A study at the Diabetes Research and Training Center, Indiana University School of Medicine, Indianapolis, was done to determine, for individuals with type 2 diabetes and microalbuminuria, the effects of 6 weeks of meals containing plant-based protein (PP) versus meals with predominantly animal-based protein (AP) on renal function and secondarily on glycemia, lipid levels, and blood pressure.

In a randomized crossover trial, they compared 6 weeks of meals containing only PP with meals containing primarily AP (60% animal, 40% plant) in 17 subjects with type 2 diabetes and microalbuminuria treated with diet and/or oral antidiabetic agents. Protein content was equivalent to the average American diet, and calories provided weight maintenance. Nutrients were equivalent between the two diets. Meals were prepared and packaged by a metabolic kitchen staff and were sent home weekly. At the beginning and end of each 6-week period, subjects were studied for 36 h on a metabolic unit.

The results showed that there were no significant differences between diets for glomerular filtration rate, renal plasma flow, albumin excretion rate, total cholesterol, HDL cholesterol, triglyceride area under the curve (AUC), glucose and insulin AUC, HbA(1c,) blood pressure, or serum amino acids. For both diets, at the end of the treatment periods as compared with baseline, total cholesterol was significantly lower (PP and AP: from 4.75 to 4.34 mmol/l, P < 0.01), HbA(1c) had significantly improved (PP: from 8.1 to 7.5%, P < 0.01; AP: from 7.9 to 7.4%, P < 0.01), and diastolic blood pressure was significantly lower (PP: from 83 to 80 mmHg, P < 0.02; AP: from 82 to 78, P < 0.02).

The researchers concluded that there is no clear advantage for the recommendation of diets containing only PP rather than diets containing protein that is primarily animal-based for individuals with type 2 diabetes and microalbuminuria. There are, however, potential lipid, glycemic, and blood pressure benefits for following a carefully constructed, weight-maintaining, healthy diet, regardless of protein source. Diabetes Care 2002 Aug;25(8):1277-82