The Role of Collagen

• A network of protein fibers called collagen comprises much of the skin, forming a framework that holds it taut and firm. Normally collagen strands slide easily over one another, giving elasticity to the skin. If you pinch and release healthy skin, you'll see that it quickly springs back in place.
  
  

Bad Effects of Sugar

• According to dermatologist and skin care entrepreneur Dr. Nicholas Perricone, foods with a high glycemic index rapidly convert to sugar in the bloodstream. While a type of sugar called glucose is an essential fuel for the body and is always present in the bloodstream, it also has a damaging effect: sugar molecules attach to collagen and damages it through a process known as glycation.
  
  

Cross-Linking

• Glycation causes collagen strands to gradually accumulate irreversible cross-links between adjoining collagen molecules. Skin loses its elasticity and no longer snaps back or smooths out.
  
  

Glycation and Vision

• Glycation affects protein tissues other than the skin, too. Protein glycation in the lenses of eyes causes them to become opaque, leading to cataracts (See Reference 2).
  
  

Protect Collagen Tissues

• Perricone advocates a diet that emphasizes complex carbohydrates rather than foods with a high glycemic index. He suggests that lean proteins and foods rich with antioxidants help maintain youthful skin. Collagen can also be damaged by sunlight, so protecting skin by wearing sunscreen or dark clothing may also help.