A Danish analysis of data from 21 research studies on the effects of saturated fat intake has concluded that swapping refined carbohydrates, such as pasta and white bread, for fat causes spikes in blood sugar that are harmful to the heart. However, cutting down on saturated fats while increasing consumption of whole-grain breads and vegetables-low glycemic index* foods-had a discernible positive impact on heart health.
The researchers, from Aarhus University near Copenhagen, also found that the 21 studies, which involved a total of 350,000 people, showed that saturated fats by themselves did not increase the risk of heart attack. Instead, it was how people responded to the perceived threat from saturated fats that created the highest risk of heart damage. In a subsequent study, other researchers had found that substituting polyunsaturated for saturated fats did, indeed, lead to greater heart health. The Aarhus researchers took the next step and looked at the effects of substituting carbohydrates for saturated fats.
Their study tracked the diets of more than 53,000 men and women who had never had heart attacks, dividing them into three groups based on the average glycemic index of the carbohydrates they normally consumed. The researchers believed that based on that consumption, they could calculate each group’s respective risk for heart attack.
They found that people who had the highest average glycemic index to begin with experienced a 33 percent increase in the risk of heart attack for every 5 percent increase in the calories that they derived from carbohydrates. For people in the middle range of the glycemic index, an increase in carb consumption, accompanied by a reduction in saturated fats, had no effect on the risk of heart attack.
Interestingly, even though the Danish researchers found that heart attack risk among the low glycemic index group fell by 12 percent for each additional 5 percent of carbohydrate-derived calories in their diets, the results were not statistically reliable enough to declare a cause-and-effect relationship. However, the research does indicate that people who decide to cut down on saturated fats by shifting to greater carbohydrate consumption should be careful not to actually increase their risk of heart attack by loading up on high-glycemic carbs.
*The glycemic index assigns numbers to carbohydrates that indicate how quickly a specific carb will raise blood sugar. Foods low on the index are best and tend to be high in fiber and unrefined, such as whole grains. Foods high on the index include such refined carbs as pasta and white bread.
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subbing ‘Bad’ Carbs for ‘Bad’ Fats Ups Heart Risk