High-Glycemic Diet Linked to Oxidative Stress

Ongoing, regular consumption of high-glycemic foods might lead to chronically high oxidative stress, according to a new study performed collectively by researchers from the University of California, Berkeley; Our Lady of Mercy Medical Center, Bronx, NY; Vanderbilt University, Nashville, TN; and the Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston. On the opposite end of the spectrum, the researchers suggest that a low-glycemic diet--but not necessarily a low-carbohydrate diet--appears to beneficially reduce oxidative stress. The results of the study were published in the July 2006 issue of the American Journal of Clinical Nutrition (see http://www.ajcn.org/cgi/content/abstract/84/1/70).

The researchers measured lipid peroxidation markers in 292 healthy adults. They then derived individual dietary glycemic index (GI) and glycemic load (GL) numbers from the results of a food-frequency questionnaire.

The results indicated dietary GI was positively associated with both the subjects' lipid peroxidation markers. Increased oxidative stress--an imbalance between pro-oxidants and antioxidants, with the former prevailing over the latter--has been directly related to an increase of free-radical cell damage, which can increase the risk of a number of diseases. This increased stress may also affect cell signaling, a process by which an organism communicates among its individual cells to coordinate their behavior to benefit the organism as a whole.