A team from the University of Maastricht in the Netherlands tested insulin responses and the subsequent plasma glucose disposal rates in 10 men with type 2 diabetes, and nine healthy control subjects, after a carbohydrate drink.
Then they measured the same parametres after adding a casein hydrolysate, supplied by DSM Food Specialties, and the amino acids leucine and phenylalanine.
Plasma insulin responses were 299 per cent higher in the diabetics and 132 per cent in the control subjects after ingestion of the protein enriched drink, write the researchers in the July issue of the American Journal of Clinical Nutrition (vol 82, no 1, pp76-83).
And the diabetics had an average 28 per cent lower blood sugar response after consuming this drink than the carbohydrate drink alone.
The researchers had previously demonstrated the benefits of such a protein mix on insulin in healthy subjects, as well as subjects with type 2 diabetes.
But Dr Luc J.C. van Loon, the study's senior author, told NutraIngredients.com that the new study also tested whether improving insulin response had a direct benefit on blood sugar levels.
"It is no use increasing insulin levels if a person is insulin-resistant. In this trial we found the increased insulin actually reduced blood sugar levels," he said.
He added: "We have also seen an effect on insulin using just protein hydrolystate but the response is higher when adding the amino acids."
His team will next investigate whether these findings are confirmed after a real meal rather than a test drink.
"Protein and amino acid-enriched drinks are already available for athletes but these aren't advised for diabetics as they are high in carbohydrates. But this is definitely the way to go for clinical nutrition outside of the hospital for this group," said Dr van Loon.
A Swedish team also reported in the same journal that diabetic subjects taking a whey supplement at the same time as a high GI breakfast or lunch, had lower blood sugar response and higher insulin production.