Low glycemic diet better for glycemic control of type 2 diabetes than whole grains

Dec 18, 2008 By Jenn Humphries

(PhysOrg.com) -- Low glycemic foods - beans, peas, lentils, pasta, rice boiled briefly and breads like pumpernickel and flaxseed - do a better job of managing glycemic control for type 2 diabetes and risk factors for coronary heart disease than high-fibre diets, including whole grain breads, crackers and breakfast cereals.

The study, Effect of a Low-Glycemic Index or a High-Cereal Fiber Diet on Type-2 Diabetes: A Randomized Trial, is published in the Dec. 17 issue of JAMA (Journal of the American Medical Association). Professor David Jenkins of nutritional studies and a doctor at St. Michael's Hospital is the lead author.

"At a time when the incidence of type 2 diabetes is likely to double in the next 20 years, any information that refines how we can manage this disease better is welcome. Our study shows that a low GI diet can also minimize the risk factors associated with cardiovascular disease. It does this better than a diet high in fibre, but with a higher glycemic index," Jenkins said. "Pharmaceuticals used to control type 2 diabetes have not shown the expected benefits in terms of reducing cardiovascular disease. Our hope is that the low GI diet may help all the complications of diabetes."

The study assessed the effects of a low glycemic index diet versus a high cereal fibre diet on glycemic control and cardiovascular risk factors for 210 patients with type 2 diabetes. The participants, who were treated with antihyperglycemic medications, were randomly assigned to receive one of the two diet treatments for six months.

In the low glycemic index diet, the following foods were emphasized: beans, peas, lentils, pasta, rice boiled briefly and low glycemic index breads (including pumpernickel, rye pita and quinoa bread with flaxseed) and breakfast cereals (including large flake oatmeal and oat bran). In the high cereal fibre diet, participants were advised to take the "brown" option (whole grain breads; whole grain breakfast cereals; brown rice; potatoes with skins; and whole wheat bread, crackers and breakfast cereals). Three servings of fruit and five servings of vegetables were encouraged on both treatments but temperate climate fruit (apples, pears, oranges and berries) was advised on the low GI diet.

The researchers found that hemoglobin A1c (HbA1c; a substance in red blood cells tested to measure the blood glucose level) decreased by -0.50 per cent absolute HbA1c units in the low glycemic index diet compared with -0.18 per cent absolute HbA1c units in the high cereal fibre diet. Significant treatment effects were observed for high-density lipoprotein cholesterol (HDL-C) and the low-density lipoprotein cholesterol (LDL-C): HDL-C ratio. HDL-C increased in the low glycemic index diet group by 1.7 mg/dL and decreased by -0.2 mg/dL in the high cereal fibre diet group. The LDL-C:HDL-C ratio showed a greater reduction in the low glycemic index diet group compared with the high cereal fibre diet group.

Provided by University of Toronto

Explore further: Researchers discover target for treating dengue fever

add to favorites email to friend print save as pdf

Related Stories

Nutrition's potential to save sight

Jul 01, 2010

While 20/20 vision is a symbol of visual acuity, between now and the year 2020, more and more people will experience some extent of vision loss due to age-related macular degeneration (AMD) and other sight-robbing diseases.

Low-carb diets prove better at controlling type 2 diabetes

Jan 05, 2009

In a six-month comparison of low-carb diets, one that encourages eating carbohydrates with the lowest-possible rating on the glycemic index leads to greater improvement in blood sugar control, according to Duke University ...

Study reveals good news about the GI of rice

Jul 09, 2012

(Phys.org) -- Research analyzing 235 types of rice from around the world has found its glycemic index (GI) varies from one type of rice to another with most varieties scoring a low to medium GI.

Recommended for you

Researchers discover target for treating dengue fever

6 hours ago

Two recent papers by a University of Colorado School of Medicine researcher and colleagues may help scientists develop treatments or vaccines for Dengue fever, West Nile virus, Yellow fever, Japanese encephalitis and other ...

Tracking flu levels with Wikipedia

7 hours ago

Can monitoring Wikipedia hits show how many people have the flu? Researchers at Boston Children's Hospital, USA, have developed a method of estimating levels of influenza-like illness in the American population by analysing ...

User comments : 0

More news stories

Turning off depression in the brain

Scientists have traced vulnerability to depression-like behaviors in mice to out-of-balance electrical activity inside neurons of the brain's reward circuit and experimentally reversed it – but there's ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...