The glycemic index measures how fast 50g of carbohydrates are converted into blood sugar. Glycemic index diets like the Atkins and South Beach diets feature foods with low glycemic-index scores. Foods with high glycemic-index scores cause the fastest blood-sugar spikes. They include bakery products, breads, cereal, starchy and sugary vegetables and fruits such as potatoes and pineapples, pasta and rice. Eating foods with low glycemic-index scores may have numerous health benefits, according to studies published in "The American Journal of Clinical Nutrition."
Diabetes
University of Toronto researcher David Jenkins devised the glycemic index in 1981 to ascertain which foods helped diabetics. He concluded that many complex carbohydrates, including some fruits and vegetables, increased blood-sugar and insulin levels as much as sugary foods. High-fat and high-protein foods cause very little elevation so they have become a crucial part of glycemic-index diets. Most vegetables and several fruits, particularly berries, also have low glycemic-index scores.
A study published in "The American Journal of Clinical Nutrition" in July 2002 concluded that foods with high glycemic-index scores increase your risk of developing type 2 diabetes and high-fiber foods reduce diabetes risks. Fiber reduces foods' glycemic-index scores by slowing the entry of sugar into your bloodstream. The study also pointed out that the Canadian Diabetes Association and the European Association for the Study of Diabetes recommend that diabetics eat a low glycemic-index diet, although the American Diabetes Association does not because it is concerned about the effect of high-fat foods.
Cancer
"The higher the glycemic index, the greater the risk of colorectal cancer," concluded another article published in "The American Journal of Clinical Nutrition." The article stated that there is also a direct correlation between foods with high glycemic-index scores and breast cancer and there may be a correlation between the glycemic index and ovarian and prostate cancer.
"Dr. Atkins' New Diet Revolution" attributed the correlation between cancer and the glycemic index to the fact that cancer cells "feed off sugar." The book also reports that women with breast cancer are more likely to survive and less likely to have a recurrence of the disease if their bodies have lower insulin levels.
Heart Disease
Your heart-disease risk increases when your body's total cholesterol, bad cholesterol and triglyceride levels increase and your good cholesterol rises. The American Journal of Clinical Nutrition's "Implications in Health and Disease" article reported that a low glycemic-index diet reduced patients' bad cholesterol and triglyceride levels within one month. It also reported that low glycemic-index diets had a positive effect on good cholesterol, while reducing the number of fatal and overall myocardial infarctions.
The late Dr. Robert Atkins and "The South Beach Diet" author Dr. Arthur Agatston reported that their low glycemic-index diets dramatically affected dieters' cholesterol and triglyceride levels. Agatston wrote that one man's triglyceride level fell from 400 to 100mg per deciliter (dL) in one month. Atkins wrote that one man's total cholesterol fell from 207 to 134mg/dL and his triglycerides fell from 134 to 31mg/dL in three months.
References
- "The American Journal of Clinical Nutrition"; Glycemic Index: Implications in Health and Disease; David JA Jenkins, et al; July 2002
- "The American Journal of Clinical Nutrition"; International Table of Glycemic Index and Glycemic Load Values; K. Foster-Powell, et al.; 2002
- "Dr. Atkins' New Diet Revolution"; Dr. Robert Atkins; 2002
- "The South Beach Diet"; Dr. Arthur Agatston; 2003
- Harvard Heart Letter: Carbohydrates and Health: Not that Simple...or that Complex
