Refined Carbohydrates Up Diabetes Risk
But Researchers Say Foods Like Bran Cereal and Oatmeal Can Reduce Risk of Type 2 Diabetes
WebMD News Archive
Nov. 26, 2007 -- Eating the right kind of carbohydrates may help lower the
type 2 diabetes, researchers say.
Two new studies suggest that eating simple or refined carbohydrates with a
glycemic index -- like white bread and rice -- raise the risk of type 2
diabetes. But eating whole grains like bran cereal and oatmeal can lower
The glycemic index measures the effect of carbohydrates on blood sugar
levels. Foods with a high glycemic index, such as simple carbohydrates, cause a
rapid rise and then decline in blood sugar levels; those with a low glycemic
index, including whole grains, are absorbed more slowly into the bloodstream
and have a more gradual effect on blood sugar levels.
The studies, published in the Archives of Internal Medicine, looked
at the effects of carbohydrates on diabetes risk on two different groups of
Whole-Grain Cereal Fights Diabetes
The first study involved more than 40,000 African-American women in the U.S.
During eight years of follow-up, nearly 2,000 of them developed type 2
The results showed that glycemic index was linked to increased risk of
developing type 2 diabetes. African-American women who ate the most foods with
a high glycemic index were more likely to develop type 2 diabetes that those
who ate the least.
But cereal fiber was linked to a lower risk of diabetes. Women with the
highest intake of cereal fiber had a lower risk of developing type 2 diabetes
compared to those with the lowest intake.
"Our results indicate that black women can reduce their risk of diabetes
by eating a diet that is high in cereal fiber," writes Supriya Krishnan,
DSc, of Boston University School of Public Health, and colleagues.
"Incorporating fiber sources into the diet is relatively easy: a simple
change from white bread (two slices provides 1.2 grams of fiber) to whole-wheat
bread (two slices provides 3.8 grams of fiber) or substituting a cup of raisin
bran (5 to 8 grams of fiber) or oatmeal (4 grams of fiber) for a cup of corn
chex (0.5 grams of fiber) or rice chex (0.3 grams of fiber) will move a person
from a low fiber intake category to a moderate intake category, with a
corresponding 10 percent reduction in risk."
Refined Carbs Raise Diabetes Risk
In the second study, researchers followed a group of nearly 65,000 Chinese
women for about five years. During the study, 1,608 women developed
The results showed women who consumed more carbohydrates were more likely to
develop type 2 diabetes. Overall, women who ate the most carbohydrates had a
28% higher risk than those who ate the least.
The researchers also found that women who had diets with a higher glycemic
index also had a higher risk of developing type 2 diabetes. In particular,
women who ate 300 grams or more of rice per day were 78% more likely to develop
type 2 diabetes than those who ate less than 200 grams per day.
"Given that a large part of the world's population consumes rice and
carbohydrates as the mainstay of their diets, these prospective data linking
intake of refined carbohydrates to increased risk of type 2 diabetes mellitus
may have substantial implications for public health," write researcher
Raquel Villegas, PhD, of Vanderbilt University Medical Center, and