FRIDAY, June 29, 2007 (HealthDay News) -- Diets high in processed carbohydrate-rich foods could boost a woman's risk for heart disease, according to the results of a new study.
Women who ate a diet high in rapidly-absorbed carbohydrates -- nutrition experts describe these carbohydrates as having a "high glycemic index" -- were at increased risk of getting cardiovascular disease, especially if they were overweight, Dutch researchers found.
How much of a risk was there? "It's a bit hard to exactly quantify the risk based on just this study," said researcher Joline Beulens of the University Medical Center Utrecht. "However, our results showed that women consuming the highest glycemic load diets had an about 1.5 times higher risk of cardiovascular disease than those consuming the lowest glycemic load diets. Looking only among overweight women, we found that overweight women consuming the highest glycemic load diets had an about 1.8 times higher risk than overweight women consuming the lowest glycemic load diets."
The study was expected to be published in the July 3 issue of the Journal of the American College of Cardiology.
In the study, Beulens' team followed almost 16,000 Dutch women for about nine years. At the study start, the women were between 49 to 70 years of age, and all were heart-disease free. At follow-up nine years later, 556 of the women had been diagnosed with heart disease, and 243 had suffered strokes.
Beulens' team found associations between the women's dietary glycemic load and those medical conditions, even after adjusting for other cardiovascular disease risk factors they may have had, such as overweight.
A high glycemic load diet includes carbohydrates with a high glycemic index. The term "high glycemic index" refers to the quality of the carbohydrates and how fast they are absorbed. Because foods with a high glycemic index are absorbed quickly, insulin levels don't stay as stable, which isn't ideal for health.
Among high glycemic index carbs are white bread, cookies and sugary drinks, for instance.
"The study shows that it is important to choose the right carbohydrate product in your diet," said Beulens. "For example, choose whole grain bread instead of white or whole meal," Beulens said. "Choose porridge or muesli instead of cornflakes."
Evidence is mounting that a diet high in refined carbohydrates is not healthy, with other studies recently coming to the same conclusion, Beulens noted.
What's the connection between a high glycemic load diet and heart and blood vessel problems? "The most important mechanism seems to be blood lipids [fats]," she said. "A high glycemic load diet increases LDL, the bad cholesterol, and triglycerides, and may lower the good, HDL cholesterol."
In an editorial accompanying the study, Dr. Frank B. Hu, a researcher at Harvard School of Public Health, called for a change in thinking, pointing out that the old idea that reducing saturated fat intake can help heart health is too simplistic. He wrote that reducing dietary glycemic load "should be made a top public health concern."
To do that, he suggested replacing some carbs, especially refined grains and sugars, with unsaturated fats and/or protein, for instance.
Restricting your intake of sugar-sweetened beverages can also help, he wrote.
There's more on the glycemic index at Oregon State University.