Researchers have found that elevated blood glucose causes skin aging and wrinkling. They found that in both diabetics and non-diabetics, elevated levels of blood sugar resulted in the production of glycotoxins known as advanced glycation end-products (AGEs) which cross-link with collagen fibers and result in a loss of skin elasticity.
The crux of this data strongly suggests that eating a diet high in sugar (soda, sweets, desserts, anything sweetened with high fructose corn syrup, etc.) is its own risk factor for premature aging, much like sun damage and smoking are.