All carbohydrates are not created equal, at least when it comes to heart disease. A new study released today finds that carbs with a high glycemic index--those that spike blood glucose levels quickly--may be linked with a higher risk of coronary heart disease in women.
The study, in the journal Archives of Internal Medicine, surveyed 47,749 men and women from various regions of Italy who were given questionnaires or interviewed about their dietary habits. They were followed for an average of eight years. In that time, 463 people, the majority of them women, developed coronary heart disease.
Foods were analyzed to determine their glycemic index and glycemic load. The glycemic index measures how carbs effect blood sugar levels. High glycemic index foods are quickly digested and release glucose quickly into the bloodstream, making glucose levels jump. High-glycemic index foods include baked potatoes, watermelon and rice. Low glycemic index foods slowly release glucose into the bloodstream, keeping blood glucose levels more steady. Those foods include most fruits and vegetables, plus pasta and milk. Glycemic load refers to a food's ranking according to how many total grams of carbohydrate it has along with its glycemic index, and is found using a formula.
Other studies have found that high-carb diets increase triglycerides and lower HDL ("good") cholesterol levels as well as boosting blood glucose and insulin.
The Italian researchers discovered that the 25% of the women who ate the most amount of carbs had about twice the risk of heart disease as the 25% who ate the least amount of carbs. In terms of quality versus quantity carbs, quality won out: eating more high-glycemic index foods was more strongly linked with a greater risk of coronary heart disease than eating low-glycemic index foods. In the study, the authors wrote, "a high consumption of carbohydrates from high-glycemic index foods, rather than the overall quantity of carbohydrates consumed, appears to influence the risk of developing coronary heart disease."
The same corollaries between eating carbs, glycemic index and glycemic load were not found for men. Researchers speculate that a high glycemic diet could trigger harmful changes in triglyceride levels and plasma HDL cholesterol in women, making them more at risk than men for cardiovascular disease.
The authors wrote that while it appears that eating high glycemic foods may make women more vulnerable than men when it comes to heart disease, more research needs to be done.
-- Jeannine Stein
Photo credit: Marice Cohn Band / MCT