The research published in Nutrition Journal found the 80 calorie whey and guar preload 15 minutes before a breakfast of bread (two slices for women, three for men), margarine and jam lowered average glucose levels over three hours by 0.8 millimoles per litre (mmol/L). Peak glucose levels in finger-prick blood tests were reduced by 2.1 mmol/L at 45 minutes. They said this was exactly equivalent to or greater than the effect of the anti-diabetic drug sitagliptin.
The researchers from the University of South Australia and the Baker IDI Heart and Diabetes Institute sought to establish whether replacing some whey protein with the fibre guar – which reduces gastric emptying – could achieve comparable results to a straight higher dose of whey.
They said this used as a long term solution before at least two carbohydrate-rich meals a day could reduce glycated haemoglobin levels (HbA1c) by up to 1%. HbA1c is used as a measure of average blood sugar levels over a period of time - the higher this level is, the greater the risk of diabetes-related complications.
The preload was made up of 17 g whey protein, 3 g lactose, 5 g guar and 1 g flavour material of either stevia or sucralose dissolved in 150 ml water, and equated to less than 5% of daily energy intakes for the participants. The impact of this dose did not differ across those with diabetes or pre-diabetes or those on or not on medication.
Reducing dose, maintaining results
Past research has already shown large doses of protein and fat to lower glucose levels after a carbohydrate-rich meal for people with type 2 diabetes, however these higher calorie preloads came with a “considerable energy burden”.
Earlier this year, Israeli researchers demonstrated that individuals with well-controlled type 2 diabetes who took 50 g of whey in 250 ml of water before a similar breakfast of bread and jam saw glucose levels were reduced by 28% over a 180 minute post-meal period.
The Australian researchers behind this latest research said within medical nutrition therapy patient compliance was poor – with strategies including modifications in fat and complex carbohydrate intake or low glycaemic index (GI) diets, “all of which can be difficult to follow or maintain”.
They said the use of a 55 g whey preload drink had been shown to slow gastric emptying, increase insulin and lower glucose by around 3 mmol/L, while a second dietary alternative of 15-30 g of amino acid glutamine lowered postprandial glucose by 0.3 to 1 mmol/L, but these options came with energy intake implications.
Their research – involving 11 confirmed pre-diabetics and 13 type 2 diabetics given either the low calorie protein fibre mix or just water – monitored glucose levels over a period of five days with four finger prick tests a day. One subject had a fasting blood glucose of 10 mmol/L while all the rest were under 9 mmol/L.
“The drink is palatable and could be used on a daily or twice daily basis but we have no data on long term compliance yet.”
Source: Nutrition Journal
Published online ahead of print, doi:10.1186/1475-2891-13-103
“Effect of a low dose whey/guar preload on glycemic control in people with type 2 diabetes-a randomised controlled trial”
Authors: P. M Clifton, C. Galbraithand L. Coles