In a new meta-analysis published in the November 2010 issue of Diabetes Care, researchers from the Harvard School of Public Health report that consumption of just one or two sugar-sweetened beverages per day is associated with a 26% greater risk of developing type 2 diabetes and a 20% increased risk of developing metabolic syndrome. Senior author Dr. Frank Hu put this into perspective, "So for those who drink two to three sodas per day, their risk of developing type 2 diabetes would be increased by 30-40% which is not very different from the increased risk associated with cigarette smoking."
It is not clear from the study if the main reason for the increased risk is due to the increase in calories or due to the combination of excess calories and some unique metabolic effects of fructose and other components of soft drinks.
The authors note that the jury is still out on the long-term effects of artificial sweeteners in soft drinks, so they caution against substituting diet sodas or drinks for sugar sweetened ones. Water, nonsweetened tea or coffee may be better choices.