Three grams per day of the Barliv-branded barley fiber were associated with a 10.2% reduction blood glucose levels, compared with a 7.5% increase in people consuming a placebo beverage, according to findings published in Nutrition & Metabolism.
In addition, six grams per day of the barley fiber beverage for 12 weeks was associated with a 19% decrease in measures of insulin resistance, compared with a 42% increase in the placebo group. Insulin resistance occurs when cells do not respond adequately to the normal levels of insulin produced by the body – a marker of the onset of diabetes.
“Because this trial was designed to ensure study subjects underwent protocol-directed maintenance of body weight, it is noteworthy that the metabolic findings occurred without significant weight changes in any of the study groups,” wrote researchers from Louisville Metabolic & Atherosclerosis Research Center, Frestedt Incorporated, Biometrics, ClinData Services, Cargill, and the University of Kentucky,
The study was funded by Cargill.
The shadow of diabetes
The results of the study may have implications for the increasing number of people at risk of developing diabetes (pre-diabetes).
According to the World Health Organisation (WHO), diabetes affects over 220 million people globally and the consequences of high blood sugar kill 3.4 million every year. If such statistics weren’t scary enough, the WHO is predicting deaths to double between 2005 and 2030.
The total costs associated with the condition in the US alone are thought to be as much as $174 billion, with $116 billion being direct costs from medication, according to 2005-2007 American Diabetes Association figures.
The researcher recruited 50 “generally healthy” volunteers to participate in their prospective, randomized, placebo controlled, double blind, parallel group trial. Forty-four people completed the trial, and none had diabetes at the start of the study.
Volunteers were randomized to one of three groups, all of which were given a raspberry-flavored beverage to consume daily. One group consumed a beverage containing placebo (control group), and the other two groups received the beverage containing 3 or 6 grams of the barley beta-glucan.
Results showed that subjects receiving the barley beta-glucan at a daily dose of 3 grams had a 10% reduction in glucose levels. A similar trend was observed for the 6 grams per day dose, but this did not achieve statistical significance, said the researchers.
Insulin levels between meals (fasting insulin levels) were 8% lower in the 6 grams per day group, while levels increased from baseline values in the placebo group.
In addition, insulin resistance measures for the 6 grams per day group decreased from 2.1 at the start of the study, to 1.7 after 12 weeks.
The researchers also recorded changes in body fat levels, with a 3.9% reduction in fat levels in the hips, buttocks and thighs. However, no overall change in body weight was observed.
“This study supports that the 6 g/d barley beta-glucan beverage consumed over 12 weeks improves insulin sensitivity among hyperglycemic individuals who have no prior diagnosis of diabetes mellitus and no change in body weight,” wrote the researchers.
“This study suggests barley beta-glucan may slow the deterioration of insulin sensitivity for individuals at increased risk for diabetes mellitus,” they concluded.
Source: Nutrition & Metabolism
2011, 8:58, doi:10.1186/1743-7075-8-58
“Reduced viscosity Barley β-Glucan versus placebo: a randomized controlled trial of the effects on insulin sensitivity for individuals at risk for diabetes mellitus”
Authors: H. Bays, J.L. Frestedt, M. Bell, C. Williams, L. Kolberg, W. Schmelzer, J.W. Anderson